The new natural 2-quinoline alkaloid acusine in addition to N-methyl-2-phenylquinolin-4-one and pedicine were isolated from Haplophyllum acutifolium. The structure of acusine was determined using IR and NMR spectral data. The structures of N-methyl-2-phenylquinolin-4-one and pedicine were proven by XSAs. © 2020, Springer Science+Business Media, LLC, part of Springer Nature.