五种二氢吡啶光稳定性比较

 目的：比较5种1，4-二氢吡啶在阳光、漫射光和灯光下的稳定性，探讨4-位取代基与光稳定性的定量构效关系(QSAR)。方法：5种1，4-二氢吡啶分别曝露于阳光、漫射光和灯光下，不同时间点取样进行反相HPLC分析，测定各自条件下的光解反应速率常数(K_app)和半衰期(t_1\2)，分别建立4-位取代基的VX常数与K_app和t_1\2的QSAR。结果：硝苯吡啶在阳光、漫射光和灯光下均呈一级动力学降解，K_app分别为(1.02±0.20)min^-1,(0.022±0.006)min^-11和(0.015±0.004)min^-1。间硝苯啶、呋喃吡啶、氯苯吡啶和苯吡啶在漫射光和灯光下保持稳定，在阳光下可被光解，各自的K_app分别为(0.21±0.07)h^-1,(0.03±0.02)h^-1,(0.019±0.003)h^-1和(0.012±0.001)h^-1?阳光下5种1,4-二氢吡啶的t_1\22分别为0.68min，3.3，24，37和58h。QSAR:K_app=2.0081-2.9876V_X+1.0885(V_X)²-2.5749×10^-5(V_X)(r=0.9046)。结论：1，4-二氢吡啶类化合物的光稳定性，不仅与4-位取代基

Comparison of photosensitivity of five dihydropyridines

OBJECTIVES: To compare the photosensitivity of five 1, 4-dihydropyridines (1, 4-DHPs) to sunlight, diffused light and tungsten lamp and study the quantitative structure activity relationship of five 1, 4-DHPs between the photosensitivity and 4-substituents and 4-substituented phenyl group. METHODS: Five 1, 4-DHPs were exposed to sunlight, diffused light and tungsten lamp respectively. Samples taken at different time were analyzed by reversed phase high performance liquid chromatography. Photochemical degradation rate constant (K_app) and half time (t_1/2) of each 1, 4-DHPs were determined. The QSAR of five 1, 4-DHPs between the V_X and 4-substituents and K_app and t_1/2 was worked out respectively. RESULTS: Nifedipine was photochemically degraded in first order reaction when exposed to sunlight, diffused light and tungsten lamp, and the K_app was (1.02±0.20)min^-1, (0.022±0.006)min^-1 and (0.015±0.004)min^-1, respectively. M nifedipine, furandipine, chlorophenyldipine and phenyldipine were photochemically stable when exposed to diffused light and tungsten lamp. However, they were photochemically degrable when exposed to direct sunlight and the K_app of them was (0.21±0.07)h^-1, (0.03±0.02)h^-1, (0.019±0.003)h^-1 and (0.012±0.001)h^-1, respectively. The t_1/2 of five 1, 4-DHPs when exposed to sunlight was 0.68 min, 3.3, 24, 37 and 58 h, respectively. QSAR equation: K_app=2.008 1-2.987 6V_X+1.088 5(V_X)2-2.574 9×10^-5(V_X)3(r=0.904 6). CONCLUSION: The photosensitivity of 1, 4-DHPs are related not only to 4-substituents, but also to the properties and positions of the substituents on 4-phenyl group.