You can look at the recent paper from Brglez Mojzer et al. in Molecules journal. You will show the numerous activities of phenolics (antioxidant, anticancerous, antidiabetic, neuroprotective, antiinflammatory,...).
you start with the study of antioxidant activities (DPPH, ABTS, .....) and anti enzymatic (alpha glucosidase, colinesterase ....) Biological activity is the inhibition of microorganisms (bacteria and fungi) There are plenty of articles and studies on that. Good luck