The new hypotrachynin A (1) and B (2) along with the know (+)-(9b-R)- usnic (3) and methylstictic acids (4) were isolated for the first time from Hypotrachyna caraccensis. Additionally, their potency and reactivity as DPPH• scavengers was determined by a kinetic study calculating their EC50 and second-order rate constants (k2). Considering 1-4 could be dermatological agents, their n-octanol water partition coefficients and standard molar Gibbs free energies of transfer were calculated as a estimation of their lipophilicity and skin penetration. Compounds 1,3 and 4 were less potent than 2 (EC50=3.3014; 1.7540; 2.6652 vs 0.7376) as DPPH• scavengers, in turn 4, was the most reactive with a comparable k2 to the antioxidant BHT (k2= (232 ? 24) X 10-2 vs (564 ? 12) X 10-2 M-1 s-1, respectively). Since 2 and4 had an optimal lipophilicity and permeability for skin penetration, they might bedeveloped as topical ingredients to prevent oxidative damage.
Published Date: 2021-12-07;