Phytochemical profiling of Curcuma kwangsiensis rhizome extract, and identification of labdane diterpenoids as positive GABAA receptor modulators

By HPLC-based activity profiling, labdane diterpenoids from Curcuma kwangsiensis were identified as positive GABAA receptor modulators. A total of 11 compounds, among them four new natural products, were characterized. Their interaction with GABAA receptors was established with two-microelectrode voltage-clamp measurements on Xenopus oocytes expressing recombinant α1β2γ2S GABAA receptors. The absolute configuration of labdane diterpenoids was assigned by ECD.