Components of the extracts of the knot wood of Dalbergia Sissoo Linn. and their antioxidant activity

The composition of the extract from the Dalbergia Sissoo Linn. knot wood was studied. Components obtained by extraction with 95% aqueous acetone were isolated, purified by HPLC, and identified by NMR spectroscopy and mass spectrometry as 7,6,3’,5’-trihydroxyflavanone (1), 7,3’,4’-trihydroxy-6-methoxyflavanone (2), 7,3’,5’-trihydroxyflavanone (3), 6-hydroxy-7-methoxy-4-phenyl-2H-chromen-2-one (dalbergin) (4), 2-methoxy-5-(1-phenylallyl)cyclohexa-2,5-diene-1,4-dione (dalbegione) (5), and 2,4-dimethoxy-5-(1-phenylallyl)phenol (dalbergiphenol) (6). In the extract from the Dalbergia Sissoo Linn. wood knots, compounds 1–3 were found for the first time. The isolated compounds demonstrated notable antioxidant ability determined by using the amperometric method.