Prenylated flavonoids of Erythrina lysistemon grown in Egypt

Three prenylated flavonoid derivatives; 5,7,4′-trihydroxy-8-(3-methylbut-2-enyl)-6-(2″-hydroxy-3″-methylbut-3″enyl) isoflavone (isoerysenegalensein E), 5,7,2′-trihydroxy-4′-methoxy-5′-(3″-methylbut-2″-enyl) isoflavanone (lysisteisoflavanone), 5, 4′-dihydroxy-6-(3-methylbut-2-enyl)-2″-hydroxyisopropyl dihydrofurano [4″,5″:8,7] isoflavone (isosenegalensin), together with the four known flavonoids abyssinone V-4′-methylether, alpinumisoflavone, wighteone and burttinone were isolated from the stem bark of Erythrina lysistemon Hutch. (Leguminosae). Structures were elucidated by spectroscopic methods.     

Effect on prolactin secretion of Echinacea purpurea, Hypericum perforatum and Eleutherococcus senticosus

It has been recently reported that prolactin (PRL) plays an important role in immune system regulation. In this study we investigated the activity of three natural drugs with immunomodulatory activity: Echinacea purpurea (EP), Hypericum perforatum (HP) and Eleutherococcus senticosus (ES) on PRL production. Male rats were orally treated with two different doses (30 and 100 mg/kg) of extract of these drugs for 3 or 15 days. A 3-day treatment was not able to modify PRL serum levels, whereas a 15-day treatment with EP and HP at the higher dose significantly inhibits PRL production. A treatment with ES was always ineffective. A possible mechanism for this effect could be that both HP and EP extracts display a direct dopaminergic activity, although an involvement of the GABA-ergic system cannot be excluded.     

Two flavonoids from tephrosia purpurea

Purpurenone, a new β-hydroxychalcone; (+)-purpurin, a diastereoisomer of(?)purpurin; dehydroisoderricin, and (?)-maackiain have been isolated from the roots of Tephrosio purpurea in addition to the earlier reported flavonoids [1, 2]. Pseudosemiglabrin was obtained in admixture with (?)-semiglabrin     

圆叶牵牛化学成分研究

圆叶牵牛植物资源丰富但全草少有研究,对其进行系统的化学成分与生物活性认识很有必要。该文对采自云南大理的圆叶牵牛干燥全草化学成分进行了系统地研究,通过75%乙醇冷浸提取,浸膏以水分散,依次以乙酸乙酯和正丁醇萃取。结果表明:采用硅胶、Sephadex LH-20、RP-18等多种材料柱层析结合重结晶等方法,从圆叶牵牛醇提物乙酸乙酯部分分离得到12个单体化合物,运用现代波谱学技术分别鉴定为木栓酮(1),β-木栓烷醇(2),β-香树脂醇(3),α-香树脂醇(4),6β-羟基豆甾-4-烯-3-酮(5),胡萝卜苷(6),β-谷甾醇(7),豆甾醇(8),7-羟基香豆素(9),对香豆酸-对羟基苯乙醇酯(10),山奈酚香豆酰基葡萄吡喃糖苷(11),单棕榈酸甘油酯(12)。化合物2-5、10-12为首次从该属植物中分离得到。     

青海高原紫花针茅草原群落数量分类与排序

紫花针茅草原是青藏高原高寒草原中分布面积最大、最重要的群落类型。该文选择青海高原典型紫花针茅草原为研究对象,在大量群落学调查的基础上,采用双向指示种分析(TWINSPAN)和典范对应分析(CCA)等多元数量分析方法研究了青海高原紫花针茅草原群落的数量分类。结果显示:(1)所调查的紫花针茅草原是物种组成相对较简单、菊科和禾本科植物最多、北温带分布的属为主体的草原群落。(2)青海高原紫花针茅草原的90条样带可划分为8个群丛类型:紫花针茅+川青早熟禾群丛、紫花针茅+矮嵩草群丛、紫花针茅+多枝黄芪群丛、紫花针茅+高山嵩草群丛、紫花针茅+二裂委陵菜群丛、紫花针茅+沙生凤毛菊群丛、紫花针茅+弱小火绒草群丛、紫花针茅+梭罗草群丛。(3)影响青海高原紫花针茅草原群丛分布的主要环境因子是空间因子(海拔、经度、纬度)和热量因子(温度),其次是湿润度、降雨量等水分因子。(4)对于紫花针茅草原群落内部的群丛划分,CCA可以补充矫正TWINSPAN等级分划,使分类结果更符合实际生态意义,更清晰地反映群丛类型与环境梯度之间的关系。     

