Angelic acid is the (Z)-isomer of 2-methylbut-2-enoic acid. It is found in plant species of the family Apiaceae. It has a role as a plant metabolite. It is functionally related to an isocrotonic acid. Angelic acid is a monocarboxylic unsaturated organic acid, which is useful as perfume materials.

Tracheloside significantly decreases the activity of alkaline phosphatase (AP), an estrogen-inducible marker enzyme, with an IC(50) value of 0.31 microg/ml, a level of inhibition comparable to that of tamoxifen (IC(50) = 0.43 microg/ml). Tracheloside is a natural product found particularly in Carthamus tinctorius and Trachelospermum. It has a role as a metabolite. It is a glycoside and a lignan.