A new macrolactin derivate, 7-O-2'E-butenoyl macrolactin A (1), together with three known macrolactin compounds, macrolactin A (2), 7-O-malonyl macrolactin A (3) and 7-O-succinyl macrolactin A (4), was isolated from the bacterial strain Bacillus subtilis B5, which was isolated from the 3000 m deep sea sediment of the Southwest Pacific Ocean. The structures of the new compounds were assigned by spectroscopic methods including 1-D/2-D NMR and MS analysis techniques. Compounds 1 and 2 demonstrated antifungal activities against tea pathogenic fungi Pestalotiopsis theae and Colletotrichum gloeosporioides.
Keywords: B5; 7--2′-butenoyl macrolactin A; antifungal activity.