A bioactivity-guided investigation of the lichen Parmotrema cristiferum (Taylor) Hale (Parmeliaceae) led to the isolation of two new depsidones, cristifones A and B (1 and 2). The structures of the isolated compounds were identified by spectroscopic methods and comparison with the literature data. Compound 1 showed the initial combined structures of depsidone and depside cores. The two isolated compounds were then evaluated for α-glucosidase inhibition. Compounds 1 and 2 were confirmed as potent, with IC₅₀ values of 21.5 and 18.4 μM, respectively. Compound 2 was a non-competitive inhibitor against α-glucosidase, as indicated by the intersect in the second quadrant of each respective plot.

中文翻译：

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来自 Lichen Parmotrema cristiferum (Taylor) Hale 的两种新的 α-葡萄糖苷酶抑制性 Depsidone

对地衣Parmotrema cristiferum (Taylor) Hale (Parmeliaceae) 的生物活性引导调查导致分离出两种新的 depsidones，cristifones A 和 B（1和2）。分离化合物的结构通过光谱方法鉴定并与文献数据比较。化合物1显示出 depsidone 和 depside 核心的初始组合结构。然后评估这两种分离的化合物对α -葡萄糖苷酶的抑制作用。化合物1和2被证实有效，IC ₅₀值分别为 21.5 和 18.4 μM。化合物2是一种非竞争性抑制剂α-葡萄糖苷酶，如每个相应图的第二象限中的交叉点所示。