Enhanced cytotoxicity of benzimidazole carbamate derivatives and solubilisation by encapsulation in cucurbit[n]uril
作者:Yunjie Zhao、Mohammad H. Pourgholami、David L. Morris、J. Grant Collins、Anthony I. Day
DOI:10.1039/c003732j
日期:——
The albendazole derivatives (2-methoxyethyl) 5-propylthio-1H-benzimidazole-2-yl carbamate (MEABZ), N1-(2-methoxyethoxycarbonyl)-2-amino-5-propylthiobenzimidazole and N1-(2-methoxyethoxycarbonyl)-2-amino-6-propylthiobenzimidazole (MEABZ isomers A and B) and (2-hydroxyethyl) 5-propylthio-1H-benzimidazole-2-yl carbamate (HEABZ) have been synthesised. The cytotoxicity of these compounds was evaluated against a human colorectal cancer cell line (HT-29) and a human prostate cancer cell line (PC-3). The results demonstrate MEABZ, a new benzimidazole, is up to ten times more cytotoxic than the parent drug albendazole, whereas the MEABZ isomers A and B and HEABZ show no activity. A comparison of the cytotoxicity of these compounds, relative to ABZ, provides structure–activity data for this important class of anticancer agents. The aqueous solubilities of MEABZ encapsulated in Q[n] have been determined by 1H NMR spectroscopy. The aqueous solubility of MEABZ at a physiologically relevant pH increased by 1200-fold by encapsulation in Q[8], from 8 μM to 9.4 mM, while Q[6,7] encapsulation substantially increased the solubility to more than 2 mM. Encapsulation in Q[7] and Q[8] induced significant upfield shifts for the MEABZ propyl and benzimidazole resonances. The upfield shifts indicate that the propyl and benzimidazole protons are located within the Q[7] and Q[8] cavity upon encapsulation. By contrast, encapsulation in Q[6] induced large upfield shifts for the 1H resonances from the carbamate functional group, indicating that MEABZ associates with Q[6] at its portals, with only the carbamate group binding within the cavity.
阿苯达唑衍生物(2-甲氧基乙基)5-丙硫基-1H-苯并咪唑-2-基氨基甲酸酯(MEABZ)、合成了 N1-(2-甲氧基乙氧羰基)-2-氨基-5-丙基硫苯并咪唑和 N1-(2-甲氧基乙氧羰基)-2-氨基-6-丙基硫苯并咪唑(MEABZ 异构体 A 和 B)以及(2-羟乙基)5-丙硫基-1H-苯并咪唑-2-基氨基甲酸酯(HEABZ)。评估了这些化合物对人类结直肠癌细胞系(HT-29)和人类前列腺癌细胞系(PC-3)的细胞毒性。结果表明,新型苯并咪唑 MEABZ 的细胞毒性是母药阿苯达唑的 10 倍,而 MEABZ 异构体 A 和 B 以及 HEABZ 则没有活性。通过比较这些化合物相对于阿苯达唑的细胞毒性,为这一类重要的抗癌药物提供了结构-活性数据。通过 1H NMR 光谱测定了 Q[n] 中封装的 MEABZ 的水溶性。封装在 Q[8] 中的 MEABZ 在生理相关 pH 值下的水溶性增加了 1200 倍,从 8 μM 增至 9.4 mM,而封装在 Q[6,7] 中的溶解度则大幅增至 2 mM 以上。在 Q[7] 和 Q[8] 中封装会引起 MEABZ 丙基和苯并咪唑共振的显著上场移动。上场移动表明,封装后丙基和苯并咪唑质子位于 Q[7] 和 Q[8] 腔内。相比之下,封装在 Q[6] 中会导致氨基甲酸酯官能团的 1H 共振发生较大的上场移动,这表明 MEABZ 与 Q[6] 的结合点在其端口,只有氨基甲酸酯基团结合在空腔内。