Terpene and Aliphatic Products of Saponification of the Ether Extract of Euphorbia virgata Waldst. et Kit
T. P. KUKINA1, I. A. ELSHIN2
1Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
2Novosibirsk State University, Novosibirsk, Russia
Keywords: Euphorbia virgata Waldst. et Kit, GC-MS, triterpenoids, sterols
Abstract
The composition of the lipophilic components of Euphorbia virgata Waldst. et Kit. has been studied. Acidic and neutral components have been identified using gas-liquid chromatography with mass spectrometric detection (GC-MS) following alkaline hydrolysis of the whole extract. The plant material was extracted with methyl tert -butyl ether (MTBE). Total acids isolated during sample preparation were analysed after methylation with diazomethane. The composition of the neutral components of unsaponifiable residue was studied without derivatisation, but after separation by column chromatography on silica gel into the groups of substances of different polarity. As a result, aliphatic acids with the chain length 10-30 carbon atoms, including unsaturated ones, were identified by comparison with databases. In addition, two compounds rarely occurring in plant materials were detected: ricinoleic and octadeca-9-en-12-ynic acids. More than 100 triterpene and aliphatic compounds of the unsaponifiable residue and 25 components of acidic fractions were identified. The hydrocarbon fraction was determined to contain, in addition to n- alkanes, also substantial amounts of unsaturated branched hydrocarbon squalene. Highly active triterpene alcohols and ketones are mainly represented by ursane, lupane and cycloartane derivatives. The main sterol component (β-sitosterol) is accompanied by cholesterol, campesterol, stigmasterol, stigmast-7-en-3-β-ol and stigmastan-3-β-ol. A substantial contribution from euphanic compounds characteristic of the plants of the Euphorbiaceae family has been revealed.
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