Blue-grained wheat derived from the hybrid Triticum aestivum L. X Thinopyrum ponticum (Podp.) Barkworth et D. R. Dewey (Agropyron elongatum (Host) P. Beauv., 2n=70). The molecular biological mechanism of the biosynthe...Blue-grained wheat derived from the hybrid Triticum aestivum L. X Thinopyrum ponticum (Podp.) Barkworth et D. R. Dewey (Agropyron elongatum (Host) P. Beauv., 2n=70). The molecular biological mechanism of the biosynthetic pathway of blue pigments in the blue grain remains unclear yet. Dihydroflavonol 4-reductase (DFR) is one of the key enzymes controlling flavonoid synthesis in anthocyanin biosynthetic pathway, and may directly participate in the formation of blue pigment in the aleurone layer of blue-grained wheat. Here we cloned a DFR cDNA (TaDFR) from the developing seeds of blue-grained wheat, and four DFR genomic DNAs from Th. ponticum (ThpDFR.t), blue-grained wheat (TaDFR.bg), white-grained offspring of light blue-grained wheat (TaDFR.wg) and Chinese Spring (2n=42) (TaDFR.csg), respectively. TaDFR cDNA encodes a 354 amino-acids polypeptide with high identity to DFR from Hordeum vulgare L. (94%), Oryza sativa L. (83%), Zea mays L.(84%). The result of cluster analysis showed that TaDFR cDNA nucleotide sequence has 100% identity with that of TaDFR.csg. The four DFR genomic DNAs have extraordinary high homology and each has three introns. The differences of the four DFR genomic DNAs mainly exist in introns. Southern blotting analysis showed that there are at least 3-5 DFR copies in wheat, the copy numbers in different color grain wheats are not significantly different. The hybridization band patterns were the same, but different from that of Th. ponticum. DFR in blue-grained wheat belongs to a DFR superfamily. Northern blotting analysis indicated that the DFR expressed in the developing seeds of both blue- and white-grained wheat at 15 d after flowering (DAF), the mRNA levels of DFR reached the highest at 18 DAF, then declined quickly and disappeared at 33 DAF But the expression levels in blue-grained seeds were higher than that in white grain at the same seed developing stages. DFR transcripts accumulated in young leaves, and leaf sheaths of blue- and white-grained wheat and Th ponticum, but not detected in roots from different color wheats and developing seeds of Th. ponticum. Results indicated that there may exist some regulatory gene(s) which can increase the expression of DFR in the aleurone layer of blue-grained wheat, and thus resulting in the formation of blue pigments.展开更多
Danshen,the dried roots and rhizomes of Salvia miltiorrhiza Bunge(S.miltiorrhiza),is widely used in the treatment of cardiovascular and cerebrovascular diseases.Tanshinones,the bioactive compounds from Danshen,exhibit...Danshen,the dried roots and rhizomes of Salvia miltiorrhiza Bunge(S.miltiorrhiza),is widely used in the treatment of cardiovascular and cerebrovascular diseases.Tanshinones,the bioactive compounds from Danshen,exhibit a wide spectrum of pharmacological properties,suggesting their potential for future therapeutic applications.Tanshinone biosynthesis is a complex process involving at least six P450 enzymes that have been identified and characterized,most of which belong to the CYP76 and CYP71 families.In this study,CYP81C16,a member of the CYP71 clan,was identified in S.miltiorrhiza.An in vitro assay revealed that it could catalyze the hydroxylation of four para-quinone-type tanshinones,namely neocryptotanshinone,deoxyneocryptotanshinone,and danshenxinkuns A and B.SmCYP81C16 emerged as a potential broad-spectrum oxidase targeting the C-18 position of para-quinone-type tanshinones with an impressive relative conversion rate exceeding 90%.Kinetic evaluations and in vivo assays underscored its highest affinity towards neocryptotanshinone among the tested substrates.The overexpression of SmCYP81C16 promoted the accumulation of(iso)tanshinone in hairy root lines.The characterization of SmCYP81C16 in this study accentuates its potential as a pivotal tool in the biotechnological production of tanshinones,either through microbial or plant metabolic engineering.展开更多
Carotenoid biosynthetic pathway produces not only pigments that protect photosynthetic system against photo-oxidative damage, but also precursors of abscisic acid, the major hormone regulates stress responses. To unde...Carotenoid biosynthetic pathway produces not only pigments that protect photosynthetic system against photo-oxidative damage, but also precursors of abscisic acid, the major hormone regulates stress responses. To understand the response of carotenoid biosynthetic pathway to salt stress, the expression of the genes involved in carotenoid and ABA biosynthesis were compared in cultivated tomato Solanum lycopersicon cv. Moneymaker and its relative wild genotype S. pimpinellifolium （PI365967） together with the contents of carotenoids and ABA. The results showed that 11 of the 15 genes investigated were up-regulated and four unaltered in Moneymaker after 5 h of salt stress; whereas only four genes were up-regulated, four unaltered, and seven down-regulated in PI365967 after stress. Further comparison revealed that 11 salinity-induced genes were expressed significantly lower in Moneymaker than in PI365967 under normal condition, and 8 of them were induced to similar levels after salt stress. In consistence, ABA level was doubled in Moneymaker but kept consistent in PI365967 after salt stress, though the contents of neoxanthin, violaxanthin, [3-carotene, lutein, and total carotenoids were kept unchanged in both species. Since it is known that PI365967 is more tolerant to salt stress than Moneymaker, we proposed that the constitutive high level of carotenoid and ABA biosynthetic pathway under normal growth condition could be benefit to PI365967 for establishing the early response to salt stress. In addition, CrtR-bl and CrtR-b2 that encode [3-carotenoid hydroxylases were the only genes in carotenoid biosynthetic pathway that were up-regulated by salt stress in both species. The CrtR-b2 gene was cloned from both species and no essential difference was found in the encoded amino acid sequences. Transformation of CrtR-b2 to tobacco improved the seed germination under salt stress condition, indicating that the hydrolysis of β-carotenoid is the target of transcriptional regulation of the carotenoid biosynthesis in both tomato cultivar and wild relative.展开更多
Quality marker(Q-marker)of Chinese materia medica(CMM)plays an important role in quality control of CMM products.However,its research strategy and technique remain unclear.Based on the fact that quality standard of CM...Quality marker(Q-marker)of Chinese materia medica(CMM)plays an important role in quality control of CMM products.However,its research strategy and technique remain unclear.Based on the fact that quality standard of CMM should be associated with clinical efficacy,taking Jinqi Jiangtang tablet treating type 2 diabetes as an example,the Q-marker related to activity via the reverse analysis of drug metabolism in clinic and traceability of botanic biosynthetic pathways is discovered and validated.Therefore,we proposed a new research strategy of Q-marker of CMM with"Discovery of clinical active constituents as guidance,Reverse analysis of metabolic transformations as link,and Traceability of biosynthesis pathways as key",to improve quality control of CMM products.展开更多
