Twenty-two alkaloids, were isolated from Fumaria densiflora. Two of these alkaloids, N-methyl-5-hydroxystylopine chloride and fumaricine N-oxide, were isolated for the first time from natural sources. Parfumine and fumaritine, in concentrations ranging from 3 × 10−7 to 9 × 10−4M, caused concentration–dependent relaxation of ileum longitudinal segment. Also, parfumine and fumaritine in concentrations ranging from 3 × 10−4 to 9 × 10−2M, caused concentration–dependent decrease in heart rate of the isolated perfused heart. A concentration of parfumine of 3 × 10−2 M increased but a higher concentration (9 × 10−2 M) decreased the amplitude of contraction of the isolated perfused heart. On the other hand, fumaritine, in concentrations ranging from 3 × 10−4 to 3 × 10−2 M, caused concentration–dependent increase, but a higher concentration (9 × 10−2 M) caused a decrease in the amplitude of contraction of the isolated perfused heart. (Figure presented.). © 2019, © 2019 Informa UK Limited, trading as Taylor & Francis Group.