An aqueous fraction and dioclein (5,2',5'-trihydroxy-6,7-dimethoxyflavanone) obtained from the ethanolic extract of the Dioclea grandiflora were tested for their analgesic effect in mice and rats employing acetic-induced writhing and tail flick tests, respectively. When administered
Dioflorin (1) was isolated as a minor constituent from the rootbark of Dioclea grandiflora, the crude extract of which demonstrated analgesic activity. The structure of 1 has been determined to be 5,7,2'-trihydroxy-8-methoxy-6-(3-methyl-2-butenyl)flavanone on the basis of spectral analysis.