A novel phenylpropanoid glycosides 1, named parispolyside E and a novel derivation of phenolic glycoside 2, named parispolyside G, as well as two known flavonoid glycosides were isolated from the rhizome of Paris poly...A novel phenylpropanoid glycosides 1, named parispolyside E and a novel derivation of phenolic glycoside 2, named parispolyside G, as well as two known flavonoid glycosides were isolated from the rhizome of Paris polyphylla var. yunnanensis. Their structures were elucidaed by spectroscopic methods.展开更多
Paris polyphylla var. yunnanensis is an important medicinal plant with abundant saponins that are widely used in the pharmaceuticals industry. It is unclear why the levels of active ingredients increase as these plant...Paris polyphylla var. yunnanensis is an important medicinal plant with abundant saponins that are widely used in the pharmaceuticals industry. It is unclear why the levels of active ingredients increase as these plants age. We speculated that the concentrations of those components in the rhizomes are mediated by fungal endophytes. To test this hypothesis, we took both culture-dependent and-independent(metagenomics) approaches to analyze the communities of endophytic fungi that inhabit those rhizomes in plants of different age classes(four, six, and eight years old). In all, 147 isolates representing 18 fungal taxa were obtained from 270 segments(90 per age class). Based on morphological and genetic characteristics, Fusarium oxysporum(46.55% frequency of occurrence) was the predominant endophyte,followed by Leptodontidium sp.(8.66%) and Trichoderma viride(6.81%). Colonization of endophytic fungi was maximized in the eight-year-old rhizomes(33.33%) when compared with four-year-old(21.21%) and six-year-old(15.15%) rhizomes. Certain fungal species were present only at particular ages. For example,Alternaria sp., Cylindrocarpon sp., Chaetomium sp., Paraphaeosphaeria sporulosa, Pyrenochaeta sp., Penicillium swiecickii, T. viride, and Truncatella angustata were found only in the oldest plants. Analysis of(metagenomics) community DNA extracted from different-aged samples revealed that, at the class level,the majority of fungi had the highest sequence similarity to members of Sordariomycetes, followed by Eurotiomycetes and Saccharomycetes. These results were mostly in accord with those we obtained using culture methods. Fungal diversity and richness also changed over time. Our investigation is the first to show that the diversity of fungi in rhizomes of P. polyphylla var. yunnanensis is altered as plants age, and our findings provide a foundation for future examinations of useful compounds.展开更多
Paris polyphylla var.yunnanensis is a traditional Chinese medicinal plant,in which polyphyllin as the main medicinal component is an important secondary metabolite with bioactivity.Arbuscular mycorrhizal fungi(AMF)hav...Paris polyphylla var.yunnanensis is a traditional Chinese medicinal plant,in which polyphyllin as the main medicinal component is an important secondary metabolite with bioactivity.Arbuscular mycorrhizal fungi(AMF)have multiple positive effects on plants,while it is not clear whether AMF increase the content of medicinal components in medicinal plants.In this study,a total of nine AMF treatments were laid to analyze the mycorrhizal effect on polyphyllin accumulation and PpHMGR and PpSE expression of P.polyphylla var.yunnanensis.AMF increased the content of polyphyllin in the cultivated variety with low relation to the increase of inoculation intensity.Polyphyllin I,II,and VII were identified and partly improved by AMF inoculation,dependent on AMF treatments and culture environments.Similarly,the PpHMGR and PpSE expression was induced by mycorrhization,dependent on AMF species,whilst the induction was more obvious in PpSE than in PpHMGR after mycorrhization.It concluded that the symbiotic relationship between P.polyphylla var.yunnanensis and AMF increased polyphyllin content level in the plant,which was associated with the up-regulation of PpSE transcripts.展开更多
