Abstract

Chemical investigation of the ethanol extract of the leaves of Newbouldia laevis (P. Beauv) led to the isolation of two new caffeic acid glycosides, Newboulasides A (1) and B (2). The structures of these compounds were determined on the basis of extensive spectroscopic methods, including 1D-, 2D-NMR and MS data. The extracts and fractions and the isolated compounds were evaluated for their inhibition of α-amylase enzyme activity. The extract showed inhibition of α-amylase activity with IC₅₀ value of 102.91 µg/mL, while the isolated compounds (1 and 2) exhibited pronounced inhibition with IC₅₀ values of 4.95 and 4.44 µg/mL respectively, comparable to the standard – Acarbose with IC₅₀ value of 4.05 µg/mL. Our findings demonstrated that the inhibition of α-amylase activity may be part of the mechanisms through which N. leavis exhibits antidiabetic effect.

摘要

对Newbouldia laevis (P. Beauv)叶子的乙醇提取物的化学研究导致分离出两种新的咖啡酸糖苷，Newboulasides A (1)和 B (2)。这些化合物的结构是基于广泛的光谱方法确定的，包括 1D-、2D-NMR 和 MS 数据。评价提取物和级分以及分离的化合物对α-淀粉酶活性的抑制。提取物显示出对 α-淀粉酶活性的抑制作用，IC ₅₀值为 102.91 µg/mL，而分离的化合物（1和2）显示出显着的抑制作用，IC _50值值分别为 4.95 和 4.44 µg/mL，与标准阿卡波糖相当，IC ₅₀值为 4.05 µg/mL。我们的研究结果表明，α-淀粉酶活性的抑制可能是N. leavis表现出抗糖尿病作用的机制的一部分。