CONTACT ALLERGY DUE TO COLOPHONY .9. SENSITIZATION STUDIES WITH FURTHER PRODUCTS ISOLATED AFTER OXIDATIVE-DEGRADATION OF RESIN ACIDS AND COLOPHONY

Degradation of abietic, levopimaric and dehydroabietic acids after exp osure to air and light over a period of one to several months, as well as examination of degraded French tall oil rosin and Portuguese colop hony, led to the isolation of numerous oxidation products. These compo unds were synthesized and consigned to experimental sensitization in g uinea pigs. From 20 substances studied as acids or as their methyl est ers, in the present and preceding paper, at least 2 can be named: 8,12 -peroxydo-DELTA13(14)-dihydroabietic acid and 12 alpha-hydroxyabietic acid, that contribute a great deal to colophony allergy by both their sensitizing capacity and their determined concentration in the mixture of degradation products. We recommend the preparation of a new mixtur e of colophony oxidation products for patch testing in the diagnosis o f contact allergy to colophony.