Enzymatic hydrolysis of esters of alkali labile carotenols

Esters of alkali labile carotenols were hydrolyzed enzymatically with pig liver esterase in Tris-HCl buffer containing 10-85% methanol or acetone. The natural acetates peridinin, fucoxanthin, 19'-butanoyloxyfucoxanthin, pyrrhoxanthin and synthetic actinioerythrol diacetate provided the corresponding carotenols in 85%, 45%, (5 + 5 + 30)%, 65% and (30 + 3)% of the recovered carotenoid with total pigment recoveries 60%, 73%, 88%, 52% and 66%, respectively. (3RS, 3'RS)-Astaxanthin dipalmitate was converted enzymatically with lipase in low yield to the monopalmitate and free astaxanthin (5% + 6%, pigment recovery 93%) with a preferred hydrolysis of the S-ester. The (R,R:R,S:S,S) ratio of substrate dipalmitate and product astaxanthin changed from 1:2:1 to 1:5:3.