Production of optically active sphingoid compound

A method for producing an optically active erythro sphingoid ester of the formula I:

• wherein R1 and R2, may be the same or different, represent an aliphatic hydrocarbon having 7 to 31 carbon atoms which may be substituted by one or more hydroxyl groups, and
• R3 and R4 may be the same or different and represent an acyl group having 1 to 7 carbon atoms,
• which comprises:
• allowing a racemic mixture comprising the optically active sphingoid ester of the formula I as defined above and its enantiomer to contact with an esterase having an ability to selectively hydrolyze the said enatiomer of the optically active sphingoid ester of the formula I to produce an optically active sphingoid alcohol compound of the formula II:
• wherein R1 and R2 have the same meaning as defined above, and
• R3*, and R4* represent a hydrogen atom and an acyl group having to 7 carbon atoms provide that R3*, and R4* do not simultaneously represent an acyl group having 1 to 6 carbon atoms;
• and
• recovering the optically active erythro sphingoid ester of the formula I.