甘肃产毛叶香茶菜二萜成分及其化感潜能评估

Chemical constituents and allelopathic potential of Isodon japonica(Burman f.) Hara

采用硅胶柱色谱法对甘肃产毛叶香茶菜化学成分进行了分离,通过波谱学方法对分离得到的化合物进行结构鉴定,共鉴定出5个对映-贝壳杉烷型二萜化合物:RabdosinB(Ⅰ),Rabdosinate(Ⅱ),Epinodosin(Ⅲ),Epinodosinol(Ⅳ)和Lasiokaurin(Ⅴ);并对其粗提物及单体化合物Epinodosin进行了生物活性测试.结果表明:粗提物对莴苣和黑麦草种子的萌发表现为延迟作用,对苗高和根长表现出较强的生长抑制作用.化合物Epinodosin对莴苣幼苗根生长有显著的"低促高抑"作用.根尖压片技术显示:低浓度(25-100μmol.L-1)的促进作用与根尖细胞有丝分裂活性成正相关;高浓度(150-200μmol.L-1)的抑制作用与根尖细胞有丝分裂指数成负相关.该类化合物很有可能作为一种潜在的化感物质在其自然生境中发挥着重要的生态学作用.

Chemical constituents of Isodon japonica （Burman f.）Hara are isolated by silica gel column chromatography and the structures are elucidated by spectral analysis. Five compounds （ent-kaurene diterpenoid） are isolated and identified as Rabdosin B（ I ）, Rabdosinate（ II ）, Epinodosin（III）, Epinodosinol（IV） and Lasiokaurin（ V ）, respectively. Effects of the CHCl3 extracts and EtOAc extracts of Isodon japonica on the germination and seedling growth in lettuce and ryegrass plants are both determined by bioassay. The results show that the germination time is delayed by CHCl3 and EtOAc extracts of Isodon japonica. The shoot length and root length of the two receptor plants are inhibited in a dosedependent manner at higher concentrations. The root growth respond to Epinodosin in a dual stimulatory and inhibitory way. Lower levels of Epinodosin（25-100 μmol·L^-1） significantly promote root growth. Inhibitory effects are observed at the higher concentrations of Epinodosin （150-200μmol·L^-1）. The squash techniques demonstrate that the root growth inhibition is positive correlated with the decrease of the mitotic index. Promotion of root growth at the lower concentrations might result from enhanced mitotic activity. Based on the obtained results, we presume that the compound might act as a potential allelochemical and play ecological roles in natural surroundings.