Lipids of the seeds and flesh of the fruit ofMandragora turcomanica

Abstract

The lipid compositions of the seeds and the flesh of the fruit of Mandragora turcomanica have been investigcaed The qualitative identity of the lipid compositions of the two parts of the fruit has been shown and it has been found that the degrees of saturation of the fatty acids of the trlacylglycerides and phospholipids and of the free fatty acids of the fruit flesh are higher than those of the lipid classes of the seeds.We have previously investigated the composition of the lipids [1] and the structure of the triacylglycerides [2] of the tuberous roots of the mandrake Mandragora turcomo~ca Mizger. (faro. Solanaceae). Continuing the study of the lipids of this plant, we have made a comparative analysis of the lipids of the seeds (I) and of the flesh with peel (II) of the ripe fruit. The seeds made up 13% of the crude weight of the ~xfit.The neutral lipids (NLs) of (I) and (11) were extracted repeatedly with hexane, after which the total polar lipids (PLs) were isolated with chloroform--methanol (2:1, v/v) according to Folch. The PLs, contaminated with a small amount of NLs, were separated with the aid of CC into NLs, glyco-GLs, and phospholipids (PhLs). The NLs eluted from the column were combined with the hexane extract. The components of the NLs and the GLs were obtained by the use of CC in combination with preparative TLC on silica gel, and were estimated gravimetrically. The PhLs were identified qualitatively. The assignment of the comlxments of the three groups was made on the basis of their chromatographic and spectral characteristics in comparison with known substances and with the aid of qualitative reactions and chemical transformations. The composition of the fatty acids (FAs) of the main acyl-containing lipids and that of the free fatty acids were established by the GLC of their methyl esters. Alkaloids were present among the nonlipid components of the PLs of the fruit. The amounts and compositions of the NLs, GLs, and PhLs of (I) and (1I) are shown in Table 1, and the fatty acid compositions of lipids (I) and (11) in Tables 2 and 3. The yields of total lipids from the seeds and flesh of the fruit amounted to 221.02 and 19.95 mg/g a.d.w, respectively. In spite of the large difference in their amounts, the main components of both samples were NLs with a predominance of triacylglycerides. The second components of the NLs q-antitatively were fatty acid esters with cyclic and aliphatic alcohols (FAEs) and, in the flesh, free fatty acids (FFAs). We must mention the presence of monoacylglycerols and diacylglycerols in the lipids of both samples, their proportion in the lipids of the flesh being higher than in the seeds and the tuberous roots [1].The level of polar lipids in the seeds of M. turcomanica was the same as in the tuberous roots [ 1] but far smaller than in the fruit flesh. Of the two groups of polar lipids, the GLs predominated in the flesh, and the PhLs in the seeds. The qualitative compositions of the GLs in the samples studied and in the tuberous roots were the same, but substantial difference...