Institute of Fundamental and Applied Sciences, Duy Tan University, Ho Chi Minh City, Vietnam.
Faculty of Natural Sciences, Duy Tan University, Da Nang, Vietnam.
Nat Prod Res. 2023 May;37(9):1480-1490. doi: 10.1080/14786419.2021.2023143. Epub 2022 Jan 5.
The lichen is a fruticose lichen belonging to the . It is well known as a rich source of natural xanthone dimers and possesses various bioactivities. Nevertheless, the chemical investigation on this type of lichen is still rare as most of researches reported its components without structural elucidation. Herein, in the continuous study on this type of lichen, we further isolate xanthone dimers from the dichloromethane extract and explore three new xanthone dimers, eumitrins F - H (-). Their structures were elucidated unambiguously by spectroscopic analyses, including high resolution electrospray ionisation mass spectrometry (HRESIMS), 1 D and 2 D nuclear magnetic resonance spectroscopy (1 D and 2 D NMR), and DP4 probability. All compounds were evaluated for their enzyme inhibition against α-glucosidase, tyrosinase, and antibacterial activity. They revealed moderate antimicrobial and weak tyrosinase inhibition. For α-glucosidase inhibition, compound displayed the most significant inhibitory against α-glucosidase possessing an IC value of 64.2 µM.
该地衣是一种木本石蕊，属于地衣科。它是天然黄烷酮二聚体的丰富来源，具有多种生物活性。然而，由于大多数研究报告的成分都没有进行结构解析，因此对这种地衣的化学研究仍然很少。在此，在对该种地衣的持续研究中，我们进一步从二氯甲烷提取物中分离出黄烷酮二聚体，并探索了三种新的黄烷酮二聚体，即 eumitrins F-H(-)。它们的结构通过光谱分析，包括高分辨电喷雾电离质谱（HRESIMS）、1D 和 2D 核磁共振波谱（1D 和 2D NMR）和 DP4 概率得到了明确的阐明。所有化合物均评估了其对α-葡萄糖苷酶、酪氨酸酶的抑制活性和抗菌活性。结果表明，这些化合物具有中等的抗菌活性和较弱的酪氨酸酶抑制活性。对于α-葡萄糖苷酶抑制活性，化合物 对α-葡萄糖苷酶表现出最显著的抑制作用，其 IC 值为 64.2μM。
