Metacridamide B methanol-d₄ monosolvate

The title compound, C₃₅H₅₃NO₅· CH₃OH {systematic name: (3S,6E,8S,9R,10E,12S,13S,14E,16S,17R)-3- benzyl-9,13-dihydroxy-6,8,10,12,14,16-hexamethyl-17-[(2S,4S)-4-methylhexan-2-yl] -1-oxa-4-azacycloheptadeca-6,10,14-triene-2,5-dione methanol-d 4 monosolvate}, was extracted from conidia of the fungus Metarhizium acridum. Crystals were obtained as a methanol-d 4 solvate. The tail part of the 4-methylhexan-2-yl group exhibits disorder over two positions, with an occupancy ratio of 0.682 (9):0.318 (9). The crystal structure confirms the absolute configuration of nine stereocenters determined previously for the acetylated compound metacridamide A. In the crystal, the methanol-d4 molecule is positioned close to the O atom in the carbonyl group of the peptide bond, forming an O - H⋯O hydrogen bond. It also forms an O - H⋯O hydrogen bond with an adjacent molecule. N - H⋯O and O - H⋯O hydrogen bonds are observed between neighboring molecules.