Dear Editor,Paper derived from rice straw has inferior physical properties compared with paper derived from wood pulp.This study reports engineering the biosynthetic pathway of bacterial cellulose into rice to improve...Dear Editor,Paper derived from rice straw has inferior physical properties compared with paper derived from wood pulp.This study reports engineering the biosynthetic pathway of bacterial cellulose into rice to improve the performance of rice-straw-derived paper.This work offers novel insights into the reuse of agricultural waste and provides guidance for the bio-breeding of woody plants.展开更多
Taxus,commonly known as yew,is a well-known gymnosperm with great ornamental and medicinal value.In this study,by assembling a chromosome-level genome of the Himalayan yew(Taxus wallichiana)with 10.9 Gb in 12 chromoso...Taxus,commonly known as yew,is a well-known gymnosperm with great ornamental and medicinal value.In this study,by assembling a chromosome-level genome of the Himalayan yew(Taxus wallichiana)with 10.9 Gb in 12 chromosomes,we revealed that tandem duplication acts as the driving force of gene family evolution in the yew genome,resulting in the main genes for paclitaxel biosynthesis,i.e.those encoding the taxadiene synthase,P450s,and transferases,being clustered on the same chromosome.The tandem duplication may also provide genetic resources for the nature to sculpt the core structure of taxoids at different positions and subsequently establish the complex pathway of paclitaxel by neofunctionalization.Furthermore,we confirmed that there are two genes in the cluster encoding isoenzymes of a known enzyme in the paclitaxel biosynthetic pathway.The reference genome of the Himalayan yew will serve as a platform for decoding the complete biosynthetic pathway of paclitaxel and understanding the chemodi-versity of taxoids in gymnosperms.展开更多
Catharanthus roseus is one of the most extensively investigated medicinal plants, which can produce more than 130 alkaloids, including the powerful antitumor drugs vinblastine and vincristine. Here we review the recen...Catharanthus roseus is one of the most extensively investigated medicinal plants, which can produce more than 130 alkaloids, including the powerful antitumor drugs vinblastine and vincristine. Here we review the recent advances in the biosynthetic pathway of terpenoid indole alkaloids （TIAs） in C. roseus, and the identification and characterization of the corresponding enzymes involved in this pathway. Strictosidine is the central intermediate in the biosynthesis of different TIAs, which is formed by the condensation of secologanin and tryptamine. Secologanin is derived from terpenoid （isoprenoid） biosynthetic pathway, while tryptamine is derived from indole biosynthetic pathway. Then various specific end products are produced by different routes during downstream process. Although many genes and corresponding enzymes have been characterized in this pathway, our knowledge on the whole TIA biosynthetic pathway still remains largely unknown up to date. Full elucidation of TIA biosynthetic pathway is an important prerequisite to understand the regulation of the TIA biosynthesis in the medicinal plant and to produce valuable TIAs by synthetic biological technology.展开更多
The aim of our study was to assess differences in the expression of genes involved in fruit softening and ethylene biosynthetic pathways under different temperature storage conditions. Different peach cultivars of ‘X...The aim of our study was to assess differences in the expression of genes involved in fruit softening and ethylene biosynthetic pathways under different temperature storage conditions. Different peach cultivars of ‘Xiacui' and ‘Yumyeong', which are stonyhard, ‘Yinhualu', which is softmelting, ‘Hujing Milu', which is hard-melting, and ‘Baby Gold 6', which is non-melting at 80% ripening, were collected as test materials. The results showed that only slight ethylene production was detected after harvesting of ‘Yumyeong' and ‘Xiacui' under either a room temperature(25 °C) or low temperature(4 °C). The fruit firmness of stonyhard cultivars was retained at a high level under room temperature over time, whereas a low temperature induced ‘Yumyeong' fruit to soften. Quantitative real-time PCR results indicated that the PpACS1 gene was highly expressed in soft-melting, hard-melting and non-melting cultivars; however, expression was extremely low in stonyhard peaches. PpACS2 or PpACS3, however,was not detected in all five cultivars. Interestingly, cold treatment significantly decreased firmness along with endo-PG expression obviously upregulated in ‘Yumyeong', but not in ‘Xiacui' peaches. In conclusion, this study revealed that fruit softening of peaches with different flesh textures was closely related to ethylene biosynthesis during the storage period, which was controlled via regulating relevant gene expression levels under different storage temperatures.展开更多
Mescaline,among the earliest identified natural hallucinogens,holds great potential in psychotherapy treatment.Nonetheless,despite the existence of a postulated biosynthetic pathway for more than half a century,the sp...Mescaline,among the earliest identified natural hallucinogens,holds great potential in psychotherapy treatment.Nonetheless,despite the existence of a postulated biosynthetic pathway for more than half a century,the specific enzymes involved in this process are yet to be identified.In this study,we investigated the cactus Lophophora williamsii(Peyote),the largest known natural producer of the phenethylamine mescaline.We employed a multi-faceted approach,combining de novo whole-genome and transcriptome sequencing with comprehensive chemical profiling,enzymatic assays,molecular modeling,and pathway engineering for pathway elucidation.We identified four groups of enzymes responsible for the six catalytic steps in the mescaline biosynthetic pathway,and an N-methyltransferase enzyme that N-methylates all phenethylamine intermediates,likely modulating mescaline levels in Peyote.Finally,we reconstructed the mescaline biosynthetic pathway in both Nicotiana benthamiana plants and yeast cells,providing novel insights into several challenges hindering complete heterologous mescaline production.Taken together,our study opens up avenues for exploration of sustainable production approaches and responsible utilization of mescaline,safeguarding this valuable natural resource for future generations.展开更多
