T R Seshadri’s Contributions to the Chemistry - Resonance

Seshadri developed many reagents and synthetic procedures which he used for elucidation and synthesis of natural products, in particular flavonoids.

It is by no means easy to bring under the confines of an article the research output of someone like T R Seshadri whose scientific studies spanned nearly half a century and were prolific. To choose just a few examples from as many as a thousand and odd papers is a Herculean task and I am aware that my selections will not be free from subjective considerations. One or two cases have been chosen only because I can write about them with familiarity on account of my own personal involvement in them. Through these examples I can, therefore, convey the manner in which he trained his students in research methods. His approach towards elucidating the structure of a new naturally occurring compound was comprehensive and classical in the sense that it involved analytical, degradative as well as synthetic experiments. In later years, spectroscopic data were also extensively used in addition to conventional chemical methods. At Andhra University, he focused his attention almost exclusively on the flavonoids. At Delhi, while building up on the foundations laid at Waltair, he also considerably widened the scope of his investigations and several other types of secondary metabolites, such as the different types of terpenoids, seneceo alkaloids, quinonoids and lichen metabolites (such as depsides, depsidones, etc.), were isolated and their structures elucidated. However, his main forte remained the chemistry of oxygen heterocyclics, which he enriched in no small measure. What follows is a very brief account of some of his achievements in this area.