From aerial parts of Austroeupatorium inulifolium was isolated the ent-nor-furano triol labdane austroeupatol 1.The compound 1 was treated with IBX showing an unexpected selectivity at the potentially oxidizable sites...From aerial parts of Austroeupatorium inulifolium was isolated the ent-nor-furano triol labdane austroeupatol 1.The compound 1 was treated with IBX showing an unexpected selectivity at the potentially oxidizable sites of the sub-strate yielding the 2-oxoaustroeupatol(2)and 2,19-dioxoaustroeupatol(3).The treatment of 2 with sodium periodate yields a heterocyclic derivative(ε-caprolactone derivate 4)formed by oxidative cleavage and unexpected intramo-lecular attack of the hydroxymethylene(C-19)oxygen to the ketonic carbon(C-2).A plausible mechanistic pathway for the obtention of compound 4 is proposed.展开更多
During the course of our program in the synthesis of natural products by retroDiels-Alder reaction using a rigid molecule tricyclo-[5.2.1.0]-deca-4,8-dien-3-one（1） as the starting material, it was observed that aldo...During the course of our program in the synthesis of natural products by retroDiels-Alder reaction using a rigid molecule tricyclo-[5.2.1.0]-deca-4,8-dien-3-one（1） as the starting material, it was observed that aldol condensation of compound （2）展开更多
The unique fruity aroma of strawberries enhances their appeal to consumers.Fragaria nilgerrensis,a wild strawberry distributed in Southwest China and known for its distinctive peach-like aroma,represents a valuable re...The unique fruity aroma of strawberries enhances their appeal to consumers.Fragaria nilgerrensis,a wild strawberry distributed in Southwest China and known for its distinctive peach-like aroma,represents a valuable resource for improving the fragrance of cultivated strawberries.However,the molecular mechanism underlying the peach-like aroma biosynthesis remains largely unexplored.In this study,we integrated metabolomic and transcriptomic data across four developmental stages of F.nilgerrensis fruits to construct a detailed profile of volatile organic compounds(VOCs)and the associated gene expression alterations during fruit maturation.Our findings reveal that g-decalactone,d-decalactone,and g-undecalactone are the primary compounds responsible for the pronounced peach-like aroma,with their levels showing a significant correlation with the activity of the FngFAD2 enzyme.The silencing of the FngFAD2 gene through tobacco rattle viral(TRV)induction resulted in notable reductions in both the peach-like aroma and lactone content in the fruit.In addition,integrating dual luciferase assays,yeast one-hybrid(Y1H)and subcellular localization experiments,we also identified three transcription factors(FngDOF1.2,FngWRKY3,and FngWRI1)that enhance FngFAD2 expression.These findings elucidate the molecular regulatory network involved in the complex developmental process of peach-like flavor in strawberry fruits.Additionally,our research also provides a foundation for the utilization of the wild strawberry as well as improving the flavor and quality of cultivated strawberries.展开更多
Traumatic axonal lesions of peripheral nerves disrupt neuronal connections with their targets,resulting in the loss of motor and sensory functions.Despite the peripheral nervous system’s capacity for axonal regrowth,...Traumatic axonal lesions of peripheral nerves disrupt neuronal connections with their targets,resulting in the loss of motor and sensory functions.Despite the peripheral nervous system’s capacity for axonal regrowth,this may lead to permanent impairements resulting in a loss of quality of life and a high socioeconomic burden.展开更多
Mycobacterium marinum can cause disease in both human beings and fishes.Infected fish exhibits symptoms commonly referred to as fish tuberculosis.In this research,we screened a 14-Membered Resorcylic Acid Lactones(RAL...Mycobacterium marinum can cause disease in both human beings and fishes.Infected fish exhibits symptoms commonly referred to as fish tuberculosis.In this research,we screened a 14-Membered Resorcylic Acid Lactones(RALs)library constructed in the laboratory for in vitro anti-Mycobacterium marinum activity and found that several compounds,including compounds 3,4,6,10,and 17–26,showed good activity.Notably,the trace natural product cochilimycin B(compound 3)possesses significant long-lasting inhibitory function to Mycobacterium marinum.It also shows synergistic effects with drugs like isoniazid,ethambutol,and bedaquiline(FICI≤0.5).In addition,cochilimycin B showed a significant inhibitory effect on the biofilm produced by Mycobacterium marinum,with an inhibition rate of 65.9%.To solve the bottleneck problem of natural product drug sources,we realized an efficient one-step semi-synthetic method to obtain compound 3 with a yield of 32.1%.In vivo,inflammatory changes in BALB/c mice infected with Mycobacterium marinum were characterized.After 12 h of infection,IL-1βwas 20%–30%lower in the spleen and tail of the3-treated group compared to the control group.In the thymus and tail of the treated group,TNF-αlevels were 30%–60%lower than in the control group.This is the first time that the significant anti-Mycobacterium marinum effect of cochilimycin B from 14-Membered Resorcylic Acid Lactones(14-RALs)was reported,offering a new chemical molecule for anti-Mycobacterium marinum drug research.展开更多