Mollemycin A(MOMA)is a unique glyco-hexadepsipeptide-polyketide that was isolated from a Streptomyces sp.derived from the Australian marine environment.MOMA exhibits remarkable inhibitory activity against both drug-se...Mollemycin A(MOMA)is a unique glyco-hexadepsipeptide-polyketide that was isolated from a Streptomyces sp.derived from the Australian marine environment.MOMA exhibits remarkable inhibitory activity against both drug-sensitive and multidrug-resistant malaria parasites.Optimizing MOMA through structural modifications or product enhancements is necessary for the development of effective analogues.However,modifying MOMA using chemical approaches is challenging,and the production titer of MOMA in the wild-type strain is low.This study identified and characterized the biosynthetic gene cluster of MOMA for the first time,proposed its complex biosynthetic pathway,and achieved an effective two-pronged enhancement of MOMA production.The fermentation medium was optimized to increase the yield of MOMA from 0.9 mg L^(-1)to 1.3 mg L^(-1),a 44%boost.Additionally,a synergistic mutant strain was developed by deleting the momB3 gene and overexpressing momB2,resulting in a 2.6-fold increase from 1.3 mg L^(-1)to 3.4 mg L^(-1).These findings pave the way for investigating the biosynthetic mechanism of MOMA,creating opportunities to produce a wide range of MOMA analogues,and developing an efficient strain for the sustainable and economical production of MOMA and its analogues.展开更多
De novo nucleotide biosynthetic pathway is a highly conserved and essential biochemical pathway in almost all organisms.Both purine nucleotides and pyrimidine nucleotides are necessary for cell metabolism and prolifer...De novo nucleotide biosynthetic pathway is a highly conserved and essential biochemical pathway in almost all organisms.Both purine nucleotides and pyrimidine nucleotides are necessary for cell metabolism and proliferation.Thus,the dysregulation of the de novo nucleotide biosynthetic pathway contributes to the development of many human diseases,such as cancer.It has been shown that many enzymes in this pathway are overactivated in different cancers.In this review,we summarize and update the current knowledge on the de novo nucleotide biosynthetic pathway,regulatory mechanisms,its role in tumorigenesis,and potential targeting opportunities.展开更多
The study focused on the regulatory role of Carthamus tinctorius Dof in the safflower seed oil biosynthetic pathway.Through bioinformatics analysis,yeast expression system validation,and transgenic Arabidopsis thalian...The study focused on the regulatory role of Carthamus tinctorius Dof in the safflower seed oil biosynthetic pathway.Through bioinformatics analysis,yeast expression system validation,and transgenic Arabidopsis thaliana experiments,it was found that the expression of the safflower family of transcription factors was significantly increased at 25 post-flowering days of safflower seed development,which coincided with the peak of fatty acid accumulation.Stearic acid content was reduced by 20.33%and oleic acid content was increased by 27.54%in transgenic yeast,and C20:0 and C22:0 long-chain saturated fatty acids were detected.Arabidopsis thaliana seeds overexpressing the safflower Dof transcription factor gene had significantly higher fatty acid composition than the wild type,while mutant seeds had lower fatty acid composition than the wild type.GC-MS analysis indicated that the safflower Dof transcription factor gene variant had limited effect on the overall composi-tion of fatty acids.The results provide molecular targets for improving the quality of safflower seed oil and help to reveal the mechanism of Carthamus tinctorius Dof in the regulation of lipid biosynthesis,which is of great significance for improving the lipid content and composition of oilseed crops.展开更多
Ganoderma polysaccharides(GPs),derived from various species of the Ganoderma genus,exhibit diverse bioactivities,including immune modulation,anti-tumor effects,and gut microbiota regulation.These properties position G...Ganoderma polysaccharides(GPs),derived from various species of the Ganoderma genus,exhibit diverse bioactivities,including immune modulation,anti-tumor effects,and gut microbiota regulation.These properties position GPs as dual-purpose agents for medicinal and functional food development.This review comprehensively explores the structural complexity of six key GPs and their specific mechanisms of action,such as TLR signaling in immune modulation,apoptosis pathways in anti-tumor activity,and their prebiotic effects on gut microbiota.Additionally,the structure-activity relationships(SARs)of GPs are highlighted to elucidate their biological efficacy.Advances in green extraction techniques,including ultrasonic-assisted and enzymatic methods,are discussed for their roles in enhancing yield and aligning with sustainable production principles.Furthermore,the review addresses biotechnological innovations in polysaccharide biosynthesis,improving production efficiency and making large-scale production feasible.These insights,combined with ongoing research into their bioactivity,provide a solid foundation for developing health-promoting functional food products that incorporate GPs.Furthermore,future research directions are suggested to optimize biosynthesis pathways and fully harness the health benefits of these polysaccharides.展开更多
(±)-Talapyrones A−F(1−6),six pairs of dimeric polyketide enantiomers featuring unusual 6/6/6 and 6/6/6/5 ring systems,were isolated from the fungus Talaromyces adpressus.Their structures were determined by spectr...(±)-Talapyrones A−F(1−6),six pairs of dimeric polyketide enantiomers featuring unusual 6/6/6 and 6/6/6/5 ring systems,were isolated from the fungus Talaromyces adpressus.Their structures were determined by spectroscopic analysis and HR-ESI-MS data,and their absolute configurations were elucidated using a modified Mosher’s method and electronic circular dichroism(ECD)calculations.(±)-Talapyrones A−F(1−6)possess a 6/6/6 tricyclic skeleton,presumably formed through a Michael addition reaction between one molecule ofα-pyrone derivative and one molecule of C8 poly-β-keto chain.In addition,compounds 2/3 and 4/5 are two pairs of C-18 epimers,respectively.Putative biosynthetic pathways of 1−6 were discussed.展开更多
Melatonin is a multifunctional molecule found in all organisms that has been shown to play a crucial role in plant growth, development, and stress response. Plant melatonin is typically synthesized in organelles terme...Melatonin is a multifunctional molecule found in all organisms that has been shown to play a crucial role in plant growth, development, and stress response. Plant melatonin is typically synthesized in organelles termed chloroplasts, and the mechanisms of its synthesis and metabolic pathways have been extensively studied. Melatonin serves a significant regulatory function in plant growth and development, influencing the morphological and physiological characteristics of plants by modulating biological processes. While studies on plant melatonin receptors are in their early stages compared to studies in animal receptors, the binding mechanism with melatonin is now recognized as the key initiating step that triggers a series of downstream protective effects. This suggests that melatonin in plants may exert its effects through two main modes of target binding. The CAND2/PMTR1 protein binds to melatonin with a high degree of affinity. This binding activates downstream heterotrimeric G proteins, which trigger rapid intracellular signaling cascades. These cascades include activating the MAPK pathway and modulating ion channel activity. This action swiftly regulates stomatal closure in response to physiological processes such as drought stress. Additionally, melatonin has been demonstrated to regulate the plant stress response through two main mechanisms. First, it directly inhibits the accumulation of reactive oxygen species. Second, it indirectly influences the stress response pathways. This paper examines plant melatonin from three perspectives: the synthesis pathways of melatonin, its effects on plant growth, and its applications in plants under stress. Finally, the prospects for melatonin study and its applications in plants are discussed.展开更多
