Sterols, methylsterols, and triterpene alcohols in three Theaceae and some other vegetable oils.

Abstract

AbstractThe unsaponifiables from threeTheaceae (Camellia japonica L.,Camellia Sasanqua Thunb., andThea sinensis L.) oils and alfalfa, garden balsam, and spinach seed oils and shea fat were separated into four fractions: sterols, 4‐methylsterols, triterpene alcohols, and less polar compounds by thin layer chromatography. While the sterol fraction was the major one for the unsaponifiables from alfalfa and spinach seed oils, the triterpene alcohol fraction was predominant for the unsaponifiables from all other oils. The sterol, 4‐methylsterol, and triterpene alcohol fractions were analyzed by gas chromatography. All the sterol fractions were alike in their compositions, consisting exclusively of Δ7‐sterols, such as α‐spinasterol and Δ7‐stigmastenol as predominant components together with Δ7‐avenasterol and 24‐methylcholest‐7‐enol. Obtusifoliol, gramisterol (occasionally accompanied with cycloeucalenol), and citrostadienol, together with several other unidentified components, were found in the 4‐methylsterol fractions from all of the oils except shea fat. The 4‐methylsterol fraction from shea fat showed a characteristic composition containing a large proportion of unidentified components which had relative retention time greater than that of citrostadienol, while no citrostadienol was detected. β‐Amyrin, lupeol, and butyospermol were major components of the triterpene alcohol fractions from most of the oils, but the fraction from spinach seed oil contained cycloartenol and 24‐methylene‐cycloartanol as predominant components. There is a close similarity in the compositions of unsaponifiables (sterols, 4‐methylsterols, and triterpene alcohols) of the threeTheaceae oils. Two sterols, α‐spinasterol and Δ7‐stigmastenol, and five triterpene alcohols were isolated from tea seed oil. Moreover, five unidentified components beside parkeol, butyrospermol, α‐amyrin, and lupeol were isolated from the triterpene alcohol fraction of shea fat.