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

Abstract

BackgroundPreparation of tyrosyl lipophilic derivatives was carried out as a response to the food, cosmetic and pharmaceutical industries' increasing demand for new lipophilic antioxidants.ResultsA 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.ConclusionThese results open up potential applications to use medium tyrosyl derivatives surfactants, antioxidants, antimicrobial and antileishmanial compounds in cosmetic, food and pharmaceutical industries.

Valorization of antioxidants extracted from olive mill wastewater

“…In fact, with Gram‐positive bacteria, MIC values ranged from 0.0312 to 0.5 mg/mL and the MBC values are between 0.5 and 4 mg/mL, while Gram‐negative bacteria appear to be less sensitive to the tested compounds. These findings are in agreement with our previous observations showing that only medium‐chain tyrosyl esters had an antibacterial activity especially against Staphylococcus strains . In the same context, lauryl rosmarinate has been reported by Suriyarak et al.…”

“…An increase in the phenolic derivatives acyl chain length leads to a decrease in the antiradical activity. These results recall those reported by Grasso et al [32] and Aissa et al [14] showing that the esterification of HyT and Ty with aliphatic chain acids decreased their ability to scavenge peroxyl radicals.…”

“… and Aissa et al. showing that the esterification of HyT and Ty with aliphatic chain acids decreased their ability to scavenge peroxyl radicals.…”

“…However, because of the limited solubility of these phenols in lipid media, the search for their lipophilic derivatives with enhanced properties is of great interest. In addition to their applications as food additives and as pharmaceutical active substances, Ty and HyT lipophilic derivatives have a great potential as cosmetic ingredients . Therefore, an effort in the synthesis of hydroxytyrosyl and tyrosyl derivatives with a better hydrophile/lipophile balance was carried out and their antioxidant activities were investigated in polar and apolar media .…”

Antioxidant and antimalarial properties of butein and homobutein based on their ability to chelate iron (II and III) cations: a DFT study in vacuo and in solution

“…In order to protect against cellular damage by excess ROS and transition metal ions, both synthetic and natural antioxidant molecules are increasingly utilised to enhance the antioxidant capability of the body system. However, synthetic antioxidants are less preferred to natural products because of their adverse side effects on some of the body organs, such as liver [26][27][28]. Thus, considerable attention has been given to the search for natural antioxidants (often from plant sources).…”