Crystal structure of Staudtienic acid, a diterpenoid from Staudtia kamerunensis Warb. (Myristicaceae).

This title compound, C 20 H 26 O 2 , was isolated from the benzene fraction of the stem bark of Staudtia kamerunensis Warb. (Myristicaceae) using column chromatography techniques over silica gel. The compound was fully characterized by single-crystal X-ray diffraction, one and two-dimensional NMR spectroscopy, IR and MS spectrometry. The compound has two fused cyclo-hexane rings attached to a benzene ring, with a carb-oxy-lic acid on C-4. This cyclo-hexene ring has a chair conformation while the other adopts a half-chair conformation. The benzene ring is substituted with a propenyl moiety. The structure is characterized by inter-molecular O-H⋯O hydrogen bonds, two C-H⋯O intra-molecular hydrogen bonds and two C-H⋯π inter-actions. The mol-ecular structure confirms previous studies carried out by spectroscopic techniques.