Antifungal cyclic peptides from the marine spongeMicroscleroderma herdmani.
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 spongeMicroscleroderma herdmani, along with microsclerodermins A (3) and B (4), previously isolated from an unidentifiedMicrosclerodermaspecies. 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 pathogensCandida albicans, Candida glabrata, Candida krusei, Cryptococcus neoformans, andAspergillus fumigatus.
National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, School of Pharmacy, The University of Mississippi, University, MS.
Xiaohui
X
Zhang
Melissa R
MR
Jacob
R Ranga
RR
Rao
Yan-Hong
YH
Wang
Ameeta K
AK
Agarwal
David J
DJ
Newman
Ikhlas A
IA
Khan
Alice M
AM
Clark
Xing-Cong
XC
Li
Microscleroderma herdmani; antifungal; microsclerodermins; opportunistic fungal pathogens