Identification of small molecules formed from polymethyl glyoxylate degradation in vitro

The ultimate degradation of poly(methyl glyoxylate) (PMG) leads to glyoxyli c acid which is a metabolite. Nevertheless, in a confined medium, various e quilibria can occur between ester, acid, hemiacetal and acetal functions an d a priori different molecules can be formed. Thus, whatever the applicatio n expected for this polymer and particularly in the case of pharmaceutical applications, it is of the first importance to know the compounds able to b e released during its degradation. In this work, hydrolysis of small model molecules was followed by using H-1 NMR to understand the hydrolytic mechan ism of this type of molecule. Consequently, the degradation of PMG in a con fined aqueous medium is elucidated and, among the considered molecules, fou r are finally detected in water: methyl glyoxylate hydrate (HMG), 2-hydroxy -2-methoxy-methylacetate (HMMA) and, as main products, glyoxylic acid hydra te (HGA) and 2-hydroxy-2-methoxy-acetic acid (HMAA). (C) 1999 Elsevier Scie nce Ltd. All rights reserved.