Three new norlignans from Glechoma longituba.

Three new norlignans, glechomols A-C (1-3, respectively), together with a known compound, 4-ethylcatechol (4), were isolated from the ethyl acetate extract of Glechoma longituba (NaKai) Kupr. Their structures were elucidated by the detailed analysis of 1D and 2D NMR and HR-MS data. Glechomols A-C were the first norlignans reported from genus Glechoma, and compound 4 was also isolated from genus Glechoma for the first time. Intracellular antioxidant assays showed that compounds 1-4 displayed significant protective effects on H2O2-induced cardiac cell injury.