Alduronic acid lactones and glyconolactones are highly functionalized and versatile chiral building blocks.Herein,we describe a novel approach to these compounds via decarboxylative oxygenation of uronic acids.The tra...Alduronic acid lactones and glyconolactones are highly functionalized and versatile chiral building blocks.Herein,we describe a novel approach to these compounds via decarboxylative oxygenation of uronic acids.The transformations proceed using Selectfluor and TEMPO as oxidants,either in the presence of catalytic amounts of Ag_(2)CO_(3)or in the absence of this catalyst.The methodology provides structurally diverse alduronic acid lactones and enables the preparation of rare sugar glyconolactones from easily available D-C-glycosides.Based on the^(18)O-labeling experiments,control experiments,and isolation of the key intermediates,a radical-polar crossover reaction mechanism is proposed.The utility of this method is demonstrated through efficient conversions of alduronic acid lactones into polyhydroxylated cyclic alkaloids and castanospermine-type architectures.展开更多
Direct converting carbon dioxide(CO_(2))and propane(C_(3)H_(8))into aromatics with high carbon utilization offers a desirable opportunity to simultaneously mitigate CO_(2)emission and adequately utilize C_(3)H_(8) in ...Direct converting carbon dioxide(CO_(2))and propane(C_(3)H_(8))into aromatics with high carbon utilization offers a desirable opportunity to simultaneously mitigate CO_(2)emission and adequately utilize C_(3)H_(8) in shale gas.Owing to their thermodynamic resistance,converting CO_(2)and C_(3)H_(8) respectively remains difficult.Here,we achieve 60.2%aromatics selectivity and 48.8%propane conversion over H-ZSM-5-25 via a zeolite-catalyzing the coupling of CO_(2)and C_(3)H_(8).Operando dual-beam FTIR spectroscopy combined with ^(13)C-labeled CO_(2)tracing experiments revealed that CO_(2)is directly involved in the generation of aromatics,with its carbon atoms selectively embedded into the aromatic ring,bypassing the reverse water-gas shift pathway.Accordingly,a cooperative aromatization mechanism is proposed.Thereinto,lactones,produced from CO_(2)and olefins,are proven to be the key intermediate.This work not only provides an opportunity for simultaneous conversion of CO_(2)and C_(3)H_(8),but also expends coupling strategy designing of CO_(2)and alkanes over acidic zeolites.展开更多
The inhibitory effects of zinc oxide nanoparticles(ZnO NPs)and impacts of N-acylhomoserine lactone(AHL)-based quorum sensing(QS)on biological nitrogen removal(BNR)performance have beenwell-investigated.However,the eff...The inhibitory effects of zinc oxide nanoparticles(ZnO NPs)and impacts of N-acylhomoserine lactone(AHL)-based quorum sensing(QS)on biological nitrogen removal(BNR)performance have beenwell-investigated.However,the effects of ammonia nitrogen(NH_(4)^(+)-N)concentrations on NP toxicity and AHL regulation have seldom been addressed yet.This study consulted on the impacts of ZnO NPs on BNR systems when high NH_(4)^(+)-N concentrationwas available.The synergistic toxic effects of high-strength NH_(4)^(+)-N(200 mg/L)and ZnO NPs resulted in decreased ammonia oxidation rates and dropped the nitrogen removal efficiencies by 17.5%±0.2%.The increased extracellular polymeric substances(EPS)production was observed in response to the high NH_(4)^(+)-N and ZnO NP stress,which indicated the defensemechanism against the toxic effects in the BNR systemswas stimulated.Furthermore,the regulatory effects of exogenous N-decanoyl-homoserine lactone(C_(10)-HSL)-mediated QS system on NP-stressed BNR systems were revealed to improve the BNR performance under different NH_(4)^(+)-N concentrations.The C_(10)-HSL regulated the intracellular reactive oxygen species levels,denitrification functional enzyme activities,and antioxidant enzyme activities,respectively.This probably synergistically enhanced the defense mechanism against NP toxicity.However,compared to the low NH_(4)^(+)-N concentration of 60 mg/L,the efficacy of C_(10)-HSL was inhibited at high NH_(4)^(+)-N levels of 200 mg/L.The findings provided the significant application potential of QS system for BNR when facing toxic compound shock threats.展开更多
As a recently emerging wastewater treatment technology,Algal-bacterial granular sludge(ABGS)process shows significant advantages.However,current research on the ABGS system is a lack of a clear and complete understand...As a recently emerging wastewater treatment technology,Algal-bacterial granular sludge(ABGS)process shows significant advantages.However,current research on the ABGS system is a lack of a clear and complete understanding of the potential mechanism of signal molecules on the growth of ABGS.This study comprehensively explores the variations in the ABGS under different N-acyl-homoserine lactone(AHL)conditions by constructing three sequencing batch reactor(SBR)systems.The results indicate that N-hexanoyl-l-homoserine lactone(C6-HSL)accelerates the granulation process in the early stages by promoting the loosely bound extracellular polymeric substances(LB-EPS)secretion and filamentous bacteria growth,thereby shortening required time for initial granule formation.On the other hand,N-(3-oxodecanoyl)-l-homoserine lactone(3-oxo-C12-HSL)expedites the granulation process by promoting the tightly bound extracellular polymeric substances(TB-EPS)and aromatic protein secretion,benefiting structural stability and nitrogen and phosphorus removal efficiency of mature ABGS.展开更多
