Effects of organic acids (oxalic, acetic, and citric) on adsorption characteristics of Cadmium (Cd) on soil clay minerals (kaolinite, goethite, and bayerite) were studied under different concentrations and different p...Effects of organic acids (oxalic, acetic, and citric) on adsorption characteristics of Cadmium (Cd) on soil clay minerals (kaolinite, goethite, and bayerite) were studied under different concentrations and different pH values. Although the types of organic acids and minerals were different, the effects of the organic acids on the adsorption of Cd on the minerals were similar, i.e., the amount of adsorbed Cd with an initial solution pH of 5.0 and initial Cd concentration of 35 mg L-1 increased with increasing concentration of the organic acid in solution at lower concentrations, and decreased at higher concentrations. The percentage of Cd adsorbed on the minerals in the presence of the organic acids increased considerably with increasing pH of the solution. Meanwhile, different Cd adsorption in the presence of the organic acids, due to different properties on both organic acids and clay minerals, on kaolinite, goethite, or bayerite for different pHs or organic acid concentrations was found.展开更多
The relationship between Solidago canadensis L. invasion and soil microbial community diversity including functional and structure diversities was studied across the invasive gradients varying from 0 to 40%, 80%, and ...The relationship between Solidago canadensis L. invasion and soil microbial community diversity including functional and structure diversities was studied across the invasive gradients varying from 0 to 40%, 80%, and 100% coverage of Solidago canadensis L. using sole carbon source utilization profiles analyses, principle component analysis （PCA） and phospholipid fatty acids （PLFA） profiles analyses. The results show the characteristics of soil microbial community functional and structure diversity in invaded soils strongly changed by Solidago canadensis L. invasion. Solidago canadensis L. invasion tended to result in higher substrate richness, and functional diversity. As compared to the native and ecotones, average utilization of specific substrate guilds of soil microbe was the highest in Solidago canadensis L. monoculture. Soil microbial functional diversity in Solidago canadensis L. monoculture was distinctly separated from the native area and the ecotones. Aerobic bacteria, fungi and actinomycetes population significantly increased but anaerobic bacteria decreased in the soil with Solidago canadensis L. monoculture. The ratio of cyl9：0 to 18：1 co7 gradually declined but mono/sat and fung/bact PLFAs increased when Solidago canadensis L. became more dominant. The microbial community composition clearly separated the native soil from the invaded soils by PCA analysis, especially 18： lco7c, 16： lco7t, 16： lco5c and 18：2co6, 9 were present in higher concentrations for exotic soil. In conclusion, Solidago canadensis L. invasion could create better soil conditions by improving soil microbial community structure and functional diversity, which in turn was more conducive to the growth ofSolidago canadensis L.展开更多
To assess the effects of single and combined pollution of cadmium (Cd) and mercury (Hg) on soil micro-bial community structural and functional diversities, an incubation experiment was conducted, by employing two soil...To assess the effects of single and combined pollution of cadmium (Cd) and mercury (Hg) on soil micro-bial community structural and functional diversities, an incubation experiment was conducted, by employing two soils, namely, the marine sediment silty loam soil and the yellowish-red soil, in which five levels of Cd, Hg and Cd and Hg in combination were added. After being incubated for 56 days, the phospholipid fatty acids (PLFAs) profile and sole carbon source utilization pattern (BIOLOG) of the samples were tested. The results showed that the compo-sition of the microbial communities changed significantly at different levels of metals application. The principal component analyses (PCA) of PLFAs indicated that the structure of the microbial community was also significantly altered with increasing levels of metals, with increasing PLFAs biomarkers for fungi and actinomycetes, and in-creasing ratio of Gram-positive to Gram-negative bacteria. Sole carbon source utilization pattern analysis revealed that single and combined application of Cd and Hg inhibited significantly the functional activity of soil microorgan-isms, the functional diversity indices [Richness (S), Shannon-Wiener indices (H) and Evenness (EH)] were signifi-cantly lower in polluted soils than those in non-polluted soils, which also significantly altered with increasing levels of metals. PCA for the sole carbon source utilization pattern also indicated that the metal contamination could result in a variable soil microbial community. The results revealed that the combination of Cd and Hg had higher toxicity to soil microbial community structural and functional diversities than the individual application of Cd or Hg.展开更多
Major and REE geochemistry and multi-fractal analysis of two types of bauxite(primary bauxite and accumulated bauxite) ores were studied in Pingguo bauxite orefield in western Guangxi,China.The results of geochemical ...Major and REE geochemistry and multi-fractal analysis of two types of bauxite(primary bauxite and accumulated bauxite) ores were studied in Pingguo bauxite orefield in western Guangxi,China.The results of geochemical data show that the accumulated bauxite has a feature of high Al_2O_3 whereas relative low Fe_2O_3 and SiO_2 contents compared to the primary bauxite.The similar chondrite-normalized rare earth element(REE) patterns illustrate that they have a cognate relationship.However,the negative Ce anomalies of primary bauxite and positive Ce anomalies of accumulated bauxite indicate that the ore-forming system changed from reducing environment to oxidation environment.The results of multi-fractal spectrum and parameters of Al_2O_3,Fe_2O_3 and SiO_2 between primary bauxite and accumulated bauxite show that the distinct multi-fractal spectrum parameters reflect the different grade distribution between accumulated and primary bauxite ores.Metallogenic process from primary bauxite to accumulated bauxite is accompanied by the loss of diffluent elements(e.g.,Si and S) and enrichment of stable elements(e.g.,Al and Fe) in the surface environment.Among the rest,the migration mechanism of iron during the evolutionary process from primary ore to accumulated ore can be described as combined leaching and chemical weathering action with participation of sulfur.展开更多
The present study was designed to explore the mechanism by which ethanol extract of Bombax ceiba leaves(BCE) and its main constituent mangiferin(MGF) affect diabetic nephropathy by combating oxidative stress. Oral adm...The present study was designed to explore the mechanism by which ethanol extract of Bombax ceiba leaves(BCE) and its main constituent mangiferin(MGF) affect diabetic nephropathy by combating oxidative stress. Oral administration of BCE and MGF to normal and streptozotocin(STZ)-induced diabetic mice were carried out. Fasting blood glucose, 24-h urinary albumin, serum creatinine, and blood urea nitrogen were tested, histopathology, and immunohistochemical analysis of kidney tissues were performed. Moreover, mesangial cells were treated with BCE and MGF for 48 h with or without 25 mmol·L^(-1) of glucose. Immunofluorescence, Western blot and apoptosis analyses were used to investigate their regulation of oxidative stress and mitochondrial function. BCE and MGF ameliorated biochemical parameters and restored STZ-induced renal injury in the model mice. In vitro study showed that high glucose stimulation increased oxidative stress and cell apoptosis in mesangial cells. BCE and MGF limited mitochondrial membrane potential(Δψm) collapse by inhibiting Nox4, mitochondrially bound hexokinase II dissociation, and subsequent ROS production, which effectively reduced oxidative stress, cleaved caspase-3 expression and cell apoptosis. Our work indicated that BCE and MGF had protective effects on diabetic caused kidney injury and prevented oxidative stress in mesangial cells by regulation of hexokinase II binding and Nox4 oxidase signaling.展开更多
