Iridoid aglycones from the underground parts of Lathraea squamaria

Two epimeric pairs of iridoid aglycones (1a, 1b, 2a, and 2b) were isolated from the underground parts of Lathraea squamaria L. (Orobanchaceae) in a phytochemical study. Their structures were elucidated by UV, 1D and 2D NMR, and comparison with data in the literature. This is the first report of the isolation of these compounds from the species L. squamaria and the family Orobanchaceae. The chemophenetic significance and possible reasons for the occurrence of such iridoid aglycones in holoparasitic plants are discussed