Separation of organic compounds binding trace elements in seeds of Leuzea carthamoides (Willd.) DC

The distribution of trace elements into important groups of compounds in seeds was investigated using a seven-step sequential extraction of seed biomass (solvents used: petroleum ether, ethyl acetate, butanol, methanol, methanol + H2O (1 + 1; v/v), H2O, methanol + H2O + HCl (49.3 + 49.3 + 1.4; v/v/v)). Isolated fractions were partially characterized using IR spectroscopy. Results of sequential analysis showed different portions of the elements investigated in individual fractions. The dominant portions of cadmium (60.6% of total content), lead (41%), zinc (77.8%) and copper (33.9%) were found in the methanol + H2O + HCl fractions (compounds isolated from cell walls and cytoskeleton after hydrolysis - phytic acid and its salts, proteins). The second most significant fractions for cadmium, zinc and lead were in the water fractions (pectin, phytin) and for copper in the methanol fraction (acids of citric cycle). The ethyl acetate fraction, mainly containing lignans and phospholipids, had the highest portion of arsenic (34.2%). Lignans are common compounds for seeds of Leuzea carthamoides. Therapeutic compounds of L. carthamoides (20-hydroxyecdysone, N-feruloylserotonin isomers) were confirmed in the first four fractions by thin-layer chromatography. Copyright (C) 2004 John Wiley Sons, Ltd.