BUTENYLBITHIOPHENE, ALPHA-TERTHIENYL AND HYDROXYTREMETONE AS CONTACT ALLERGENS IN CULTIVARS OF MARIGOLD (TAGETES SP)

Ornamental cultivars of Tagetes sp., commonly named marigold, are one of the presently most popular pot and garden plants. Sensitizing exper iments in guinea pigs with short ether extracts and isolated compounds revealed the presence of 3 constituents that must be considered as co ntact allergens. They were identified as 5-(3-buten-1-ynyl)-2,2'-bithi ophene, alpha-terthienyl and hydroxytremetone. In sensitized animals, butenylbithiophene showed moderate to strong sensitizing potency, whil e alpha-terthienyl was less strong and hydroxytremetone weak. The resu lts demonstrate, for the first time, that at least some of the thiophe nes abundantly occurring in many species of the Compositae family poss ess not only phototoxic activity but also sensitizing properties.