Amidepsine D

Based on UV spectrum-guided purification, new monordens C, D and E, known monordens A (radicicol) and B and 5-O-methylsclerone were isolated from the fermentation broth of amidepsine-producing Humicola sp. FO-2942 by solvent extraction, silica-gel column chromatography, ODS column chromatography and HPLC. All monordens cause the cell cycle arrest at G1 and G2/M phases in Jurkat cells. But among them, monordens A and E show antifungal activity only against Aspergillus niger.

Structures of three novel compounds designated monordens C to E, isolated from the fermentation broth of amidepsine-producing fungus Humicola sp. FO-2942, were elucidated by spectroscopic evidence. Monordens C is 6,7-dihydromonorden A. Monordens D and E lack the epoxide moiety of monordens C and B, respectively.

Structures of amidepsines A, B, C and D, diacylglycerol acyltransferase (DGAT) inhibitors, were determined by spectroscopic studies including various NMR measurements. They were elucidated as 2-hydroxy-4-[[2-hydroxy-4-[(2,4-dimethoxy-6-methylbenzoyl) oxy]6-methylbenzoyl]-oxy]-6-methylbenzoic acid N-alanine amide for amidepsine A, 2-hydroxy-4-[[2-hydroxy-4-[(2-hydroxy-4-methoxy-6-methylbenzoyl) oxy]6-methylbenzoyl]oxy]-6-methylbenzoic acid N-alanine amide for amidepsine B and 2-hydroxy-4-[[2-hydroxy-4-[(2-hydroxy-4-methoxy-6-methylbenzoyl) oxy]6-methylbenzoyl]oxy]-6-methylbenzoic acid N-valine amide for amidepsine C. Amidepsine D was identified with 2,4-di-O-methylgryphoric acid.