紫茎泽兰一种潜在化感活性物质的分离鉴定

【背景】紫茎泽兰潜在的化感效应可能是其具有极强入侵性的重要原因。目前，针对紫茎泽兰潜在化感活性物质的研究主要集中于偏小极性的萜烯类化合物，而对大极性化学物质的研究相对较少。【方法】采用活性跟踪分析法对紫茎泽兰乙酸乙酯提取物大极性亚组分进行潜在化感活性物质的跟踪分离，并用现代波谱技术解析其化学结构，最后就分离获得的单体成分与已报道的化感活性物质羟基泽兰酮（2）和泽兰二酮（3）以及信号分子JA-Ile在抑制拟南芥种子萌发和幼苗根生长方面进行潜在化感活性的对比分析。【结果】分离鉴定出一个具有潜在强化感活性的大极性化合物2．香豆酸葡萄糖苷（1），研究发现该化合物虽然对拟南芥种子萌发的抑制作用不显著，但在0．1mmol·L^-1的浓度条件下对拟南芥幼苗根生长却有着比羟基泽兰酮和泽兰二酮更为显著的抑制活性，且其抑制作用的浓度一活性关系与信号分子JA-Ile类似。【结论与意义】紫茎泽兰中潜在大极性的非萜烯类化感活性物质对于紫茎泽兰的综合化感效应可能同样具有重要而不可或缺的作用，化合物1等潜在大极性化感活性物质的逐步揭示对于系统解析紫茎泽兰的化感效应机制具有重要意义。

Isolation and identification of a potential allelochemical from the invasive plant Eupatorium adenophorum

Abstract： Background] Being capable of strongly exerting allelopathie effects on neighboring plants possibly would be the most im- portant factors that enables Eupatorium adenophorum to be such a strongly aggressive plant world-wide. Presently, studies on poten- tial allelochemicals of E. adenophorum were mainly focused on less polar compounds, especially terpenoids, while few reports is fo- cusing on large polar ones. Method] Bioassay-directed phytochemical study was carried out to isolate potential allelochemicals from polar sub-fractions of EtOAc extract of E. adenophorum. The chemical structures of the purified compounds were identified by spec- troscopy, including MS and NMR techniques. The allelopathic potential of sub-fractions of EtOAc extract and isolated pure com- pounds as well as two literature reported terpenoid allelochemicals, 8-hydroxy-4-cadinen-3-one （2） and 4,7 （11 ）-cadinadiene-3,8- dione （3）, and signaling compound JA-Ile, were all evaluated by detecting their inhibitory activity against seeds germination and seedling root growth using Arabidopsis thaliana as test plant. Result] A bioactive compound was isolated from one polar sub-frac- tion of EtOAe extract of E. adenophorum and its chemical structure was identified as 2-coumarie acid glucoside （ 1 ）. Bioassay indi- cated that compound 1 showed significant inhibitory activity against A. thaliana seedling root growth at concentration as low as 0.1 mmol. L- l, which is more potent than the other two identified compounds. A closely similar inhibition pattern of 1 to that of the signaling compound JA-Ile were also observed. Conclusion and significance ] In addition to less polar terpenoids, potentially existing large polar alleloehemieals in E. adenophorum might significantly contribute the total allelopathic effects. The discovery of compound 1 and other potential polar allelochemicals from E. adenophorum may significantly promote the elucidation of the potential allelopathic mechanism possessed by this well-known invasive plant.