Bioactive secondary metabolites from marine streptomyces griseorubens f8: Isolation, identification and biological activity assay

Abstract

Marine actinomycetes are a potential source of a wide variety of bioactive natural products. Herein, four cyclic dipeptides, namely, cyclo(L‐Val‐L‐Pro) (compound 1), cyclo(L‐Pro‐L‐Leu) (compound 2), cyclo(L‐Pro‐L‐Tyr) (compound 3) and cyclo(L‐Pro‐L‐Phe) (compound 5), and an N‐acetyltyramine (compound 4) were first isolated and identified as products of the marine Streptomyces griseorubens f8. Compounds 3 and 5 exhibit antibacterial activity against Staphylococcus aureus, Klebsiella aerogenes and Proteus vulgaris. The minimum inhibitory concentrations (MICs) against Staphylococcus aureus, Klebsiella aerogenes and Proteus vulgaris are 160 μg/mL, 100 μg/mL, 120 μg/mL for the compound 3 and 180 μg/mL, 130 μg/mL 150 μg/mL for the compound 5, respectively. In addition, compounds 1, 2, 3 and 5 was first found to have the ability to inhibit the invasion and migration of A549 cells (lung cancer cells), which exhibited the potentiality for these compounds to be used as novel anticancer drugs. This study provides a novel production strain for compounds 1, 2, 3 and 5, and four potential promising anticancer agents.