尕海-则岔地区紫果云杉种群结构与动态特征

紫果云杉(Picea purpurea)为我国特有树种,为了解其种群生存现状及动态特征,以尕海-则岔自然保护区则岔沟的紫果云杉天然纯林为研究对象,通过样地调查和数据统计,绘制了种群结构图,编制了静态生命表,分析了存活曲线,运用生存分析理论与数量化分析法研究种群结构与动态,并运用时间序列模型对种群数量动态进行预测,以揭示本区域紫果云杉的种群结构与动态特征。结果表明,紫果云杉种群龄级结构、高度结构和冠幅结构总体均呈倒"J"型。种群自然更新能力强,幼苗、幼树储量丰富,前期有较高的死亡率,种群存活曲符合Deevey-Ⅲ型。生存分析也说明紫果云杉种群具有前期锐减,中、后期稳定的特点。竞争和自疏作用造成的幼苗、幼树存活率偏低是影响紫果云杉种群自然更新和结构的关键因素。种群动态指数Vpi0,表明种群属于增长型,V'pi趋近于0,表明该种群趋近于稳定型。时间序列预测分析表明,在未来2、4、6、8个龄级后,紫果云杉个体数均有所增加,种群呈一定的增长趋势。说明该保护区的成立使本区域紫果云杉种群得到了相对完整的保存,该种群适应当前的生存环境,能实现自然更新且仍有一定的增长潜力。紫果云杉种群更新主要受制于建成限制,幼苗、幼树存活率过低,可采取适当的人为干扰措施来促进种群更新与增长,而保护幼苗生存环境并提高幼苗质量和存活率才是种群更新和发展的关键。     

In vitro pathogenicity assay for the ergot fungus Claviceps purpurea

The pathogenic development of the biotrophic ergot fungus Claviceps purpurea is strictly limited to the ovary of grasses. Early colonization stages occur within a defined spatio-temporal course of events, including the directed growth to the vascular tissue for nutrient supply. To characterize mutant strains with putative defects in pathogenicity, the close observation of the infection pathway is therefore indispensable. Here, we describe the establishment of a new pathogenicity assay, based on the in vitro cultivation of isolated rye ovaries. The pathogenic development of a wild-type strain of C. purpurea was compared with the infection of mature rye flowers on whole plants. Up to the sixth day post inoculation, the route of infection within the isolated ovaries was maintained and temporally equal to that seen in mature flowers. Therefore, the in vitro pathogenicity assay is an effective alternative to the whole-plant infection tests, and suitable for detailed infection studies and screening high numbers of mutants for defects in early pathogenesis.     

川西亚高山不同年龄紫果云杉径向生长对气候因子的响应

运用树木年轮气候学的基本方法,建立王朗自然保护区紫果云杉在集中分布上限区域的年轮宽度年表,选取差值年表分析不同年龄云杉的径向生长同逐月气候因子的相关及响应关系,结果显示:幼龄组云杉年表的敏感度高于中龄组和老龄组云杉,幼龄组云杉对生长季前及生长季的气温状况显著正相关;中龄组云杉年表仅与当年4月份和7月份的月平均最低气温显著正相关;老龄组云杉的年轮宽度指数同上年生长季(上年8月份)的月平均气温和月平均最低温显著负相关,上年生长季高温的"滞后效应"在老龄组云杉体现的更为突出;幼龄组与中龄组云杉对当年6月份降水持续增加显示出明显的负相关关系,上年12月份的降水会对幼龄组和老龄组云杉径向生长不利。研究表明幼龄组云杉包含的气候信息要优于中龄组和老龄组云杉,在该区域进行相关研究时应根据研究需要选取不同年龄跨度的云杉年表。     

