熊果酸衍生物的合成及其体外抗肿瘤活性评价

目的 通过合成系列熊果酸衍生物,测试其抑制肿瘤细胞增殖活性,探讨熊果酸衍生物抑制肿瘤细胞增殖的构效关系,获得抗肿瘤活性更好的熊果酸衍生物.方法 通过乙酰化反应对熊果酸的3-位羟基进行保护后,再将其28-位羧基制备成酰氯并与氨基酸酯反应,最后再在碱性条件下水解制备得28-位羧基被修饰的熊果酸衍生物.所有熊果酸衍生物的结构通过核磁共振氢谱(1HNMR)、核磁共振碳谱(13CNMR)和高分辨质谱(HRMS)进行确认.采用MTT法测试熊果酸衍生物抑制U937、HL-60、Jurkat、K562、DU145、EC109、MDA231和SMMC7721肿瘤细胞的增殖活性.结果 仪器分析结果表明所制备的熊果酸衍生物均为设计的目标化合物.对抑制U937肿瘤细胞增殖结果表明熊果酸28-位羧基被对4-氨甲基苯甲酸、7-氨基己酸和8-氨基辛酸修饰后,在给药浓度为5.0×10-6 mol/L时对U937细胞增殖的抑制率分别达到(18.84 ±2.58)％、(43.17±4.52)％和(68.38±7.95)％,明显优于母体熊果酸母体(10.06 ±2.35)％ (P ＜0.05).对Jurkat细胞增殖的抑制率则分别达到(68.42±8.19)％、(58.36±7.99)％和(61.08±5.77)％,远高于熊果酸的(6.89±2.31)％(P＜0.05).结论 对熊果酸28-位羧基进行延长修饰,有利于提高熊果酸的抗肿瘤活性,当延长7～8个碳原子,抗肿瘤效果最好.

Synthesis and in vitro antitumor activity of ursolic acid derivatives

Objective To investigate the quantitative structure-activity relationship of ursolic acid derivatives and antitumor activity by synthesizing a series of new derivatives and testing antitumor activity in vitro,in order to obtain novel ursolic acid derivatives with high antitumor activity.Methods After 3β-hydroxyl of ursolic acid was protected by acetylation reaction,the C28-carboxyl group was activated by oxalyl chloride following conjugated with different amino acid.The structures of all compounds were confirmed by 1HNMR,13CNMR spectroscopy and high resolution mass spectrometry (HRMS).Antitumor cell proliferative effects were quantified in the tumor cell lines U937,HL-60,Jurkat,K562,DU145,EC109,MDA231 and SMMC7721 by MTT assay.Results All prepared ursolic acid derivatives were desirable compounds that we had designed.When C28-carboxyl group of ursolic acid was conjugated with amino methyl benzoic acid,7-aminoheptanoic acid and 8-aminooctanoic acid respectively,the inhibitory activities of these derivatives against U937 cells at the concentration of 5.0 × 10-6 mol/L were (18.84 ±2.58)％,(43.17 ±4.52) ％ and (68.38 ± 7.95) ％,which significantly higher than ursolic acid [(10.06 ± 2.35) ％,P ＜ 0.05].Noteworthy,when these derivatives against Jurkat cells at the concentration of 5.0 × 10-6 mol/L,the inhibitory activities were(68.42 ± 8.19) ％,(58.36 ± 7.99) ％ and (61.08 ± 5.77) ％ respectively,and all of them were remarkably higher than that of ursolic acid [(6.89±2.31)％,P＜0.05].Conelusion Extended modification of C28-carboxyl group of ursolic acid is helpful to increase the antitumor activity of ursolic acid derivatives.The inhibitory activity will be more significant after extension of 7 to 8 carbon atoms.