A field experiment was conducted to determine the effects of two commercial strains composed of mulple arbuscular mycorrhizal fungi(AMF)species on plant growth,antioxidant capacity,and medicine quality of Paris polyph...A field experiment was conducted to determine the effects of two commercial strains composed of mulple arbuscular mycorrhizal fungi(AMF)species on plant growth,antioxidant capacity,and medicine quality of Paris polyphylla var.yunnanensis in three subtropical soils from Wanzhou,Anshun and Baoshan in fields.The results showed that AMF inoculation enhanced the fungal colonization rate and activities of both succinate dehydrogenase and alkaline phosphatase,thereby,enhancing the mycorrhizal viability of P.polyphylla var.yunnanensis.The concentrations of photosynthetic pigments(chlorophyll a,b,a+b and carotenoids),soluble sugar,soluble protein and photosynthetic capacity were higher in AMF-inoculated plants than in non-AMF-treated plants in field.AMFtreated plants recorded higher activities of catalase,peroxidase and superoxide dismutase,and caused the reduction in malondialdehyde content,indicating lower oxidative damage,compared with non-AMF plants.Polyphyllin I,Polyphyllin II,Polyphyllin III,Polyphyllin IV and total polyphyllin contents were increased by AMF treatment.In conclusion,AMF improved the plant growth,antioxidant capacity and medicinal quality of P.polyphylla var.yunnanensis seedlings.Hereinto,AMF effects on the soil from Wanzhou was relatively greater than on other soils.展开更多
In this study,the resource distribution,morphological characteristics,artificial cultivation and market circulation of Paris Polyphylla var.yunnanensis and its polygerm varieties in Yunnan were investigated by referri...In this study,the resource distribution,morphological characteristics,artificial cultivation and market circulation of Paris Polyphylla var.yunnanensis and its polygerm varieties in Yunnan were investigated by referring to the research literature,field investigation and our planting experience.It is found that P.polyphylla var.yunnanensis is widely distributed in Yunnan Province,realizing large-scale artificial cultivation,while the wild resources of polygerm varieties are almost on the verge of extinction and are in urgent need of protection.展开更多
[Objective] This study aimed to isolate the endophytic fungi of Paris polyphylla var. yunnanensis and investigate their effects on the embryo development of P. polyphylla var. yunnanensis seeds. [Method] The endophyti...[Objective] This study aimed to isolate the endophytic fungi of Paris polyphylla var. yunnanensis and investigate their effects on the embryo development of P. polyphylla var. yunnanensis seeds. [Method] The endophytic fungi of P. polyphylla were isolated and identified morphologically, and their effects on the embryo development of P. polyphylla var. yunnanensis seeds were studied by using paraffin sectioning and microphotography. [Result] Nine endophytic fungi, i.e. P. polyphylla var. yunnanensis endophytic fungi PPYEF-1, PPYEF-2, PPYEF-3, PPYEF-4, PPYEF-5, PPYEF-6, PPYEF-7, PPYEF-8 and PPYEF-9 belonging to seven genera in five families, three orders were isolated from the rhizomes. Except PPYEF-4 (Cladosporium sp.), other fungi could promote the embryo development of the P. polyphylla var. yunnanensis seeds, mostly reaching the extremely significant or significant level. PPYEF-9 (Trichoderma sp.) resulted in the highest embryo length and embryo-emerging ratio. [Conclusion] This paper could provide a reference for the application of the endophytic fungi of P. polyphylla var. yunnanensis in the dormancy-breaking of P. polyphylla var. yunnanensis seeds.展开更多
[Objectives] To determine the content of 10 kinds of inorganic elements(Pb,Cu,As,Cd,Hg,Zn,Fe,Mn,Sr and Cr) in samples of Paris polyphylla Smith var. yunnanensis( Franch.) Hand.-Mazz.( and polygerm varieties) produced ...[Objectives] To determine the content of 10 kinds of inorganic elements(Pb,Cu,As,Cd,Hg,Zn,Fe,Mn,Sr and Cr) in samples of Paris polyphylla Smith var. yunnanensis( Franch.) Hand.-Mazz.( and polygerm varieties) produced in different areas. [Methods] The wet digestion and technique of inductively coupled plasma optical emission spectrometry( ICP-OES) were used. [Results] Under the experimental conditions,elements were not related to each other,and several kinds of elements could be measured at the same time. The content of Pb exceeding the standard only in sample S4 of P. polyphylla Smith var. yunnanensis( and polygerm varieties),Hg was not detected in all samples,and the rest heavy metals did not exceed the limit. [Conclusions] This study was expected to provide a certain reference for the development and utilization of P. polyphylla Smith var. yunnanensis( and polygerm varieties).展开更多
