Two New Eremophilane-Type Sesquiterpenoids from Japanese Liverwort Bazzania japonica

Two new eremophilane-type sesquiterpenoids, fusumaols A (1) and B (2), were isolated from the stem-leafy liverwort, Bazzania japonica collected in Mori-Machi, Shizuoka, Japan. Their structures were established using extensive spectroscopic (IR, MS, and 2D NMR) data, and the absolute configuration of 1 was determined by the modified Mosher's method. This is the first time eremophilanes have been discovered in the liverwort genus Bazzania. Compounds 1 and 2 were evaluated for their repellent activity against the adult population of the rice weevil Sitophilus zeamais using the modified filter paper impregnation method. Both sesquiterpenoids showed moderate repellent activities.

Automated summary

Two new eremophilane-type sesquiterpenoids, fusumaols A and B, were isolated from the stem-leafy liverwort, Bazzania japonica, collected in Mori-Machi, Shizuoka, Japan. The structures of the compounds were determined using extensive spectroscopic techniques, and the absolute configuration of compound 1 was determined by the modified Mosher's method. This is the first report of eremophilanes in the liverwort genus Bazzania. The repellent activities of compounds 1 and 2 against rice weevils were evaluated using the modified filter paper impregnation method, showing moderate repellent activities.