Structure–Activity Relationship of Oligomeric Flavan-3-ols: Importance of the Upper-Unit B-ring Hydroxyl Groups in the Dimeric Structure for Strong Activities
作者:Yoshitomo Hamada、Syota Takano、Yoshihiro Ayano、Masahiro Tokunaga、Takahiro Koashi、Syuhei Okamoto、Syoma Doi、Masahiko Ishida、Takashi Kawasaki、Masahiro Hamada、Noriyuki Nakajima、Akiko Saito
DOI:10.3390/molecules201018870
日期:——
Proanthocyanidins, which are composed of oligomeric flavan-3-ol units, are contained in various foodstuffs (e.g., fruits, vegetables, and drinks) and are strongly biologically active compounds. We investigated which element of the proanthocyanidin structure is primarily responsible for this functionality. In this study, we elucidate the importance of the upper-unit of 4–8 condensed dimeric flavan-3-ols for antimicrobial activity against Saccharomyces cerevisiae (S. cerevisiae) and cervical epithelioid carcinoma cell line HeLa S3 proliferation inhibitory activity. To clarify the important constituent unit of proanthocyanidin, we synthesized four dimeric compounds, (−)-epigallocatechin-[4,8]-(+)-catechin, (−)-epigallocatechin-[4,8]-(−)-epigallocatechin, (−)-epigallocatechin-[4,8]-(−)-epigallocatechin-3-O-gallate, and (+)-catechin-[4,8]-(−)-epigallocatechin and performed structure–activity relationship (SAR) studies. In addition to antimicrobial activity against S. cerevisiae and proliferation inhibitory activity on HeLa S3 cells, the correlation of 2,2-diphenyl-l-picrylhydrazyl radical scavenging activity with the number of phenolic hydroxyl groups was low. On the basis of the results of our SAR studies, we concluded that B-ring hydroxyl groups of the upper-unit of the dimer are crucially important for strong and effective activity.
原花青素是由低聚黄烷-3-醇单位组成的,存在于各种食品(如水果、蔬菜和饮料)中,是一种具有很强生物活性的化合物。我们研究了原花青素结构中哪种元素主要负责这种功能。在这项研究中,我们阐明了 4-8 缩合二聚体黄烷-3-醇上部单元对酿酒酵母(S. cerevisiae)和宫颈上皮样癌细胞株 HeLa S3 增殖抑制活性的重要性。(-)-表没食子儿茶素-[4,8]-(-)-表没食子儿茶素-3-O-没食子酸酯,以及(+)-儿茶素-[4,8]-(-)-表没食子儿茶素,并进行了结构-活性关系(SAR)研究。 除了对葡萄孢菌的抗菌活性和对 HeLa S3 细胞的增殖抑制活性外,2,2-二苯基-l-苦基肼自由基清除活性与酚羟基数目的相关性较低。根据我们的 SAR 研究结果,我们得出结论:二聚体上部单元的 B 环羟基对于强有效的活性至关重要。