Significant contributions have been made in the area of medicinal chemistry. Detailed chemical and biological investigations of selected Indian medicinal and aromatic plants resulted in the isolation and identification of a number of new anticancer, antimalarial, antifilarial, antipsychotic, antitubercular, immunomodulatory, antidiabetic, antioxidant, antimicrobial and bioenhancing leads. Similarly many semi-synthetic derivatives have shown potent anticancer activity against hormone-dependent breast cancer, oral and liver cancer cell lines. Some of these natural compounds were also studied for QSAR, docking and ADMET guided lead optimization and the results are very interesting and may be of great help in the drug development from very common, inexpensive, and nontoxic natural products. Using modern Fast Centrifugal Partition Chromatographic (FCPC) method, novel preparative scale isolation processes for several bioactive molecules have been developed.