植物低聚糖提取和生物活性鉴定

应用酶解法从小麦细胞壁中提取出低聚糖。经过活性鉴定,具有诱导大豆和小麦抗毒素产生,特别是从小麦代谢、细胞、植株等水平上改善该作物体内防御功能等生物作用。水解酶的种类、纯度、酶活值与所降解低聚糖的活性程度密切相关;高纯度、高酶活单位的水解酶提取的低聚糖,具有较强的生物功能。对来源不同的低聚糖进行了活性差异的比较,同时还讨论了其它因素——诸如小麦细胞的生理状态,低聚糖保存条件等对低聚糖活性的影响。     

水稻纹枯病菌粗毒素提取及活性初步研究

[目的]研究水稻纹枯病菌的致病机制及毒素的活性成分。[方法]将水稻纹枯病菌Rhizoctoniasolani在改良Richard培养基中培养,培养滤液经离心、灭菌、活性炭粒吸附层析、甲醇洗脱、蒸馏水洗脱、浓缩得培养液粗提物、甲醇粗提物以及水粗提物,并对3种粗提物进行活性测定。[结果]3种粗提物均为黄褐色膏状物;活性测定表明,3种粗提物对水稻胚根、胚芽都有明显的生长抑制作用,对水稻4叶期幼苗都有致萎作用,对水稻离体叶片也有不同程度的毒害作用,能产生与病原茵侵染类似的云纹状褪绿斑。[结论]水稻纹枯病茵毒素的活性组分可能有多种成分。     

A new anxiolytic fatty acid from Aethusa cynapium

The present investigation was carried out with a view to separate bioactive constituent from Aethusa cynapium. Bioactivity guided fractionation of the anxiolytic methanol extract has led to the isolation of a novel unsaturated fatty acid. Structure of the acid characterized by UV, IR, 1H NMR, C13 NMR, MS techniques was found to be trideca-7, 9, 11-trienoic acid. Antianxiety activity was confirmed using the mCPP-induced hypolocomotion test. This new fatty acid—trideca-7,9,11-trienoic acid, isolated from A. cynapium was found to be responsible for the antianxiety activity of the plant.     

Resources and bioactive substances from Taiwania (<Emphasis Type="Italic">Taiwania cryptomerioides</Emphasis>)

 Taiwania (Taiwania cryptomerioides Hayata), native to Taiwan, is one of the most economically important tree species grown there. In this article we summarize the current results of phytochemistry and bioactivity of Taiwania extracts, including antifungal, antitermite, antibacterial, and antimite activities as well as cytotoxicity against three tumor cells. The resources of Taiwania are also addressed. Received: January 23, 2002 / Accepted: March 8, 2002 Acknowledgment The authors thank the National Science Council of R.O.C. for financial support (NSC-90-2313-B-002-344). Correspondence to:S.-T. Chang     

芽孢杆菌非核糖体肽的研究进展

芽孢杆菌产生的非核糖体肽主要有脂肽、多肽、线状聚酰胺物等类型,其生物合成是通过“硫模板多聚酶机制(th iotemp late mu ltienzym e m echan ism)”的多功能酶复合系统进行的,并经甲基化、酰基化、糖基化、杂环化和环化等进一步修饰而成。特殊的生物合成机制决定了非核糖体肽具有氨基酸组成及分子形式复杂、分子量较小、理化性质稳定、生物活性多样等特点,同时表现出了对病原微生物不同的抑、杀菌机制。非核糖体肽作为人类丰富的新型抗菌药物资源,在植物病害的生物防治、人类和动物疾病的治疗等方面显示了诱人的前景。研究芽孢杆菌及其产生的非核糖体肽在蚕业上的应用,有利于绿色、生态蚕业的发展。     

蓼属植物的黄酮类化合物研究

蓼（Polygonum）是蓼科中的一个药用大属。本文综述了近年来国内外对蓼属植物的黄酮类化合物及其生物活性的研究概况。     

生防菌HB-2发酵液中活性代谢产物的抑菌作用及理化性质

用不同极性溶剂青花椒(Zanthoxylum bungeanume Sieb.et Zucc)的提取物对小菜蛾(Plutella xylostella L.)的生物活性进行了初步测定。结果表明,氯仿为溶剂的提取物对小菜蛾具有较高的杀卵和对幼虫的触杀作用;以石油醚为溶剂的提取物对幼虫有较高的胃毒作用;4种溶剂提取物对小菜蛾的化蛹率、蛹重及羽化率的影响不显著。此结论对杀虫植物青花椒的进一步研究利用有重要意义。     

Induction of a viable but not culturable (VBNC) state in some Pseudomonas syringae pathovars upon exposure to oxidation of an apoplastic phenolic,acetosyringone

Acetosyringone is a phenolic metabolite often found in plant apoplasts. Its oxidation by hydrogen peroxide and peroxidase results in a prolonged increase in the redox potential of the reaction mixture, similar to redox increases observed in tobacco suspension cells upon treatment with incompatible bacteria. Since high redox potentials, being oxidative, are generally detrimental to bacteria, the effect of acetosyringone oxidation on bacterial viability was examined. Pseudomonas syringae pv. syringae was added to reaction mixtures containing acetosyringone, hydrogen peroxide and peroxidase and samples were removed to determine viability by dilution plating. Initial studies were done with low bacterial concentrations, 10⁵ CFU ml⁻¹, to ensure that scavenging of H₂O₂ was negligible and did not interfere with the reaction mixture. No colonies were formed by bacteria that had been added to reaction mixtures with acetosyringone ranging from 25 to 100 μΜ. Examination of the bacteria by microscopy and flow cytometry, using fluorescent stains that indicate bacterial membrane integrity, suggested that these bacteria had maintained their membrane integrity. In addition they were able to respire based on oxygen uptake. When bacteria were added to on-going reaction mixtures at a time point after the prolonged redox response, the CFU ml⁻¹ increased indicating that a stable reaction product was not responsible for the non-culturability bioactive effect. Other bacterial isolates, P. s. pv. tabaci and Pseudomonas fluorescens, were less susceptible to the bioactive effect of the acetosyringone oxidation. Other phenolics were tested and had lesser degrees of bioactivity and in some cases reduced the bioactivity of acetosyringone oxidation. The ‘viable but non-culturable’ (VBNC) state of the bacteria in this study is compared to that described for other medical and plant pathogens.     

金耳糖肽胶囊的基础药理学研究

药理学研究表明,金耳糖肽胶囊能 抗动物 肝损伤、保护肝细胞、降低转氨酶,其作用明显优于对照组（P＜0.05）,还能调节动物细胞生物活性,提高机体的代谢水平,增强免疫力,与对照组相比差异显著（P＜0.05）。此外,金耳糖肽可提高动物的应激能力,说明该胶囊主要是通过保护肝细胞,调节或稳定细胞功能活动,提高免疫力和机体的应激能力来防治肝炎等慢性疾病的。     

辣蓼粗提物对茶尺蠖的生物活性

辣蓼（Polygonum hydropiper L）粗提物对茶尺蠖3龄幼虫的室内生物活性测定结果表明,以95％的酒精为溶剂的辣蓼提取物效果最佳。在触杀试验中,95％酒精提取物处理后3d和7d的校正死亡率分别达到了44.22％和52.40％,乙酸乙酯提取物在3d和7d后校正死亡率也达到了29.25％和31.97％;非选择性拒食作用结果表明,95%的酒精提取物具有良好的拒食效果,12h和24h的拒食率分别达到了90.29％和84.15%。