A Pimarane Diterpene and Cytotoxic Angucyclines from a Marine-Derived Micromonospora sp. in Vietnam’s East Sea
Michael W. Mullowney,
Eoghainín Ó hAinmhire,
Urszula Tanouye,
Joanna E. Burdette,
Van Cuong Pham,
Brian T. Murphy
Affiliations
Michael W. Mullowney
Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, 833 South Wood Street (MC 781), Room 539, Chicago, IL 60612-7231, USA
Eoghainín Ó hAinmhire
Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, 833 South Wood Street (MC 781), Room 539, Chicago, IL 60612-7231, USA
Urszula Tanouye
Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, 833 South Wood Street (MC 781), Room 539, Chicago, IL 60612-7231, USA
Joanna E. Burdette
Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, 833 South Wood Street (MC 781), Room 539, Chicago, IL 60612-7231, USA
Van Cuong Pham
Institute of Marine Biochemistry, Vietnam Academy of Science and Technology, 18 Hoàng Quốc Việt, Cầu Giấy, Hà Nội 10000, Vietnam
Brian T. Murphy
Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, 833 South Wood Street (MC 781), Room 539, Chicago, IL 60612-7231, USA
A screening of our actinomycete fraction library against the NCI-60 SKOV3 human tumor cell line led to the isolation of isopimara-2-one-3-ol-8,15-diene (1), lagumycin B (2), dehydrorabelomycin (3), phenanthroviridone (4), and WS-5995 A (5). These secondary metabolites were produced by a Micromonospora sp. isolated from sediment collected off the Cát Bà peninsula in the East Sea of Vietnam. Compound 1 is a novel Δ8,9-pimarane diterpene, representing one of approximately 20 actinomycete-produced diterpenes reported to date, while compound 2 is an angucycline antibiotic that has yet to receive formal characterization. The structures of 1 and 2 were elucidated by combined NMR and MS analysis and the absolute configuration of 1 was assigned by analysis of NOESY NMR and CD spectroscopic data. Compounds 2–5 exhibited varying degrees of cytotoxicity against a panel of cancerous and non-cancerous cell lines. Overall, this study highlights our collaborative efforts to discover novel biologically active molecules from the large, underexplored, and biodiversity-rich waters of Vietnam’s East Sea.
