Stereochemistries of monapinones produced by Talaromyces pinophilus FKI-3864

Monapinones A (1) to E (5), half parts of dinapinones, were produced by fermentation of Talaromyces pinophilus FKI-3864 in seawater-containing medium and have a common dihydronaphthopyranone skeleton with a different long alkyl chain. The relative stereochemistries of 3–5 were elucidated by various NMR experiments including analysis of 1H NMR coupling constants, ROESY and the dihedral angles. The absolute stereochemistries of 3–5 at C-3 were determined by the circular dichroism spectra in comparison to the data of (R)- and (S)-semivioxanthins (6 and 7). Accordingly, total absolute stereochemistries of 3–5 were concluded to be 3S,13R,15R,17R,19R,3S,13R,15R,17R and 3S,13R,15R, respectively.

Graphical abstractMonapinones A (1)–E (5), half parts of dinapinones, were produced by fermentation of Talaromyces pinophilus FKI-3864 in seawater-containing medium and have a common dihydronaphthopyranone skeleton with a different long alkyl chain. Total absolute stereochemistries of 3–5 were concluded to be 3S, 13R, 15R, 17R, 19R, 3S, 13R, 15R, 17R and 3S, 13R, 15R, respectively. Figure optionsDownload full-size imageDownload as PowerPoint slide