红豆属植物化学成分及其药理活性研究进展

豆科红豆属Ormosia Jacks.植物共有135种,中国有35种,2变种,2变型,主要分布于福建、广东、广西、云南等地,具有较高的药用价值。目前,红豆属植物中已发现的化学成分主要有生物碱类、黄酮类、三萜类及其他类型化合物,具有良好的抗氧化、抗癌、杀虫、抑菌等药理活性。对红豆属植物的化学成分及药理活性进行综述,为进一步开发该属药用植物资源和有效物质基础提供理论依据。     

国内外中草药吡咯里西啶类生物碱控制情况浅析

吡咯里西啶生物碱(PAs)是一类分布广泛的植物性毒素,具有1,2位双键结构和7、9位酯基取代的PAs具有较强肝毒性(HPAs),其在国内外食品、中草药中的控制得到广泛关注。本文重点阐述蜂蜜、茶产品、中草药等不同产品中PAs前处理方法、检测方法以及相关控制要求,为多种中药材和其他产品中PAs的检测和控制提供参考依据。     

Box-Behnken效应面法优化龙葵中总生物碱的提取工艺

目的 优选龙葵中总生物碱的提取工艺。方法 采用单因素试验结合Box-Behnken 效应面法,以总生物碱提取率为指标,考察乙醇体积分数、料液比、提取时间、提取次数等因素对提取工艺的影响,采用酸性染料比色法,利用紫外分光光度计测定总生物碱的含量。结果 确定龙葵中总生物碱提取的最佳工艺条件：乙醇体积分数为63.72%,料液比为1∶41.23,提取时间为54.93 min,提取2次,总生物碱提取率为1.40 mg·g^-1。结论 Box-Behnken 效应面法用于龙葵中总生物碱提取工艺条件的优选是可行的,模型预测效果较好。     

蔓荆子生物碱体外化学模拟抗氧化活性的研究

目的：研究蔓荆子生物碱体外抗氧化的活性。方法：运用Fenton体系和邻苯三酚自氧化法评价蔓荆子生物碱体外抗氧化的能力,采用多元线性回归分析生物碱浓度与抗氧化活性的相关性。结果：蔓荆子生物碱对—OH和O2-清除能力与其浓度呈明显的量效关系;其生物碱浓度与对—OH清除能力呈正相关,与对O^2-清除能力呈负相关。结论：蔓荆子生物碱具有较强的抗氧化能力,是1种天然有效的抗氧化剂。     

蛴螬生物碱提取工艺及体内外抗肿瘤活性研究

目的研究蛴螬生物碱的提取工艺并对其抗肿瘤活性进行评价。方法采用单因素实验和L9(34)正交实验得到最佳提取蛴螬生物碱的方法;采用MTT和荷瘤小鼠抑瘤率的方法测定生物碱的体内外抗肿瘤活性。结果最佳提取工艺为蛴螬粗粉用体积分数95%乙醇浸泡提取24h;蛴螬生物碱对体内外肿瘤细胞有明显抑制作用,且具有质量浓度依赖性。结论蛴螬粗粉用体积分数95%乙醇浸泡24h提取,浓缩浸膏经过酸化萃取得到的生物碱抗肿瘤活性显著。     

Diversification of Ergot Alkaloids in Natural and Modified Fungi

Several fungi in two different families––the Clavicipitaceae and the Trichocomaceae––produce different profiles of ergot alkaloids, many of which are important in agriculture and medicine. All ergot alkaloid producers share early steps before their pathways diverge to produce different end products. EasA, an oxidoreductase of the old yellow enzyme class, has alternate activities in different fungi resulting in branching of the pathway. Enzymes beyond the branch point differ among lineages. In the Clavicipitaceae, diversity is generated by the presence or absence and activities of lysergyl peptide synthetases, which interact to make lysergic acid amides and ergopeptines. The range of ergopeptines in a fungus may be controlled by the presence of multiple peptide synthetases as well as by the specificity of individual peptide synthetase domains. In the Trichocomaceae, diversity is generated by the presence or absence of the prenyl transferase encoded by easL (also called fgaPT1). Moreover, relaxed specificity of EasL appears to contribute to ergot alkaloid diversification. The profile of ergot alkaloids observed within a fungus also is affected by a delayed flux of intermediates through the pathway, which results in an accumulation of intermediates or early pathway byproducts to concentrations comparable to that of the pathway end product.     

Ergot Alkaloids Produced by Endophytic Fungi of the Genus Epichlo?

The development of fungal endophytes of the genus Epichloë in grasses results in the production of different groups of alkaloids, whose mechanism and biological spectrum of toxicity can differ considerably. Ergot alkaloids, when present in endophyte-infected tall fescue, are responsible for “fescue toxicosis” in livestock, whereas indole-diterpene alkaloids, when present in endophyte-infected ryegrass, are responsible for “ryegrass staggers”. In contrast, peramine and loline alkaloids are deterrent and/or toxic to insects. Other toxic effects in livestock associated with the consumption of endophyte-infected grass that contain ergot alkaloids include the “sleepy grass” and “drunken horse grass” diseases. Although ergovaline is the main ergopeptine alkaloid produced in endophyte-infected tall fescue and is recognized as responsible for fescue toxicosis, a number of questions still exist concerning the profile of alkaloid production in tall fescue and the worldwide distribution of tall fescue toxicosis. The purpose of this review is to present ergot alkaloids produced in endophyte-infected grass, the factors of variation of their level in plants, and the diseases observed in the mammalian species as relate to the profiles of alkaloid production. In the final section, interactions between ergot alkaloids and drug-metabolizing enzymes are presented as mechanisms that could contribute to toxicity.     

薏苡叶总碱抗氧化研究

目的:研究广西薏苡叶总碱的抗氧化性,为薏苡叶的开发利用提供参考依据。方法:以75%乙醇为溶剂提取薏苡叶中的总碱类物质,采取比色法测定薏苡叶总碱对DPPH·、O2-和·OH 3三种自由基的清除作用以及对Fe3+还原能力。结果:薏苡叶有较强的清除作用及还原Fe3+能力。结论:清除率与浓度存在明显的量效关系,当总碱浓度为0.50 mg/ml时,其清除率O2-·为43.5%,DPPH·为69.2%,·OH为11.2%;还原Fe3+能力随总碱的浓度增加而增强。     

Three new Lycopodium alkaloids from Lycopodium japonicum

Three new Lycopodium alkaloids (1–3), together with 15 known alkaloids, were isolated from club moss Lycopodium japonicum. Their structures were determined by extensive spectroscopic analysis, including 1D and 2D NMR spectra. Compound 1 has an unusual β-oriented methyl group substituted at C-15 and an α-hydroxy cyclopentenone moiety. All new alkaloids were evaluated for the inhibition of T-type calcium channel.