Studies On Chemical Constituents Of Cyanobacteria Lyngbya Majuscula From Hainan Sanya And Sponge Mycale Sp. From The Paracel Islands In The South China Sea

Cyclic peptides widely exist in marine organisms,they have good ability to resist digestion and bioavailability in vivo,have always been one of the most active field of marine natural products research.Cyclic peptides with a variety of biological activity have been found in cyanobacteria Lyngbya sp.and sponge Demospongiae many times.In order to discover new bioactive compounds or leading compounds,we successfully investigated the cyanobacteria Lyngbya majuscula from Hainan Sanya and sponge Mycale sp.from the paracel islands in the south China sea.A total of 20 compounds were obtained by chromatography techniques and their planar structures were unambiguously elucidated by a combination of spectroscopic technologies(UV,IR,ORD,MS,NMR and X-ray)and comparison with the reported data in literature.In addtion,Marfey’s method were applied to determine the absolute configurations.Among these compounds,5 of them were proved to be new compounds.From the cyanobacteria Lyngbya majuscula,10 compounds were isolated and characterized.The structure type of these metabolites were categorized as linear lipopeptides(A1-A2,2 in total),cyclic depsipeptides(A3-A10,8 in total),involving 5new compounds namely Sunpeptide A-B(A1-A2),homodolastatin16-1(A3),homodolastatin 16-2(A4),veraguamide M(A5)respectively.From the sponge Mycale sp.,10 compounds were isolated and characterized.The structure type of these metabolites were categorized as cyclic dipeptides(B1-B7),nucleosides(B8),thymine(B9),lactones(B10).