The gene encoded for tryptophan decarboxylase (TDC), which is the key enzyme in terpenoil indole alkaloids pathway, was targeted to different subcellular compartments and stably expressed in transgenic tobacco (Nicoti...The gene encoded for tryptophan decarboxylase (TDC), which is the key enzyme in terpenoil indole alkaloids pathway, was targeted to different subcellular compartments and stably expressed in transgenic tobacco (Nicotiana tabacum L.) plants at the levels detected by Western blot and tryptamine accumulation analysis. It was shown that the TDC was located in subcellular compartments, the chloroplasts and cytosol. The recombinant TDC targeted to chloroplasts and cytosol in tobacco plants was effectively expressed as soluble protein by Western blot analysis and enzymatic assay. The level of tryptamine accumulation in chloroplast was higher than that in cytosol and very low in vacuole and endoplasmic reticulum (ER) to be hardly detected by Western blot analysis. It was indicated that the highest amount of tryptamine was in chloroplasts, lower in endoplasmic reticula and the lowest in vacuoles as compared to those in wild type plants. The TDC targeted to different subcellular compartments of tobacco plants and its expression level were studied by different nucleotide sequences coding signal peptides at 5'-end of tdc gene in order to know the effects of the TDC in compartmentation on its functionality.展开更多
Connexin subunits are proteins that form gap junction channels, and play an important role in communication between adjacent cells. This review article discusses the function of connexins/hemichannels/gap junctions un...Connexin subunits are proteins that form gap junction channels, and play an important role in communication between adjacent cells. This review article discusses the function of connexins/hemichannels/gap junctions under physiological conditions, and summarizes the findings re-garding the role of connexins/hemichannels/gap junctions in the physiological and pathological mechanisms underlying central nervous system diseases such as brain ischemia, traumatic brain and spinal cord injury, epilepsy, brain and spinal cord tumor, migraine, neuroautoimmune disease, Alzheimer’s disease, Parkinson’s disease, X-linked Charcot-Marie-Tooth disease, Peli-zaeus-Merzbacher-like disease, spastic paraplegia and maxillofacial dysplasia. Connexins are considered to be a potential novel target for protecting the central nervous system.展开更多
Schisandra chinensis Turcz.(Baill.) is a plant species with fruits that have been well known in Far Eastern medicine for a long time. It has traditionally been used as a stimulating and fortifying agent in cases of ph...Schisandra chinensis Turcz.(Baill.) is a plant species with fruits that have been well known in Far Eastern medicine for a long time. It has traditionally been used as a stimulating and fortifying agent in cases of physical exhaustion and to inhibit fatigue.The major bioactive compounds found in S. chinensis are lignans with a dibenzocyclooctadiene skeleton, but little is known about their biosynthesis in plants. S. chinensis is the ideal medicinal plant for studying the biosynthesis of lignans, especially the dibenzocyclooctadiene skeleton. Genomic information for this important herbal plant is unavailable. To better understand the lignan biosynthesis pathway, we generated transcriptome sequences from the fruit during ripening and performed de novo sequence assembly, yielding136 843 unique transcripts with N50 of 1778 bp. Putative functions could be assigned to 41 824 transcripts(51.57%) based on BLAST searches against annotation databases including GO(Gene ontology) and KEGG(Kyoto Encyclopedia of Genes and Genomes). Furthermore, 22 candidate cytochrome P450 genes and 15 candidate dirigent proteins genes that were most likely involved in the lignan biosynthesis pathway were discovered based on transcriptome sequencing of S. chinensis. The genomic data obtained from S. chinensis, especially the identification of putative genes involved in the lignan biosynthesis pathway, will facilitate our understanding of lignan biosynthesis at the molecular level. The lignan metabolite profiles were analyzed by metabolomes, the accumulation patterns of 30 metabolites involved in the lignan pathway were studied. Co-expression network of lignan contents and transcriptional changes showed355 strong correlations(correlation coefficient, R^2 > 0.9) between 21 compounds and 153 transcripts. Furthermore, the comprehensive analysis and characterization of the genes involved in lignan pathways and the metabolite profiles of lignans are expected to provide better insight regarding the diversity of the chemical composition, synthetic characteristics, and regulatory mechanisms of this medical herb.展开更多
Sarcandra glabra(Thunb.)Nakai is a perennial evergreen herb categorised within the Sarcandra Gardner genus under the Chloranthaceae family.Indigenous to tropical and subtropical regions of East Asia and India,this spe...Sarcandra glabra(Thunb.)Nakai is a perennial evergreen herb categorised within the Sarcandra Gardner genus under the Chloranthaceae family.Indigenous to tropical and subtropical regions of East Asia and India,this species is extensively distributed across China,particularly in the southern regions(Sichuan,Yunnan,and Jiangxi).In addition to its high ornamental value,S.glabra has a rich history of use in traditional Chinese medicine,evident through its empirical prescriptions for various ailments like pneumonia,dysentery,fractures,bruises,numbness,amenorrhea,rheumatism,and other diseases.Besides,modern pharmacological studies have revealed various biological activities,such as antitumour,anti-bacterial,anti-viral anti-inflammatory and immunomodulatory effects.The diverse chemical constituents of S.glabra have fascinated natural product researchers since the 1900s.To date,over 400 compounds including terpenoids,coumarins,lignans,flavonoids,sterols,anthraquinones,organic acids,and organic esters have been isolated and characterised,some featuring unprecedented structures.This review comprehensively examines the current understanding of S.glabra’s phytochemistry and pharmacology,with emphasis on the chemistry and biosynthesis of its unique chemotaxonomic marker,the lindenane-type sesquiterpenoids.展开更多
One novel（named palcernuine, 1） and five known cernuane-type（2–6） alkaloids were isolated from the whole plant of Palhinhaea cernua f. sikkimensis. The structure of 1, possessing an unprecedented [5/6/6/6]-tetrac...One novel（named palcernuine, 1） and five known cernuane-type（2–6） alkaloids were isolated from the whole plant of Palhinhaea cernua f. sikkimensis. The structure of 1, possessing an unprecedented [5/6/6/6]-tetracyclic ring system containing two nitrogen atoms, was established on the basis of spectroscopic methods, and its absolute configuration was determined by comparison of the experimental and calculated electronic circular dichroism（ECD） spectra. A plausible biosynthetic pathway to 1 is proposed.展开更多
