Investigation on Metabolites in Structure and Biosynthesis from the Deep-Sea Sediment-Derived Actinomycete sp. SCSIO 52865.

For exploring structurally diverse metabolites and uniquely metabolic mechanisms, we systematically investigated the chemical constituents and putative biosynthesis of sp. SCSIO 52865 derived from the deep-sea sediment based on the OSMAC strategy, molecular networking tool, in combination with bioinformatic analysis. As a result, one new diketopiperazine (), along with seven known cyclodipeptides (-), -cinnamic acid (), -phenethylacetamide () and five fatty acids (-), was isolated from the ethyl acetate extract of SCSIO 52865. Their structures were elucidated by a combination of comprehensive spectroscopic analyses, Marfey's method and GC-MS analysis. Furthermore, the analysis of molecular networking revealed the presence of cyclodipeptides, and compound was produced only under mBHI fermentation condition. Moreover, bioinformatic analysis suggested that compound was closely related to four genes, namely A-D, encoding core non-ribosomal peptide synthetase and acetyltransferase.