A new alkaloid designated as aspergicin (1), together with a previous secondary metabolite, neoaspergillic acid (2), and a common compound, ergosterol (3), were isolated from the mixed cultured mycelia of two marine-derived mangrove epiphytic Aspergillus sp. fungi. Extensive application of 1D and 2D NMR techniques was made to characterize the structure and to establish the 1H and 13C assignments of compound 1. In the antibacterial assays, both compounds 1 and 2 showed significant antibacterial activity against some selected Gram bacteria.