Thanks everyone for the great responses.

The thing that fascinates me is the lack of information about it, which means that there is so much to explore. I would like to try to do an extraction, when I have the suitable amount of plant material.

My plan is to dissolve it in ethyl acetate (possibly some other solvent) and apply the Dragendorff reagent to it, to determine if alkaloids are present.

If the reagent shows negative results, I want to devise a method for testing if terpens are present and test that.

My other plan is to test if it is at all psychoactive, which it might or might not be.

EDIT: I managed to discover a paper about compounds contained in Coleus from 2001, which seemed to go unnoticed on the internet, which renders my diterpens test obsolete, though I might still do the alkaloid, just to be sure. http://cpb.pharm.or.jp/cpb/200107/c07_0927.pdf