STEROL COMPOSITION IN COINCYA (BRASSICACEAE)

Sterol composition was determined for seed oils and leaf waxes in elev en taxa belonging to the genus Coincya (Brassicaceae) on the Iberian P eninsula (Spain and Portugal). Seed sterols ranged from 1.2 to 6.7%. T he major components were sitosterol (42.6-54.6%), campesterol (20.4-33 .2%), and brassicasterol (10.8-23.5%). In leaf waxes, the major free s terols were sitosterol (40.9-74.2%), campesterol (9.6-17.0%), and chol esterol (4.6-17.0%). In leaf wax esters, the major sterols were sitost erol (22.2-56.5%), cholesterol (7.3-32.8%), and campesterol (5.8-25.6% ). An apparent substitution of brassicasterol in free sterols from the seeds by cholesterol in free sterols from the leaves was observed. Th ere was an increase of cholesterol in sterols from leaf wax esters wit h respect to free sterols from leaves and seeds. In C. monensis subsp, nevadensis, the composition in sterols from leaf waxes may be an adap tation to low temperatures.