Triterpene alcohols and sterols of Siberian larch (Larix sibirica Ldb.) needles

Abstract

The composition of triterpene alcohols and sterols in the fraction of Siberian larch (Larix sibirica Ldb.) conifer needles is considered in paper. The needles areextracted with propan-2-ol; resinous substances are extracted with petroleum ether (40–70°C);substances extracted with petroleum ether are divided into free acids and neutral substances. Neutral substances are separated in a silica gel column; eluent - petroleum ether supplemented with diethyl ether. The isolated esters fraction is hydrolyzed with potassium hydroxide in ethanol, and the “bound” acids are separated from unsaponifiable substances. Non-saponified substances are separated by chromatography into 5 fractions of phytosterols, the alcohol components of esters. The fractions are acetylated; the alcohol acetates are separatedonsilica gel with added silver nitrate. The isolated compounds was identified by NMR and GC-MS methods. Cycloartenol (6.82%, hereafter based onunsaponifiable substances), 24-methylenecycloartanol (6.75%), citrastadienol (7.69%), sitosterol (7.18%), cycloevcalenol (0.09%) are identified, obtussifoliol (0.01%), 24-methylenelophenol (0.10%), methyllophenol (1.84%) and campesterol (0.33%).