Dear Arun

You have not mentioned the nature of compound (phytochemicals, peptides, enzymes etc.,). Generally for low molecular weight phytochemicals you can use soxhlet or different types of esperimental designs for the extraction. Then you can use column or preparative thin layer chromatography for isolation. You can use HPLC coupled with LC-MS for structure prediction. For volatile compounds you can use GC-MS for structure prediction.

Thank you

Dear Arun Kumar Ramu to isolate any compound from plant material we must be know the nature of these copound and what classes it belong to, flavonoids, alkaloids, terpens, saponins or any compounds. there are many different types of isolation methods paper chromatography, thin layer chromatography, HPLC, or any methods according to the type of the major constituents occur