[Objectives] To make original plant and microscopic identification and study the traits of Paris polyphylla Smith var. yunnanensis( Franch.) Hand.-Mazz.( polygerm varieties) produced in Gaoligong Mountain areas,and pr...[Objectives] To make original plant and microscopic identification and study the traits of Paris polyphylla Smith var. yunnanensis( Franch.) Hand.-Mazz.( polygerm varieties) produced in Gaoligong Mountain areas,and provide experimental data for their identification and application. [Methods] The original plant powder was used,and paraffin sections and physicochemical properties were identified. [Results]P. polyphylla Smith var. yunnanensis( polygerm varieties) produced in Gaoligong Mountain areas showed obvious microscopic features and physicochemical properties. [Conclusions] This study was expected to provide certain reference for identification of original plant and medicine and formulation of quality standard for P. polyphylla Smith var. yunnanensis( polygerm varieties) produced in Gaoligong Mountain areas,and provided basis for their further research and development.展开更多
Paris polyphylla var. yunnanensis (Franch.), one of the best-known medicinal plants in China, has a dehiscent anther which physiologically work in pollination, however, the dehiscent anther always closes in response t...Paris polyphylla var. yunnanensis (Franch.), one of the best-known medicinal plants in China, has a dehiscent anther which physiologically work in pollination, however, the dehiscent anther always closes in response to darkness every day, and watering or raining every time. To explore this frequently closing and its unkown physiology, next-generation sequencing was performed, and the transcriptome was de novo assembled. RNA-sequencing was carried out in 15 samples including seven openning samples, four closed samples owing to darkness or watering, and tissue samples (leaf, petal, calyx, and stigma) were used for control. We obtained 72.75 GB data, assembled into 79,815 unigenes. Differentially expressed unigenes (DEGs) between opened and closed anther samples were 6231 and the DEGs between anther and control samples were 2831. Comparation between the two DEGs by KEGG enrichment showed that “plant hormone signal transduction” pathway is the most significant pathway for DEGs from closing anther vs. opening anther, and expression model of DEGs in the pathway might elicit change in germination and seed dormancy. Further examination of the action of the signal pathway on physiology showed “chromatin binding” function was prominent in “DNA binding” function of annotated DEGs between opened and closed anthers, of the 215 “chromatin binding” unigenes, 120 were involved in epigenetic silencing, and 50 of the epigenetic unigenes were directly related to germination or seed dormancy, strongly correlating anther closing to epigenetic modification and seed dormancy. These results were verified that at least three auxins involved in seed dormancy showed same expression patterns occurred in abnormal closing anther and seed embryo in Paris polyphylla var. yunnanensis. In conclusion, the information from transcriptome point out that frequent abnormal closing of dehiscent anthers possibly transfer the impact on seed dormancy, and epigenetic modification happened in closing may be the cause.展开更多
