皱瘤海鞘Styela plicata化学成分及生物活性的研究

Study on the chemical constituents and bioactivity of the Ascidian Styela plicata

目的研究皱瘤海鞘Styela plicata具有卤虫致死活性的乙醇提取物的化学成分。方法 95%乙醇(体积分数)粗浸膏用乙酸乙酯萃取后得乙酸乙酯相,运用硅胶柱层析、Sephadex-LH20凝胶柱层析法和高效液相色谱(HPLC)对其进行分离纯化。运用核磁共振,质谱等波谱学方法对分离所得化合物的结构进行鉴定,并对化合物进行卤虫活性测试。结果从皱瘤海鞘乙醇提取物中分离得到6个化合物,结构分别鉴定为2个比较少见的吡喃酮类化合物tetillapyrone(1)和nortetillapyrone(2),2个核苷类化合物thymidine(3)和uracil(4),以及2个多羟基甾醇类化合物dendronesterol A(5)和(20S,22E,24R)-ergosta-7,22-dien-3β,5α,6β-triol(6)。卤虫致死活性结果显示,多羟基甾醇类化合物5和6的活性较强,而核苷类化合物3和4的活性较弱。结论所有化合物均为首次从该海鞘中分离获得,本研究为进一步研究开发皱瘤海鞘中的活性物质提供基础资料。

Objective To screen the chemical constituents of the ethanolic extract from Styela plicata and determine its lethality to brine shrimp Artemia salina. Methods EtOAc fraction extracted from the eth- anolic （95% v/v） extract showed lethality to brine shrimp A. salina, and it was further purified by re- peated silica gel column chromatography, Sephadex LH-20 chromatography and HPLC. The structures of all isolated compounds were identified by spectroscopic methods including NMR and MS, and their lethal activities toward brine shrimp A. salina were also evaluated. Results Six compounds designated as tetillapyrone （1） and nortetillapyrone （2）, two nucleosides thymidine （3） and uracil （4）, two poly- hydroxy sterols dendronesterol A （5） and （20S, 22E, 24R）-ergosta-7, 22-dien-3β, 5α, 6β-triol （6） were isolated from the EtOAc fraction of S. plicata. Compounds 1 and 2 showed moderate lethality to brine shrimp A. salina, while compounds 3 and 4 had weak activities. Conclusion The six compounds were obtained from S. plicata for the first time. Secondary metabolites of S. plicata exhibited brine shrimp lethal activity. This research provided basic data for the further development of bioactive com- pounds from marine ascidians.