Etsassala Ninon G E R, Badmus Jelili A, Waryo Tesfaye T, Marnewick Jeanine L, Cupido Christopher N, Hussein Ahmed A, Iwuoha Emmanuel I
Chemistry Department, University of the Western Cape, Private Bag X17, Bellville 7535, South Africa.
Oxidative Stress Research Unit, Cape Peninsula University of Technology, Symphony Rd. Bellville 7535, South Africa.
Antioxidants (Basel). 2019 Sep 20;8(10):421. doi: 10.3390/antiox8100421.
The re-investigation of a methanolic extract of collected from the Cape Floristic Region, South Africa (SA), afforded four new abietane diterpenes, namely 19-acetoxy-12-methoxycarnosic acid (), 3β-acetoxy-7α-methoxyrosmanol (), 19-acetoxy-7α-methoxyrosmanol (), 19-acetoxy-12-methoxy carnosol (), and two known named clinopodiolides A (), and B (), in addition to four known triterpenes, oleanolic, and ursolic acids (, ), 11,12-dehydroursolic acid lactone () and β-amyrin (). The chemical structural elucidation of the isolated compounds was determined on the basis of one and two dimensional nuclear magnetic resonance (1D and 2D NMR), high-resolution mass spectrometry (HRMS), ultra violet (UV), fourier transform infrared (IR), in comparison with literature data. The in vitro bio-evaluation against alpha-glucosidase showed strong inhibitory activities of , , and , with the half inhibitory concentration (IC) values of 11.3 ± 1.0, 17.1 ± 1.0 and 22.9 ± 2.0 µg/mL, respectively, while demonstrated the strongest in vitro alpha-amylase inhibitory activity among the tested compounds with IC of 12.5 ± 0.7 µg/mL. Additionally, some of the compounds showed significant antioxidant capacities. In conclusion, the methanolic extract of is a rich source of terpenoids, especially abietane diterpenes, with strong antioxidant and anti-diabetic activities that can be helpful to modulate the redox status of the body and could therefore be an excellent candidate for the prevention of the development of diabetes, a disease where oxidase stress plays an important role.
对从南非开普植物区系采集的[植物名称未给出]甲醇提取物进行重新研究，得到了四种新的枞酸型二萜，即19 - 乙酰氧基 - 12 - 甲氧基鼠尾草酸（[具体名称未给出]）、3β - 乙酰氧基 - 7α - 甲氧基迷迭香酚（[具体名称未给出]）、19 - 乙酰氧基 - 7α - 甲氧基迷迭香酚（[具体名称未给出]）、19 - 乙酰氧基 - 12 - 甲氧基鼠尾草酚（[具体名称未给出]），以及两种已知的化合物，即斜叶泽兰内酯A（[具体名称未给出]）和B（[具体名称未给出]），此外还有四种已知的三萜类化合物，齐墩果酸和熊果酸（[具体名称未给出]）、11,12 - 脱氢熊果酸内酯（[具体名称未给出]）和β - 香树脂醇（[具体名称未给出]）。通过一维和二维核磁共振（1D和2D NMR）、高分辨率质谱（HRMS）、紫外（UV）、傅里叶变换红外（IR）等方法，并与文献数据对比，确定了分离出的化合物的化学结构。对α - 葡萄糖苷酶的体外生物评价显示，[具体化合物未给出]、[具体化合物未给出]和[具体化合物未给出]具有较强的抑制活性，其半数抑制浓度（IC）值分别为11.3±1.0、17.1±1.0和22.9±2.0μg/mL，而[具体化合物未给出]在测试化合物中表现出最强的体外α - 淀粉酶抑制活性，IC为12.5±0.7μg/mL。此外，一些化合物还表现出显著的抗氧化能力。总之，[植物名称未给出]的甲醇提取物是萜类化合物的丰富来源，尤其是枞酸型二萜，具有很强的抗氧化和抗糖尿病活性，有助于调节身体的氧化还原状态，因此可能是预防糖尿病发展的极佳候选物，糖尿病是一种氧化应激起重要作用的疾病。
