Withanolides from Physalis angulata L.

Abstract

The compounds (17S,20R,22R,24R,25S)-5β,6β:20,24-diepoxy-4β,25-dihydroxy-1-oxowith-2-en-26,22-olide and (20R,22R)-5α,14α,20-Trihydroxy-1-oxo-6α,7α-epoxywitha-2-enolide were isolated from a chloroform extract of the aerial parts of Physalis angulata L. (Solanaceae). Two products were isolated from the chromatographic separation extract. Compound I corresponds to physangulide B chloroform monosolvate, C28H38O7·CHCl3, while compound II is 14α-hydroxyixocarpanolide, C28H40O7. In the two molecular structures, the conformation of the steroid part (rings A, B, C, D) does not differ. In both crystals, molecules are linked by intermolecular O—H...O hydrogen bonds along the c-axis direction and form a two-dimensional network parallel to the ac plane. The absolute configuration was determined from X-ray diffraction data.

Keywords

• physalis angulata l.
• physangulide b
• 14α-hydroxyixocarpanolide
• molecular structure
• hydrogen bonding
• chloroform solvate
• crystal structure