The present study aimed at exploring the therapeutic potential of standard extract of Bombax ceiba L.leaves(BCE) in type 2 diabetic mellitus(T2DM).Oral administration of BCE at doses of 70,140,and 280 mg·kg^(-1),...The present study aimed at exploring the therapeutic potential of standard extract of Bombax ceiba L.leaves(BCE) in type 2 diabetic mellitus(T2DM).Oral administration of BCE at doses of 70,140,and 280 mg·kg^(-1),to the normal rats and the high-fat-diet-and streptozotocin-induced T2 DM rats were carried out.Effects of BCE on blood glucose,body weight,and a range of serum biochemical parameters were tested,and histopathological observation of pancreatic tissues was also performed.HPLC-ESI-Q/TOF-MS/MS analysis indicated that the chemical composition of BCE mainly contained mangiferin,isoorientin,vitexin,isomangiferin,isovitexin,quercetin hexoside,2'-trans-O-cumaroyl mangiferin,and nigricanside.BCE caused a significant decrease in the concentrations of fasting blood glucose,glycosylated hemoglobin,total cholesterol,triglyceride,low density lipoprotein-cholesterol,serum insulin,and malondialdehyde,and increases in oral glucose tolerance,high density lipoprotein-cholesterol,and superoxide dismutase in the T2 DM model rats.Moreover,considerable pancreatic β-cells protection effect and stimulation of insulin secretion from the remaining pancreatic β-cells could be observed after BCE treatment.The results indicated that BCE exhibited an excellent hypoglycemic activity,and alleviated dyslipidemia which is associated with T2 DM.Antioxidant activity and protecting pancreatic β-cells are the possible mechanisms involved in anti-diabetic activity of BCE.展开更多
"Wu zhu yu", which is obtained from the dried unripe fruits of Tetradium ruticarpum(A. Jussieu) T. G. Hartley, has been used as a traditional Chinese medicine for treatment of headaches, abdominal colic, and..."Wu zhu yu", which is obtained from the dried unripe fruits of Tetradium ruticarpum(A. Jussieu) T. G. Hartley, has been used as a traditional Chinese medicine for treatment of headaches, abdominal colic, and hypertension for thousands of years. The present study was designed to assess the molecular genetic diversity among 25 collected accessions of T. ruticarpum(Wu zhu yu in Chinese) from different areas of China, based on inter-primer binding site(i PBS) markers and inter-simple sequence repeat(ISSR) markers. Thirteen ISSR primers generated 151 amplification bands, of which 130 were polymorphic. Out of 165 bands that were amplified using 10 iPBS primers, 152 were polymorphic. The iPBS markers displayed a higher proportion of polymorphic loci(PPL = 92.5%) than the ISSR markers(PPL = 84.9%). The results showed that T. ruticarpum possessed high loci polymorphism and genetic differentiation occurred in this plant. The combined data of iPBS and ISSR markers scored on 25 accessions produced five clusters that approximately matched the geographic distribution of the species. The results indicated that both iPBS and ISSR markers were reliable and effective tools for analyzing the genetic diversity in T. ruticarpum.展开更多
Adsorption isotherms of metsulfuron and bensulfuron on a hexadecyltrimethylammonium （HDTMA） bromide-modified paddy soil under different ionic strengths, with divalent cation Cu^2＋, or having different pH were studi...Adsorption isotherms of metsulfuron and bensulfuron on a hexadecyltrimethylammonium （HDTMA） bromide-modified paddy soil under different ionic strengths, with divalent cation Cu^2＋, or having different pH were studied to describe their adsorptive behavior, and to try to explain the adsorption process of a sulfonylurea compound with a carbamoylsulfamoyl group in the modified soil environment. All the adsorption isotherms fitted the Freundlich equation well, and the HDTMA treatment of paddy soil dramatically enhanced adsorption capacity of metsulfuron or bensulfuron. Also, an increase of ionic strength and the addition of divalent heavy metal cation Cu^2＋ on the HDTMA-modified paddy soil increased the adsorption of metsulfuron or bensulfuron. Additionally, for metsulfuron and bensulfuron in the aqueous phase, adsorption capacity of the HDTMA-modified paddy soft gradually increased with decreasing pH.展开更多
Adsorption isotherms of 2,4-dinitrophenol and 2,4-dichlorophenol on hexadecyltrimethylammonium (HDTMA) bromide modified red soil under different ionic strength, divalent cation Cu 2+ or different pH conditions were st...Adsorption isotherms of 2,4-dinitrophenol and 2,4-dichlorophenol on hexadecyltrimethylammonium (HDTMA) bromide modified red soil under different ionic strength, divalent cation Cu 2+ or different pH conditions were studied. All the adsorption isotherms were well fitted to the Freundlich equation. The adsorption capacities of 2,4-dinitrophenol or 2,4-dichlorophenol were dramatically enhanced by HDTMA treatment of red soil. The increase of ionic strength and the addition of divalent heavy metal cation Cu 2+ significantly enhanced the adsorption of 2,4-dinitrophenol or 2,4-dichlorophenol on the HDTMA-modified red soil. Adsorption capacities of HDTMA-modified red soil for 2,4-dinitrophenol and 2,4-dichlorophenol gradually increased with decreasing pH in the aqueous phase.展开更多
The relationship between Solidago canadensis L. invasion and soil microbial communities was studied across the invasive gradients varying from 0 to 40, 80, and 100% coverage of S. canadensis. The results showed both s...The relationship between Solidago canadensis L. invasion and soil microbial communities was studied across the invasive gradients varying from 0 to 40, 80, and 100% coverage of S. canadensis. The results showed both soil microbial biomass C （Cmic） and N （Nmic） increased as the coverage of S. canadensis increased. Soil microbial quotient Cmic/Corg （microbial biomass C/organic C） tended to increase linearly with the coverage of S. canadensis. Soil basal respiration （BR） also showed a similar trend. The soil respiratory quotient qCO2 decreased with S. canadensis invasion, and remained at quite a constantly low level in the invasive soils. Sole carbon source utilization profiles analyses indicated that S. canadensis invasion tended to result in higher microbial functional diversity in the soil. Average utilization of specific substrate guilds was highest in the soil with S. canadensis monoculture. Principle component analysis of sole carbon source utilization profiles further indicated that microbial functional diversity in the soil with S. canadensis monoculture was distinctly separated from those soils in the native area and the ecotones. In conclusion, S. canadensis invasion improved soil microbial biomass, respiration and utilization of carbon sources, and decreased qCO2, thus created better soil conditions, which in turn were more conducive to the growth of S. canadensis.展开更多
