Four highly oxidized pimarane diterpenoids were isolated from Kaempferia takensis rhizomes. Kaemtakols A–C possess a tetracyclic ring with either a fused tetrahydropyran or tetrahydrofuran motif. Kaemtakol D has an unusual rearranged A/B ring spiro-bridged pimarane framework with a C-10 spirocyclic junction and an adjacent 1-methyltricyclo[3.2.1.0^2,7]octene ring. Structural characterization was achieved using spectroscopic analysis, DP4 + and ECD calculations, as well as X-ray crystallography, and their putative biosynthetic pathways have been proposed. Kaemtakol B showed significant potency in inhibiting nitric oxide production with an IC₅₀ value of 0.69 μM. Molecular docking provided some perspectives on the action of kaemtakol B on iNOS protein.

Graphical Abstract

中文翻译：

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Kaemtakols A–D，高度氧化的山柰烷二萜类化合物，具有有效的抗炎活性，来自山柰

从山柰根茎中分离出四种高度氧化的海螺烷二萜类化合物。Kaemtakols A–C 具有带有稠合四氢吡喃或四氢呋喃基序的四环。Kaemtakol D 具有不寻常的重排 A/B 环螺桥 Pimarane 框架，具有 C-10 螺环连接和相邻的 1-甲基三环[3.2.1.0 ^2,7 ]辛烯环。使用光谱分析、DP4 + 和 ECD 计算以及 X 射线晶体学实现了结构表征，并提出了它们的假定生物合成途径。Kaemtakol B 显示出显着的抑制一氧化氮生成的功效，IC ₅₀值为 0.69 μM。分子对接为 kaemtakol B 对 iNOS 蛋白的作用提供了一些视角。

图形概要