Synthesis of lipophilic tyrosyl esters derivatives and assessment of their antimicrobial and antileishmania activities

BACKGROUND: Preparation of tyrosyl lipophilic derivatives was carried out as a response to the food, cosmetic and pharmaceutical industries' increasing demand for new lipophilic antioxidants. RESULTS: A large series of tyrosyl esters (TyC₂ to TyC₁₈:₁) with increasing lipophilicity was synthesized in a good yield using lipase from Candida antarctica (Novozyme 435). Spectroscopic analyses of purified esters showed that the tyrosol was esterified on the primary hydroxyl group. Synthetized compounds were evaluated for either their antimicrobial activity, by both diffusion well and minimal inhibition concentration (MIC) methods, or their antileishmanial activity against Leishmania major and Leishmania infantum parasite species.Among all the tested compounds, our results showed that only TyC₈, TyC₁₀ and TyC₁₂ exhibited antibacterial and antileishmanial activities. When MIC and IC50 values were plotted against the acyl chain length of each tyrosyl derivative, TyC₁₀ showed a parabolic shape with a minimum value. This nonlinear dependency with the increase of the chain length indicates that biological activities are probably associated to the surfactant effectiveness of lipophilic derivatives. CONCLUSION: These results open up potential applications to use medium tyrosyl derivatives surfactants, antioxidants, antimicrobial and antileishmanial compounds in cosmetic, food and pharmaceutical industries.