紫鸭跖草热激转录因子基因家族鉴定及在Cu2+胁迫下表达模式分析

热激转录因子(Hsf)是植物中最重要的转录因子家族之一,在植物遭遇热、干旱和重金属等多种非生物胁迫中具有重要的作用。为明确紫鸭跖草Hsf基因家族的结构及功能,从紫鸭跖草全长转录组数据库筛选鉴定出20个SpbHsf基因,并运用生物信息学工具和qRT-PCR进行分析。结果显示:SpbHsf蛋白均为亲水性蛋白,定位于细胞核的SpbHsf蛋白有12个,所有SpbHsf蛋白二级结构的α螺旋和无规卷曲的含量较高。SpbHsf基因分为3个亚族,各亚族都包含独特的保守基序。全部SpbHsf蛋白含有DBD和HR-A/B结构域。系统进化分析显示,与SpbHsf蛋白同源性最高的是水稻OsHsf蛋白。20个SpbHsf基因在紫鸭跖草根组织中均有表达。相比于对照组,根组织在Cu²⁺胁迫下,8个SpbHsf基因的表达量显著上调,8个SpbHsf基因的表达量显著下调。研究结果为紫鸭跖草Hsf基因家族的功能验证及表达模式提供了一定的理论参考。     

洮河上游紫果云杉群落土壤种子库特征及其与地上植被的关系

该研究以甘肃洮河国家级自然保护区大峪沟林区(TH)、冶力关林区(YLG)、尕海-则岔国家级自然保护区则岔林区(GZ)的紫果云杉(Picea purpurea)天然林群落为研究对象,通过样地调查与萌发实验,分析洮河上游紫果云杉群落土壤种子库特征,以揭示洮河上游紫果云杉群落土壤种子库特征及与地上植被的关系,为紫果云杉群落恢复和管理提供依据。结果表明:(1)3个林区土壤种子库共萌发27科45属50种植物,种子库密度在958~1129粒/m²之间,草本植物是构成研究区土壤种子库的主体。(2)3个林区紫果云杉群落土壤种子库垂直结构明显,物种数及种子密度随土层的加深呈减少趋势。(3)3个林区地上植被物种数大于土壤种子库物种数,相似性系数在0.15~0.23之间,表现为极不相似性;土壤种子库的多样性指数除Pielou指数高于地上植被外,Margalef指数、Shannon-Wiener指数、Simpson指数均低于地上植被。研究认为,洮河上游紫果云杉群落土壤种子库以草本植物为主,乔木和灌木的储量较小,特别是建群种紫果云杉的储量较小;地上植被和土壤种子库之间相互的贡献力较低,仅依靠紫果云杉林土壤种子库进行自然恢复,远不能缓解现阶段紫果云杉林退化的问题,因此需开展人工育苗、造林等措施来促进紫果云杉的更新与发展。     

Yojironins E-I, prenylated acylphloroglucinols from Hypericum yojiroanum

Five new prenylated acylphloroglucinols, yojironins E-Ι (1-5), were isolated from the whole plants of Hypericum yojiroanum. Their structures were elucidated by spectroscopic data. Yojironin E (1) exhibited antimicrobial activity against Aspergillus niger, Candida albicans, Cryptococcus neoformans, and Trichophyton mentagrophytes.     