Low-temperature Sb(Au-Hg) deposits in South China account for more than 50% of the world’s Sb reserves,however,their genesis remains controversial.Here we report the first study that integrates U-Pb and Lu-Hf analysi...Low-temperature Sb(Au-Hg) deposits in South China account for more than 50% of the world’s Sb reserves,however,their genesis remains controversial.Here we report the first study that integrates U-Pb and Lu-Hf analysis by LA-(MC)-ICPMS and conventional(U-Th)/He analysis,all applied to single zircon crystals,in an attempt to constrain the origin and timing of world-class Sb(Au-Hg) deposits in Banxi(South China).Zircon separated from a quartz-stibnite ore and an altered country rock samples revealed similar U-Pb age spectra defining two major populations-Paleoproterozoic(~1900-2500 Ma) and Neoproterozoic(~770 Ma),which are characterized by variable εHf(t) values(-10.7 to 9.1 and-16.5 to 11.2,respectively) and Hf crustal model ages(TDMC)(2.48 to 3.24 Ga and 0.97 to 2.71 Ga,respectively).The U-Pb age and Hf isotopic features of the zircons are consistent with the Banxi Group in the region,indicating that the zircons involved in the low-temperature hydrothermal system were originally from the Banxi Group country rocks.Thirty-three mineralization-related zircon crystals yielded a mean(U-Th)/He age of 123.8±3.8 Ma,which is interpreted to represent the timing of the latest low-temperature mineralization stage of the Banxi Sb deposit.The combined U-Pb,Lu-Hf and(U-Th)/He data suggest that Precambrian basement rocks were the major contributors to the low-temperature mineralization,and that Early Cretaceous(130-120 Ma) could be the most important ore-forming epoch for the Sb deposits in South China.This study also demonstrates the analytical feasibility of integrated U-Pb-Lu-Hf-(U-Th)/He "triple-dating",all applied to single zircon crystals.This approach reveals the full evolution of zircon,from its origin of the magmatic source,through its crystallization and low-temperature cooling.Although this study demonstrates the usefulness of this integrated approach in dating low-temperature mineralization,it has great potential for zircon provenance and other studies that may benefit from the large amount of information that can be extracted from single zircon crystals.展开更多
The Batang Group in the Zhaokalong area not only hosts an important Fe-Cu polymetallic deposit but also reveal important insights for the Late Triassic tectonism in the northern Sanjiang region. In order to delineate ...The Batang Group in the Zhaokalong area not only hosts an important Fe-Cu polymetallic deposit but also reveal important insights for the Late Triassic tectonism in the northern Sanjiang region. In order to delineate the tectonic setting and evolutionary process of the paleo arc-basin system, geochemical studies on the Batang Group strata have been carried out. The results suggest that andesite in the Zhaokalong area mainly belongs to the tholeiite series and is characterized by obvious fractionation of LREE and HREE, enrichment in LILE and depletion in HFSE, and a distinctly elevated δ^（34）SCDT average of 10.5‰. The sandstone is classified as lithic sandstone, which is also characterized by obvious fractionation of LREE and HREE, as well as weak negative Ce and Eu anomalies. The limestone displays positive Eu anomalies, with δ^（13）CPDB ranging from-1.3‰ to 4.4‰ and δ^（18） OSMOW ranging from 14.6‰ to 22.5‰. These results indicate that the andesite has a dual signature of both arc andesite and rift volcanic rocks, whereas the sandstone may be formed in an active continental margin, and the limestone could be deposited in a weak oxidizing shallow sea. The sandstone in the Zhaokalong area represents sedimentation in a platform slope facies, corresponding to the main stage of the Jinshajing oceanic basin subduction during the middle period of Late Triassic. The continental arc volcanic activity resulted from subsequent strengthened subduction, forming the andesite in the North Qiangtang backarc basin. Afterwards, the limestone was formed after the cessation of magmatic activity. The information gleaned from the Batang Group strata helped constrain the evolution of the paleo-Jomda island arc and Jinshajiang oceanic subduction in the Late Triassic.展开更多
Corydalis yanhusuo W.T.Wang is a classic herb that is frequently used in traditional Chinese medicine and is efficacious in promoting blood circulation,enhancing energy,and relieving pain.Benzylisoquinoline alkaloids(...Corydalis yanhusuo W.T.Wang is a classic herb that is frequently used in traditional Chinese medicine and is efficacious in promoting blood circulation,enhancing energy,and relieving pain.Benzylisoquinoline alkaloids(BIAs)are the main bioactive ingredients in Corydalis yanhusuo.However,few studies have investigated the BIA biosynthetic pathway in C.yanhusuo,and the biosynthetic pathway of species-specific chemicals such as tetrahydropalmatine remains unclear.We performed full-length transcriptomic and metabolomic analyses to identify candidate genes that might be involved in BIA biosynthesis and identified a total of 101 full-length transcripts and 19 metabolites involved in the BIA biosynthetic pathway.Moreover,the contents of 19 representative BIAs in C.yanhusuo were quantified by classical targeted metabolomic approaches.Their accumulation in the tuber was consistent with the expression patterns of identified BIA biosynthetic genes in tubers and leaves,which reinforces the validity and reliability of the analyses.Full-length genes with similar expression or enrichment patterns were identified,and a complete BIA biosynthesis pathway in C.yanhusuo was constructed according to these findings.Phylogenetic analysis revealed a total of ten enzymes that may possess columbamine-O-methyltransferase activity,which is the final step for tetrahydropalmatine synthesis.Our results span the whole BIA biosynthetic pathway in C.yanhusuo.Our full-length transcriptomic data will enable further molecular cloning of enzymes and activity validation studies.展开更多
Two new acylated C-glycosylflavones were isolated from the leaves of Iris lactea var. chinensis, and their structures were elucidated on the basis of extensive NMR experiments and mass spectrometry methods and were as...Two new acylated C-glycosylflavones were isolated from the leaves of Iris lactea var. chinensis, and their structures were elucidated on the basis of extensive NMR experiments and mass spectrometry methods and were assigned as 5-hydroxy-4＇- methoxyflavone-7-O-（β-D-2＇＇＇＇4＇＇＇＇-diacetylrhamnopyranosyl）-6-C-[ O-（α-L-6＇＇＇-acetyl-glucpyranosyl）-1→2-β-D-glucopyrano- side] （irislactin A） and 5-hydroxy-4＇,7-dimethoxyflavone-6-C-[O-（α-L-2＇＇＇,3＇＇＇-diacetylrhanmo-pyranosyl）-1→ 2-β-D-glucopyranoside] （irislactin B）.展开更多
In the storage of Radix Ophiopogonis, browning often happens to cause potential risk with regard to safety. Previously few reports investigate the browning of Radix Ophiopogonis. In this research, the causes and mecha...In the storage of Radix Ophiopogonis, browning often happens to cause potential risk with regard to safety. Previously few reports investigate the browning of Radix Ophiopogonis. In this research, the causes and mechanisms of the browning of Radix Ophiopogonis were preliminarily elucidated. Content determination by high-performance liquid chromatogra- phy （HPLC） and spectrophotometry, enzyme activity determination by colorimetry, and morphological observation by electron mi- croscopy were performed in the present study. Uniform design and three-dimensional response surfaces were applied to investigate the relationship between browning and storage factors. The cortex cell wall of browned Radix Ophiopogonis was ruptured. Compared with the normal Radix Ophiopogonis, cellulase and polyphenol oxidase enzymes were activated, the levels of 5-hydroxymethylfurfural （5-HMF）, total sugars, and reducing sugars were increased, while the levels of polysaccharides and methylophiopogonanone A were de- creased in browned Radix Ophiopogonis. The relationship between the storage factors and degree of browning （Y） could be described by following correlation equation： Y= - 0.625 4 ＋ 0.020 84 × X3 ＋ 0.001 514×X1×x X2 - 0.000 964 4 × X2 × X3. Accompanied with browning under storage conditions, the chemical composition of Radix Ophiopogonis was altered. Following the activation of cellulase, the rupture of the cortex cell wall and the outflow of cell substances flowed out, which caused the Radix Ophiopogonis tissue to become soft and sticky. The main causes of the browning were the production of 5-HMF, the activation of polyphenol oxidase, Maillard reactions and enzymatic browning. Browning could be effectively prevented when the air relative humidity （HR）, temperature, and moisture content were under 25% RH, 12 ℃ and 18%, respectively.展开更多
