Planta Med 2008; 74 - P-68
DOI: 10.1055/s-2008-1075264

Mollamides B and C, Bioactive Cyclic Hexapeptides from an Indonesian Tunicate Didemnum molle

MS Donia 1, B Wang 1, DC Dunbar 1, PV Desai 2, A Patny 2, M Avery 2, MT Hamann 1
  • 1The Department of Pharmacognosy, School of Pharmacy, The University of Mississippi, University, MS 38677, USA
  • 2The Department of Medicinal Chemistry and NationalCenter for Natural Products Research, School of Pharmacy, The University of Mississippi, University, MS 38677, USA

Two new cyclic hexapeptides mollamides B (1) and C (2) were isolated from an Indonesian tunicate Didemnum molle [1] along with the known peptide keenamide A [2]. The structures were established using 1D and 2D NMR experiments. The relative configuration of mollamide B at the thiazoline moiety was determined using molecular modeling coupled with NMR derived restraints. Their absolute configuration was determined using Marfey's method. The new peptides have been evaluated for their antimicrobial, antimalarial, anticancer, antiHIV-1, antiMtb, and antiinflammatory activities. Keenamide A and mollamide B show cytotoxicity against several cancer cell lines. Acknowledgment: We appreciate the help of the National Cancer Institute (NCI), the National Center for Natural Products Research, Mr. Frank T. Wiggers, and Dr. Abbas. G. Shilabin. We are grateful for financial support from NIH (grant number 1RO1AI36596). References: [1] Rinehart KL (2000) Med. Res. Rev. 20: 1–27. [2] Wesson KJ, Hamann MT (1996) J. Nat. Prod. 59: 629–631.