Nirurin: a new prenylated flavanone glycoside from Phyllanthus nirurii.

: A new prenylated flavanone glycoside, nirurin, has been isolated from Phyllanthus nirurii. On the basis of chemical and spectral studies, its structure is proposed as 5,6,7,4'-tetrahydroxy-8-(3-methylbut-2-enyl) flavanone-5-O-rutinoside (1). The aglycone, also a new flavanone, has been characterized as 5,6,7,4'-tetrahydroxy-8-(3-methylbut-2-enyl) flavanone, which may be designated as nirurinetin (2).