flavonol glycosides from euphorbia microsciadia bioss. with their immunomodulatory activities

four known flavonoids: quercetin 3-o-β-d-rutinoside (q3rut), myricetin 3-o-β-d-galactopyranoside (m3gal), quercetin 3-o-β-d-galactopyranoside (q3gal) and quercetin 3-o-β-d-glucopyranoside (q3glc), for the first time were isolated from aerial parts of euphorbia microsciadia. the chemical structure of them was elucidated on the basis of 1 and 2 d-nmr spectra and different spectroscopic techniques. the immunomodulatory activities of isolated compounds were compared using standard t-cell proliferation assay. these data showed that lymphocyte suppression activity of flavonoids (1-4) were comparatively lower than prednisolon as a standard drug. immunosuppressive activity of flavonoids with hydroxyl groups at both 3′-and 4′-positions in their b-ring (q3gal) were more than those with 3′-,4′-and 5′-hydroxyl substitution (m3gal). in these compounds, q3gal showed the most inhibitory activity, whereas m3gal showed the least lymphocyte antiprolifeartive activity.