A new acetylated dihydroflavonol and cardiovascular protective chemical constituents of Aframomum letestuanum Gagnep. seeds (Zingiberaceae).

One previously unreported acetylated dihydroflavonol derivative named (2 R,3R)-3-acetoxy-5-hydroxy-7,4'-dimethoxyflavonol (1), along with twelve known compounds (2-13), were isolated from the ethyl acetate soluble fraction of the methanol extract of the seeds of Aframomum letestuanum Gagnep. (Zingiberaceae). Their structures were established by means of spectroscopic techniques (1D and 2D NMR), High Resolution Electrospray Ionisation Mass Spectrometry (HR-ESIMS) as well as by comparison of their spectroscopic data with those reported in the literature. The absolute configuration of compound 1 was determined by Electronic Circular Dichroism analysis. Some of the isolated compounds were screened for their antibacterial activity and only rhamnocitrin (9) exhibited a moderate activity against Staphylococcus aureus with a MIC of 106 µM. Based on the traditional use of the seeds of this plant to manage heart palpitations and previous works demonstrating their pharmacological effects on some cardiovascular disorders, a correlation was established between their chemical constituents and the pharmacological activities.