Antimicrobial and cytotoxic activity of 18 prenylated flavonoids isolated from medicinal plants: Morus alba L., Morus mongolica Schneider, Broussnetia papyrifera (L.) Vent, Sophora flavescens Ait and Echinosophora koreensis Nakai

Antimicrobial activity of the 18 prenylated flavonoids, which were purified from five different medicinal plants, was evaluated by determination of MIC using the broth microdilution methods against four bacterial and two fungal microorganisms (Candida albicans, Saccaromyces cerevisiae, Escherichia coli, Salmonella typhimurium, Staphylococcus epidermis and S. aureus). Papyriflavonol A, kuraridin, sophoraflavanone D and sophoraisoflavanone A exhibited a good antifungal activity with strong antibacterial activity. Kuwanon C, mulberrofuran G, albanol B, kenusanone A and sophoraflavanone G showed strong antibacterial activity with 5–30 μg/ml of MICs. Morusin, sanggenon B and D, kazinol B, kurarinone, kenusanone C and isosophoranone were effective to only gram positive bacteria, and broussochalcone A was effective to C. albicans. IC₅₀ values of papyriflavonol A, kuraridin, sophoraflavanone D, sophoraisoflavanone A and broussochalcone A in HepG2 cells were 20.9, 37.8, 39.1, 22.1, and 22.0 μg/ml, respectively. These results support the use of prenylated flavonoids in Asian traditional medicine to treat microbial infection and indicate a high potential for prenylated flavonoids as antimicrobial agents as well as anti-inflammatory agents.     

紫花针茅根际和体内真菌群落结构及与土壤环境因子的相关性研究

[目的] 探究青藏高原不同地区高寒草原紫花针茅根际和体内真菌群落的组成、多样性等特征,及与土壤环境因子（理化性质和酶活性）间的相互关系。[方法] 从青藏高原不同地区采集紫花针茅样品,应用土壤化学方法分析根际土壤理化性质和酶活性,并采用Illumina Miseq高通量测序技术,解析根际土壤和体内真菌群落组成和丰度、Alpha多样性和菌群结构,同时分析了紫花针茅根际真菌种群多样性与土壤环境因子的相关性,厘清了影响紫花针茅根际真菌区系的土壤环境因素。[结果] 三个采样地的根际土壤呈中性偏碱,土壤理化性质和酶活性变化各异。高通量测序共得到314801条有效序列和4491个OTUs;XZ样地的紫花针茅真菌多样性和丰富度相对偏低,GS样地最高。在门分类水平上,子囊菌门Ascomycota和担子菌门Basidiomycota是主要内生真菌类群,占总菌群的88.28%。不同采样地区紫花针茅体内真菌群落结构存在明显差异,而根际土壤真菌群落结构差异不大。相关性分析表明,紫花针茅真菌多样性与土壤pH、有效钾、铁、钙、镁、多酚氧化酶、过氧化物酶和脱氢酶呈显著（P<0.05）或极显著（P<0.01）正相关,而与海拔、土壤酸性磷酸酶呈极显著负相关。RDA分析发现,紫花针茅根际土壤真菌不同,影响的土壤环境因子也不同。[结论] 青藏高原高寒草地紫花针茅根际和体内栖息着丰富的真菌群落,其组成和多样性受多种土壤环境因子影响,且影响不同真菌群落的主要土壤环境因子也不同。本研究对于有益微生物资源的开发、利用及保护具有重要意义,并为紫花针茅草原保育和合理开发利用提供科学依据。     

基于GIS和MaxEnt模型分析气候变化背景下紫果云杉的潜在分布区

该研究收集到紫果云杉的108处数字化标本信息及野外调查采集分布点数据,筛选出13个环境变量,利用CMIP6提供的未来2个时期3种气候情景模式数据,采用MaxEnt模型和GIS技术分析不同时期分布区变化,绘制影响紫果云杉生长的主要环境因子的响应曲线,定量描述适宜紫果云杉生长、生存的环境条件.结果表明:(1)MaxEnt模...     

