A new diarylheptanoid containing a chalcone moiety, katsumain H (1), was isolated from the seeds of Alpinia katsumadai. The structure was elucidated using a combination of 1D/2D NMR spectroscopy and mass spectrometry data analysis. The absolute configurations of C-3, C-5, and C-7 in 1 were assigned based on its optical rotation and after comparing its NMR chemical shifts with those of its diastereoisomers, katsumain E and katsumain F, which were previously isolated from this plant and characterized. In this study, the stimulatory effects of compounds 1 and 2 were evaluated on heat shock factor 1 (HSF1), heat shock protein 27 (HSP27), and HSP70. Compounds 1 and 2 increased the expression of HSF1 (1.056- and 1.200-fold, respectively), HSP27 (1.312- and 1.242-fold, respectively), and HSP70 (1.234- and 1.271-fold, respectively), without increased cytotoxicity.
Keywords: Alpinia katsumadai; chalcone; diarylheptanoid; heat shock factor (HSF); heat shock protein (HSP).