Quorum quenching (QQ)-based strategies are efficient for biofouling control.However,the feasibility of using QQ bacteria in antibiotic-stressed membrane bioreactors (MBRs) remains unknown.In this study,we isolated thr...Quorum quenching (QQ)-based strategies are efficient for biofouling control.However,the feasibility of using QQ bacteria in antibiotic-stressed membrane bioreactors (MBRs) remains unknown.In this study,we isolated three novel QQ strains (Bacillus sp.QX01 and QX03,Delftia sp.QX14) from the activated sludge of an actual MBR.They can degrade 11 N-acylhomoserine lactones (AHLs) with high efficiencies and rates through intracellular QQ pathways involving putative acylases and lactonases.Running two lab-scale MBRs,we found that introducing antibiotics (sulfamethoxazole,azithromycin,and ciprofloxacin,each at100μg/L) shortened the fouling cycle by 71.4%.However,the immobilized inoculation of QX01 into one MBR extended the fouling cycle by 1.5-2.0 times.Quantitative detection revealed that QX01 significantly reduced the concentrations of two AHLs (C4-HSL and C8-HSL),which were positively correlated with the contents of extracellular polymeric substances(EPS)(Pearson’s r=0.62-0.83,P<0.01).This suggests that QX01 could perform its QQ activity robustly under antibiotic stress,thereby inhibiting EPS production (proteins especially) and biofilm formation.Moreover,QX01 notably altered the succession patterns of both sludge and fouling communities,with more pronounced effects on abundant taxa.Genera associated with AHL synthesis and EPS production,such as Terrimonas and Rhodobacter,were significantly depleted,contributing to the mitigated biofouling.Additionally,QX01 increased the bacterial community diversity (evenness especially),which was inhibited by antibiotics.Overall,we demonstrate that the novel QQ bacteria could be effective for biofouling control in antibiotic-stressed MBRs,though future work is needed to develop practical approaches for prolonging QQ activity.展开更多
Chiral aryl cyclohex-3-en ether scaffold is widely present in bioactive natural products and drugs.The exploitation of efficient and enantioselective methods for the construction of aryl cyclohex-3-en ether scaffold i...Chiral aryl cyclohex-3-en ether scaffold is widely present in bioactive natural products and drugs.The exploitation of efficient and enantioselective methods for the construction of aryl cyclohex-3-en ether scaffold is significant.Herein we disclose a chiral N,N’-dioxide/Lewis acid complex-catalyzed asymmetric inverse-electron-demand Diels-Alder(IEDDA)reaction using electron-deficient 3-carboalkoxyl-2-pyrones and less electron-enriched aryl enol ethers as reactants.A wide range of non-and 1,2-disubstituted acyclic aryl enol ethers are applicable to deliver diverse chiral bridged bicyclic lactones in high yields and stereoselectivities(up to 96%yield,>20:1 dr,97:3 er).The bridged bicyclic lactone core can be easily converted into chiral aryl cyclohex-3-en ether scaffold.Notably,DFT calculations revealed a stepwise and endo mechanism to explain the high enantioselectivity controlled by the cooperative effect of the steric factors and the dispersion interactions between ligands and enol ethers.展开更多
A chemical investigation of the aerial parts ofArtemisia vestita Wall. led to the isolation of 12 known sesquiterpenes, including 2 furan-containing sesquiterpenoids and 10 eudesmane sesquiterpene lactones. Their stru...A chemical investigation of the aerial parts ofArtemisia vestita Wall. led to the isolation of 12 known sesquiterpenes, including 2 furan-containing sesquiterpenoids and 10 eudesmane sesquiterpene lactones. Their structures were identified as negunfurol （1）, schensianol A （2）, artemine （3）, erivanin （4）, 1,5-diepi-artemin （5）, acetylartemin （6）, naphtho[1,2-b]furan-2（3H）-one, 6-（acetyloxy） decahydro-9a-hydroxy-3,Sa-dimethyl-9-methylene-（3S,3aS,5aS,6S,9aS, ghS） （7）, naphtho[1,2-b]furan-2（3H）-one, 6-（acetyloxy）- 3a,4,5,5a,6,7,8,9b-octahydro-8-hydroxy-3,Sa,9-trimethyl- （3S,3aS, SaR,6S, SS,9bS） （8）, isoerivanin （9）, harrelierin （10）, （11S）-1- oxoeudesm-4（14）-eno-13,6a-lactone （11）, 1-epi-dehydroisoeranin （12）, respectively. All of these compounds were isolated from Artemisia vestita for the first time, and compounds 1 and 2 were isolated from the genus Artemisia for the first time.展开更多
[Objective]The relationship between signal molecule N-acety-homoserine lactones（AHLs） and Microcystis aeruginosa cell apoptosis was studied.[Method]With M.aeruginosa as the test materials treated by 5 μmol/L N-acet...[Objective]The relationship between signal molecule N-acety-homoserine lactones（AHLs） and Microcystis aeruginosa cell apoptosis was studied.[Method]With M.aeruginosa as the test materials treated by 5 μmol/L N-acety-homoserine lactones（AHLs）,the morphology of cell apoptosis was observed through staining with DAPI.[Result]Microcystis aeruginosa cell apoptosis was induced by signal molecule N-acetyhomoserine lactones（AHLs） with the concentration of 1 μmol/L to inhibit the growth and proliferation of Microcystis aeruginosa.[Conclusion] The results provided the important scientific basis and new management ideas for the treatment of water bloom of Microcystis aeruginosa.展开更多