Two prenylated flavonoids from the stem bark of Erythrina burttii

From the stem bark of Erythrina burttii, a new isoflavone, 5,2',4'-trihydroxy-7-methoxy-6-(3-methylbut-2-enyl)isoflavone (trivial name, 7-O-methylluteone) and a new flavanone, 5,7-dihydroxy-4'-methoxy-3'-(3-methylbutadienyl)-5'-(3-methylbut-2-enyl)flavanone (trivial name, burttinonedehydrate) along with three known isoflavonoids (8-prenylluteone, 3-O-methylcalopocarpin and genistein) were isolated. The structures were determined on the basis of spectroscopic evidence.     

Antiparasitic activity of prenylated benzoic acid derivatives from Piper species

Fractionation of dichloromethane extracts from the leaves of Piper heterophyllum and P. aduncum afforded three prenylated hydroxybenzoic acids, 3-[(2E,6E,10E)-11-carboxy-3,7,15-trimethyl-2,6,10,14-hexadecatetraenyl)-4,5-dihydroxybenzoic acid, 3-[(2E,6E,10E)-11-carboxy-13-hydroxy-3,7,15-trimethyl-2,6,10,14-hexadecatetraenyl]-4,5-dihydroxybenzoic acid and 3-[(2E,6E,10E)-11-carboxy-14-hydroxy-3,7,15-trimethyl-2,6,10,15-hexadecatetraenyl]-4,5-dihydroxybenzoic acid, along with the known compounds, 4,5-dihydroxy-3-(E,E,E-11-formyl-3,7,15-trimethyl-hexadeca-2,6,10,14-tetraenyl)benzoic acid (arieianal), 3,4-dihydroxy-5-(E,E,E-3,7,11,15-tetramethyl-hexadeca-2,6,10,14-tetraenyl)benzoic acid, 4-hydroxy-3-(E,E,E-3,7,11,15-tetramethyl-hexadeca-2,6,10,14-tetraenyl)benzoic acid, 3-(3,7-dimethyl-2,6-octadienyl)-4-methoxy-benzoic acid, 4-hydroxy-3-(3,7-dimethyl-2,6-octadienyl)benzoic acid and 4-hydroxy-3-(3-methyl-1-oxo-2-butenyl)-5-(3-methyl-2-butenyl)benzoic acid. Their structures were elucidated on the basis of spectroscopic data, including homo- and heteronuclear correlation NMR experiments (COSY, HSQC and HMBC) and comparison with data reported in the literature. Riguera ester reactions and optical rotation measurements established the compounds as racemates. The antiparasitic activity of the compounds were tested against three strains of Leishmania spp., Trypanosoma cruzi and Plasmodium falciparum. The results showed that 3-(3,7-dimethyl-2,6-octadienyl)-4-methoxy-benzoic acid exhibited potent and selective activity against L. braziliensis (IC₅₀ 6.5 μg/ml), higher that pentamidine used as control. Moreover, 3-[(2E,6E,10E)-11-carboxy-3,7,15-trimethyl- 2,6,10,14-hexadecatetraenyl)-4,5-dihydroxybenzoic acid and 4-hydroxy-3-(3-methyl-1-oxo-2-butenyl)-5-(3-methyl-2-butenyl)benzoic acid showed moderate antiplasmodial (IC₅₀ 3.2 μg/ml) and trypanocidal (16.5 μg/ml) activities, respectively.     

