The present invention, in one or more embodiments, comprises water-soluble derivatives of 3-n-pentadecylcatechol (poison ivy urushiol saturated congener) and/or 3-n-heptadecylcatechol (poison oak urushiol saturated congener) as compositions for the prevention and/or prophylactic treatment of contact dermatitis caused by poison ivy and poison oak. The present invention is also directed towards processes for making such compounds. Disclosed are compounds which are effective for tolerizing and desensitizing a subject against allergens contained in plants of the Anacardiaceae and Ginkgoaceae families comprising water soluble urushiol esters of general formula (I) Tolerizing and desensitizing mammals, including humans, to allergens contained in plants of the Anacardiaceae and Ginkgoaceae families is attained by administering a composition containing at least one water soluble urushiol ester compound.