Sakkarn ChanadechDuangkamol Ruen-ngamChakapong IntaraudomPattama PittayakhajonwutSumet ChongruchirojJaturong PratuangdejkulChitti ThawaiRajamangala University of Technology RattanakosinKing Mongkut's Institute of Technology LadkrabangMahidol UniversityThailand National Center for Genetic Engineering and Biotechnology2022-08-042022-08-042021-03-01Research in Microbiology. Vol.172, No.2 (2021)17697123092325082-s2.0-85101816356https://repository.li.mahidol.ac.th/handle/20.500.14594/76265A marine actinomycete strain C1-2 was taxonomically characterized as the genus Streptomyces, based on whole-genome sequence analysis. The highest average nucleotide identity (ANI) value (98.96%) and digital DNA–DNA hybridization (DDH) value (90.4%) were observed between Streptomyces sp. C1-2 and Streptomyces griseoaurantiacus. Thus, Streptomyces sp. C1-2 could be identified as S. griseoaurantiacus. Genome analysis revealed that Streptomyces sp. C1-2 contained 22 biosynthetic gene clusters (BGCs) for secondary metabolites, where among them, 54% have low similarities with known BGCs. The chemical investigation led to the isolation of three new manumycin-type derivatives and two known analog antibiotics named SW-B and cornifronin B. All compounds showed antioxidant activity with the half-maximal inhibitory concentration (IC50) values in a range of 50.82 ± 0.8–112.04 ± 1.0 μg/mL with no cytotoxicity against Vero cells. This is the first report of the antioxidant property of manumycin-type derivatives. Moreover, two known compounds exhibited antifungal activity against Phytophthora capsici, Fusarium oxysporum f. sp. cucumerinum, and Magnaporthe grisea, with the minimum inhibitory concentration (MIC) values in a range of 125–500 μg/mL.Mahidol UniversityBiochemistry, Genetics and Molecular BiologyImmunology and MicrobiologyArticleSCOPUS10.1016/j.resmic.2021.103812