Three previously undescribed nor-eremophilane sesquiterpenoids from the fungus Penicillium sp. L1 associated with basalt fibre

Three new nor-eremophilane sesquiterpenoids, namely nor-eremophilanol A-C (1–3), along with two known eremophilanes (4–5), were isolated from the culture of the fungus Penicillium sp. L1 that was obtained from the surface of basalt fibre composite bars. The structures of the new compounds were elucidated by a combined analysis of the 1D, 2D NMR, and HRMS spectroscopic data, and the absolute configuration of 1 was determined by the modified Mosher's method. The biosynthetic pathway leading to the nor-eremophilanes were proposed with the oxidative cleavage of the double bond as a key step. Compound 1 displayed antibacterial activities against the tested pathogenic bacteria.