Synthesis of glycopolymers bearing mannaric pendants as inhibitors on the β‐glucuronidase activity: The inhibition mechanisms of mannaric‐ and glucaric‐compounds

A new styrene derivative having D ‐mannaric moiety, N‐p‐vinylbenzyl‐D ‐mannaramic acid (VB‐D ‐ManaH, 8 ) was synthesized though the ring‐opening reaction of D ‐mannaro‐1,4:6,3‐dilactone (D ‐MDL) with p‐vinylbenzylamine. VB‐D ‐ManaH was copolymerized with acrylamide (AAm) to give novel polymers having D ‐mannaric moiety in the pendants, P(VB‐D ‐ManaH‐co‐AAm), 10 . The resulting glycomonomer and polymer ( 8 and 10 ) bearing D ‐mannaric pendants were found to inhibit the β‐glucuronidase activity, although the inhibition ability of the corresponding saccharodilactone (D ‐MDL) was known to be low. Additionally, the inhibition ability of P(VB‐D ‐ManaH‐co‐AAm), 10 , was almost the same as that of the glycopolymer having D ‐glucaric pendants, P(VB‐6‐D ‐GlcaH‐co‐AAm), 1 , which was one of the most effective inhibitors for β‐glucuronidase, reported in our previous work. Thus, 10 and 8 may be the first D ‐mannaric strong inhibitors to the β‐glucuronidase activity. The Lineweaver–Burk plot suggested that the inhibition mechanisms of 10 and 8 were more complicated than in the case of the competitive and uncompetitive inhibition of N‐p‐(vinylbenzyl)‐6‐D ‐glucaramic ( 11 ) and N‐p‐(vinylbenzyl)‐1‐D ‐glucaramic acids ( 12 ), respectively. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2032–2042, 2009