Chemo-enzymatic synthesis of vinyl and L-ascorbyl phenolates and their inhibitory effects on advanced glycation end products

This study successfully established the feasibility of a two-step chemo-enzymatic synthesis of L-ascorbyl phenolates. Intermediate vinyl phenolates were first chemically produced and then underwent trans-esterification with L-ascorbic acid in the presence of Novozyme 435 (R)(Candida Antarctica lipase B) as a catalyst. Twenty vinyl phenolates and 11 ascorbyl phenolates were subjected to in vitro bioassays to investigate their inhibitory activity against advanced glycation end products (AGEs). Among them, vinyl 4-hydroxycinnamate (17VP), vinyl 4-hydroxy-3-methoxycinnamate (18VP), vinyl 4-hydroxy-3,5-dimethoxycinnamate (20VP), ascorbyl 4-hydroxy-3-methoxycinnamate (18AP) and ascorbyl 3,4-dimethoxycinnamate (19AP) showed 2-10 times stronger inhibitory activities than positive control (aminoguanidine and its precursors). These results indicated that chemo-enzymatically synthesized compounds have AGE inhibitory effect and thus are effective in either preventing or retarding glycation protein formation. (C) 2016 Elsevier Ltd. All rights reserved.