The ginkgo terpenoids including bilobalide and ginkgolides are the main pharmaceutical components in the leaves or extracts of Ginkgo biloba L. In this paper, the analysis of bilobalide and ginkgolides in leaves of Gi...The ginkgo terpenoids including bilobalide and ginkgolides are the main pharmaceutical components in the leaves or extracts of Ginkgo biloba L. In this paper, the analysis of bilobalide and ginkgolides in leaves of Ginkgo biloba L. by high performance liquid chromatography (HPLC)-electrospray ionization (ESI)-mass spectrometry (MS) was carried out. The separation was performed on Inertsil ODS3 column with methanol-water (36:64) as mobile phase, with 1 mL·min -1 of flow rate at 35℃. Then the mass spectrum analysis was conducted by ZMD micromass electrospray ionization (ESI)-mass spectrometer (MS). The HPLC total ion chromatogram and selected ion chromatogram (with 325, 407, 423, 439 of m/z) of the sample and ESI-/MS mass spectra of the peaks in the chromatograms were obtained. So bilobalide, ginkgolide A, B, C and J in Ginkgo biloba L. leaves were identified. The method is easy and rapid, with a good accuracy.展开更多
From the dried roots and leaves of Tripterygium wilfordii^(1.2),a new diter- penoid triepoxide,16-hydroxytriptolide was isolated,and its structure and stereochemistry elucidated as 16-(S)-hydroxy-triptolide on the bas...From the dried roots and leaves of Tripterygium wilfordii^(1.2),a new diter- penoid triepoxide,16-hydroxytriptolide was isolated,and its structure and stereochemistry elucidated as 16-(S)-hydroxy-triptolide on the basis of spectral data(IR, MS, UV,~1HNMR,^(13)CNMR,2d-NMR,Selective Long-range DEPT)and x-ray crystallographic analysis.This compound showed definite antiinflammatory action,strong immunosuppressive and antifertile activities.In addition,a known compound,triptolide was also isolated and all the spectral signals of^1 HNMR and ^(13)CNMR were assigned.展开更多
Ginkgo diterpene lactones meglumine injection(GDLI)is a commercially available product used for neuroprotection.However,the pharmacokinetic properties of the prototypes and hydrolyzed carboxylic forms of the primary c...Ginkgo diterpene lactones meglumine injection(GDLI)is a commercially available product used for neuroprotection.However,the pharmacokinetic properties of the prototypes and hydrolyzed carboxylic forms of the primary components in GDLI,i.e.,ginkgolide A(GA),ginkgolide B(GB),and ginkgolide K(GK),have never been fully evaluated in beagle dogs.In this work,a simple,sensitive,and reliable method based on ultra-fast liquid chromatography-tandem mass spectrometry(UFLC-MS/MS)was developed,and the prototypes and total amounts of GA,GB,and GK were determined in beagle dog plasma.The plasma concentrations of the hydrolyzed carboxylic forms were calculated by subtracting the prototype concentrations from the total lactone concentrations.For the first time,the pharmacokinetics of GA,GB,and GK were fully assessed in three forms,i.e.,the prototypes,the hydrolyzed carboxylic forms,and the total amounts,after intravenous administration of GDLI in beagle dogs.It was shown that ginkgolides primarily existed in the hydrolyzed form in plasma,and the ratio of hydrolysates to prototype forms of GA and GB decreased gradually to a homeostatic ratio.All of the three forms of the three ginkgolides showed linear exposure of AUC to the dosages.GA,GB,and GK showed a constant half-life approximately 2.7,3.4,and 1.2 h,respectively,which were consistent for the forms at three dose levels(0.3,1.0,and 3.0 mg·kg^(-1))and after a consecutive injection of GDLI for 7 days(1.0 mg·kg^(-1)).展开更多
Polyesters,as a class of high-performance and versatile polymer materials,often suffer from some drawbacks,such as hydrophobicity and brittleness due to their single structure nature.Thus,modifications have attracted ...Polyesters,as a class of high-performance and versatile polymer materials,often suffer from some drawbacks,such as hydrophobicity and brittleness due to their single structure nature.Thus,modifications have attracted much attention for enhancing their desirable properties,of which one efficient way is incorporating the aliphatic polyether segment into the main chain of the polyester.However,this approach is of much challenge because the obtained polyesters are problematic in either low alternating degree or low molecular weight.Herein,we describe an efficient strategy to incorporate polyether fragment into polyester by developing a novel Co-Al based heterodinuclear complex for mediating the copolymerization of propylene oxide(PO)withε-caprolactone(CL).The tracking experiments reveal that PO and CL convert into the polymer chain throughout the polymerization process.Especially,the linear increase in the molecular weight with conversion of CL indicates the controllable nature of the copolymerization.The competition polymerization,offering the monomer reactivity ratios of rCL=0.96 and rPO=1.04,suggests that the tendency of self-propagation or incorporation of monomers is nearly identical.interestingly,the obtained polymers with different ether contents exhibit tunable thermal properties with enhanced decomposition temperature for the polymer with higher ether content.The newly developed heterodinuclear complex for new polymerization provides an idea to synthesize new functional polymeric materials.展开更多
基金supported by the National Fund of Science,Technology and Innovation (FONACIT) (Grant N°201300288)within the framework of the project PCP France-Venezuelaby the CDCHTA-ULA (Grant N°C-1935-15-08-ED).
