Bioactive compounds from marine sponge-associated bacteria

Abstract

As a part of searching for bioactive compounds from marine organisms, this research describes the chemical constituents of an Australia sponge Aplysilla sulphurea and marine bacteria associated with tropical Thai sponge. Two known chromodorolides A (2a), B (2b) and a new derivative chromdorolide C (2c) have been isolated from an Australian sponge and characterized by 1D and 2D NMR experiments. Chromodorolides exhibited the significant cytotoxicity against P388 mouse leukemia cell lines and also showed nematocidal activity against the larval stages of Haemonchus contortus and Trichostrongylus colubriformis, two important pathogens of sheep and other ruminants. In the chemical investigation of marine microorganism from Thailand, six peptides : cyclo [phenylalanyl-leucyl][subscript 2] (3a), cyclo [leucyl-ileucyl] [subscript 2] (3b), cyclo [leucyl-leucyl] [subscript 2] (3c), cyclo [leucyl-prolyl-leucyl-prolyl] (4a), cyclo [phenylalanyl-prolyl-phenylalanyl-prolyl] (4b), and cyclo [phenylalanyl-prolyl-leucyl-prolyl](4c), including unidentified heteroaromatic unit were isolated from bacteria associate with tropical Thai sponge. The peptide structures were determined using spectroscopic methods and the absolute configuration were deduced using Marfey's analysis. Four peptides 3a-3c and 4c were identified as a new metabolites from marine bacteria. The bioassay for peptide will be undertaken