Ultralong Fatty Acyl Derivatives As Occlusive Structure Lipids for Cosmetic Applications: Synthesis and Characterization

Abstract

Finding sustainable and commercially viable sources of occlusive materials, as an alternative to petroleum, is of great interest. Inspired by the fundamental role of long chain fatty acids in maintaining skin barrier, ultralong fatty acyl derivatives with diverse structures (varied acyl chain length and different polar head; i.e. glycerol, ethylene glycol, and diethylene glycol) were synthesized. These molecules can be feasibly obtained via enzymatic esterification of fatty acids or fractionated from commercial glycerides mixture via short path distillation. The molecular packing behaviors of compounds were characterized via differential scanning calorimetry, Fourier transform infrared, and Langmuir isotherm measurements. The structure–property relationship study reveals that a glycerol molecule monoacylated with an ultralong fatty acyl is the derivative which entails the most occlusive properties of the series of ultralong chain fatty acid derivatives. Fast Fourier transform filtering (FFTF) analysis of atomic force microscopy images verified a homogeneous monolayer packing of glyceryl monobehenate monolayer, and the water vapor transmission study demonstrated that the formulation of glyceryl monobehenate at 3% w/w in a phospholipid-containing emulsion generates an occlusive film significantly superior to a 3% w/w petrolatum formulation. This work demonstrated that natural glyceryl monobehenate can be a novel source of sustainable occlusive structuring agents and green replacements for petrolatum.

Fractionated aliphatic alcohols as synthetic precursors of ultra long‐chain monoacylglycerols for cosmetic applications

“…On the other hand, monoacylglycerols derived from Performacol 425 (MAG160) showed a melting point of 80°C suggesting that increasing the number of hydrogen bond donors promote molecular interaction between the polar head group leading to higher melting point. The latter agrees with previous work performed using Compritol ATO 888 as a source for occlusive lipids [36]. Accordingly, results suggest that monoacylglycerols derived from Performacol 425 can potentially generate more occlusive skincare formulations than FA160 and FA60+PE.…”

“…In addition, WVTR data suggest that the most occlusive agent evaluated in this study are the monoacylglycerol derivatives of Performacol 425 with WVTR data superior to a comparable formulation containing petrolatum. This material displayed slightly lower WVTR results compared to glycerol monobehenate (WVTR = 64 g m −2 h −1 ) and WVTR results comparable to monoacylglycerols derived from Compritol ATO 888 (WV TR = 51 g m −2 h −1 ) reported previously . This work demonstrated the potential use of Performacol 425 as a source of fatty alcohols to generate monoacylglycerols containing fatty acid with chain length similar to those found in healthy SC.…”

“…The desired fatty acids enriched in C22-C26 fatty acids were obtained in good yields (35-49%) even though the fatty alcohols (starting material) could not be completely dissolved in acetone to carry out the oxidation. The resulting fatty acids were then used to obtain the respective monoacylglycerols following previously described procedures using Novozym 435, t-butanol as a solvent [36,38]. Based on TLC analysis using silica gel plate previously immersed in a hydroethanolic solution (50%, v/v) of boric acid (1.2% wt), sn-1 monoacylglycerols were the major product of the reaction which is in agreement with the well-known 1,3 regioselectivity of Novozyme 435.…”

A new group of synthetic phenolic-containing amphiphilic molecules for multipurpose applications: Physico-chemical characterization and cell-toxicity study

“…The amphiphilic lipids were characterized by means of DSC to determine their melting transition temperatures. This is relevant for applications as emulsifiers 12 , skin lipids 5 , 6 , or nanocarriers 9 . No clear melting transition temperatures were observed for compounds C10 ‒ C16 when temperature scanning from was done −60 °C to 60 °C.…”

“…In addition, due to structural similarities to other compounds in the literature 1 – 9 , the synthesized amphiphiles could potentially find applications not only in food but also in cosmetics, or as nanocarriers. For instance, longer alkyl chain derivatives of this series of compounds could be applied in cosmetic formulations as protective skin barriers 5 , 6 .

Figure 1 General structure of malic acid esters of monoglycerides.

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