The accumulation of Pb in the food chain is one of the great concerns as it can cause chronic health problems and the available Pb is easily absorbed by crops. To shed light on Pb bioavailability in lead-contaminated ...The accumulation of Pb in the food chain is one of the great concerns as it can cause chronic health problems and the available Pb is easily absorbed by crops. To shed light on Pb bioavailability in lead-contaminated agricultural soils of Zhejiang Province, a series of plant growth experiments were performed in a greenhouse to select more suitable extractants from five commonly used extractants (0.1 M HCl, 1 M NH4OAc, 0.1 M CaCl2, DTPA-TEA and Mehlich 3). The results showed that 1 M NH4OAc can extract Pb best, indicating the Pb bioavailability, then, DTPA-TEA and 0.1 M HCl in the tested soils. In case 1 M NH4OAc was used as an extractant, the critical Pb concentrations in soils were 50.19 mg/kg, 21.16 mg/kg and 114.00 mg/kg (1 M NH4OAc extracted Pb) in silty loam, yellowish-red soil and purplish soil, respectively. When the values exceed the above ones, the contents of Pb in Chinese cabbage leaves will exceed the Chinese Tolerance Limit of Lead in Foods (GB14935-94), as a result, potential ecological risk and hazard to human health via the food chain will appear.展开更多
A pot experiment was conducted under submerged conditions with hybrid rice Zhenong 7 to study the variation in the soil microbial biomass carbon （Cmic）, soil microbial biomass nitrogen （Nmic）, soil respiration rat...A pot experiment was conducted under submerged conditions with hybrid rice Zhenong 7 to study the variation in the soil microbial biomass carbon （Cmic）, soil microbial biomass nitrogen （Nmic）, soil respiration rate, soil microbial metabolic quotient, soil enzyme activities, chlorophyll content, proline content and peroxidase activity （POD） in rice leaf at different growth stages. The soil Cmic, Nmic and soil respiration rate significantly increased at the early stage and then declined during rice growth, but ascended slightly at maturity. However, soil metabolic quotient declined at all the stages. Soil urease activity increased at first and then decreased, while acid phosphatase and dehydrogenase activities descended before ascended and then descended again. Soil urease activity and acid phosphatase activity showed a peak value at the tillering stage about 30 days after rice transplanting, but the peak value of dehydrogenase activity emerged at about 50 days after rice transplanting and the three soil enzymatic activities were significantly different at the different developmental stages. As rice growing, chlorophyll content in rice leaf descended at the early stage then ascended and a peak value appeared at about the 70th after rice transplanting, after that declined drastically, while POD activity increased gradually, but proline content declined gradually. There was a slight relation between rice physiological indices and soil biochemical indices, which indicated that soil biochemical characteristics were affected significantly by rice growth in the interaction system of the rice. soil and microorganisms.展开更多
A new C-glycosylflavone,5-hydroxyl-4′,7-dimethoxyflavone-6-C-[0-(α-L-3″-acetylrhamno-pyranosy)-1→2-β-D-glucopyranoside](1),along with five known C-glycosylflavones,5-hydroxy-4′,7-dimethoxyfavone-6-C-[0-(α-L-2′...A new C-glycosylflavone,5-hydroxyl-4′,7-dimethoxyflavone-6-C-[0-(α-L-3″-acetylrhamno-pyranosy)-1→2-β-D-glucopyranoside](1),along with five known C-glycosylflavones,5-hydroxy-4′,7-dimethoxyfavone-6-C-[0-(α-L-2′″-acetylrhamnopyranosy1)-1→2-β-D-glucopyranoside](2),embinin(3),embigenin(4),swertisin(5)and swertiajaponin(6)were isolated from the leaves of Iris tectorum Maxim.Their structures were elucidated on the basis of extensive NM R experiments and spectral methods and their cytotoxic activities against A 549(lung cancer)human cell lines were determined.展开更多
Coumarins,derived from the phenylpropanoid pathway,represent one of the primary metabolites found in angiosperms.The alignment of the tetrahydropyran(THP)and tetrahydrofuran(THF)rings with the lactone structure result...Coumarins,derived from the phenylpropanoid pathway,represent one of the primary metabolites found in angiosperms.The alignment of the tetrahydropyran(THP)and tetrahydrofuran(THF)rings with the lactone structure results in the formation of at least four types of complex coumarins.However,the mechanisms underlying the structural diversity of coumarin remain poorly understood.Here,we report the chromosome-level genome assembly of Notopterygium incisum,spanning 1.64 Gb,with a contig N50 value of 22.7 Mb and 60,021 annotated protein-coding genes.Additionally,we identified the key enzymes responsible for shaping the structural diversity of coumarins,including two p-coumaroyl CoA 2′-hydroxylases crucial for simple coumarins basic skeleton architecture,two UbiA prenyltransferases responsible for angular or linear coumarins biosynthesis,and five CYP736 cyclases involved in THP and THF ring formation.Notably,two bifunctional enzymes capable of catalyzing both demethylsuberosin and osthenol were identified for the first time.Evolutionary analysis implies that tandem and ectopic duplications of the CYP736 subfamily,specifically arising in the Apiaceae,contributed to the structural diversity of coumarins in N.incisum.Conclusively,this study proposes a parallel evolution scenario for the complex coumarin biosynthetic pathway among different angiosperms and provides essential synthetic biology elements for the heterologous industrial production of coumarins.展开更多
Pyran-and furanocoumarins are key representatives of tetrahydropyrans and tetrahydrofurans,respectively,exhibiting diverse physiological and medical bioactivities.However,the biosynthetic mechanisms for their core str...Pyran-and furanocoumarins are key representatives of tetrahydropyrans and tetrahydrofurans,respectively,exhibiting diverse physiological and medical bioactivities.However,the biosynthetic mechanisms for their core structures remain poorly understood.Here we combined multiomics analyses of biosynthetic enzymes in Peucedanum praeruptorum and in vitro functional verification and identified two types of key enzymes critical for pyran and furan ring biosynthesis in plants.These included three distinct P.praeruptorum prenyltransferases(PpPT1e3)responsible for the prenylation of the simple coumarin skeleton 7 into linear or angular precursors,and two novel CYP450 cyclases(PpDC and PpOC)crucial for the cyclization of the linear/angular precursors into either tetrahydropyran or tetrahydrofuran scaffolds.Biochemical analyses of cyclases indicated that acid/base-assisted epoxide ring opening contributed to the enzyme-catalyzed tetrahydropyran and tetrahydrofuran ring refactoring.The possible acid/base-assisted catalytic mechanisms of the identified cyclases were theoretically investigated and assessed using site-specific mutagenesis.We identified two possible acidic amino acids Glu303 in PpDC and Asp301 in PpOC as vital in the catalytic process.This study provides new enzymatic tools in the epoxide formation/epoxide-opening mediated cascade reaction and exemplifies how plants become chemically diverse in terms of enzyme function and catalytic process.展开更多
基金Supported by the National Key Basic Research Support Foundation of China (No. 2002CB410804) the National Natural Science Foundation of China (No. 40201026).
