Aldotetroses and C(3)-Modified Aldohexoses as Substrates for N-Acetylneuraminic Acid Aldolase: A Model for the Explanation of the Normal and the Inversed Stereoselectivity
作者:Wolfgang Fitz、Jan-Robert Schwark、Chi-Huey Wong
DOI:10.1021/jo00117a016
日期:1995.6
The four stereoisomeric aldotetroses were accepted with different reactivities by N-acetylneuraminic acid aldolase. C(3)-modified D-mannose and D-glucose derivatives, respectively, failed to undergo enzymatic aldol addition. Based on the observed reactivities of the tested compounds (about 58), a mechanistic scheme is proposed which relates substrate structure, reactivity and stereochemical outcome observed in Neu5Ac aldolase-catalyzed reactions. The condensation products obtained in the L-erythrose and D-threose reactions are side-chain modified sialic acid and D-KDO derivatives, respectively, of biological interest.