Cerebrosides in Mature-green and Red-ripe Bell Pepper and Tomato Fruits

Almtract--Cerebrosides (CBs) isolated from pericarp lipids of green and red bell pepper and tomato fruits were separated by a new HPLC method into/> six components. HPLC profiles were similar for the two fruits and changed little with ripening. CB 1 was the major peak, CB 2 was found only in bell pepper, and CBs 4, 5 and 6 were more abundant in pepper than in tomato. Total CBs and HPLC CB fractions were cleaved for analysis of fatty acid (FA), sphingoid (SP) and sugar moieties. FAs of total CBs were >95% saturated 2-hydroxyl. In CBs 1 and 2, 2-hydroxyl 16: 0 was i>98% of the total FAs, whereas 2-hydroxyl 22: 0, 23 : 0 and 24: 0 predominated in CBs 4-6. The SPs of CBs 1 and 2 were tentatively identified as the 8-cis and 8-trans isomers of 4,8-sphingadienine and 8-sphingenine, respectively, whereas the SPs of CBs 4-6 were identified as isomers of 4-hydroxy-8-sphingenine. Glucose was the only sugar in bell pepper and tomato CBs. The major CB in both fruits was deduced to be 1 -O-flglucosyl-N(2' hydroxypalmitoyl)-4-trans8-cissphingadienine.