文摘Effects of organic acids (oxalic, acetic, and citric) on adsorption characteristics of Cadmium (Cd) on soil clay minerals (kaolinite, goethite, and bayerite) were studied under different concentrations and different pH values. Although the types of organic acids and minerals were different, the effects of the organic acids on the adsorption of Cd on the minerals were similar, i.e., the amount of adsorbed Cd with an initial solution pH of 5.0 and initial Cd concentration of 35 mg L-1 increased with increasing concentration of the organic acid in solution at lower concentrations, and decreased at higher concentrations. The percentage of Cd adsorbed on the minerals in the presence of the organic acids increased considerably with increasing pH of the solution. Meanwhile, different Cd adsorption in the presence of the organic acids, due to different properties on both organic acids and clay minerals, on kaolinite, goethite, or bayerite for different pHs or organic acid concentrations was found.
基金Project(2009QNA6015) supported by the Fundamental Research Funds for the Central Universities of ChinaProject(Y3110055)supported by the Natural Science Foundation of Zhejiang Province,ChinaProject(Y200803219) supported by the Foundation of Zhejiang Educational Committee of China
文摘The relationship between Solidago canadensis L. invasion and soil microbial community diversity including functional and structure diversities was studied across the invasive gradients varying from 0 to 40%, 80%, and 100% coverage of Solidago canadensis L. using sole carbon source utilization profiles analyses, principle component analysis （PCA） and phospholipid fatty acids （PLFA） profiles analyses. The results show the characteristics of soil microbial community functional and structure diversity in invaded soils strongly changed by Solidago canadensis L. invasion. Solidago canadensis L. invasion tended to result in higher substrate richness, and functional diversity. As compared to the native and ecotones, average utilization of specific substrate guilds of soil microbe was the highest in Solidago canadensis L. monoculture. Soil microbial functional diversity in Solidago canadensis L. monoculture was distinctly separated from the native area and the ecotones. Aerobic bacteria, fungi and actinomycetes population significantly increased but anaerobic bacteria decreased in the soil with Solidago canadensis L. monoculture. The ratio of cyl9：0 to 18：1 co7 gradually declined but mono/sat and fung/bact PLFAs increased when Solidago canadensis L. became more dominant. The microbial community composition clearly separated the native soil from the invaded soils by PCA analysis, especially 18： lco7c, 16： lco7t, 16： lco5c and 18：2co6, 9 were present in higher concentrations for exotic soil. In conclusion, Solidago canadensis L. invasion could create better soil conditions by improving soil microbial community structure and functional diversity, which in turn was more conducive to the growth ofSolidago canadensis L.
基金supported by the National Natural Science Foundation of China (Project No. 40201026)the State Key Basic Research and Development Plan of China (No. 2002CB410804)
文摘To assess the effects of single and combined pollution of cadmium (Cd) and mercury (Hg) on soil micro-bial community structural and functional diversities, an incubation experiment was conducted, by employing two soils, namely, the marine sediment silty loam soil and the yellowish-red soil, in which five levels of Cd, Hg and Cd and Hg in combination were added. After being incubated for 56 days, the phospholipid fatty acids (PLFAs) profile and sole carbon source utilization pattern (BIOLOG) of the samples were tested. The results showed that the compo-sition of the microbial communities changed significantly at different levels of metals application. The principal component analyses (PCA) of PLFAs indicated that the structure of the microbial community was also significantly altered with increasing levels of metals, with increasing PLFAs biomarkers for fungi and actinomycetes, and in-creasing ratio of Gram-positive to Gram-negative bacteria. Sole carbon source utilization pattern analysis revealed that single and combined application of Cd and Hg inhibited significantly the functional activity of soil microorgan-isms, the functional diversity indices [Richness (S), Shannon-Wiener indices (H) and Evenness (EH)] were signifi-cantly lower in polluted soils than those in non-polluted soils, which also significantly altered with increasing levels of metals. PCA for the sole carbon source utilization pattern also indicated that the metal contamination could result in a variable soil microbial community. The results revealed that the combination of Cd and Hg had higher toxicity to soil microbial community structural and functional diversities than the individual application of Cd or Hg.
基金Project(GX2007CAQB01)supported by the Key Research Project of Aluminum Corporation of China LimitedProject(41502067)supported by the National Natural Science Foundation of China
文摘Major and REE geochemistry and multi-fractal analysis of two types of bauxite(primary bauxite and accumulated bauxite) ores were studied in Pingguo bauxite orefield in western Guangxi,China.The results of geochemical data show that the accumulated bauxite has a feature of high Al_2O_3 whereas relative low Fe_2O_3 and SiO_2 contents compared to the primary bauxite.The similar chondrite-normalized rare earth element(REE) patterns illustrate that they have a cognate relationship.However,the negative Ce anomalies of primary bauxite and positive Ce anomalies of accumulated bauxite indicate that the ore-forming system changed from reducing environment to oxidation environment.The results of multi-fractal spectrum and parameters of Al_2O_3,Fe_2O_3 and SiO_2 between primary bauxite and accumulated bauxite show that the distinct multi-fractal spectrum parameters reflect the different grade distribution between accumulated and primary bauxite ores.Metallogenic process from primary bauxite to accumulated bauxite is accompanied by the loss of diffluent elements(e.g.,Si and S) and enrichment of stable elements(e.g.,Al and Fe) in the surface environment.Among the rest,the migration mechanism of iron during the evolutionary process from primary ore to accumulated ore can be described as combined leaching and chemical weathering action with participation of sulfur.
基金supported by the Preponderant Discipline Construction Project for Traditional Chinese Medicines of Jiangsu Province
文摘The present study was designed to explore the mechanism by which ethanol extract of Bombax ceiba leaves(BCE) and its main constituent mangiferin(MGF) affect diabetic nephropathy by combating oxidative stress. Oral administration of BCE and MGF to normal and streptozotocin(STZ)-induced diabetic mice were carried out. Fasting blood glucose, 24-h urinary albumin, serum creatinine, and blood urea nitrogen were tested, histopathology, and immunohistochemical analysis of kidney tissues were performed. Moreover, mesangial cells were treated with BCE and MGF for 48 h with or without 25 mmol·L^(-1) of glucose. Immunofluorescence, Western blot and apoptosis analyses were used to investigate their regulation of oxidative stress and mitochondrial function. BCE and MGF ameliorated biochemical parameters and restored STZ-induced renal injury in the model mice. In vitro study showed that high glucose stimulation increased oxidative stress and cell apoptosis in mesangial cells. BCE and MGF limited mitochondrial membrane potential(Δψm) collapse by inhibiting Nox4, mitochondrially bound hexokinase II dissociation, and subsequent ROS production, which effectively reduced oxidative stress, cleaved caspase-3 expression and cell apoptosis. Our work indicated that BCE and MGF had protective effects on diabetic caused kidney injury and prevented oxidative stress in mesangial cells by regulation of hexokinase II binding and Nox4 oxidase signaling.
