ABSTRACT
Uracil (I) (2,4-Diketo-pyrimidine) was isolated from the radix aconiti collected from Jiangyou region of Sichuan Province.The chemical structure of this principle was determined by elemental analysis,IR,UV,MS,'H and 13C-NMR spectral data. The experiments were made to study the effect of uracil (I) on the cardiac contractile force and beating rate of the isolated toad hearts in comparison with uracil (II) (artificial synthesis). The results indicated that the 5?mol/L of uracil (I) and uracil (II) both had the effect of increasing the amplitude of myocardial contraction (P0.05) at 3 and 5 min. When the concentration was increased to 10 and 20?mol/L, the amplitudes of myocardial contraction were more incremental and 3 min later,the estimated value of uracil (I) and uracil (II) to increase the amplitude of myocardial contraction by 50% approached to 4.17 and 4.68, respectively. As described above, uracil (I) is a new cardiotonic in Jiangyou Fuzi.