Antifungal cyclic peptides from the marine sponge Microscleroderma herdmani

ntifungal cyclic peptides from the marine sponge Microscleroderma herdmani Original Research (2055) Total Article Views Authors: Zhang X, Jacob MR, Ranga Rao R, Wang YH, Agarwal AK, Newman DJ, Khan IA, Clark AM, Li XC Published Date May 2012 Volume 2012:2 Pages 7 - 14 DOI: http://dx.doi.org/10.2147/RRMC.S30895 Received: 25 February 2012 Accepted: 17 April 2012 Published: 22 May 2012 Xiaohui Zhang,1 Melissa R Jacob,1 R Ranga Rao,1 Yan-Hong Wang,1 Ameeta K Agarwal,1 David J Newman,2 Ikhlas A Khan,1,3 Alice M Clark,1,3 Xing-Cong Li1,3 1National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, School of Pharmacy, The University of Mississippi, University, MS, 2Natural Products Branch, Developmental Therapeutics Program, Division of Cancer Treatment and Diagnosis, National Cancer Institute – Frederick, Frederick, MD, 3Department of Pharmacognosy, School of Pharmacy, The University of Mississippi, University, MS, USA Abstract: Screening natural product extracts from the National Cancer Institute Open Repository for antifungal discovery afforded hits for bioassay-guided fractionation. Using LC–MS analysis to generate chemical structure information on potentially active compounds, two new cyclic hexapeptides, microsclerodermins J (1) and K (2), were isolated from the deep-water sponge Microscleroderma herdmani, along with microsclerodermins A (3) and B (4), previously isolated from an unidentified Microscleroderma species. The structures of the new compounds were elucidated by spectroscopic analysis and chemical methods. In vitro antifungal testing showed that the four compounds possessed strong activities against the opportunistic fungal pathogens Candida albicans, Candida glabrata, Candida krusei, Cryptococcus neoformans, and Aspergillus fumigatus.