Amycolapeptins A and B, Cyclic Nonadepsipeptides Produced by Combined-culture of <i>Amycolatopsis</i> sp. and <i>Tsukamurella pulmonis</i>
Chengqian Pan, Takefumi Kuranaga, Xun Cao, Takehiro Suzuki, Naoshi Dohmae, Naoya Shinzato, Hiroyasu Onaka, Hideaki Kakeya
Abstract
Two nonapeptide natural products, amycolapeptins A (1) and B (2) with a 22-membered cyclic depsipeptide skeleton, β-hydroxytyrosine, and a highly modified side chain, which were not produced in a monoculture of the rare actinomycete Amycolatopsis sp. 26-4, were discovered in broth of its combined-culture with Tsukamurella pulmonis TP-B0596. The planar structures were elucidated by spectroscopic analyses (extensive 2D-NMR and MALDI-TOF MS/MS). The absolute configurations of component amino acids were unambiguously determined by the highly sensitive advanced Marfey’s method we recently developed. Additionally, the structures of unstable/unusual moieties were corroborated by chemical synthesis and CD analysis.