A new sesquiterpene glucoside (1), two new norsesquiterpenes (2, 3), and a new homomonoterpene (4), named myobontioids A-D respectively, along with twelve known flavonoids and lignans (5-16) were isolated from Myoporum bontioides A. Gray. Flavanones 5-11 specifically inhibited Phytophthora capsici and Magnaoeporthe grisea at the concentrations of 125, 250 and 500 µg.mL-1. Notably, the new compound 4 possessed a strong activity against Phytophthora capsici with IC50 below 63.5 µg.mL-1 and 90.4% inhibition at 125 µg.mL-1.
Keywords: Myoporum bontioides; antifungal activity; homomonoterpene; myobontioids A-D; norsesquiterpene; sesquiterpene glucoside.