Iridoid glucosides of the genus Veronica s.l. and their systematic significance

16 iridoid glucosides and 3 aromatic compounds were isolated from Bulgarian natural populations of Veronica L. and Pseudolysimachion Opiz species. The distribution of 11 compounds in 34 species (96 samples) was shown. Seven Veronica and Pseudolysimachion species were screened for iridoids for the first time and a phenylethanoid glycoside, calceolarioside C, was found for the first time in the genus Veronica. The systematic significance of iridoid glucosides at subspecies, species, sectional, and generic levels is discussed. A correlation between the chemical characters (iridoids and flavonoids) and the chromosome base numbers of the perennial Veronica species was established. Origin of the annual species from the perennials through two evolutionary lines was supposed.