Novel Bioactive Metabolites from a Marine Derived Bacterium Nocardia sp. ALAA 2000

摘要: Extracts of the Egyptian marine actinomycete, Nocardia sp. ALAA 2000, were found to be highly bioactive. It was isolated from red alga Laurenica spectabilis collected off Ras-Gharib coast Red Sea, Egypt. According detailed identification studies, strain classified as a member genus Nocardia. The cultivation and chemical analysis this species yielded four structurally related compounds namely, chrysophanol 8-methyl ether (1), asphodelin; 4,7'-bichrysophanol (2) justicidin B (3), in addition novel bioactive compound ayamycin; 1,1-dichloro-4-ethyl-5-(4-nitro-phenyl)-hexan-2-one (4) which is unique contain both chlorination rarely observed nitro group. by series chromatographic steps their structures 1approximately 3 secured spectroscopic MS NMR data whereas that 4 elucidated single crystal X-ray diffraction studies. These displayed different potent antimicrobial activity against Gram-positive Gram-negative bacteria well fungi with MIC ranging 0.1 10 microg/ml.