AIM:To investigate the quinoline alkaloids from the roots of Dictamnus angustifolius G.Don ex Sweet(Rutaceae).METHOD:The quinoline alkaloids were isolated by various column chromatographic methods and their structures were elucidated on the basis of spectral analysis.RESULTS:A new quinoline alkaloid,5-methoxylrobustine(1),along with five known quinoline alkaloids were obtained,and their structures were identified as dictamnine(2),robustine(3),isopteleine(4),γ-fagarine(5),and skimmianine(6).Cytotoxicity testing of these alkaloids showed that all of them had weak cytotoxic activities against human breast cancer cells(MCF7).CONCLUSION:Compound 1 is a new quinoline alkaloid.Alkaloid 3 showed stronger anti-proliferation effect than the other alkaloids. A to investigate the quinoline alkaloids from the roots of Dictamnus angustifolius G. Don ex Sweet (Rutaceae). METHOD: The quinoline alkaloids were isolated by various column chromatographic methods and their structures were elucidated on the basis of spectral analysis .RESULTS: A new quinoline alkaloid, 5-methoxylrobustine (1), along with five known quinoline alkaloids were obtained, and their structures were identified as dictamnine (2), robustine (3), isopteleine (4), γ-fagarine (5), and skimmianine 6). Cytotoxicity testing of these alkaloids showed that all had them weak cytotoxic activities against human breast cancer cells (MCF7) .CONCLUSION: Compound 1 is a new quinoline alkaloid. Alkaloid 3 showed stronger anti-proliferation effect than the other alkaloids.