Cystargamide B, a cyclic lipodepsipeptide with protease inhibitory activity from Streptomyces sp.

Shigeru Kitani, Mitsuki Yoshida, Ousana Boonlucksanawong, Watanalai Panbangred, Atchareeya Anuegoonpipat, Takeshi Kurosu, Kazuyoshi Ikuta, Yasuhiro Igarashi, Takuya Nihira

Index: 10.1038/s41429-018-0044-0

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Abstract

We identified a new cyclic lipodepsipeptide, cystargamide B (1), from the mycelial extract of a Kaempferia galanga rhizome-derived actinomycete strain, Streptomyces sp. PB013. The planar structure was elucidated based on high resolution fast-atom bombardment mass spectrometry (HRFABMS) spectroscopy and one-dimensional (1D) and two-dimensional (2D) nuclear magnetic resonance (NMR) spectroscopic data. The absolute configurations of the constituent amino acids were determined using advanced Marfey’s method. Cystargamide B (1) includes rare structural units: a 5-hydroxytryptophan residue and a 2,3-epoxy fatty acid side chain. Notably, cystargamide B (1) inhibited the protease activity of the NS2B/NS3 complex from dengue virus.