| abstract |
Compounds of the general formula: <IMAGE> (I') wherein A and B are both hydrogen, or one of A and B is a group (G) of the formula: <IMAGE> (G) and the other is a group R5 wherein R1 is an aryl group or a heterocyclic group, both of them being optionally substituted, and R4 and R5 are both hydrogen or together form a single chemical bond, R2 and R2' are independently hydrogen, halogen, nitro, lower alkyl or lower alkoxy, and R3 and R3' are independently carboxy or its functional derivative, with the proviso that (a) when A and B are both hydrogen, then R2 and R2' cannot be both hydrogen, and, where applicable, pharmaceuticably acceptable salts thereof are hyaluronidase inhibitors, and useful as anti-allergic agent and anti-ulcerous agent. Among the compound (I'), those wherein when one of A and B is the group (G) and the other is the group R5 wherein R4 and R5 together form a single chemical bond, R1 is unsubstituted aryl and R2 and R2' are both hydrogen, then R3 and R3' are independently carboxy or its functional derivative other than methyl ester, are novel. |