Theiler Barbara A, Istvanits Stefanie, Zehl Martin, Marcourt Laurence, Urban Ernst, Caisa Lugardo O Espinoza, Glasl Sabine
Department of Pharmacognosy, University of Vienna, Althanstraße 14, A-1090, Vienna, Austria.
Department of Pharmaceutical Chemistry, University of Vienna, Althanstraße 14, A-1090, Vienna, Austria.
Phytochem Anal. 2017 Mar;28(2):87-92. doi: 10.1002/pca.2651. Epub 2016 Dec 2.
α-Glucosidase inhibitors form an essential basis for the development of novel drugs in diabetes type 2 treatment. Searching for α-glucosidase inhibitors in plants, TLC bioautographic assays have been established and improved within the last years. In traditional medicine, extracts from the leaves of Justicia secunda Vahl are used to treat diabetes mellitus symptoms.
To screen for α-glucosidase inhibitors in J. secunda via HPTLC bioautography. Methodology - Extracts from the leaves of J. secunda and fractions thereof were evaluated in terms of their α-glucosidase inhibiting potential by subjecting them to HPTLC bioautography. The aqueous (AQ) fraction deriving from the methanol extract was further fractionated via column chromatography on polystyrene Diaion® HP-20. Two AQ subfractions revealed active compounds, which were isolated via preparative HPTLC and semipreparative HPLC. Their identification and structure elucidation was achieved employing HPLC-ESI-MS , HRESI-MS, and NMR analyses.
α-Glucosidase inhibitors were visualised as white zones on violet background on the TLC plate. The crude water extract, the methanol extract, and the methanol extract derived AQ fraction showed α-glucosidase inhibiting effects. In the latter, two diastereomeric mixtures responsible for the α-glucosidase inhibition were enriched. They were identified as the novel 2-caffeoyloxy-4-hydroxy-glutaric acid and the diastereomers secundarellone B and C.
The current study presents the α-glucosidase inhibiting potential of J. secunda supporting its traditional medicinal use in diabetes mellitus treatment. HPTLC bioautography screening for α-glucosidase inhibitors provides a simple and effective method for the investigation of complex samples, such as plant extracts. Copyright © 2016 John Wiley & Sons, Ltd.
α-葡萄糖苷酶抑制剂是2型糖尿病新型药物研发的重要基础。近年来，已建立并改进了在植物中寻找α-葡萄糖苷酶抑制剂的薄层色谱生物自显影分析方法。在传统医学中，二花紫萼爵床（Justicia secunda Vahl）叶的提取物用于治疗糖尿病症状。
通过高效薄层色谱生物自显影法筛选二花紫萼爵床中的α-葡萄糖苷酶抑制剂。方法——对二花紫萼爵床叶提取物及其馏分进行高效薄层色谱生物自显影分析，评估其α-葡萄糖苷酶抑制潜力。甲醇提取物的水相（AQ）馏分通过在聚苯乙烯Diaion® HP-20上进行柱色谱进一步分离。两个AQ亚馏分显示出活性化合物，通过制备型高效薄层色谱和半制备型高效液相色谱进行分离。采用高效液相色谱-电喷雾电离质谱、高分辨电喷雾电离质谱和核磁共振分析对其进行鉴定和结构解析。
α-葡萄糖苷酶抑制剂在薄层色谱板上呈现为紫色背景上的白色区域。粗水提取物、甲醇提取物以及甲醇提取物衍生的AQ馏分均显示出α-葡萄糖苷酶抑制作用。在后者中，富集了两种导致α-葡萄糖苷酶抑制的非对映异构体混合物。它们被鉴定为新型的2-咖啡酰氧基-4-羟基戊二酸以及非对映异构体二花紫萼素B和C。
本研究揭示了二花紫萼爵床的α-葡萄糖苷酶抑制潜力，支持其在糖尿病治疗中的传统药用价值。利用高效薄层色谱生物自显影法筛选α-葡萄糖苷酶抑制剂为研究复杂样品（如植物提取物）提供了一种简单有效的方法。版权所有© 2016约翰威立父子有限公司。
