(−)-Ternatin, a highly N-methylated cyclic heptapeptide that inhibits fat accumulation: structure and synthesis

A highly N-methylated cyclic heptapeptide, (−)-ternatin, was isolated from the mushroom Coriolus versicolor, which significantly suppressed fat accumulation against 3T3-L1 murine adipocytes (EC50 = 0.14 μg/mL). Although ternatin was previously reported to be antibacterial or antimicrobial compound, its inhibitory effect on fat accumulation has been first shown. The structure of (−)-ternatin was revised to be a cyclo [d-allo-Ile1-l-(NMe)Ala2-l-(NMe)Leu3-l-Leu4-l-(NMe)Ala5-d-(NMe)Ala6-(2R,3R)-3-hydroxy-Leu7] by spectroscopic analysis and chemical synthesis.