Search for Bioactive Marine Natural Products

海洋生物包括50多万个物种。与陆地生物相比，海洋生物特殊的生存环境使其代谢产生各种物质，这些物质往往具有各种前所未有的化学结构和生物活性。在从海洋生物中寻找新的生物活性物质的持续研究过程中，我们研究了在冲绳县和帕劳岛的珊瑚礁收集的几种海绵。从冲绳海绵Theonella swinhoei中分离得到5个具有生物活性的内酯化合物Theonellapeptoldes Ia，Ib，Ic，Id和Ie，并用一种新的N-甲基氨基酸高效液相色谱方法确定了它们的绝对立体结构。这些多肽内酯对L1210细胞具有细胞毒性，对Na^、K^和Ca^&lt；&gt；2具有离子传递活性。从帕劳海绵海绵Asteropus sarasinosum中分离得到9个新的降棉烷三萜低聚糖苷：沙拉辛苷A_1、A_2、A_3、B_1、B_2、B_3、C_1、C_2和C_3，并对它们的结构进行了鉴定。这些寡糖具有鱼毒活性，并抑制海星受精卵的细胞分裂。从冲绳海绵Xestospongia sp.中分离得到9个新的大环生物碱，分别为Araguspongines A-H和J。并测定了它们的绝对构型。这些含有两个L-恶喹利定结构的生物碱具有很强的血管扩张活性。

Marine organisms comprise over half a million species. Due to their unusual living environment as compared with terrestrial organisms, marine organisms metabolite and produce a variety of substances which often have various unprecedented chemical structures and biological activities. During the course of continuing studies in search of new biologically active substances from marine organisms, we have studied several marine sponges collected in the coral reef of Okinawa Prefecture and Palau Islands.1. Bioactive five lactones named theonellapeptolides Ia, Ib, Ic, Id, and Ie were isolated from the Okinawan marine sponge Theonella swinhoei and elucidated their absolute stereostructures by a new HPLC method for N-methly amino acids which was developed to analyze the amino acid composition of these peptide lactones. These peptide lactones are cytotoxic for L1210 cell and exhibit ionophoric activities to Na^+, K^+, and Ca^<++>2. Nine new norlanostane-triterpenoid oligoglycosides, sarasinosides A_1, A_2, A_3, B_1, B_2, B_3, C_1 C_2, and C_3 were isolated from the Palauan marine sponge Asteropus sarasinosum and their structures were determined. These oligoglycosides exhibit ichthyotoxic activity and inhibit cell division of fertilized eggs ofthe starfish.3. Nine novel macrocyclic alkaloids, araguspongines A-H, and J were isolated from an Okinawan marine sponge Xestospongia sp. and their absolute stereostructures were determined. These alkaloids having two l-oxaquinolizidine moieties exhibit potent vasodilative activity.