Isatin: A Scaffold with Innumerable Biodiversity
: Isatin is an endogenous and a significant category of fused heterocyclic component, widely been a part of several potential biologically useful synthetics. Since its discovery, tons of research work has been conducted with respect to the synthesis, chemical properties, and biological and industrial applications. It contains indole nucleus having both lactam and keto moiety which while being a part of a molecular framework exerted several biological effects, viz.; antimicrobial, antitubercular, anticonvulsant, anticancer etc. Isatin derivatives are synthetically significant substrates, which can be utilized for the synthesis of huge diversified chemical entities of which few members emerged to be a drug. The reason for this review is to provide extensive information pertaining to the chemistry and its significance in altering several pathological states of isatin and its derivatives. A Structure Activity Relationships study thus developed through a gamut of scientific information indicates the importance of mostly electron withdrawing groups, halogens, nitro, alkoxy and to a minor extent groups with positive inductive effects, such as methyl at position 1, 5, 6 and 7 of isatin in alleviating several clinical conditions. It is also observed from the survey that the presence of two oxo groups at position 2 and 3 sometimes become insignificant as fusion with a heterocycle at those position resulted in a biologically relevant compound.