Division of Pharmaceutical Biology, University of Basel, Klingelbergstrasse 50, 4056 Basel, Switzerland.
Phytochemistry. 2013 Dec;96:318-29. doi: 10.1016/j.phytochem.2013.08.004. Epub 2013 Sep 3.
An ethyl acetate extract of Curcuma kwangsiensis S.G. Lee & C.F. Liang (Zingiberaceae) rhizomes (100 μg/ml) enhanced the GABA-induced chloride current (IGABA) through GABAA receptors of the α1β2γ2S subtype by 79.0±7.0%. Potentiation of IGABA was measured using the two-microelectrode voltage-clamp technique and Xenopus laevis oocytes. HPLC-based activity profiling of the crude extract led to the identification of 11 structurally related labdane diterpenoids, including four new compounds. Structure elucidation was achieved by comprehensive analysis of on-line (LC-PDA-ESI-TOF-MS) and off-line (microprobe 1D and 2D NMR) spectroscopic data. The absolute configuration of the compounds was established by comparison of experimental and calculated ECD spectra. Labdane diterpenes represent a new class of plant secondary metabolites eliciting positive GABAA receptor modulation. The highest efficiency was observed for zerumin A (maximum potentiation of IGABA by 309.4±35.6%, and EC50 of 24.9±8.8 μM).
广西莪术根茎的乙酸乙酯提取物（100μg/ml）通过 GABAA 受体的 α1β2γ2S 亚型将 GABA 诱导的氯离子电流（IGABA）增强了 79.0±7.0%。使用双微电极电压钳技术和非洲爪蟾卵母细胞测量 IGABA 的增强作用。基于 HPLC 的粗提取物活性分析导致鉴定出 11 种结构相关的拉巴烷二萜，包括 4 种新化合物。通过在线（LC-PDA-ESI-TOF-MS）和离线（微探针 1D 和 2D NMR）光谱数据的综合分析实现了结构阐明。通过比较实验和计算的 ECD 光谱确定了化合物的绝对构型。拉巴烷二萜代表了一类新的植物次生代谢产物，可引发阳性 GABAA 受体调节。泽乳宁 A 的效率最高（IGABA 的最大增强作用为 309.4±35.6%，EC50 为 24.9±8.8μM）。