文摘From aerial parts of Austroeupatorium inulifolium was isolated the ent-nor-furano triol labdane austroeupatol 1.The compound 1 was treated with IBX showing an unexpected selectivity at the potentially oxidizable sites of the sub-strate yielding the 2-oxoaustroeupatol(2)and 2,19-dioxoaustroeupatol(3).The treatment of 2 with sodium periodate yields a heterocyclic derivative(ε-caprolactone derivate 4)formed by oxidative cleavage and unexpected intramo-lecular attack of the hydroxymethylene(C-19)oxygen to the ketonic carbon(C-2).A plausible mechanistic pathway for the obtention of compound 4 is proposed.
基金supported by the national Natural Science Foundation of China.
文摘During the course of our program in the synthesis of natural products by retroDiels-Alder reaction using a rigid molecule tricyclo-[5.2.1.0]-deca-4,8-dien-3-one（1） as the starting material, it was observed that aldol condensation of compound （2）
基金supported by grants from National Natural Science Foundation of China(Grant Nos.32372655,32060085,32260094,32060237)Applied Basic Research Project of Yunnan(Grant Nos.202301AS070071,and 202101AZ070001-166)Yunnan Innovation Guidance and Technology Enterprise Cultivation Plan Project(Grant No.202304BT090032).
文摘The unique fruity aroma of strawberries enhances their appeal to consumers.Fragaria nilgerrensis,a wild strawberry distributed in Southwest China and known for its distinctive peach-like aroma,represents a valuable resource for improving the fragrance of cultivated strawberries.However,the molecular mechanism underlying the peach-like aroma biosynthesis remains largely unexplored.In this study,we integrated metabolomic and transcriptomic data across four developmental stages of F.nilgerrensis fruits to construct a detailed profile of volatile organic compounds(VOCs)and the associated gene expression alterations during fruit maturation.Our findings reveal that g-decalactone,d-decalactone,and g-undecalactone are the primary compounds responsible for the pronounced peach-like aroma,with their levels showing a significant correlation with the activity of the FngFAD2 enzyme.The silencing of the FngFAD2 gene through tobacco rattle viral(TRV)induction resulted in notable reductions in both the peach-like aroma and lactone content in the fruit.In addition,integrating dual luciferase assays,yeast one-hybrid(Y1H)and subcellular localization experiments,we also identified three transcription factors(FngDOF1.2,FngWRKY3,and FngWRI1)that enhance FngFAD2 expression.These findings elucidate the molecular regulatory network involved in the complex developmental process of peach-like flavor in strawberry fruits.Additionally,our research also provides a foundation for the utilization of the wild strawberry as well as improving the flavor and quality of cultivated strawberries.
文摘Traumatic axonal lesions of peripheral nerves disrupt neuronal connections with their targets,resulting in the loss of motor and sensory functions.Despite the peripheral nervous system’s capacity for axonal regrowth,this may lead to permanent impairements resulting in a loss of quality of life and a high socioeconomic burden.
基金supported by the Program of National Natural Science Foundation of China(Nos.42376116,41322037,U1706210)the Special Funds of Shandong Province for Qingdao National Laboratory of Marine Science and Technology(No.2022QNLM030003-3)+1 种基金the Shandong Province Special Fund‘Frontier Technology and Free Exploration’from Laoshan Laboratory(No.8-01)the State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources,Guangxi Normal University(No.CMEMR2023-B16)。
文摘Mycobacterium marinum can cause disease in both human beings and fishes.Infected fish exhibits symptoms commonly referred to as fish tuberculosis.In this research,we screened a 14-Membered Resorcylic Acid Lactones(RALs)library constructed in the laboratory for in vitro anti-Mycobacterium marinum activity and found that several compounds,including compounds 3,4,6,10,and 17–26,showed good activity.Notably,the trace natural product cochilimycin B(compound 3)possesses significant long-lasting inhibitory function to Mycobacterium marinum.It also shows synergistic effects with drugs like isoniazid,ethambutol,and bedaquiline(FICI≤0.5).In addition,cochilimycin B showed a significant inhibitory effect on the biofilm produced by Mycobacterium marinum,with an inhibition rate of 65.9%.To solve the bottleneck problem of natural product drug sources,we realized an efficient one-step semi-synthetic method to obtain compound 3 with a yield of 32.1%.In vivo,inflammatory changes in BALB/c mice infected with Mycobacterium marinum were characterized.After 12 h of infection,IL-1βwas 20%–30%lower in the spleen and tail of the3-treated group compared to the control group.In the thymus and tail of the treated group,TNF-αlevels were 30%–60%lower than in the control group.This is the first time that the significant anti-Mycobacterium marinum effect of cochilimycin B from 14-Membered Resorcylic Acid Lactones(14-RALs)was reported,offering a new chemical molecule for anti-Mycobacterium marinum drug research.
