New dihydrochalcone glycosides from Lithocarpus litseifolius and the phenomenon of C-H -> C-D exchange observed in NMR spectra of phenolic components

Two new dihydrochalcone glycosides named 6 ''-O-acetyltrilobatin (1) and 3 ''-O-acetylphloridzin (2) as well as four known compounds were isolated from the leaves of Lithocarpus litseifolius (Hance) Chun (family Fagaceae). Their structures were elucidated on the basis of spectroscopic analyses. The phenomena of C-H -> C-D exchange were observed in NMR spectra of the isolated phenolic components when measured in deuterated methanol.