Momordicin-28 or 13-hydroxy-28-methoxy-urs-11-en-3-one is a triterpene compound with formula C31H50O3 found in the fresh fruit of the bitter melon (Momordica charantia).

[1] The compound is soluble in ethyl acetate and chloroform but not in petrol.

It crystallizes as fine needles that melt at 121−122 °C.

It was isolated in 1997 by S. Begum and others.

[1]