基金financial support from the Marine S&T Fund of Shandong Province for Qingdao Marine Science and Technology Center(No.2022QNLM030003-2)the National Key Research&Development Program of China(No.2022YFA2104902)the National Natural Science Foundation of China(Nos.21977088 and22377114)。
文摘Alduronic acid lactones and glyconolactones are highly functionalized and versatile chiral building blocks.Herein,we describe a novel approach to these compounds via decarboxylative oxygenation of uronic acids.The transformations proceed using Selectfluor and TEMPO as oxidants,either in the presence of catalytic amounts of Ag_(2)CO_(3)or in the absence of this catalyst.The methodology provides structurally diverse alduronic acid lactones and enables the preparation of rare sugar glyconolactones from easily available D-C-glycosides.Based on the^(18)O-labeling experiments,control experiments,and isolation of the key intermediates,a radical-polar crossover reaction mechanism is proposed.The utility of this method is demonstrated through efficient conversions of alduronic acid lactones into polyhydroxylated cyclic alkaloids and castanospermine-type architectures.
文摘Direct converting carbon dioxide(CO_(2))and propane(C_(3)H_(8))into aromatics with high carbon utilization offers a desirable opportunity to simultaneously mitigate CO_(2)emission and adequately utilize C_(3)H_(8) in shale gas.Owing to their thermodynamic resistance,converting CO_(2)and C_(3)H_(8) respectively remains difficult.Here,we achieve 60.2%aromatics selectivity and 48.8%propane conversion over H-ZSM-5-25 via a zeolite-catalyzing the coupling of CO_(2)and C_(3)H_(8).Operando dual-beam FTIR spectroscopy combined with ^(13)C-labeled CO_(2)tracing experiments revealed that CO_(2)is directly involved in the generation of aromatics,with its carbon atoms selectively embedded into the aromatic ring,bypassing the reverse water-gas shift pathway.Accordingly,a cooperative aromatization mechanism is proposed.Thereinto,lactones,produced from CO_(2)and olefins,are proven to be the key intermediate.This work not only provides an opportunity for simultaneous conversion of CO_(2)and C_(3)H_(8),but also expends coupling strategy designing of CO_(2)and alkanes over acidic zeolites.
基金supported by the National Natural Science Foundation of China(No.52270119).
文摘The inhibitory effects of zinc oxide nanoparticles(ZnO NPs)and impacts of N-acylhomoserine lactone(AHL)-based quorum sensing(QS)on biological nitrogen removal(BNR)performance have beenwell-investigated.However,the effects of ammonia nitrogen(NH_(4)^(+)-N)concentrations on NP toxicity and AHL regulation have seldom been addressed yet.This study consulted on the impacts of ZnO NPs on BNR systems when high NH_(4)^(+)-N concentrationwas available.The synergistic toxic effects of high-strength NH_(4)^(+)-N(200 mg/L)and ZnO NPs resulted in decreased ammonia oxidation rates and dropped the nitrogen removal efficiencies by 17.5%±0.2%.The increased extracellular polymeric substances(EPS)production was observed in response to the high NH_(4)^(+)-N and ZnO NP stress,which indicated the defensemechanism against the toxic effects in the BNR systemswas stimulated.Furthermore,the regulatory effects of exogenous N-decanoyl-homoserine lactone(C_(10)-HSL)-mediated QS system on NP-stressed BNR systems were revealed to improve the BNR performance under different NH_(4)^(+)-N concentrations.The C_(10)-HSL regulated the intracellular reactive oxygen species levels,denitrification functional enzyme activities,and antioxidant enzyme activities,respectively.This probably synergistically enhanced the defense mechanism against NP toxicity.However,compared to the low NH_(4)^(+)-N concentration of 60 mg/L,the efficacy of C_(10)-HSL was inhibited at high NH_(4)^(+)-N levels of 200 mg/L.The findings provided the significant application potential of QS system for BNR when facing toxic compound shock threats.
基金financially supported by the Open Project of Sanya Science and Education Innovation Park of Wuhan University of Technology(No.2022KF0005)Researchers Supporting Project(No.RSP-2024-R20)King Saud University,Riyadh,Saudi Arabia.
文摘As a recently emerging wastewater treatment technology,Algal-bacterial granular sludge(ABGS)process shows significant advantages.However,current research on the ABGS system is a lack of a clear and complete understanding of the potential mechanism of signal molecules on the growth of ABGS.This study comprehensively explores the variations in the ABGS under different N-acyl-homoserine lactone(AHL)conditions by constructing three sequencing batch reactor(SBR)systems.The results indicate that N-hexanoyl-l-homoserine lactone(C6-HSL)accelerates the granulation process in the early stages by promoting the loosely bound extracellular polymeric substances(LB-EPS)secretion and filamentous bacteria growth,thereby shortening required time for initial granule formation.On the other hand,N-(3-oxodecanoyl)-l-homoserine lactone(3-oxo-C12-HSL)expedites the granulation process by promoting the tightly bound extracellular polymeric substances(TB-EPS)and aromatic protein secretion,benefiting structural stability and nitrogen and phosphorus removal efficiency of mature ABGS.