Sugar-sugar glycosyltransferases play important roles in constructing complex and bioactive saponins.Here,we characterized a series of UDP-glycosyltransferases responsible for biosynthesizing the branched sugar chain ...Sugar-sugar glycosyltransferases play important roles in constructing complex and bioactive saponins.Here,we characterized a series of UDP-glycosyltransferases responsible for biosynthesizing the branched sugar chain of bioactive steroidal saponins from a widely known medicinal plant Paris polyphylla var.yunnanensis.Among them,a 2'-O-rhamnosyltransferase and three 6'-O-glucosyltrasferases catalyzed a cascade of glycosylation to produce steroidal diglycosides and triglycosides,respectively.These UDP-glycosyltransferases showed astonishing substrate promiscuity,resulting in the generation of a panel of 24 terpenoid glycosides including 15 previously undescribed compounds.A mutant library containing 44 variants was constructed based on the identification of critical residues by molecular docking simulations and protein model alignments,and a mutant UGT91AH1^(Y187A)with increased catalytic efficiency was obtained.The steroidal saponins exhibited remarkable antifungal activity against four widespread strains of human pathogenic fungi attributed to ergosterol-dependent damage of fungal cell membranes,and 2'-O-rhamnosylation appeared to correlate with strong antifungal effects.The findings elucidated the biosynthetic machinery for their production of steroidal saponins and revealed their potential as new antifungal agents.展开更多
目的:研究滇重楼Paris polyphylla Smith var.yunnanensis根茎中具有抗肿瘤作用的活性成分。方法:利用硅胶柱色谱,Sephadex LH-20,反相制备HPLC等手段进行分离纯化,并通过波谱技术进行结构鉴定。采用MTT法对分离到的化合物进行抗...目的:研究滇重楼Paris polyphylla Smith var.yunnanensis根茎中具有抗肿瘤作用的活性成分。方法:利用硅胶柱色谱,Sephadex LH-20,反相制备HPLC等手段进行分离纯化,并通过波谱技术进行结构鉴定。采用MTT法对分离到的化合物进行抗肿瘤活性筛选。结果:从醋酸乙酯和正丁醇层中分离得到了6个化合物,鉴定为薯蓣皂苷元-3—O-α-L-呋喃阿拉伯糖基(1→4)-β-D-葡萄糖苷(1)、偏诺皂苷元-3-O-α—L-呋喃阿拉伯糖基(1→4)-β-D-葡萄糖苷(2)、异鼠李素-3—O-β-D-葡萄糖苷(3)、乙基-α—D-呋喃果糖苷(4)、偏诺皂苷元-3—O-α—L-吡喃鼠李糖基(1→4)-[α-L-吡喃鼠李糖基(1→2)]-β-D-葡萄糖苷(5)、偏诺皂苷元-3—O-α—L-吡喃鼠李糖基(1→4)-α-L-吡喃鼠李糖基(1→4)-[α-L-吡喃鼠李糖基(1→2)]-β-D-葡萄糖苷(6)。结论:化合物1—4为首次从滇重楼中分离得到,化合物3和4为首次从重楼属植物中分离得到,化合物5为首次从滇重楼的根茎中分离得到。药理实验表明,化合物1—3,5和6对小鼠肺腺癌细胞LA795都显示出一定的抑制作用,其中化合物5和6最显著。展开更多
文摘A novel phenylpropanoid glycosides 1, named parispolyside E and a novel derivation of phenolic glycoside 2, named parispolyside G, as well as two known flavonoid glycosides were isolated from the rhizome of Paris polyphylla var. yunnanensis. Their structures were elucidaed by spectroscopic methods.
基金supported by grants from the National Natural Science Foundation of China (81473310, 31260075, 31560085)
文摘Paris polyphylla var. yunnanensis is an important medicinal plant with abundant saponins that are widely used in the pharmaceuticals industry. It is unclear why the levels of active ingredients increase as these plants age. We speculated that the concentrations of those components in the rhizomes are mediated by fungal endophytes. To test this hypothesis, we took both culture-dependent and-independent(metagenomics) approaches to analyze the communities of endophytic fungi that inhabit those rhizomes in plants of different age classes(four, six, and eight years old). In all, 147 isolates representing 18 fungal taxa were obtained from 270 segments(90 per age class). Based on morphological and genetic characteristics, Fusarium oxysporum(46.55% frequency of occurrence) was the predominant endophyte,followed by Leptodontidium sp.(8.66%) and Trichoderma viride(6.81%). Colonization of endophytic fungi was maximized in the eight-year-old rhizomes(33.33%) when compared with four-year-old(21.21%) and six-year-old(15.15%) rhizomes. Certain fungal species were present only at particular ages. For example,Alternaria sp., Cylindrocarpon sp., Chaetomium sp., Paraphaeosphaeria sporulosa, Pyrenochaeta sp., Penicillium swiecickii, T. viride, and Truncatella angustata were found only in the oldest plants. Analysis of(metagenomics) community DNA extracted from different-aged samples revealed that, at the class level,the majority of fungi had the highest sequence similarity to members of Sordariomycetes, followed by Eurotiomycetes and Saccharomycetes. These results were mostly in accord with those we obtained using culture methods. Fungal diversity and richness also changed over time. Our investigation is the first to show that the diversity of fungi in rhizomes of P. polyphylla var. yunnanensis is altered as plants age, and our findings provide a foundation for future examinations of useful compounds.
