Mugla Sitki Kocman University, Faculty of Science, Department of Chemistry, 48000 Mugla, Turkey.
J Chromatogr B Analyt Technol Biomed Life Sci. 2012 Nov 15;909:51-60. doi: 10.1016/j.jchromb.2012.09.039. Epub 2012 Oct 11.
Aminophenyl boronic acid (APBA) carrying uniform-macroporous poly(chloromethylstyrene-co-divinylbenzene), poly(CMS-co-DVB) particles were synthesized for selective separation of cis-diol-containing flavonoids from plant extracts. For this purpose, 2.5 μm polystyrene seed particles were first swelled by a mixture of dibutyl phthalate (DBP), toluene and dodecanol, then by a monomer mixture including CMS and DVB. The repolymerization of the monomer phase in the swollen seed particles provided macroporous and uniform particles, approximately 7 μm in size. Chlorine atoms on the surface of these particles were derivatized with APBA to gain affinity properties for flavonoids containing vicinal hydroxyl groups. Model adsorption studies showed that these particles selectively adsorbed quercetin and rutin containing cis-diol groups, but did not adsorb apigenin similar to quercetin and not carrying cis-diol groups. These particles were also tested in adsorption/desorption studies for ethanol and ethyl acetate extracts of the Hypericum perforatum (HP) stems to obtain high antioxidant mixtures. With ethanol extract, the antioxidant activity of the desorption solution was a bit higher than that of the post-adsorption solutions. However, the DPPH radical scavenging activity of the desorption solution decreased with respect to the original extract and post-adsorption solutions. A similar result was obtained for the antioxidant activity of the desorption solution using ethyl acetate extract. An interesting result was obtained that DPPH radical scavenging activity of the post-adsorption solution was higher than that of the original ethyl acetate extract and desorption solutions. These results were attributed to selective adsorption of antioxidant characterized cis-diol-containing apolar molecules much more rather than that radical scavenger characterized polar molecules.
载有均一的大孔聚（氯甲基苯乙烯-共-二乙烯基苯）的氨苯基硼酸（APBA）被合成，用于从植物提取物中选择性分离含有顺二醇的类黄酮。为此，首先将 2.5μm 聚苯乙烯种子颗粒用邻苯二甲酸二丁酯（DBP）、甲苯和十二醇的混合物溶胀，然后用包括 CMS 和 DVB 的单体混合物溶胀。溶胀种子颗粒中的单体相的再聚合提供了大约 7μm 大小的大孔和均匀的颗粒。这些颗粒表面的氯原子被 APBA 衍生化，以获得对含有邻二醇基团的类黄酮的亲和性。模型吸附研究表明，这些颗粒选择性地吸附含有顺二醇基团的槲皮素和芦丁，但不吸附类似于槲皮素且不含有顺二醇基团的芹菜素。这些颗粒还在 Hypericum perforatum（HP）茎的乙醇和乙酸乙酯提取物的吸附/解吸研究中进行了测试，以获得高抗氧化混合物。对于乙醇提取物，解吸溶液的抗氧化活性略高于吸附后溶液。然而，与原始提取物和吸附后溶液相比，解吸溶液的 DPPH 自由基清除活性降低。对于使用乙酸乙酯提取物的解吸溶液的抗氧化活性，得到了类似的结果。一个有趣的结果是，吸附后溶液的 DPPH 自由基清除活性高于原始的乙酸乙酯提取物和解吸溶液。这些结果归因于选择性吸附特征为含有顺二醇的非极性分子的抗氧化剂，而不是特征为自由基清除剂的极性分子。
