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

This work presents the crystal structure of a natural diterpenoid, Staudtienic acid, isolated from the stem bark of Staudtia kamerunensis Warb (Myristicaceae). This work confirmed the results previously obtained from NOE spectroscopy.

This title compound, C₂₀H₂₆O₂, 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 cyclo­hexane rings attached to a benzene ring, with a carb­oxy­lic acid on C-4. This cyclo­hexene 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 inter­molecular O—H⋯O hydrogen bonds, two C—H⋯O intra­molecular hydrogen bonds and two C—H⋯π inter­actions. The mol­ecular structure confirms previous studies carried out by spectroscopic techniques.