基金supported by the National Natural Science Foundation of China(No.81260622)Chongqing Natural Science Foundation Project(cstc2018jcyjAX0267).
文摘Paris polyphylla var.yunnanensis is a traditional Chinese medicinal plant,in which polyphyllin as the main medicinal component is an important secondary metabolite with bioactivity.Arbuscular mycorrhizal fungi(AMF)have multiple positive effects on plants,while it is not clear whether AMF increase the content of medicinal components in medicinal plants.In this study,a total of nine AMF treatments were laid to analyze the mycorrhizal effect on polyphyllin accumulation and PpHMGR and PpSE expression of P.polyphylla var.yunnanensis.AMF increased the content of polyphyllin in the cultivated variety with low relation to the increase of inoculation intensity.Polyphyllin I,II,and VII were identified and partly improved by AMF inoculation,dependent on AMF treatments and culture environments.Similarly,the PpHMGR and PpSE expression was induced by mycorrhization,dependent on AMF species,whilst the induction was more obvious in PpSE than in PpHMGR after mycorrhization.It concluded that the symbiotic relationship between P.polyphylla var.yunnanensis and AMF increased polyphyllin content level in the plant,which was associated with the up-regulation of PpSE transcripts.
基金This work was supported by the National Natural Science Foundation of China(81260622)Applied Basic Research Program of Yunnan Province(2011FB081)Scientific Research Fund Key Project of Yunnan Province(2012Z119).
文摘A field experiment was conducted to determine the effects of two commercial strains composed of mulple arbuscular mycorrhizal fungi(AMF)species on plant growth,antioxidant capacity,and medicine quality of Paris polyphylla var.yunnanensis in three subtropical soils from Wanzhou,Anshun and Baoshan in fields.The results showed that AMF inoculation enhanced the fungal colonization rate and activities of both succinate dehydrogenase and alkaline phosphatase,thereby,enhancing the mycorrhizal viability of P.polyphylla var.yunnanensis.The concentrations of photosynthetic pigments(chlorophyll a,b,a+b and carotenoids),soluble sugar,soluble protein and photosynthetic capacity were higher in AMF-inoculated plants than in non-AMF-treated plants in field.AMFtreated plants recorded higher activities of catalase,peroxidase and superoxide dismutase,and caused the reduction in malondialdehyde content,indicating lower oxidative damage,compared with non-AMF plants.Polyphyllin I,Polyphyllin II,Polyphyllin III,Polyphyllin IV and total polyphyllin contents were increased by AMF treatment.In conclusion,AMF improved the plant growth,antioxidant capacity and medicinal quality of P.polyphylla var.yunnanensis seedlings.Hereinto,AMF effects on the soil from Wanzhou was relatively greater than on other soils.
基金Sichuan Provincial Department of Science and Technology(2017SZYZF0004).
文摘In this study,the resource distribution,morphological characteristics,artificial cultivation and market circulation of Paris Polyphylla var.yunnanensis and its polygerm varieties in Yunnan were investigated by referring to the research literature,field investigation and our planting experience.It is found that P.polyphylla var.yunnanensis is widely distributed in Yunnan Province,realizing large-scale artificial cultivation,while the wild resources of polygerm varieties are almost on the verge of extinction and are in urgent need of protection.
