Chemical markers in Veronica sect. Hebe

The content of iridoid glucosides and other water-soluble compounds of Veronica sect. Hebe, three species and two hybrids were investigated. Veronica (Hebe) elliptica and Veronica (Hebe) brachysiphon, both from sect. Apertae were chemically different since the former contained two esters of 6-O-rhamnopyranosylcatalpol while the latter had a 6-O-catalpol ester, compounds characteristic for most Veronica species. Veronica (Hebe) odora, from sect. Buxifoliatae as well as two presumed hybrids between this and two different “whipcord” species were also investigated. The parent species contained two 6-O-catalpol esters, one of the two hybrids had esters of 6-O-rhamnopyranosylcatalpol, while the other contained neither type of compounds but instead had arbutin and two acetophenone glucosides. All species contained verbascoside and/or derivatives of this. Among the compounds isolated, two iridoid esters brachysiphonoside and hebridoside as well as 1-O-benzoyl β-rutinose had not previously been described from nature. The results confirm previous studies in that esters of 6-O-rhamnopyranosylcatalpol could be useful chemical markers in Veronica sect. Hebe.