Isolation and structure elucidation of bio-active compounds from higher plants with special emphasis on antimicrobial, antimalarial, anticancer, immunostimulant and neuro-protective/ psychoactive agents. Isolation of marker compounds from high value dietary supplements and developing validated large-scale isolation methods. Developing new Environment-friendly isolation technology and device for the application of Centrifugal Preparative Chromatography using various types of binder- free sorbents, especially reversed- phase (C18) silica gel.