文摘[Objective] This study aimed to isolate the endophytic fungi of Paris polyphylla var. yunnanensis and investigate their effects on the embryo development of P. polyphylla var. yunnanensis seeds. [Method] The endophytic fungi of P. polyphylla were isolated and identified morphologically, and their effects on the embryo development of P. polyphylla var. yunnanensis seeds were studied by using paraffin sectioning and microphotography. [Result] Nine endophytic fungi, i.e. P. polyphylla var. yunnanensis endophytic fungi PPYEF-1, PPYEF-2, PPYEF-3, PPYEF-4, PPYEF-5, PPYEF-6, PPYEF-7, PPYEF-8 and PPYEF-9 belonging to seven genera in five families, three orders were isolated from the rhizomes. Except PPYEF-4 (Cladosporium sp.), other fungi could promote the embryo development of the P. polyphylla var. yunnanensis seeds, mostly reaching the extremely significant or significant level. PPYEF-9 (Trichoderma sp.) resulted in the highest embryo length and embryo-emerging ratio. [Conclusion] This paper could provide a reference for the application of the endophytic fungi of P. polyphylla var. yunnanensis in the dormancy-breaking of P. polyphylla var. yunnanensis seeds.
基金Supported by Key Sci-Tech Project of Sichuan Provincial Science and Technology Department(2016FZ0045)Fundamental Research Funds for the Central Universities of Southwest Minzu University(2018NZD10)
文摘[Objectives] To determine the content of 10 kinds of inorganic elements(Pb,Cu,As,Cd,Hg,Zn,Fe,Mn,Sr and Cr) in samples of Paris polyphylla Smith var. yunnanensis( Franch.) Hand.-Mazz.( and polygerm varieties) produced in different areas. [Methods] The wet digestion and technique of inductively coupled plasma optical emission spectrometry( ICP-OES) were used. [Results] Under the experimental conditions,elements were not related to each other,and several kinds of elements could be measured at the same time. The content of Pb exceeding the standard only in sample S4 of P. polyphylla Smith var. yunnanensis( and polygerm varieties),Hg was not detected in all samples,and the rest heavy metals did not exceed the limit. [Conclusions] This study was expected to provide a certain reference for the development and utilization of P. polyphylla Smith var. yunnanensis( and polygerm varieties).
基金Supported by Key Sci-Tech Project of Sichuan Provincial Science and Technology Department(2016FZ0045)Fundamental Research Funds for the Central Universities of Southwest Minzu University(2018NZD10)
文摘[Objectives] To make original plant and microscopic identification and study the traits of Paris polyphylla Smith var. yunnanensis( Franch.) Hand.-Mazz.( polygerm varieties) produced in Gaoligong Mountain areas,and provide experimental data for their identification and application. [Methods] The original plant powder was used,and paraffin sections and physicochemical properties were identified. [Results]P. polyphylla Smith var. yunnanensis( polygerm varieties) produced in Gaoligong Mountain areas showed obvious microscopic features and physicochemical properties. [Conclusions] This study was expected to provide certain reference for identification of original plant and medicine and formulation of quality standard for P. polyphylla Smith var. yunnanensis( polygerm varieties) produced in Gaoligong Mountain areas,and provided basis for their further research and development.
