Fungosides A and B, two new 7,9′:7′,9‐diepoxylignan glucosides of <i>Balanophora fungosa</i> ’s whole plant

Abstract Balanophora fungosa , also known as “Ngọc cẩu” in Vietnam, was a member of the Balanophoraceae family. B. fungosa stems are used to treat hypertension, stomachaches, and kidney tonics; their roots are utilized to lessen rash symptoms. After screening for tyrosinase, α‐glucosidase, and cholesterol esterase inhibition, it is found that the ethyl acetate extract of this plant had the most potential biological behavior among the crude extracts and then it was selected for additional research. By column chromatography method together with preparative thin‐layer chromatography, four 7,9′:7′,9‐diepoxylignan glucosides have been isolated on this extract from the whole of the plant. Their chemical structures have been elucidated by extensive NMR spectroscopic and MS analysis and comparison with the literature data as two new compounds, fungoside A ( 3 ) and fungoside B ( 4 ), along with two known lignan glucosides ( 1 and 2 ). In terms of tyrosinase inhibitory activity, the compound 4 showed the most activity with an IC 50 value of 78.2 µ m , compared to a positive control, kojic acid (IC 50 , 44.6 µ m ). In the α‐glucosidase inhibitory activity, the compound 3 had the best significant impact with an IC 50 value of 97.8 µ m and displayed stronger than that of a positive control, acarbose (IC 50 , 185.2 µ m ).