一株海绵附生芽孢杆菌的抗硅藻附着活性成分的分离鉴定

摘要

In order to search for natural antifouling compounds, the compounds inhibiting diatom settlements were purified from the metabolites of a sponge-associated Bacillus sp. UST050418-715 via purification of organic solvent extraction and semipreparative high-performance liquid chromatography (HPLC) using antidiatom- settlement assays. The structures of active compounds were analyzed via gas chromatography–mass spectroscopy (GC–MS) and1H nuclear magnetic resonance (NMR). Consequently, seven active cyclic dipeptides in addition to dozens of fractions were isolated and purified. The seven cyclic dipeptides were identified as (1) cyclo (L-leu-trans-8- hydroxy-L-pro), (2) cyclo (L-val-L-pro), (3) cyclo (D-pro-L-leu), (4) cyclo (L-pro-D-leu), (5) cyclo (gly-L-pro), (6) cyclo (L-phe-cis-8-hydroxy-D-pro), and (7) cyclo (L-phe-trans-8-hydroxy-L-pro). The results of this study indicate that multiple cyclic dipeptides exist in the metabolites of sponge-associatedBacillussp. UST050418-715 and contribute to the host’s chemical defense.%为寻找天然抗污损活性化合物，以抗硅藻附着活性为导向，采用有机溶剂萃取、半制备高压液相色谱对分离自海绵的芽孢杆菌 UST050418-715代谢产物进行分离，纯化抗硅藻附着活性物质，并利用气相色谱-质谱联用仪、核磁共振波谱分析活性物质结构。从菌株UST050418-715代谢产物中分离得到7种具有抗硅藻附着活性的环二肽类化合物，分别鉴定为：(1)环(L-亮氨酸-反式-8-羟基-L-脯氨酸-)、(2)环(L-缬氨酸-L-脯氨酸)、(3)环(D-脯氨酸-L-亮氨酸)、(4)环(L-脯氨酸-D-亮氨酸)、(5)环(甘氨酸-L-脯氨酸)、(6)环(L-苯丙氨酸-顺式-8-羟基-D-脯氨酸-)、(7)环(L-苯丙氨酸-反式-8-羟基-L-脯氨酸-)。说明海绵附生芽孢杆菌UST050418-715代谢产物中存在大量环二肽类化合物，可以帮助宿主海绵实现对硅藻附着的化学防御。