文摘The present study aimed at exploring the therapeutic potential of standard extract of Bombax ceiba L.leaves(BCE) in type 2 diabetic mellitus(T2DM).Oral administration of BCE at doses of 70,140,and 280 mg·kg^(-1),to the normal rats and the high-fat-diet-and streptozotocin-induced T2 DM rats were carried out.Effects of BCE on blood glucose,body weight,and a range of serum biochemical parameters were tested,and histopathological observation of pancreatic tissues was also performed.HPLC-ESI-Q/TOF-MS/MS analysis indicated that the chemical composition of BCE mainly contained mangiferin,isoorientin,vitexin,isomangiferin,isovitexin,quercetin hexoside,2'-trans-O-cumaroyl mangiferin,and nigricanside.BCE caused a significant decrease in the concentrations of fasting blood glucose,glycosylated hemoglobin,total cholesterol,triglyceride,low density lipoprotein-cholesterol,serum insulin,and malondialdehyde,and increases in oral glucose tolerance,high density lipoprotein-cholesterol,and superoxide dismutase in the T2 DM model rats.Moreover,considerable pancreatic β-cells protection effect and stimulation of insulin secretion from the remaining pancreatic β-cells could be observed after BCE treatment.The results indicated that BCE exhibited an excellent hypoglycemic activity,and alleviated dyslipidemia which is associated with T2 DM.Antioxidant activity and protecting pancreatic β-cells are the possible mechanisms involved in anti-diabetic activity of BCE.
基金supported by the National Science and Technology Major Projects for"Major New Drugs Innovation and Development" and the"Chinese Herbal Medicine Seeds and Seedlings Planting(breeding)Standard Platform Topics"(No.2012ZX09304006)
文摘"Wu zhu yu", which is obtained from the dried unripe fruits of Tetradium ruticarpum(A. Jussieu) T. G. Hartley, has been used as a traditional Chinese medicine for treatment of headaches, abdominal colic, and hypertension for thousands of years. The present study was designed to assess the molecular genetic diversity among 25 collected accessions of T. ruticarpum(Wu zhu yu in Chinese) from different areas of China, based on inter-primer binding site(i PBS) markers and inter-simple sequence repeat(ISSR) markers. Thirteen ISSR primers generated 151 amplification bands, of which 130 were polymorphic. Out of 165 bands that were amplified using 10 iPBS primers, 152 were polymorphic. The iPBS markers displayed a higher proportion of polymorphic loci(PPL = 92.5%) than the ISSR markers(PPL = 84.9%). The results showed that T. ruticarpum possessed high loci polymorphism and genetic differentiation occurred in this plant. The combined data of iPBS and ISSR markers scored on 25 accessions produced five clusters that approximately matched the geographic distribution of the species. The results indicated that both iPBS and ISSR markers were reliable and effective tools for analyzing the genetic diversity in T. ruticarpum.
基金Project supported by the National Key Basic Research Support Foundation of China (No. 2002CB410804) the National Natural Science Foundation of China (No. 39970146).
文摘Adsorption isotherms of metsulfuron and bensulfuron on a hexadecyltrimethylammonium （HDTMA） bromide-modified paddy soil under different ionic strengths, with divalent cation Cu^2＋, or having different pH were studied to describe their adsorptive behavior, and to try to explain the adsorption process of a sulfonylurea compound with a carbamoylsulfamoyl group in the modified soil environment. All the adsorption isotherms fitted the Freundlich equation well, and the HDTMA treatment of paddy soil dramatically enhanced adsorption capacity of metsulfuron or bensulfuron. Also, an increase of ionic strength and the addition of divalent heavy metal cation Cu^2＋ on the HDTMA-modified paddy soil increased the adsorption of metsulfuron or bensulfuron. Additionally, for metsulfuron and bensulfuron in the aqueous phase, adsorption capacity of the HDTMA-modified paddy soft gradually increased with decreasing pH.
文摘Adsorption isotherms of 2,4-dinitrophenol and 2,4-dichlorophenol on hexadecyltrimethylammonium (HDTMA) bromide modified red soil under different ionic strength, divalent cation Cu 2+ or different pH conditions were studied. All the adsorption isotherms were well fitted to the Freundlich equation. The adsorption capacities of 2,4-dinitrophenol or 2,4-dichlorophenol were dramatically enhanced by HDTMA treatment of red soil. The increase of ionic strength and the addition of divalent heavy metal cation Cu 2+ significantly enhanced the adsorption of 2,4-dinitrophenol or 2,4-dichlorophenol on the HDTMA-modified red soil. Adsorption capacities of HDTMA-modified red soil for 2,4-dinitrophenol and 2,4-dichlorophenol gradually increased with decreasing pH in the aqueous phase.
基金supported by the Fundamental Research Funds for the Central Universities of China (2009QNA6015)Foundation of Zhejiang Educational Committee of China (Y200803219)
文摘The relationship between Solidago canadensis L. invasion and soil microbial communities was studied across the invasive gradients varying from 0 to 40, 80, and 100% coverage of S. canadensis. The results showed both soil microbial biomass C （Cmic） and N （Nmic） increased as the coverage of S. canadensis increased. Soil microbial quotient Cmic/Corg （microbial biomass C/organic C） tended to increase linearly with the coverage of S. canadensis. Soil basal respiration （BR） also showed a similar trend. The soil respiratory quotient qCO2 decreased with S. canadensis invasion, and remained at quite a constantly low level in the invasive soils. Sole carbon source utilization profiles analyses indicated that S. canadensis invasion tended to result in higher microbial functional diversity in the soil. Average utilization of specific substrate guilds was highest in the soil with S. canadensis monoculture. Principle component analysis of sole carbon source utilization profiles further indicated that microbial functional diversity in the soil with S. canadensis monoculture was distinctly separated from those soils in the native area and the ecotones. In conclusion, S. canadensis invasion improved soil microbial biomass, respiration and utilization of carbon sources, and decreased qCO2, thus created better soil conditions, which in turn were more conducive to the growth of S. canadensis.
基金This work was co-financed by the National Natural Science Foundation of China(Grant No.41502067)the Fundamental Research Funds for the Central Universities,China University of Geosciences(Wuhan)(Grant No.CUG150612)+1 种基金supported by Australian Research Council Discovery funding scheme(DP160102427)a Curtin Research Fellowship
文摘Low-temperature Sb(Au-Hg) deposits in South China account for more than 50% of the world’s Sb reserves,however,their genesis remains controversial.Here we report the first study that integrates U-Pb and Lu-Hf analysis by LA-(MC)-ICPMS and conventional(U-Th)/He analysis,all applied to single zircon crystals,in an attempt to constrain the origin and timing of world-class Sb(Au-Hg) deposits in Banxi(South China).Zircon separated from a quartz-stibnite ore and an altered country rock samples revealed similar U-Pb age spectra defining two major populations-Paleoproterozoic(~1900-2500 Ma) and Neoproterozoic(~770 Ma),which are characterized by variable εHf(t) values(-10.7 to 9.1 and-16.5 to 11.2,respectively) and Hf crustal model ages(TDMC)(2.48 to 3.24 Ga and 0.97 to 2.71 Ga,respectively).The U-Pb age and Hf isotopic features of the zircons are consistent with the Banxi Group in the region,indicating that the zircons involved in the low-temperature hydrothermal system were originally from the Banxi Group country rocks.Thirty-three mineralization-related zircon crystals yielded a mean(U-Th)/He age of 123.8±3.8 Ma,which is interpreted to represent the timing of the latest low-temperature mineralization stage of the Banxi Sb deposit.The combined U-Pb,Lu-Hf and(U-Th)/He data suggest that Precambrian basement rocks were the major contributors to the low-temperature mineralization,and that Early Cretaceous(130-120 Ma) could be the most important ore-forming epoch for the Sb deposits in South China.This study also demonstrates the analytical feasibility of integrated U-Pb-Lu-Hf-(U-Th)/He "triple-dating",all applied to single zircon crystals.This approach reveals the full evolution of zircon,from its origin of the magmatic source,through its crystallization and low-temperature cooling.Although this study demonstrates the usefulness of this integrated approach in dating low-temperature mineralization,it has great potential for zircon provenance and other studies that may benefit from the large amount of information that can be extracted from single zircon crystals.
