甜菜树属--我国云南产山柚子科一原始新属及其植物地理学意义

报道了我国云南红河流域山柚子科的一个原始新属－－甜菜树属,该属具大型圆锥花序,两性,是Ｌｅｐｉｏｎｕｒｕｓ,Ｍｅｌｉｅｎｔｈａ和Ｃｈａｍｐｅｕｅｉａ３个单型属的祖型,远远无疑起源于康滇古陆即今之云南高原,其发现对山柚子科的起源分化具重要意义。     

基于叶绿体DNA trnL内含子序列数据的檀香目科间系统发育关系的研究

应用叶绿体DNAtrnL内含子序列分析檀香目科间的系统发育关系。取样研究的檀香目个体的trnL内含子序列长度在科间呈现较大差异(从291bp到587bp)。最大简约性分析产生的严格一致树与以前已发表的基于其它基因的檀香目的分子系统学研究结果大体一致。香芙木属(铁青树科)是最早分支出的类群：桑寄生科、槲寄生科分别表现为单系类群,檀香科为并系;桑寄生科和槲寄生科并不具密切亲缘关系,槲寄生科从檀香科内衍生出来。本研究表明,具相对高的核苷酸替换率的叶绿体DNAtrnL内含子序列可为高等级类群系统发育关系的研究提供更多的信息位点。     

Flavonol glycosides and lignans from the leaves of Opilia amentacea

Two previously undescribed flavonol tetraglycosides, isorhamnetin-3-O-α-l-rhamnopyranosyl-(1→6)-β-d-galactopyranosyl-(1→4)-α-l-rhamnopyranosyl-(1→6)-β-d-glucopyranoside (1) and isorhamnetin-3-O-α-l-rhamnopyranosyl-(1→6)-β-d-galactopyranosyl-(1→4)-α-l-rhamnopyranosyl-(1→6)-β-d-galactopyranoside (2), along with nine known compounds including seven flavonoids and two lignans, were isolated from the leaves of Opilia amentacea Roxb (Opiliaceae). Their structures were established on the basis of spectroscopic analysis. The DPPH radical scavenging activity of compounds 1–11 was evaluated. In addition, all compounds were evaluated for their tyrosinase inhibitions by using in vitro mushroom tyrosinase assay. Only 5,5-dimethoxylariciresinol-4-O-β-d-glucopyranoside (10) and eleutheroside E1 (11) exhibited significant tyrosinase inhibition (IC₅₀ 42.1 and 28 μM, respectively) and DPPH radical scavenging activity (IC₅₀ 85.1 and 42.1 μM, respectively) compared with the positive controls.