Composition of lipids from Peganum harmala and Thermopsis alterniflora processing wastes

Abstract

concentrated during processing of the first crude extract (produced by a polar extractant) by a less polar solvent. The yield of lipids extracted from the resinous wastes can reach 90–98% of the waste mass. Herein we communicate results from a study of processing wastes of aerial parts of Peganum harmala L. (Zygophyllaceae) and Thermopsis alterniflora Regel et Schmalh. (Fabaceae) and the biological activity of lipid concentrates obtained from them. Waste samples were obtained from the pilot plant of the Yunusov Institute of the Chemistry of Plant Substances, AS, RU. Lipids from reprocessed raw material of these plants were previously studied [5, 6]. The wastes were a dark-green resinous mass with a brown tint and herbaceous aroma. Preliminary analyses for the presence of lipids were carried out by common TLC methods on Silufol plates and plates with thin layers of silica gel [7] using comparison with authentic samples. The results showed that the samples were rich in lipids and lipophilic compounds, which were observed previously in the starting material [5, 6]. Their qualitative composition including neutral lipids (NL), glycolipids (GL), and phospholipids (PL) in addition to carotinoids and chlorophyll pigments also turned out to be identical. Next the waste samples were treated with CHCl 3 . The lipid extracts were washed of ballast materials and separated using column chromatography. Components of individual lipid groups and lipophilic compounds in the isolated fractions were identified using TLC. The solvent systems for TLC were hexane:Et 2 O:AcOH (90:10:1 and 70:30:1) for NL; (CH 3 ) 2 CO:C 6 H 6 :H 2 O (91:30:8) for GL, and CHCl 3 :MeOH:NH 4 OH (65:25:4) for PL. The yields of lipids from the two samples were >50% of the waste mass. The ratio of NL to polar lipids (GL and PL) in processing wastes of P. harmala was 2:1; in T. alterniflora wastes, 1:1. NL of the studied wastes consisted almost half of free fatty acids. The remainder consisted of triacylglycerides, esters of fatty alcohols, triterpenols, and sterols in addition to lipophilic compounds (carotinoids, hydrocarbons, fatty alcohols, phytosterols, and pigments). Lipids from P. harmala waste contained much more diacylglycerides, monoacylglycerides, and unidentified compounds than those of T. alterniflora. GL dominated the polar lipids. GL contained digalactosyldiacylglycerides, sulfoquinovosyldiacylglycerides, and sterylglycosides and their fattyacid esters. The principal component of the GL of the studied samples was monogalactosyldiacylglycerides. The PL consisted of five components. The main ones were phosphatidylethanolamines, phosphatidylinositols, and phosphatidic acids. The minor ones were phosphatidylglycerines and phosphatidylcholines. Unsaponified components and total fatty acids of all lipids were isolated from the two samples by alkaline hydrolysis under forcing conditions [7]. Quantitative analysis of the fractions showed that lipids from T. alterniflora wastes contained more unsaponified components (21.8%) than those from P. harmala wastes (17.0%).