基金co-financed by the Fundamental Research Funds for the Central Universities,China University of Geosciences(Wuhan)(Grant No.CUG150612)the National Natural Science Foundation of China(Grant No.41502067,41172087)
文摘The Batang Group in the Zhaokalong area not only hosts an important Fe-Cu polymetallic deposit but also reveal important insights for the Late Triassic tectonism in the northern Sanjiang region. In order to delineate the tectonic setting and evolutionary process of the paleo arc-basin system, geochemical studies on the Batang Group strata have been carried out. The results suggest that andesite in the Zhaokalong area mainly belongs to the tholeiite series and is characterized by obvious fractionation of LREE and HREE, enrichment in LILE and depletion in HFSE, and a distinctly elevated δ^（34）SCDT average of 10.5‰. The sandstone is classified as lithic sandstone, which is also characterized by obvious fractionation of LREE and HREE, as well as weak negative Ce and Eu anomalies. The limestone displays positive Eu anomalies, with δ^（13）CPDB ranging from-1.3‰ to 4.4‰ and δ^（18） OSMOW ranging from 14.6‰ to 22.5‰. These results indicate that the andesite has a dual signature of both arc andesite and rift volcanic rocks, whereas the sandstone may be formed in an active continental margin, and the limestone could be deposited in a weak oxidizing shallow sea. The sandstone in the Zhaokalong area represents sedimentation in a platform slope facies, corresponding to the main stage of the Jinshajing oceanic basin subduction during the middle period of Late Triassic. The continental arc volcanic activity resulted from subsequent strengthened subduction, forming the andesite in the North Qiangtang backarc basin. Afterwards, the limestone was formed after the cessation of magmatic activity. The information gleaned from the Batang Group strata helped constrain the evolution of the paleo-Jomda island arc and Jinshajiang oceanic subduction in the Late Triassic.
基金the National Key R&D Program of China(2019YFC1711000)the Basic Research Program for Natural Science of Shaanxi Province(2020JQ-862)+1 种基金the National Natural Science Foundation of China(grant number 81703637)the Natural Science Fund in Jiangsu Province(grant number BK20170736)。
文摘Corydalis yanhusuo W.T.Wang is a classic herb that is frequently used in traditional Chinese medicine and is efficacious in promoting blood circulation,enhancing energy,and relieving pain.Benzylisoquinoline alkaloids(BIAs)are the main bioactive ingredients in Corydalis yanhusuo.However,few studies have investigated the BIA biosynthetic pathway in C.yanhusuo,and the biosynthetic pathway of species-specific chemicals such as tetrahydropalmatine remains unclear.We performed full-length transcriptomic and metabolomic analyses to identify candidate genes that might be involved in BIA biosynthesis and identified a total of 101 full-length transcripts and 19 metabolites involved in the BIA biosynthetic pathway.Moreover,the contents of 19 representative BIAs in C.yanhusuo were quantified by classical targeted metabolomic approaches.Their accumulation in the tuber was consistent with the expression patterns of identified BIA biosynthetic genes in tubers and leaves,which reinforces the validity and reliability of the analyses.Full-length genes with similar expression or enrichment patterns were identified,and a complete BIA biosynthesis pathway in C.yanhusuo was constructed according to these findings.Phylogenetic analysis revealed a total of ten enzymes that may possess columbamine-O-methyltransferase activity,which is the final step for tetrahydropalmatine synthesis.Our results span the whole BIA biosynthetic pathway in C.yanhusuo.Our full-length transcriptomic data will enable further molecular cloning of enzymes and activity validation studies.
基金the National Natural Science Foundation of China (No.30170103).
文摘Two new acylated C-glycosylflavones were isolated from the leaves of Iris lactea var. chinensis, and their structures were elucidated on the basis of extensive NMR experiments and mass spectrometry methods and were assigned as 5-hydroxy-4＇- methoxyflavone-7-O-（β-D-2＇＇＇＇4＇＇＇＇-diacetylrhamnopyranosyl）-6-C-[ O-（α-L-6＇＇＇-acetyl-glucpyranosyl）-1→2-β-D-glucopyrano- side] （irislactin A） and 5-hydroxy-4＇,7-dimethoxyflavone-6-C-[O-（α-L-2＇＇＇,3＇＇＇-diacetylrhanmo-pyranosyl）-1→ 2-β-D-glucopyranoside] （irislactin B）.
基金supported by the National Natural Science Foundation of China(Nos.30672603&30901956)the "111 Project" from the Ministry of Education of China and the State Administration of Foreign Expert Affairs of China(No.11-2-07)+1 种基金Key Projects in the National Science&Technology Pillar Program during the Eleventh Five-Year Plan Period(2006BAI-09B05-6)Program for Changjiang Scholars and Innovative Research Team in University(IRT0973)
文摘In the storage of Radix Ophiopogonis, browning often happens to cause potential risk with regard to safety. Previously few reports investigate the browning of Radix Ophiopogonis. In this research, the causes and mechanisms of the browning of Radix Ophiopogonis were preliminarily elucidated. Content determination by high-performance liquid chromatogra- phy （HPLC） and spectrophotometry, enzyme activity determination by colorimetry, and morphological observation by electron mi- croscopy were performed in the present study. Uniform design and three-dimensional response surfaces were applied to investigate the relationship between browning and storage factors. The cortex cell wall of browned Radix Ophiopogonis was ruptured. Compared with the normal Radix Ophiopogonis, cellulase and polyphenol oxidase enzymes were activated, the levels of 5-hydroxymethylfurfural （5-HMF）, total sugars, and reducing sugars were increased, while the levels of polysaccharides and methylophiopogonanone A were de- creased in browned Radix Ophiopogonis. The relationship between the storage factors and degree of browning （Y） could be described by following correlation equation： Y= - 0.625 4 ＋ 0.020 84 × X3 ＋ 0.001 514×X1×x X2 - 0.000 964 4 × X2 × X3. Accompanied with browning under storage conditions, the chemical composition of Radix Ophiopogonis was altered. Following the activation of cellulase, the rupture of the cortex cell wall and the outflow of cell substances flowed out, which caused the Radix Ophiopogonis tissue to become soft and sticky. The main causes of the browning were the production of 5-HMF, the activation of polyphenol oxidase, Maillard reactions and enzymatic browning. Browning could be effectively prevented when the air relative humidity （HR）, temperature, and moisture content were under 25% RH, 12 ℃ and 18%, respectively.
基金Granted jointly by the State Key Basic Research Program(973)of China(No.2002CB410804)the National Natural Science Foundation of China(Nos.40201026 and 40371063).