文摘Blue-grained wheat derived from the hybrid Triticum aestivum L. X Thinopyrum ponticum (Podp.) Barkworth et D. R. Dewey (Agropyron elongatum (Host) P. Beauv., 2n=70). The molecular biological mechanism of the biosynthetic pathway of blue pigments in the blue grain remains unclear yet. Dihydroflavonol 4-reductase (DFR) is one of the key enzymes controlling flavonoid synthesis in anthocyanin biosynthetic pathway, and may directly participate in the formation of blue pigment in the aleurone layer of blue-grained wheat. Here we cloned a DFR cDNA (TaDFR) from the developing seeds of blue-grained wheat, and four DFR genomic DNAs from Th. ponticum (ThpDFR.t), blue-grained wheat (TaDFR.bg), white-grained offspring of light blue-grained wheat (TaDFR.wg) and Chinese Spring (2n=42) (TaDFR.csg), respectively. TaDFR cDNA encodes a 354 amino-acids polypeptide with high identity to DFR from Hordeum vulgare L. (94%), Oryza sativa L. (83%), Zea mays L.(84%). The result of cluster analysis showed that TaDFR cDNA nucleotide sequence has 100% identity with that of TaDFR.csg. The four DFR genomic DNAs have extraordinary high homology and each has three introns. The differences of the four DFR genomic DNAs mainly exist in introns. Southern blotting analysis showed that there are at least 3-5 DFR copies in wheat, the copy numbers in different color grain wheats are not significantly different. The hybridization band patterns were the same, but different from that of Th. ponticum. DFR in blue-grained wheat belongs to a DFR superfamily. Northern blotting analysis indicated that the DFR expressed in the developing seeds of both blue- and white-grained wheat at 15 d after flowering (DAF), the mRNA levels of DFR reached the highest at 18 DAF, then declined quickly and disappeared at 33 DAF But the expression levels in blue-grained seeds were higher than that in white grain at the same seed developing stages. DFR transcripts accumulated in young leaves, and leaf sheaths of blue- and white-grained wheat and Th ponticum, but not detected in roots from different color wheats and developing seeds of Th. ponticum. Results indicated that there may exist some regulatory gene(s) which can increase the expression of DFR in the aleurone layer of blue-grained wheat, and thus resulting in the formation of blue pigments.
基金This work was supported by the National Key R&D Program of China(Nos.2020YFA0908000,2018YFA0900600)the National Natural Science Foundation of China(Nos.82003904,81822046)+4 种基金the Fundamental Research Funds for the Central public welfare research institutes(No.ZZ13-YQ-083)a Scientific and Technological Innovation Project of China Academy of Chinese Medical Sciences(No.CI2021A04110)Innovation Team and Talents Cultivation Program of National Administration of Traditional Chinese Medicine(No.ZYYCXTD-D-202005)a key project at central government level(the ability to establish sustainable use of valuable Chinese medicine resources2060302,China).
文摘Danshen,the dried roots and rhizomes of Salvia miltiorrhiza Bunge(S.miltiorrhiza),is widely used in the treatment of cardiovascular and cerebrovascular diseases.Tanshinones,the bioactive compounds from Danshen,exhibit a wide spectrum of pharmacological properties,suggesting their potential for future therapeutic applications.Tanshinone biosynthesis is a complex process involving at least six P450 enzymes that have been identified and characterized,most of which belong to the CYP76 and CYP71 families.In this study,CYP81C16,a member of the CYP71 clan,was identified in S.miltiorrhiza.An in vitro assay revealed that it could catalyze the hydroxylation of four para-quinone-type tanshinones,namely neocryptotanshinone,deoxyneocryptotanshinone,and danshenxinkuns A and B.SmCYP81C16 emerged as a potential broad-spectrum oxidase targeting the C-18 position of para-quinone-type tanshinones with an impressive relative conversion rate exceeding 90%.Kinetic evaluations and in vivo assays underscored its highest affinity towards neocryptotanshinone among the tested substrates.The overexpression of SmCYP81C16 promoted the accumulation of(iso)tanshinone in hairy root lines.The characterization of SmCYP81C16 in this study accentuates its potential as a pivotal tool in the biotechnological production of tanshinones,either through microbial or plant metabolic engineering.
基金supported by the Knowledge Innovation Key Program of the Chinese Academy of Sciences (KSCXZ-YW-N-013)
文摘Carotenoid biosynthetic pathway produces not only pigments that protect photosynthetic system against photo-oxidative damage, but also precursors of abscisic acid, the major hormone regulates stress responses. To understand the response of carotenoid biosynthetic pathway to salt stress, the expression of the genes involved in carotenoid and ABA biosynthesis were compared in cultivated tomato Solanum lycopersicon cv. Moneymaker and its relative wild genotype S. pimpinellifolium （PI365967） together with the contents of carotenoids and ABA. The results showed that 11 of the 15 genes investigated were up-regulated and four unaltered in Moneymaker after 5 h of salt stress; whereas only four genes were up-regulated, four unaltered, and seven down-regulated in PI365967 after stress. Further comparison revealed that 11 salinity-induced genes were expressed significantly lower in Moneymaker than in PI365967 under normal condition, and 8 of them were induced to similar levels after salt stress. In consistence, ABA level was doubled in Moneymaker but kept consistent in PI365967 after salt stress, though the contents of neoxanthin, violaxanthin, [3-carotene, lutein, and total carotenoids were kept unchanged in both species. Since it is known that PI365967 is more tolerant to salt stress than Moneymaker, we proposed that the constitutive high level of carotenoid and ABA biosynthetic pathway under normal growth condition could be benefit to PI365967 for establishing the early response to salt stress. In addition, CrtR-bl and CrtR-b2 that encode [3-carotenoid hydroxylases were the only genes in carotenoid biosynthetic pathway that were up-regulated by salt stress in both species. The CrtR-b2 gene was cloned from both species and no essential difference was found in the encoded amino acid sequences. Transformation of CrtR-b2 to tobacco improved the seed germination under salt stress condition, indicating that the hydrolysis of β-carotenoid is the target of transcriptional regulation of the carotenoid biosynthesis in both tomato cultivar and wild relative.
基金the National Natural Science Foundation of China(81773891)the National Great New Drugs Development Project of China(2017ZX09301-040)+3 种基金the Beijing Natural Science Foundation(7162092)Beijing Talents Project(2017A19)Beijing Municipal Science&Technology Commission(XMLX201704,Z161100000516074)the Open Research Fund of the State Key Laboratory Breeding Base of Systematic Research,Development and Utilization of Chinese Medicinal Resources.
