A new series of N-arylalkylaminoquercitols were synthesized by reductive amination of aminoquercitol bisacetonide 5 and a variety of aryl aldehydes. The targeted N-substituted aminoquercitols having phenolic moiety (7a-7c) displayed significantly enhanced alpha-glucosidase inhibition, which is 26-32 times more potent than that of the unmodified aminoquercitol 6. In addition, compounds 7a-7c also retained antioxidant activity with relatively more pronounced potency than their original phenolics. This recent finding suggests an approach to develop effective antidiabetic agents by incorporating antioxidative moiety into aminocyclitol core structure. (C) 2015 Elsevier Ltd. All rights reserved.
Amine-linked diquercitols as new α-glucosidase inhibitors
Two new diastereomeric amine-linked diquercitols 7 and 8 were synthesized by reductive amination of ketoquercitol 4 and epimeric aminoquercitols 3 and 6. The ketone and amines were successfully prepared, without the formation of byproducts, from naturally available (+)-proto-quercitol (1). The amine-linked diquercitols showed inhibitory effect against alpha-glucosidases with more pronounced potency than their original aminoquercitol monomers. (C) 2014 Elsevier Ltd. All rights reserved.