Ether-linked biflavonoids from Quintinia acutifolia

The New Zealand tree Quintinia acutifolia has yielded four biflavonoids, the new 2,3,2',3'-tetrahydroochnaflavone (3), and its 7,7'-di-O-methyl derivative (1). The rare 7-O-methyl-2,3,2',3'-tetrahydroochnaflavone (2) and 2',3'-dihydroochnaflavone (4), both previously identified only from members of the Ochnaceae, were also isolated. Structures were determined by spectroscopic methods. This is the first report of biflavonoids from the Grossulariaceae.