Bacilohydrin A,a new cytotoxic cyclic lipopeptide of surfactins class produced by bacillus sp. sy27f from the indian ocean hydrothermal vent

Abstract

Bacilohydrin A, a new cyclic lipopeptide composed of seven mixed D/L-amino acids (L-IIe - -L-Leu 2 -D-Asp 3 -L-Val 4 -L-Leu 5 -L-Leu 6 -L-Gln 7 ) and a (R)-3- hydroxy-12-methyltetradecanoic acid (HMT) residue, was isolated from the crude culture extract of Bacillus sp. SY27F, which was obtained from the Indian Ocean hydrothermal vent. Its planar structure was elucidated by spectroscopic analyses, including 1D and 2D NMR spectroscopy, mass spectrometry (MS), and secondary ion mass spectrometry (MS/MS), whereas its absolute configuration was determined by modified Marfey's analysis. Bacilohydrin A displayed significant cytotoxicities against DU-145, MCF-7 and HepG2 cancer cell lines with IC50 values of 50.3-175.1 nM. Additionally, this is the first time to determine the absolute configuration of a D-aspartic acid residue in surfactin class.