Chemical And Bioactivity Studies Of Secondary Metabolites From A Spong-Derived Fungi And A South China Sea Sponge

Sponges are porous filter feeders.Their biomass accounts for only 1/15 of the total number of marine animals,but more than one-third of marine natural products are derived from sponges in the world.Sponges can filter more than 70%of the microorganisms,so a large number of microorganisms reside in their surface and bodies.Sponges and numerous microorganisms constitude a complex coexistence defense system.As early as hundreds of millions of years,the sponge and its associated microorganisms have produce biologically active compounds through co-evolution,and created a complex chemical defense system.These associated microorganisms cover bacteria,microalgae,archaea,cyanobacteria,and fungi.Compared to other marine associated bacteria,marine fungi have more complex genomes,so it has the ability to synthesize more abundant secondary metabolites.Sponge and sponge-derived fungi have attracted increasing attention from scientists because of their can produce novel structures and bioactive compounds.In order to find compounds with potential medicinal activity,professor Lin~'s research group has been devoted to the study of the bioactive secondary metabolites from marine sponges and microorganisms for many years.This paper is based on many years'research of professor Lin~'s research group.The chemical composition and biological activities of secondary metabolites from a sponge-derived fungus Penicillium chrysogenum and a sponge Mycale fibrexilis was studied.22 compounds were isolated from the secondary metabolites of the sponge-derived fungus P.chrysogenum and the sponge M.fibrexilis from the South China Sea.The structural types of the compounds include diterpenoids,alkaloids,alysinopsins alkaloids,polyketones,sterols,fatty acids and other types.Among these compounds,there are two new compounds and a compound that was initially isolated from natural.Compound A6 was tested for biomolecular interactions.The secondary metabolites of strain P.chrysogenum,an epiphytic fungus isolated from the South China Sea sponge T.swinhoei.13 compounds(A1~A13)were isolated and identified from the mycelia of strain P.chrysogenum by chromatography methods including silica gel,ODS and semi-preparative HPLC.The structure of compounds A1~A13 were determined with ESIMS,modern spectroscopy techniques such as 1D and 2D NMR techniques and literature.They are traumatic acid(A1),conidiogenone(A2),?-linolenic acid(A3),linoleic acid(A4),ergosta-4,6,8(14),22-tetraen-3-one(A5),2-((2E,4E)-hexa-2,4-dienoyl)-5,6-dihydroxy-4,6-dimethylcyclohex-4-ene-1,3-dione(A6),15?-hydroxyl-(22E,24R)-ergosta-3,5,8,22-tetraen-one(A7),cyclo-(D-Pro-D-Leu)(A8),N-benzoyl-L-phenylalanino(A9),Bis(2-ethyloctyl)phthalate(A10),(22E,24S)-5?,8?-epidioxy-24-methyl-cholesta-6,9(11),22-trien-3?-ol(A11),(22E)-5?,8?-epidioxyergosta-6,22-dien-3?-ol(A12),5?,8?-epidioxy-23-methyl-(22E,24S)-ergosta-6,22-dien-3?-ol(A13)?Compound A1 was initially isolated from natural.Compounds A7 and A12 were initially isolated from in the genus Penicillium and compound A5 was isolated from the fungus P.chrysogenum for the first time.Compound A6 has affinity with diabetes,tumors,lipid metabolism,and virus-related proteins with the PlexArray?HT biomolecular interaction analysis system.9 compounds(B1~B9)were isolated from dichloromethane extract of the South China sea sponge M.fibrexilis by chromatography methods including silica gel,ODS and semi-preparative HPLC.The structures of compounds(B1~B9)were determined with modern spectroscopy techniques such as 1D NMR,2D NMR,UV,MS,and ECD.They are ethyl(R)-2-(6-bromo-3-hydroxy-2-oxoindolin-3-yl)acetate(B1),ethyl(S)-2-(6-bromo-3-hydroxy-2-oxoindolin-3-yl)acetate(B2),aaptamine(B3),1H-indole-3-carboxaldehyde(B4),6-bromo-1H-indole-3-hydroxyacetyl(B5),Aplysinopsin(B6),6-bromo-1H-indole-3-carboxylic acid(B7),(6-Bromo-1H-indol-3-yl)oxoacetamide(B8),6-bromo-1H-indole-3-carbaldehyde(B9)?Among them,compounds B1 and B2are a pair of new racemates.The chemical compositions and biological activities of a sponge-derived fungus .chrysogenum and a sponge M.fibrexilis were studied with modern chromatographic separation techniques in this paper.We had many new discoveries.These discoveries not only expanded the types of marine natural compounds,but also accumulated research data for finding potential drug molecular template.In addition,compounds were tested with diabetes,tumors,lipid metabolism,and virus-associated proteins,providing a new direction for future evaluation of the pharmacological activities of marine natural products.At the same time,the study also showed that marine organisms have a variety of chemical structures and rich biological activities,which laid the foundation for further development and utilization of marine biology.