文摘Quality marker(Q-marker)of Chinese materia medica(CMM)plays an important role in quality control of CMM products.However,its research strategy and technique remain unclear.Based on the fact that quality standard of CMM should be associated with clinical efficacy,taking Jinqi Jiangtang tablet treating type 2 diabetes as an example,the Q-marker related to activity via the reverse analysis of drug metabolism in clinic and traceability of botanic biosynthetic pathways is discovered and validated.Therefore,we proposed a new research strategy of Q-marker of CMM with"Discovery of clinical active constituents as guidance,Reverse analysis of metabolic transformations as link,and Traceability of biosynthesis pathways as key",to improve quality control of CMM products.
基金supported by the Shanghai Municipal Commission of Agriculture and Rural Affairs(Tuizi 20221-5)the National Natural Science Foundation of China(32171977)+2 种基金the Innovation Team project of Shanghai Academy of Agricultural Sciences((2022)005)the Leading Talent Program of Minhang District of Shanghai(202245)the Shanghai Oriental Talented Youth Program.
文摘Dear Editor,Paper derived from rice straw has inferior physical properties compared with paper derived from wood pulp.This study reports engineering the biosynthetic pathway of bacterial cellulose into rice to improve the performance of rice-straw-derived paper.This work offers novel insights into the reuse of agricultural waste and provides guidance for the bio-breeding of woody plants.
基金the National Key R&D Program of China(2020YFA0908000)National Science Fund for Excellent Young Scholars(31922047)+1 种基金Tianjin Synthetic Biotechnology Innovation Capacity Improvement Project(No.TSBICIP-KJGG-002)the China Postdoctoral Science Foundation(No.2019M661032)。
文摘Taxus,commonly known as yew,is a well-known gymnosperm with great ornamental and medicinal value.In this study,by assembling a chromosome-level genome of the Himalayan yew(Taxus wallichiana)with 10.9 Gb in 12 chromosomes,we revealed that tandem duplication acts as the driving force of gene family evolution in the yew genome,resulting in the main genes for paclitaxel biosynthesis,i.e.those encoding the taxadiene synthase,P450s,and transferases,being clustered on the same chromosome.The tandem duplication may also provide genetic resources for the nature to sculpt the core structure of taxoids at different positions and subsequently establish the complex pathway of paclitaxel by neofunctionalization.Furthermore,we confirmed that there are two genes in the cluster encoding isoenzymes of a known enzyme in the paclitaxel biosynthetic pathway.The reference genome of the Himalayan yew will serve as a platform for decoding the complete biosynthetic pathway of paclitaxel and understanding the chemodi-versity of taxoids in gymnosperms.
文摘Catharanthus roseus is one of the most extensively investigated medicinal plants, which can produce more than 130 alkaloids, including the powerful antitumor drugs vinblastine and vincristine. Here we review the recent advances in the biosynthetic pathway of terpenoid indole alkaloids （TIAs） in C. roseus, and the identification and characterization of the corresponding enzymes involved in this pathway. Strictosidine is the central intermediate in the biosynthesis of different TIAs, which is formed by the condensation of secologanin and tryptamine. Secologanin is derived from terpenoid （isoprenoid） biosynthetic pathway, while tryptamine is derived from indole biosynthetic pathway. Then various specific end products are produced by different routes during downstream process. Although many genes and corresponding enzymes have been characterized in this pathway, our knowledge on the whole TIA biosynthetic pathway still remains largely unknown up to date. Full elucidation of TIA biosynthetic pathway is an important prerequisite to understand the regulation of the TIA biosynthesis in the medicinal plant and to produce valuable TIAs by synthetic biological technology.
基金supported by the Jiangsu Agriculture Science and Technology Innovation Fund[CX(14)2015]China Agriculture Research System(CARS-31)
文摘The aim of our study was to assess differences in the expression of genes involved in fruit softening and ethylene biosynthetic pathways under different temperature storage conditions. Different peach cultivars of ‘Xiacui' and ‘Yumyeong', which are stonyhard, ‘Yinhualu', which is softmelting, ‘Hujing Milu', which is hard-melting, and ‘Baby Gold 6', which is non-melting at 80% ripening, were collected as test materials. The results showed that only slight ethylene production was detected after harvesting of ‘Yumyeong' and ‘Xiacui' under either a room temperature(25 °C) or low temperature(4 °C). The fruit firmness of stonyhard cultivars was retained at a high level under room temperature over time, whereas a low temperature induced ‘Yumyeong' fruit to soften. Quantitative real-time PCR results indicated that the PpACS1 gene was highly expressed in soft-melting, hard-melting and non-melting cultivars; however, expression was extremely low in stonyhard peaches. PpACS2 or PpACS3, however,was not detected in all five cultivars. Interestingly, cold treatment significantly decreased firmness along with endo-PG expression obviously upregulated in ‘Yumyeong', but not in ‘Xiacui' peaches. In conclusion, this study revealed that fruit softening of peaches with different flesh textures was closely related to ethylene biosynthesis during the storage period, which was controlled via regulating relevant gene expression levels under different storage temperatures.
基金fellowships from the Israel Ministry of Absorption and the Dean of the Plant Science Department in the Weizmann Institute.We thank Prof.David Nelson(University of Tennessee,USA)for the systematic naming of the cytochrome P450 enzymes characterized in this studyShmuel Regev and The Regev Nursery(Beit Elazari,Israel)for help in differentiating among Lophophora species+2 种基金Dr.Ziv Spiegelman for providing several N.benthamiana plantsXINTEZA(https://xinteza.com/)for funding this researchand the Adelis Foundation,the Leona M.and Harry B.Helmsley Charitable Trust,the Jeanne and Joseph Nissim Foundation for Life Sciences,Tom and Sondra Rykoff Family Foundation Research,Ron Sklare and the Raymond Burton Plant Genome Research Fund for supporting the A.A.laboratory。
文摘Mescaline,among the earliest identified natural hallucinogens,holds great potential in psychotherapy treatment.Nonetheless,despite the existence of a postulated biosynthetic pathway for more than half a century,the specific enzymes involved in this process are yet to be identified.In this study,we investigated the cactus Lophophora williamsii(Peyote),the largest known natural producer of the phenethylamine mescaline.We employed a multi-faceted approach,combining de novo whole-genome and transcriptome sequencing with comprehensive chemical profiling,enzymatic assays,molecular modeling,and pathway engineering for pathway elucidation.We identified four groups of enzymes responsible for the six catalytic steps in the mescaline biosynthetic pathway,and an N-methyltransferase enzyme that N-methylates all phenethylamine intermediates,likely modulating mescaline levels in Peyote.Finally,we reconstructed the mescaline biosynthetic pathway in both Nicotiana benthamiana plants and yeast cells,providing novel insights into several challenges hindering complete heterologous mescaline production.Taken together,our study opens up avenues for exploration of sustainable production approaches and responsible utilization of mescaline,safeguarding this valuable natural resource for future generations.
