Further Biphenyl Lignans with a Tetrahydrofuran Moiety from <i>Gymnotheca chinensis</i>

Abstract Four new biphenyl lignans, 1 – 4 , with a tetrahydrofuran moiety were isolated from the MeOH extract of the whole plant of Gymnotheca chinensis. Their chemical structures were established by means of spectroscopic analysis, including 1D and 2D NMR spectroscopy and comparison with previously reported data. Compounds 1 – 4 occur as mixtures of atropisomers as revealed by variable‐temperature NMR experiments.