Synthesis, In Vitro Antioxidant Properties and Distribution of a New Cyanothiophene-Based Phenolic Compound in Olive Oil-In-Water Emulsions.

Sonia Losada-Barreiro,Carlos Bravo-Díaz,Matej Sova,Luciano Saso,Janez Mravljak

doi:10.3390/antiox9070623

Abstract

We synthesized and determined the antioxidant activity and distribution of a new cyanothiophene-based compound, N-(3-cyano-4,5,6,7-tetrahydrobenzo[b]thiophen-2-yl)-3,5-dihydroxybenzamide (SIM-53B), in intact stripped olive oil-in-water emulsion. The in vitro antioxidant properties of SIM-53B were evaluated and compared to those for Trolox and resveratrol. Addition of an emulsifier (Tween 20) creates a narrow region, the aqueous–oil interface, and the distribution of SIM-53B can be described by two partition constants: PWI (between aqueous/interfacial regions) and POI (between oil/interfacial regions). The effects of emulsifier concentration expressed in terms of the volume fraction, ΦI, and O/W ratio were also evaluated on its distribution. SIM-53B is predominantly distributed (>90%) in the interfacial region of 1:9 (O/W) olive oil-in-water emulsions at the lowest emulsifier volume fraction (ΦI = 0.005) and only a small fraction is located in the aqueous (<5%) and the oil (<5%) regions. Besides, the concentration of SIM-53B in the interfacial region of the emulsions is ~170–190-fold higher than the stoichiometric concentration, emphasizing the compartmentalization effects. Results suggest that the emulsifier volume fraction is a key parameter that may modulate significantly its concentration in the interface. Our study suggests that cyanothiophene-based compounds may be interesting additives for potential lipid protection in biomembranes or other lipid-based systems.

Highlights

Drug-resistant bacteria emerge as an increasing threat to human health and new antibacterials are needed to treat bacterial infections [1,2]
I by employing Equations (13)–(15) where [SIMT] stands emulsions (Figure 3) can be determined for that is primarily distributed in the interfacial region of the olive oil-in-water emulsions
We describe the synthesis of a new cyanothiophene-based compound, N-(3-cyano-4,5,6,7tetrahydrobenzo[b]thiophen-2-yl)-3,5-dihydroxybenzamide (SIM-53B), and evaluation of its antioxidant activity and distribution in intact stripped olive oil-in-water emulsions

Summary

Introduction

Drug-resistant bacteria emerge as an increasing threat to human health and new antibacterials are needed to treat bacterial infections [1,2]. Bacterial cell wall biosynthesis involves enzymes which have been engaged as targets for developing potential antibacterial candidates [3,4]. In this sense, cyanothiophene scaffold has been used in medicinal chemistry for the preparation of biologically active compounds and for this reason, the isolation and the structural characterization of innovative derivatives, the improvement of new synthetic methods and the evaluation of biological properties are topics of growing interest [2,5,6,7,8]. Cyanothiophene-based compounds showed inhibitory activity on penicillin-binding protein 2a (PBP2a) (unpublished results)

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