基金supported by The University of Queensland(UQ postdoctoral fellowship to X.Jia)and the National Natural Science Foundation of China(no.31970054 to X.Qu).
文摘Mollemycin A(MOMA)is a unique glyco-hexadepsipeptide-polyketide that was isolated from a Streptomyces sp.derived from the Australian marine environment.MOMA exhibits remarkable inhibitory activity against both drug-sensitive and multidrug-resistant malaria parasites.Optimizing MOMA through structural modifications or product enhancements is necessary for the development of effective analogues.However,modifying MOMA using chemical approaches is challenging,and the production titer of MOMA in the wild-type strain is low.This study identified and characterized the biosynthetic gene cluster of MOMA for the first time,proposed its complex biosynthetic pathway,and achieved an effective two-pronged enhancement of MOMA production.The fermentation medium was optimized to increase the yield of MOMA from 0.9 mg L^(-1)to 1.3 mg L^(-1),a 44%boost.Additionally,a synergistic mutant strain was developed by deleting the momB3 gene and overexpressing momB2,resulting in a 2.6-fold increase from 1.3 mg L^(-1)to 3.4 mg L^(-1).These findings pave the way for investigating the biosynthetic mechanism of MOMA,creating opportunities to produce a wide range of MOMA analogues,and developing an efficient strain for the sustainable and economical production of MOMA and its analogues.
文摘De novo nucleotide biosynthetic pathway is a highly conserved and essential biochemical pathway in almost all organisms.Both purine nucleotides and pyrimidine nucleotides are necessary for cell metabolism and proliferation.Thus,the dysregulation of the de novo nucleotide biosynthetic pathway contributes to the development of many human diseases,such as cancer.It has been shown that many enzymes in this pathway are overactivated in different cancers.In this review,we summarize and update the current knowledge on the de novo nucleotide biosynthetic pathway,regulatory mechanisms,its role in tumorigenesis,and potential targeting opportunities.
文摘The study focused on the regulatory role of Carthamus tinctorius Dof in the safflower seed oil biosynthetic pathway.Through bioinformatics analysis,yeast expression system validation,and transgenic Arabidopsis thaliana experiments,it was found that the expression of the safflower family of transcription factors was significantly increased at 25 post-flowering days of safflower seed development,which coincided with the peak of fatty acid accumulation.Stearic acid content was reduced by 20.33%and oleic acid content was increased by 27.54%in transgenic yeast,and C20:0 and C22:0 long-chain saturated fatty acids were detected.Arabidopsis thaliana seeds overexpressing the safflower Dof transcription factor gene had significantly higher fatty acid composition than the wild type,while mutant seeds had lower fatty acid composition than the wild type.GC-MS analysis indicated that the safflower Dof transcription factor gene variant had limited effect on the overall composi-tion of fatty acids.The results provide molecular targets for improving the quality of safflower seed oil and help to reveal the mechanism of Carthamus tinctorius Dof in the regulation of lipid biosynthesis,which is of great significance for improving the lipid content and composition of oilseed crops.
基金supported by the National Natural Science Foundation of China(Nos.82373762,31872675)Major Special Programe of science and technology of Yunnan(202402AA310032,202305AH340005)+1 种基金the Cooperation Project with DR PLANT Company(2023)the Foundation of the State Key Laboratory of Phytochemistry and Plant Resources in West China(Nos.P2020-KF02,P2022-KF10).
文摘Ganoderma polysaccharides(GPs),derived from various species of the Ganoderma genus,exhibit diverse bioactivities,including immune modulation,anti-tumor effects,and gut microbiota regulation.These properties position GPs as dual-purpose agents for medicinal and functional food development.This review comprehensively explores the structural complexity of six key GPs and their specific mechanisms of action,such as TLR signaling in immune modulation,apoptosis pathways in anti-tumor activity,and their prebiotic effects on gut microbiota.Additionally,the structure-activity relationships(SARs)of GPs are highlighted to elucidate their biological efficacy.Advances in green extraction techniques,including ultrasonic-assisted and enzymatic methods,are discussed for their roles in enhancing yield and aligning with sustainable production principles.Furthermore,the review addresses biotechnological innovations in polysaccharide biosynthesis,improving production efficiency and making large-scale production feasible.These insights,combined with ongoing research into their bioactivity,provide a solid foundation for developing health-promoting functional food products that incorporate GPs.Furthermore,future research directions are suggested to optimize biosynthesis pathways and fully harness the health benefits of these polysaccharides.
基金supported by the National Key Research and Development Program of China(No.2021YFA0910500)the National Natural Science Foundation of China(Nos.U22A20380,82173706,and 82104028)the Science and Technology Major Project of Hubei Province(No.2021ACA012).
文摘(±)-Talapyrones A−F(1−6),six pairs of dimeric polyketide enantiomers featuring unusual 6/6/6 and 6/6/6/5 ring systems,were isolated from the fungus Talaromyces adpressus.Their structures were determined by spectroscopic analysis and HR-ESI-MS data,and their absolute configurations were elucidated using a modified Mosher’s method and electronic circular dichroism(ECD)calculations.(±)-Talapyrones A−F(1−6)possess a 6/6/6 tricyclic skeleton,presumably formed through a Michael addition reaction between one molecule ofα-pyrone derivative and one molecule of C8 poly-β-keto chain.In addition,compounds 2/3 and 4/5 are two pairs of C-18 epimers,respectively.Putative biosynthetic pathways of 1−6 were discussed.
基金supported by National College Student Innovation and Entrepreneurship Train-ing Program(202410376009)Anhui Province College Student Innovation and Entrepreneurship Training Program(S202310376057,S202510376030)+2 种基金Quality Engineering Project of West Anhui University(wxxy2024011)Quality Engineering Project of Anhui Province(2024zybj032)Development of Big Data Integration and Analysis Platform for Traditional Chinese Medicine Genomics(0045025050).
