Secondary metabolites from Stachys tetragona Boiss. & Heldr. ex Boiss. and their chemotaxonomic significance

From the dichlormethane and methanol extracts of the aerial parts of Stachys tetragona Boiss. & Heldr. ex Boiss. sixteen secondary metabolites were isolated, namely one triterpenic acid and two sterols from the nonpolar extract, as well as three flavonoids, one phenolic acid, six phenylethanoid glycosides, one neolignan and two iridoids from the polar extract. Structural elucidation was mainly based on 1D & 2D NMR spectra. Comparing the flavonoid pattern of S. tetragona with previously investigated Stachys taxa growing wild in Greece, it can be seen that S. tetragon is similar to S. ionica, as both produce isoscutellarein derivatives, while from the rest of the taxa only chrysoeriol derivatives have been isolated. To the best of our knowledge, kaempferol, lamiophloside A and (7S,8R)-urolignoside are isolated for the first time from the genus Stachys L.