文摘Paris polyphylla var. yunnanensis (Franch.), one of the best-known medicinal plants in China, has a dehiscent anther which physiologically work in pollination, however, the dehiscent anther always closes in response to darkness every day, and watering or raining every time. To explore this frequently closing and its unkown physiology, next-generation sequencing was performed, and the transcriptome was de novo assembled. RNA-sequencing was carried out in 15 samples including seven openning samples, four closed samples owing to darkness or watering, and tissue samples (leaf, petal, calyx, and stigma) were used for control. We obtained 72.75 GB data, assembled into 79,815 unigenes. Differentially expressed unigenes (DEGs) between opened and closed anther samples were 6231 and the DEGs between anther and control samples were 2831. Comparation between the two DEGs by KEGG enrichment showed that “plant hormone signal transduction” pathway is the most significant pathway for DEGs from closing anther vs. opening anther, and expression model of DEGs in the pathway might elicit change in germination and seed dormancy. Further examination of the action of the signal pathway on physiology showed “chromatin binding” function was prominent in “DNA binding” function of annotated DEGs between opened and closed anthers, of the 215 “chromatin binding” unigenes, 120 were involved in epigenetic silencing, and 50 of the epigenetic unigenes were directly related to germination or seed dormancy, strongly correlating anther closing to epigenetic modification and seed dormancy. These results were verified that at least three auxins involved in seed dormancy showed same expression patterns occurred in abnormal closing anther and seed embryo in Paris polyphylla var. yunnanensis. In conclusion, the information from transcriptome point out that frequent abnormal closing of dehiscent anthers possibly transfer the impact on seed dormancy, and epigenetic modification happened in closing may be the cause.
基金supported financially by the National Natural Science Foundation of China (Nos.82222072 and U1902214)Yunnan Key Research and Development Program (No.2019ZF011-2,China)the Research Project of Sichuan Province (2022JDJQ0055,China)。
文摘Sugar-sugar glycosyltransferases play important roles in constructing complex and bioactive saponins.Here,we characterized a series of UDP-glycosyltransferases responsible for biosynthesizing the branched sugar chain of bioactive steroidal saponins from a widely known medicinal plant Paris polyphylla var.yunnanensis.Among them,a 2'-O-rhamnosyltransferase and three 6'-O-glucosyltrasferases catalyzed a cascade of glycosylation to produce steroidal diglycosides and triglycosides,respectively.These UDP-glycosyltransferases showed astonishing substrate promiscuity,resulting in the generation of a panel of 24 terpenoid glycosides including 15 previously undescribed compounds.A mutant library containing 44 variants was constructed based on the identification of critical residues by molecular docking simulations and protein model alignments,and a mutant UGT91AH1^(Y187A)with increased catalytic efficiency was obtained.The steroidal saponins exhibited remarkable antifungal activity against four widespread strains of human pathogenic fungi attributed to ergosterol-dependent damage of fungal cell membranes,and 2'-O-rhamnosylation appeared to correlate with strong antifungal effects.The findings elucidated the biosynthetic machinery for their production of steroidal saponins and revealed their potential as new antifungal agents.
文摘目的:研究滇重楼Paris polyphylla Smith var.yunnanensis根茎中具有抗肿瘤作用的活性成分。方法:利用硅胶柱色谱,Sephadex LH-20,反相制备HPLC等手段进行分离纯化,并通过波谱技术进行结构鉴定。采用MTT法对分离到的化合物进行抗肿瘤活性筛选。结果:从醋酸乙酯和正丁醇层中分离得到了6个化合物,鉴定为薯蓣皂苷元-3—O-α-L-呋喃阿拉伯糖基(1→4)-β-D-葡萄糖苷(1)、偏诺皂苷元-3-O-α—L-呋喃阿拉伯糖基(1→4)-β-D-葡萄糖苷(2)、异鼠李素-3—O-β-D-葡萄糖苷(3)、乙基-α—D-呋喃果糖苷(4)、偏诺皂苷元-3—O-α—L-吡喃鼠李糖基(1→4)-[α-L-吡喃鼠李糖基(1→2)]-β-D-葡萄糖苷(5)、偏诺皂苷元-3—O-α—L-吡喃鼠李糖基(1→4)-α-L-吡喃鼠李糖基(1→4)-[α-L-吡喃鼠李糖基(1→2)]-β-D-葡萄糖苷(6)。结论:化合物1—4为首次从滇重楼中分离得到,化合物3和4为首次从重楼属植物中分离得到,化合物5为首次从滇重楼的根茎中分离得到。药理实验表明,化合物1—3,5和6对小鼠肺腺癌细胞LA795都显示出一定的抑制作用,其中化合物5和6最显著。