Identification and Isolation of α-Glucosidase Inhibitors from <i>Siraitia grosvenorii</i> Roots Using Bio-Affinity Ultrafiltration and Comprehensive Chromatography

The discovery of bioactive compounds from medicinal plants has played a crucial role in drug discovery. In this study, a simple and efficient method utilizing affinity-based ultrafiltration (UF) coupled with high-performance liquid chromatography (HPLC) was developed for the rapid screening and targ...

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Bibliographic Details
Main Authors: Fenglai Lu, Jiayi Sun, Xiaohua Jiang, Jingru Song, Xiaojie Yan, Qinghu Teng, Dianpeng Li
Format: Article
Language:English
Published: MDPI AG 2023-06-01
Series:International Journal of Molecular Sciences
Subjects:
Online Access:https://www.mdpi.com/1422-0067/24/12/10178
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Summary:The discovery of bioactive compounds from medicinal plants has played a crucial role in drug discovery. In this study, a simple and efficient method utilizing affinity-based ultrafiltration (UF) coupled with high-performance liquid chromatography (HPLC) was developed for the rapid screening and targeted separation of α-glucosidase inhibitors from <i>Siraitia grosvenorii</i> roots. First, an active fraction of <i>S. grosvenorii</i> roots (SGR2) was prepared, and 17 potential α-glucosidase inhibitors were identified based on UF-HPLC analysis. Second, guided by UF-HPLC, a combination of MCI gel CHP-20P column chromatography, high-speed counter-current countercurrent chromatography, and preparative HPLC were conducted to isolate the compounds producing active peaks. Sixteen compounds were successfully isolated from SGR2, including two lignans and fourteen cucurbitane-type triterpenoids. The structures of the novel compounds (<b>4</b>, <b>6</b>, <b>7</b>, <b>8</b>, <b>9</b>, and <b>11</b>) were elucidated using spectroscopic methods, including one- and two-dimensional nuclear magnetic resonance spectroscopy and high-resolution electrospray ionization mass spectrometry. Finally, the α-glucosidase inhibitory activities of the isolated compounds were verified via enzyme inhibition assays and molecular docking analysis, all of which were found to exhibit certain inhibitory activity. Compound <b>14</b> exhibited the strongest inhibitory activity, with an IC<sub>50</sub> value of 430.13 ± 13.33 μM, which was superior to that of acarbose (1332.50 ± 58.53 μM). The relationships between the structures of the compounds and their inhibitory activities were also investigated. Molecular docking showed that the highly active inhibitors interacted with α-glucosidase through hydrogen bonds and hydrophobic interactions. Our results demonstrate the beneficial effects of <i>S. grosvenorii</i> roots and their constituents on α-glucosidase inhibition.
ISSN:1661-6596
1422-0067