Department of Pharmacognosy and Pharmaceutical Chemistry, College of Pharmacy, Taibah University, Al Madinah Al Munawwarah 30078, Saudi Arabia; Department of Pharmacognosy, Faculty of Pharmacy, Assiut University, Assiut 71526, Egypt.
Department of Natural Products and Alternative Medicine, Faculty of Pharmacy, King Abdulaziz University, Jeddah 21589, Saudi Arabia; Department of Pharmacognosy, Faculty of Pharmacy, Al-Azhar University, Assiut Branch, 71524 Assiut, Egypt.
Bioorg Chem. 2017 Feb;70:192-198. doi: 10.1016/j.bioorg.2016.12.010. Epub 2016 Dec 30.
Iris species are well recognized as wealthy sources of isoflavonoids. In the present study, phytochemical investigation of the rhizomes of Iris germanica (Iridaceae) procure the isolation of two new isoflavonoids namely, 8-hydroxyirilone 5-methyl ether (2) and 8-hydroxyirilone (3), along with eight known isoflavonoids: irilone 4'-methyl ether (1), irilone (4), irisolidone (5), irigenin S (6), irigenin (7), irilone 4'-O-β-d-glucopyranoside (8), iridin S (9), and iridin (10). The isolated flavonoids were structurally characterized with the assist of comprehensive spectroscopic analyses (UV, IR, 1D and 2D NMR, and HRMS) and comparing with the published data. They were estimated for their antioxidant and antidaibetic capacities using DPPH and α-amylase inhibition assays, respectively. Compounds 2, 3, and 4 exhibited prominent antioxidant activities with IC values of 12.92, 9.23, and 10.46μM, respectively compared to propyl gallate (IC 7.11μM). Moreover, 2-5 possessed highest α-amylase inhibitory activity with % inhibition 66.1, 78.3, 67.3, and 70.1, respectively in comparison to acarbose (reference α-amylase inhibitor). Additionally, their structure-activity relationship has been discussed.
虹膜物种被公认为异黄酮的丰富来源。在本研究中，对德国鸢尾（鸢尾科）根茎的植物化学研究得到了两种新的异黄酮，即 8-羟基异黄酮 5-甲醚（2）和 8-羟基异黄酮（3），以及 8 种已知的异黄酮：伊里酮 4'-甲基醚（1）、伊里酮（4）、鸢尾酮（5）、irigenin S（6）、irigenin（7）、irilone 4'-O-β-d-吡喃葡萄糖苷（8）、iridin S（9）和 iridin（10）。这些分离出的黄酮类化合物通过综合光谱分析（UV、IR、1D 和 2D NMR、HRMS）和与已发表数据的比较，结构特征得以确定。它们的抗氧化和抗糖尿病能力分别通过 DPPH 和α-淀粉酶抑制测定进行评估。化合物 2、3 和 4 表现出显著的抗氧化活性，IC 值分别为 12.92、9.23 和 10.46μM，与没食子酸丙酯（IC 7.11μM）相比。此外，2-5 具有最高的α-淀粉酶抑制活性，与阿卡波糖（参考α-淀粉酶抑制剂）相比，抑制率分别为 66.1%、78.3%、67.3%和 70.1%。此外，还讨论了它们的结构-活性关系。
