鼠尾草属药用植物及其近缘种的ITS序列分析

采用分子系统学方法分析鼠尾草属药用植物及其近缘种的遗传多样性，为准确进行基源鉴定、阐明本属内的种间关系及发现新的药用资源提供分子证据。本文从野外采集的27个鼠尾草属植物叶片样品中分离提取DNA，PCR扩增ITS区及5.8S rDNA完整序列并测序，采用Mega 3.1软件进行系统学分析。27个鼠尾草样品的ITS及5.8S rDNA区序列全长为612～617 bp，邻接法(neighbor-Joining)构建的系统发生树部分支持了形态学的属下划分，但对部分种的系统位置特别是三叶鼠尾草和黄花鼠尾草两个亚种的处理上与形态学划分存在明显的分歧。序列分析显示5.8S rDNA序列相当保守，而ITS区段则在亚属间差异明显，且原产我国的该属植物与欧美引进种明显具有不同起源。ITS系统树对于亚属和组的处理较为合理，但对组下的划分则表现出了信息量不足，需要其他相关证据的支持。ITS分析支持了丹参组内其他近缘种作为丹参类药材替代资源的合理性，同时也揭示了甘西鼠尾类高山丹参在遗传上与丹参类药材的显著不同。     

Cloning and nucleotide sequences of crotamine genes

A cDNA library containing snake toxin genes was constructed in bacteriophage lambda by using mRNA isolated from the glands of the South American rattlesnake, Crotalus durissus terrificus. The first high-density screening of 400,000 plaques for crotamine-containing genes yielded over 800 positives when a labeled cDNA probe with sequence homology to crotamine was used. Four of these clones with insert sizes from 270 to 400 base pairs were chosen and their inserts subcloned into pGEM-3Z and sequenced. Nucleotide sequence analysis of the cloned cDNAs predicted the existence of multiple variants of the crotamine toxin. The different forms, identified from the DNA sequences, displayed discrepancies in amino acid sequence for crotamine when compared with previously published reports. Direct amino acid sequencing of commercially purified crotamine and CNBr fragments thereof confirmed the structures predicted by the nucleic acid sequences.     

曼陀罗和毛曼陀罗花的最佳采收期评价

目的探索评价曼陀罗和毛曼陀罗花的最佳采收期的方法。方法将两种曼陀罗花的生长发育过程进行量化,与Logistic生长曲线方程拟合,建立数学模型,运用有序聚类分析法将其生长过程划分不同采收期,以活性成分为指标,对两者最佳采收期进行界定。结果两种曼陀罗花的生长过程与Logisitic生长曲线方程拟合良好,有序聚类分析后将其花的生长发育过程划分为5个阶段,依此确定的最佳采收期与以往研究中药材最佳采收期方法不同。结论该研究中药材最佳采收期的方法值得进一步研究并推广。     

Pharmacological screening of some Brazilian plants

Forty-five species of plants from several botanical families growing in North East Brazil have been examined for toxicity on mice and small fishes, cat blood pressure and respiration, isolated toad heart and rectus abdominis muscle, guinea-pig ileum, rabbit duodenum and rat uterus. A high toxicity to mice and fishes was exhibited by aqueous (A) and ethanolic (B) extracts from Luffa operculata, Peschiera affinis, Pithecelobium multiflorum (gall) and Zizyphus joazeiro and by extract B from Pithecelobium multiflorum (stembark). Cardiorespiratory activity was shown by Annona squamosa, Byrsonima sericea, Crataeva tapia, Erythrina velutina, Fagara rhoifolia, Operculina macrocarpa, Perschiera affinis, Pithecelobium multiflorum, Spondias lutea and Zizyphus joazeiro. Extracts A and B from Operculina macrocarpa and Pithecelobium multiflorum, extract A from Luffa operculata and Zizyphus joazeiro and extract B from Crataeva tapia and Peschiera affinis promoted a contraction of the toad rectus abdominis muscle. Both extracts from Annona aquamosa and Fagara rhoifolia (leaf) provoked a spasmogenic effect on guineapig ileum and a spasmolytic one on rabbit duodenum. Extracts A and B from Pithecelobium multiflorum, Vitex gardneriana and Zizyphus joazeiro exhibited a spasmogenic activity on both preparations, while extracts A and B from Peschiera affinis and extract B from Erythrina velutina also evidenced a spasmolytic activity on both preparations. Oxytocic activity was shown by both extracts from Annona squamosa, Byrsonima sericea, Pithecelobium multiflorum and Vitex gardneriana.     

Lipoxygenase inhibiting activity of some Malaysian plants

In this study 160 plant samples representing more than 30 plant families collected from the Malaysian forests were assessed for their ability to inhibit lipoxygenase activity. The lipoxygenase inhibiting activity was measured using the 96-well microplate-based ferric oxidation of xylenol orange (FOX) assay. The screening parameters, including z’ factor, indicated that the assay method adopted was robust and suitable for high-throughput screening. In the preliminary screen, four plant extracts displayed inhibitory activity of 70% or higher. The active plant extracts were isolated from Agelaea borneensis Merr. (Connaraceae) (bark) (IC₅₀, 1.6?μg/mL), Chisocheton polyandrus Merr. (Meliaceae) (bark) (3?μg/mL), Garcinia cuspidata King (Guttiferae) (bark) (28.3?μg/mL) and Timonius flavescens Baker (Rubiaceae) (leaf) (8.9?μg/mL).     

Antibacterial activity of some Indian medicinal plants

Aqueous extracts of ten medicinal plants were examined for their antibacterial potential against some reference strains of human pathogenic bacteria. Anethum graveolens, Elettaria cardamomum, Foeniculum vulgare, Trachyspermum ammi and Viola odorata were found to be better/equally effective compared to standard antibiotics. V. odorata was the most effective antibacterial with minimum inhibitory concentration values ranging from 1 to 2%. The results provide a scientific basis for the centuries-old usage of aqueous extracts of these medicinal plants.