洮河上游不同海拔紫果云杉根际与非根际土壤细菌多样性及影响因子

【背景】紫果云杉天然林在维护洮河上游生态环境安全方面发挥着重要作用,不同海拔梯度如何影响紫果云杉根际与非根际细菌多样性、土壤养分因子及三者之间的相关性尚不清楚。【目的】深入探索紫果云杉根际与非根际土壤细菌群落结构组成及受控因子。【方法】采用Illumina Miseq平台对洮河上游不同海拔紫果云杉天然林根际与非根际土壤细菌进行测序分析,分析土壤理化因子与细菌多样性随海拔的变化趋势,并通过相关性与冗余分析探究环境因子对细菌群落的影响。【结果】土壤养分因子随海拔升高呈先增加后降低趋势;根际土养分因子组间差异显著(P<0.05),非根际组间差异不显著(P>0.05)。随海拔升高根际微生物物种多样性指数(H)、均匀度指数(E)、丰富度指数(Chao1/ACE)和OTU数目呈单峰型变化趋势;非根际多样性指数随海拔升高呈双峰型变化趋势。土壤细菌多样性与养分因子密切相关,其中有机质、全氮和碱解氮呈显著正相关(P<0.05),而土壤pH和有效磷与细菌多样性呈负相关但不显著(P>0.05)。不同海拔梯度下紫果云杉天然林细菌群落结构一致性较高,从30个样本中获得7 159个细菌OTU,注释到37个门;细菌优势类群为放线菌门、变形菌门、酸杆菌门和绿弯菌门。不同细菌门对土壤养分因子的响应各不相同,有机质、全氮和碱解氮与变形菌门呈显著正相关(P<0.05)。【结论】土壤理化因子能够显著影响紫果云杉根际与非根际细菌多样性和组成,海拔和水热条件等环境因子对植物和土壤的驱动影响是细菌群落结构稳定组成的重要原因。本研究有助于深入理解紫果云杉天然林土壤细菌多样性的变化和驱动机制,为洮河上游天然林恢复与生态恢复提供借鉴。     

洮河自然保护区大峪沟林区紫果云杉群落木本植物种群生态位特征

基于群落调查数据,以样地代表多种资源的综合状态,物种重要值作为生态位的计测指标,利用Levins和Shannon生态位宽度,Schoener生态位相似和Pianka生态位重叠对洮河自然保护区大峪沟林区的紫果云杉群落木本植物种群生态位进行定量研究。结果表明：紫果云杉群落乔木层共有树种8种,隶属于4科6属,紫果云杉占绝对优势,岷江冷杉为次优势种;灌木层共有植物50种,隶属于16科25属,忍冬科的蓝靛果、葱皮忍冬和唐古特忍冬等以及蔷薇科的峨眉蔷薇和银露梅等构成了灌木层的主体,紫果云杉幼苗优势不明显,但生态位宽度最大。本研究表明,生态位宽度受物种生态特性及其分布和生境共同影响,重要值大的物种生态位宽度一般较大,生态位宽度大的物种之间生态位相似性和重叠性一般较大,并与其它物种重叠的概率高、重叠程度大,生态位宽度小的物种集中出现时也会出现较大的生态位重叠,同科或同属的物种间常有较大生态位相似和重叠。生态位宽度反映着种群的扩散潜力,生态位相似反映着群落的稳定性,生态位重叠反映着物种间存在或潜在的竞争程度。紫果云杉在乔、灌木层均有最大的生态位宽度,生态适应性最强,群落结构稳定,具有进一步扩散的可能。     

Seven new triterpene glycosides from the pericarps of Stryphnodendron fissuratum

Seven new triterpene glycosides on the basis of the lupane skeleton (1–7) were isolated from the pericarps of Stryphnodendron fissuratum (Leguminosae). The structures of 1–7 were determined on the basis of extensive spectroscopic analysis, including two-dimensional NMR data, and the results of hydrolytic cleavage.     

Prenylated flavonoids of Erythrina lysistemon grown in Egypt

Three prenylated flavonoid derivatives; 5,7,4′-trihydroxy-8-(3-methylbut-2-enyl)-6-(2″-hydroxy-3″-methylbut-3″enyl) isoflavone (isoerysenegalensein E), 5,7,2′-trihydroxy-4′-methoxy-5′-(3″-methylbut-2″-enyl) isoflavanone (lysisteisoflavanone), 5, 4′-dihydroxy-6-(3-methylbut-2-enyl)-2″-hydroxyisopropyl dihydrofurano [4″,5″:8,7] isoflavone (isosenegalensin), together with the four known flavonoids abyssinone V-4′-methylether, alpinumisoflavone, wighteone and burttinone were isolated from the stem bark of Erythrina lysistemon Hutch. (Leguminosae). Structures were elucidated by spectroscopic methods.