The invention discloses a novel series of compound represented by general
formula (I), ##STR00001## its derivatives, analogs, tautomeric forms,
stereoisomers, polymorphs, pharmaceutically acceptable salts, and
solvates wherein X, n, k, z, R1, R2, R3, R4, R5 and R6 are as defined in
the specification that are useful in (i) normalizing elevated blood
glucose levels in diabetics, (ii) treating disorders related to glucose
intolerance and (iii) for scavenging free radicals in mammals.