文摘Melatonin is a multifunctional molecule found in all organisms that has been shown to play a crucial role in plant growth, development, and stress response. Plant melatonin is typically synthesized in organelles termed chloroplasts, and the mechanisms of its synthesis and metabolic pathways have been extensively studied. Melatonin serves a significant regulatory function in plant growth and development, influencing the morphological and physiological characteristics of plants by modulating biological processes. While studies on plant melatonin receptors are in their early stages compared to studies in animal receptors, the binding mechanism with melatonin is now recognized as the key initiating step that triggers a series of downstream protective effects. This suggests that melatonin in plants may exert its effects through two main modes of target binding. The CAND2/PMTR1 protein binds to melatonin with a high degree of affinity. This binding activates downstream heterotrimeric G proteins, which trigger rapid intracellular signaling cascades. These cascades include activating the MAPK pathway and modulating ion channel activity. This action swiftly regulates stomatal closure in response to physiological processes such as drought stress. Additionally, melatonin has been demonstrated to regulate the plant stress response through two main mechanisms. First, it directly inhibits the accumulation of reactive oxygen species. Second, it indirectly influences the stress response pathways. This paper examines plant melatonin from three perspectives: the synthesis pathways of melatonin, its effects on plant growth, and its applications in plants under stress. Finally, the prospects for melatonin study and its applications in plants are discussed.
文摘The gene encoded for tryptophan decarboxylase (TDC), which is the key enzyme in terpenoil indole alkaloids pathway, was targeted to different subcellular compartments and stably expressed in transgenic tobacco (Nicotiana tabacum L.) plants at the levels detected by Western blot and tryptamine accumulation analysis. It was shown that the TDC was located in subcellular compartments, the chloroplasts and cytosol. The recombinant TDC targeted to chloroplasts and cytosol in tobacco plants was effectively expressed as soluble protein by Western blot analysis and enzymatic assay. The level of tryptamine accumulation in chloroplast was higher than that in cytosol and very low in vacuole and endoplasmic reticulum (ER) to be hardly detected by Western blot analysis. It was indicated that the highest amount of tryptamine was in chloroplasts, lower in endoplasmic reticula and the lowest in vacuoles as compared to those in wild type plants. The TDC targeted to different subcellular compartments of tobacco plants and its expression level were studied by different nucleotide sequences coding signal peptides at 5'-end of tdc gene in order to know the effects of the TDC in compartmentation on its functionality.
基金supported by the National Natural Science Foundation of China(General Program),No.81271293the National Science Foundation for Young Scientists of China,No.81000490
文摘Connexin subunits are proteins that form gap junction channels, and play an important role in communication between adjacent cells. This review article discusses the function of connexins/hemichannels/gap junctions under physiological conditions, and summarizes the findings re-garding the role of connexins/hemichannels/gap junctions in the physiological and pathological mechanisms underlying central nervous system diseases such as brain ischemia, traumatic brain and spinal cord injury, epilepsy, brain and spinal cord tumor, migraine, neuroautoimmune disease, Alzheimer’s disease, Parkinson’s disease, X-linked Charcot-Marie-Tooth disease, Peli-zaeus-Merzbacher-like disease, spastic paraplegia and maxillofacial dysplasia. Connexins are considered to be a potential novel target for protecting the central nervous system.
基金supported by the Achievement Conversion Project of the Ministry of Science and Technology (No.2014GB2B100007)the Science and Technology Project of Education Department of Jilin Province (No. JJKH20180640KJ)。
文摘Schisandra chinensis Turcz.(Baill.) is a plant species with fruits that have been well known in Far Eastern medicine for a long time. It has traditionally been used as a stimulating and fortifying agent in cases of physical exhaustion and to inhibit fatigue.The major bioactive compounds found in S. chinensis are lignans with a dibenzocyclooctadiene skeleton, but little is known about their biosynthesis in plants. S. chinensis is the ideal medicinal plant for studying the biosynthesis of lignans, especially the dibenzocyclooctadiene skeleton. Genomic information for this important herbal plant is unavailable. To better understand the lignan biosynthesis pathway, we generated transcriptome sequences from the fruit during ripening and performed de novo sequence assembly, yielding136 843 unique transcripts with N50 of 1778 bp. Putative functions could be assigned to 41 824 transcripts(51.57%) based on BLAST searches against annotation databases including GO(Gene ontology) and KEGG(Kyoto Encyclopedia of Genes and Genomes). Furthermore, 22 candidate cytochrome P450 genes and 15 candidate dirigent proteins genes that were most likely involved in the lignan biosynthesis pathway were discovered based on transcriptome sequencing of S. chinensis. The genomic data obtained from S. chinensis, especially the identification of putative genes involved in the lignan biosynthesis pathway, will facilitate our understanding of lignan biosynthesis at the molecular level. The lignan metabolite profiles were analyzed by metabolomes, the accumulation patterns of 30 metabolites involved in the lignan pathway were studied. Co-expression network of lignan contents and transcriptional changes showed355 strong correlations(correlation coefficient, R^2 > 0.9) between 21 compounds and 153 transcripts. Furthermore, the comprehensive analysis and characterization of the genes involved in lignan pathways and the metabolite profiles of lignans are expected to provide better insight regarding the diversity of the chemical composition, synthetic characteristics, and regulatory mechanisms of this medical herb.
文摘Sarcandra glabra(Thunb.)Nakai is a perennial evergreen herb categorised within the Sarcandra Gardner genus under the Chloranthaceae family.Indigenous to tropical and subtropical regions of East Asia and India,this species is extensively distributed across China,particularly in the southern regions(Sichuan,Yunnan,and Jiangxi).In addition to its high ornamental value,S.glabra has a rich history of use in traditional Chinese medicine,evident through its empirical prescriptions for various ailments like pneumonia,dysentery,fractures,bruises,numbness,amenorrhea,rheumatism,and other diseases.Besides,modern pharmacological studies have revealed various biological activities,such as antitumour,anti-bacterial,anti-viral anti-inflammatory and immunomodulatory effects.The diverse chemical constituents of S.glabra have fascinated natural product researchers since the 1900s.To date,over 400 compounds including terpenoids,coumarins,lignans,flavonoids,sterols,anthraquinones,organic acids,and organic esters have been isolated and characterised,some featuring unprecedented structures.This review comprehensively examines the current understanding of S.glabra’s phytochemistry and pharmacology,with emphasis on the chemistry and biosynthesis of its unique chemotaxonomic marker,the lindenane-type sesquiterpenoids.
基金supported by NSFC grants (Nos. 21472021, 81273401, 81202420)grants from the Ph.D. Programs Foundation of Ministry of Education (MOE) of China (Nos. 20120071110049, 20120071120049)the National Basic Research Program of China (973 Program, No. 2013CB530700)
文摘One novel（named palcernuine, 1） and five known cernuane-type（2–6） alkaloids were isolated from the whole plant of Palhinhaea cernua f. sikkimensis. The structure of 1, possessing an unprecedented [5/6/6/6]-tetracyclic ring system containing two nitrogen atoms, was established on the basis of spectroscopic methods, and its absolute configuration was determined by comparison of the experimental and calculated electronic circular dichroism（ECD） spectra. A plausible biosynthetic pathway to 1 is proposed.
