在B3LYP/6-31G(d, p)水平下优化了四种姜黄素类似物的几何构型, 并通过振动分析验证了其构型稳定性。 在B3LYP/6-311G(d, p)水平下计算了该类化合物的核磁共振谱, 研究结果表明: 四种化合物主体结构共平面性较好, 为一较大共轭体系。 由于羟基及甲氧基的引入, 使Compound-B/C/D中C3, C4以及Compound-A/D中C5均具有较大δ值, Compound-A中C4和C6的δ值相对较小, C3的δ值相对较大。 而在羰基与碳碳双键所形成的共轭羰基化合物中, 羰基C13的δ值(183 ppm)相对于乙醛中的δ值(201ppm)有所减小, C11, 15(α碳)的δ值(122 ppm)相对减小, 而C9, 17(β碳)的δ值(145 ppm)相对增大。 最后, 通过线性回归方法, 利用相关系数值r研究了1H NMR δ值的实验和理论计算值的相关性, 结果表明相关性较好, 实验值和理论值基本吻合。

The structure of four kinds of curcumin analogues was optimized at the level of B3LYP/6-31G(d,p), under which the stability was verified by means of vibration analysis. Moreover, NMR spectra of curcumin analogues compounds were studied at the level of B3LYP/6-311G(d,p) by GIAO method. The results show that the structure of four kinds of compounds, a larger conjugated system, has good planarity. Because of introducing hydroxyl and methoxy, the compound-B/C/D-C3, C4 and compoud-A and compound-D-C5 have greater δ value. δ value of compound-A-C4. C6 is relatively smaller, and δ value of C3 is relatively larger. In the conjugated carbonyl compounds, compared with the acetaldehyde δ value (201 ppm), carbonyl C13 δ value(183 ppm) decreases relatively, C11, 15(α-carbon) δ value(122 ppm) decreases relatively, and C9,17(β-carbon) δ value(145 ppm) increases relatively. Finally, the correlation between experimental δ value and theoretical δ value of the 1H NMR was analyzed through the linear regression method. Results show that they have good correlation, and the experimental values coincide with the theoretical values.