Design and synthesis of novel series of pyrrole based chemotypes and their evaluation as selective aldose reductase inhibitors. A case of bioisosterism between a carboxylic acid moiety and that of a tetrazole Original Research Article

Pyrrolyl-propionic and butyric-acid derivatives 1 and 2 were synthesized in order to study the effect of the variation of the methylene chain in comparison to the previously reported pyrrolyl-acetic acid compound I, which was found as potent aldose reductase inhibitor, while the pyrrolyl-tetrazole derivatives 3–5 were prepared as a non-classical bioisosteres of a carboxylic acid moiety. Also, pyrrolyl-tetrazole isomers 6 and 7 without an alkyl chain between the two aromatic rings were synthesized. The in vitro aldose reductase inhibitory activity of the prepared 1–7 compounds were estimated and compared with that of the initial compound (I). Overall, the data indicate that the presented chemotypes 6 and 7 are a promising lead compounds for the development of selective aldose reductase inhibitors, aiming to the long-term complications of diabetes mellitus.