Is it important to mention the assay, the purification and characterization in the title? Yes if you are developing a new technique or way of purification, then the technique should be mentioned first because that's your main headlines. If you are reporting the characteristics of xxxxx bioactive compounds, then better to mention what it is for. For example, "the bioactive principles from xxxxx demonstrate anti-cancer/anti-aging/....whatever..." or "the bioactive principles from xxxxx is a potent yyyyyy".

I shall be using a plant which is yet to be screened for bioactive compounds. During chromatographic separation i will continuously screen the compounds for in-vitro radical scavenging activity and the ones showing activity will be spectroscopically elucidated.