基金supported by the National Natural Science Foundation of China (Nos.51938001 and 52300073)。
文摘Quorum quenching (QQ)-based strategies are efficient for biofouling control.However,the feasibility of using QQ bacteria in antibiotic-stressed membrane bioreactors (MBRs) remains unknown.In this study,we isolated three novel QQ strains (Bacillus sp.QX01 and QX03,Delftia sp.QX14) from the activated sludge of an actual MBR.They can degrade 11 N-acylhomoserine lactones (AHLs) with high efficiencies and rates through intracellular QQ pathways involving putative acylases and lactonases.Running two lab-scale MBRs,we found that introducing antibiotics (sulfamethoxazole,azithromycin,and ciprofloxacin,each at100μg/L) shortened the fouling cycle by 71.4%.However,the immobilized inoculation of QX01 into one MBR extended the fouling cycle by 1.5-2.0 times.Quantitative detection revealed that QX01 significantly reduced the concentrations of two AHLs (C4-HSL and C8-HSL),which were positively correlated with the contents of extracellular polymeric substances(EPS)(Pearson’s r=0.62-0.83,P<0.01).This suggests that QX01 could perform its QQ activity robustly under antibiotic stress,thereby inhibiting EPS production (proteins especially) and biofilm formation.Moreover,QX01 notably altered the succession patterns of both sludge and fouling communities,with more pronounced effects on abundant taxa.Genera associated with AHL synthesis and EPS production,such as Terrimonas and Rhodobacter,were significantly depleted,contributing to the mitigated biofouling.Additionally,QX01 increased the bacterial community diversity (evenness especially),which was inhibited by antibiotics.Overall,we demonstrate that the novel QQ bacteria could be effective for biofouling control in antibiotic-stressed MBRs,though future work is needed to develop practical approaches for prolonging QQ activity.
基金National Natural Science Foundation of China(Nos.22001177,22203023)Guangdong Pearl River Talent Program(no.2021QN020268)+3 种基金the Natural Science Foundation of Guangdong Province(Nos.2024A1515012381,2022A1515011859)Shenzhen Bay Laboratory Startup Fund(No.S201100003)Major Program of Shenzhen Bay Laboratory(No.S211101001-4)Shenzhen Bay Qihang Fellow Program(No.QH23001)for generous financial support.
文摘Chiral aryl cyclohex-3-en ether scaffold is widely present in bioactive natural products and drugs.The exploitation of efficient and enantioselective methods for the construction of aryl cyclohex-3-en ether scaffold is significant.Herein we disclose a chiral N,N’-dioxide/Lewis acid complex-catalyzed asymmetric inverse-electron-demand Diels-Alder(IEDDA)reaction using electron-deficient 3-carboalkoxyl-2-pyrones and less electron-enriched aryl enol ethers as reactants.A wide range of non-and 1,2-disubstituted acyclic aryl enol ethers are applicable to deliver diverse chiral bridged bicyclic lactones in high yields and stereoselectivities(up to 96%yield,>20:1 dr,97:3 er).The bridged bicyclic lactone core can be easily converted into chiral aryl cyclohex-3-en ether scaffold.Notably,DFT calculations revealed a stepwise and endo mechanism to explain the high enantioselectivity controlled by the cooperative effect of the steric factors and the dispersion interactions between ligands and enol ethers.
基金National Natural Science Foundation of China(Grant No.30973629)National Key Technology R&D Program "New Drug Innovation" of China(Grant No.2012ZX09301002-002-002,2012ZX09304-005)
文摘A chemical investigation of the aerial parts ofArtemisia vestita Wall. led to the isolation of 12 known sesquiterpenes, including 2 furan-containing sesquiterpenoids and 10 eudesmane sesquiterpene lactones. Their structures were identified as negunfurol （1）, schensianol A （2）, artemine （3）, erivanin （4）, 1,5-diepi-artemin （5）, acetylartemin （6）, naphtho[1,2-b]furan-2（3H）-one, 6-（acetyloxy） decahydro-9a-hydroxy-3,Sa-dimethyl-9-methylene-（3S,3aS,5aS,6S,9aS, ghS） （7）, naphtho[1,2-b]furan-2（3H）-one, 6-（acetyloxy）- 3a,4,5,5a,6,7,8,9b-octahydro-8-hydroxy-3,Sa,9-trimethyl- （3S,3aS, SaR,6S, SS,9bS） （8）, isoerivanin （9）, harrelierin （10）, （11S）-1- oxoeudesm-4（14）-eno-13,6a-lactone （11）, 1-epi-dehydroisoeranin （12）, respectively. All of these compounds were isolated from Artemisia vestita for the first time, and compounds 1 and 2 were isolated from the genus Artemisia for the first time.
基金Supported by National Natural Science Fund(30960036)Key Schoollevel Project of Kunming University(20091016)~~
文摘[Objective]The relationship between signal molecule N-acety-homoserine lactones（AHLs） and Microcystis aeruginosa cell apoptosis was studied.[Method]With M.aeruginosa as the test materials treated by 5 μmol/L N-acety-homoserine lactones（AHLs）,the morphology of cell apoptosis was observed through staining with DAPI.[Result]Microcystis aeruginosa cell apoptosis was induced by signal molecule N-acetyhomoserine lactones（AHLs） with the concentration of 1 μmol/L to inhibit the growth and proliferation of Microcystis aeruginosa.[Conclusion] The results provided the important scientific basis and new management ideas for the treatment of water bloom of Microcystis aeruginosa.