文摘The accumulation of Pb in the food chain is one of the great concerns as it can cause chronic health problems and the available Pb is easily absorbed by crops. To shed light on Pb bioavailability in lead-contaminated agricultural soils of Zhejiang Province, a series of plant growth experiments were performed in a greenhouse to select more suitable extractants from five commonly used extractants (0.1 M HCl, 1 M NH4OAc, 0.1 M CaCl2, DTPA-TEA and Mehlich 3). The results showed that 1 M NH4OAc can extract Pb best, indicating the Pb bioavailability, then, DTPA-TEA and 0.1 M HCl in the tested soils. In case 1 M NH4OAc was used as an extractant, the critical Pb concentrations in soils were 50.19 mg/kg, 21.16 mg/kg and 114.00 mg/kg (1 M NH4OAc extracted Pb) in silty loam, yellowish-red soil and purplish soil, respectively. When the values exceed the above ones, the contents of Pb in Chinese cabbage leaves will exceed the Chinese Tolerance Limit of Lead in Foods (GB14935-94), as a result, potential ecological risk and hazard to human health via the food chain will appear.
基金the National Natural Science Foundation of China (40201026 , 40371063) China National Basic Research Program (2002CB410804).
文摘A pot experiment was conducted under submerged conditions with hybrid rice Zhenong 7 to study the variation in the soil microbial biomass carbon （Cmic）, soil microbial biomass nitrogen （Nmic）, soil respiration rate, soil microbial metabolic quotient, soil enzyme activities, chlorophyll content, proline content and peroxidase activity （POD） in rice leaf at different growth stages. The soil Cmic, Nmic and soil respiration rate significantly increased at the early stage and then declined during rice growth, but ascended slightly at maturity. However, soil metabolic quotient declined at all the stages. Soil urease activity increased at first and then decreased, while acid phosphatase and dehydrogenase activities descended before ascended and then descended again. Soil urease activity and acid phosphatase activity showed a peak value at the tillering stage about 30 days after rice transplanting, but the peak value of dehydrogenase activity emerged at about 50 days after rice transplanting and the three soil enzymatic activities were significantly different at the different developmental stages. As rice growing, chlorophyll content in rice leaf descended at the early stage then ascended and a peak value appeared at about the 70th after rice transplanting, after that declined drastically, while POD activity increased gradually, but proline content declined gradually. There was a slight relation between rice physiological indices and soil biochemical indices, which indicated that soil biochemical characteristics were affected significantly by rice growth in the interaction system of the rice. soil and microorganisms.
基金The project supported by the National Natural Science Foundation of China(Grant No.30170103).
文摘A new C-glycosylflavone,5-hydroxyl-4′,7-dimethoxyflavone-6-C-[0-(α-L-3″-acetylrhamno-pyranosy)-1→2-β-D-glucopyranoside](1),along with five known C-glycosylflavones,5-hydroxy-4′,7-dimethoxyfavone-6-C-[0-(α-L-2′″-acetylrhamnopyranosy1)-1→2-β-D-glucopyranoside](2),embinin(3),embigenin(4),swertisin(5)and swertiajaponin(6)were isolated from the leaves of Iris tectorum Maxim.Their structures were elucidated on the basis of extensive NM R experiments and spectral methods and their cytotoxic activities against A 549(lung cancer)human cell lines were determined.
基金supported by the Western Light Project of the Chinese Academy of Sciences and the Young Qihuang Scholars Project of the National Administration of Traditional Chinese Medicine.This research was also funded by the open foundation of Shaanxi University of Chinese Medicine state key laboratory of R&D of Characteristic Qin Medicine Resources(SUCM-QM202202,China)the fund of Traditional Chinese Medicine Institute of Anhui Dabie Mountain(TCMADM-2023-18,China)+2 种基金“Double FirstClass”University Project of China Pharmaceutical University(CPU2022QZ27,China)supported by the key project at the central government level:the ability establishment of sustainable use for valuable Chinese medicine resources(2060302,China)the open research fund of Yunnan characteristic plant extraction laboratory(YKKF2023002,China)。
文摘Coumarins,derived from the phenylpropanoid pathway,represent one of the primary metabolites found in angiosperms.The alignment of the tetrahydropyran(THP)and tetrahydrofuran(THF)rings with the lactone structure results in the formation of at least four types of complex coumarins.However,the mechanisms underlying the structural diversity of coumarin remain poorly understood.Here,we report the chromosome-level genome assembly of Notopterygium incisum,spanning 1.64 Gb,with a contig N50 value of 22.7 Mb and 60,021 annotated protein-coding genes.Additionally,we identified the key enzymes responsible for shaping the structural diversity of coumarins,including two p-coumaroyl CoA 2′-hydroxylases crucial for simple coumarins basic skeleton architecture,two UbiA prenyltransferases responsible for angular or linear coumarins biosynthesis,and five CYP736 cyclases involved in THP and THF ring formation.Notably,two bifunctional enzymes capable of catalyzing both demethylsuberosin and osthenol were identified for the first time.Evolutionary analysis implies that tandem and ectopic duplications of the CYP736 subfamily,specifically arising in the Apiaceae,contributed to the structural diversity of coumarins in N.incisum.Conclusively,this study proposes a parallel evolution scenario for the complex coumarin biosynthetic pathway among different angiosperms and provides essential synthetic biology elements for the heterologous industrial production of coumarins.
基金National Key Research and Development Program of China (2018YFA0902000)the key project at central government level:the ability establishment of sustainable use for valuable Chinese medicine resources(2060302,China)+3 种基金the open foundation of Shaanxi University of Chinese Medicine state key laboratory of R&D of Characteristic Qin Medicine Resources (SUCM-QM202202,China)the fund of Traditional Chinese Medicine Institute of Anhui Dabie Mountain (TCMADM-2023-18,China)National Natural Science Foundation of China (32070364)Hainan Provincial Natural Science Foundation of China(2019RC309)
文摘Pyran-and furanocoumarins are key representatives of tetrahydropyrans and tetrahydrofurans,respectively,exhibiting diverse physiological and medical bioactivities.However,the biosynthetic mechanisms for their core structures remain poorly understood.Here we combined multiomics analyses of biosynthetic enzymes in Peucedanum praeruptorum and in vitro functional verification and identified two types of key enzymes critical for pyran and furan ring biosynthesis in plants.These included three distinct P.praeruptorum prenyltransferases(PpPT1e3)responsible for the prenylation of the simple coumarin skeleton 7 into linear or angular precursors,and two novel CYP450 cyclases(PpDC and PpOC)crucial for the cyclization of the linear/angular precursors into either tetrahydropyran or tetrahydrofuran scaffolds.Biochemical analyses of cyclases indicated that acid/base-assisted epoxide ring opening contributed to the enzyme-catalyzed tetrahydropyran and tetrahydrofuran ring refactoring.The possible acid/base-assisted catalytic mechanisms of the identified cyclases were theoretically investigated and assessed using site-specific mutagenesis.We identified two possible acidic amino acids Glu303 in PpDC and Asp301 in PpOC as vital in the catalytic process.This study provides new enzymatic tools in the epoxide formation/epoxide-opening mediated cascade reaction and exemplifies how plants become chemically diverse in terms of enzyme function and catalytic process.
