ANTIFUNGAL BIPHENYL COMPOUNDS ARE THE PHYTOALEXINS OF THE SAPWOOD OF SORBUS-AUCUPARIA

An examination of the sapwood tissue of Sorbus aucuparia L. has reveal ed that aucuparin and its derivatives are essentially absent from heal thy tissue, and are only produced as phytoalexins following fungal inf ection. Five biphenyls were identified: aucuparin, 2'-methoxyaucuparin , 4'-methoxyaucuparin, 2'-hydroxyaucuparin and isoaucuparin (2'-hydrox y-3,5-dimethoxybiphenyl). The latter is a new phytoalexin. A survey of II individual Sorbus trees showed that not all these compounds are ne cessarily produced in the phytoalexin response.