Isolation and synthesis of a new chromenochalcone and a new chromene from Orthosiphon glabratus.
Chemical investigation on Orthosiphon glabratus afforded 10 compounds, among which a chromenochalcone and a chromene are new. The structures of the new constituents were settled from their 1D- and 2D-NMR spectra. The synthesis of these two compounds and some of their analogues have been accomplished.