文摘The ginkgo terpenoids including bilobalide and ginkgolides are the main pharmaceutical components in the leaves or extracts of Ginkgo biloba L. In this paper, the analysis of bilobalide and ginkgolides in leaves of Ginkgo biloba L. by high performance liquid chromatography (HPLC)-electrospray ionization (ESI)-mass spectrometry (MS) was carried out. The separation was performed on Inertsil ODS3 column with methanol-water (36:64) as mobile phase, with 1 mL·min -1 of flow rate at 35℃. Then the mass spectrum analysis was conducted by ZMD micromass electrospray ionization (ESI)-mass spectrometer (MS). The HPLC total ion chromatogram and selected ion chromatogram (with 325, 407, 423, 439 of m/z) of the sample and ESI-/MS mass spectra of the peaks in the chromatograms were obtained. So bilobalide, ginkgolide A, B, C and J in Ginkgo biloba L. leaves were identified. The method is easy and rapid, with a good accuracy.
文摘From the dried roots and leaves of Tripterygium wilfordii^(1.2),a new diter- penoid triepoxide,16-hydroxytriptolide was isolated,and its structure and stereochemistry elucidated as 16-(S)-hydroxy-triptolide on the basis of spectral data(IR, MS, UV,~1HNMR,^(13)CNMR,2d-NMR,Selective Long-range DEPT)and x-ray crystallographic analysis.This compound showed definite antiinflammatory action,strong immunosuppressive and antifertile activities.In addition,a known compound,triptolide was also isolated and all the spectral signals of^1 HNMR and ^(13)CNMR were assigned.
基金financially supported by the National Key Special Project of Science and Technology for Innovation Drugs of China(Nos.2013zx09402203 and 2013zx09402202)the Natural Science Foundation of Jiangsu Province,China(No.BK20130403)+1 种基金the National Natural Science Foundation of China(No.81503342)the Project for Jiangsu Province Key Lab of Drug Metabolism and Pharmacokinetics(No.BM2012012)
文摘Ginkgo diterpene lactones meglumine injection(GDLI)is a commercially available product used for neuroprotection.However,the pharmacokinetic properties of the prototypes and hydrolyzed carboxylic forms of the primary components in GDLI,i.e.,ginkgolide A(GA),ginkgolide B(GB),and ginkgolide K(GK),have never been fully evaluated in beagle dogs.In this work,a simple,sensitive,and reliable method based on ultra-fast liquid chromatography-tandem mass spectrometry(UFLC-MS/MS)was developed,and the prototypes and total amounts of GA,GB,and GK were determined in beagle dog plasma.The plasma concentrations of the hydrolyzed carboxylic forms were calculated by subtracting the prototype concentrations from the total lactone concentrations.For the first time,the pharmacokinetics of GA,GB,and GK were fully assessed in three forms,i.e.,the prototypes,the hydrolyzed carboxylic forms,and the total amounts,after intravenous administration of GDLI in beagle dogs.It was shown that ginkgolides primarily existed in the hydrolyzed form in plasma,and the ratio of hydrolysates to prototype forms of GA and GB decreased gradually to a homeostatic ratio.All of the three forms of the three ginkgolides showed linear exposure of AUC to the dosages.GA,GB,and GK showed a constant half-life approximately 2.7,3.4,and 1.2 h,respectively,which were consistent for the forms at three dose levels(0.3,1.0,and 3.0 mg·kg^(-1))and after a consecutive injection of GDLI for 7 days(1.0 mg·kg^(-1)).
基金the National Natural Science Foundation of China(Nos.21722402 and 21674015)the Fundamental Research Funds for the Central Universities(No.DUT18ZD105).
文摘Polyesters,as a class of high-performance and versatile polymer materials,often suffer from some drawbacks,such as hydrophobicity and brittleness due to their single structure nature.Thus,modifications have attracted much attention for enhancing their desirable properties,of which one efficient way is incorporating the aliphatic polyether segment into the main chain of the polyester.However,this approach is of much challenge because the obtained polyesters are problematic in either low alternating degree or low molecular weight.Herein,we describe an efficient strategy to incorporate polyether fragment into polyester by developing a novel Co-Al based heterodinuclear complex for mediating the copolymerization of propylene oxide(PO)withε-caprolactone(CL).The tracking experiments reveal that PO and CL convert into the polymer chain throughout the polymerization process.Especially,the linear increase in the molecular weight with conversion of CL indicates the controllable nature of the copolymerization.The competition polymerization,offering the monomer reactivity ratios of rCL=0.96 and rPO=1.04,suggests that the tendency of self-propagation or incorporation of monomers is nearly identical.interestingly,the obtained polymers with different ether contents exhibit tunable thermal properties with enhanced decomposition temperature for the polymer with higher ether content.The newly developed heterodinuclear complex for new polymerization provides an idea to synthesize new functional polymeric materials.
