Synthesis of α-Hydroxy Fatty Acids from Fatty Acids by Intermediate α-Chlorination with TCCA under Solvent-Free Conditions: A Way to Valorization of Waste Fat Biomasses

Abstract

Within food wastes, including edible and inedible parts, fat biomasses represent a significant portion, often uneconomically used or improperly disposed causing pollution issues. Interesting perspectives for their management and valorization could be opened by conversion of fatty acids (FAs), which are their main constituents, into α-hydroxy FAs (α-HFAs), fine chemicals of great, but largely untapped potential, possibly due to current poor availability. Here, a simple and efficient procedure is reported to α-chlorinate FAs with trichloroisocyanuric acid (TCCA), a green halogenating agent, under solvent-free conditions and to directly convert the resultant α-chloro FAs, without previous purification, into α-HFAs. The procedure was applied to stearic, palmitic, and myristic acid and, with analogous success, to their mixture, ad hoc created to simulate a FAs mixture obtainable from a fat biomass.

Fractioning and Compared 1H NMR and GC-MS Analyses of Lanolin Acid Components

“…The qualitative and semi-quantitative compositions of the extracts were evaluated using 1 H NMR spectroscopy analysis. FAs and α-HFAs can be distinguished by two singular peaks, as previously reported [ 18 ]: FAs are characterised by a triplet at 2.35 ppm (-CH 2 -CO-, 2H, Figure S1 ), α-HFAs by a doublet of doublets at 4.26 ppm (-CHOH-CO-, 1H, Figure S2 ). The extraction of acid components of lanolin was performed in triplicate, as follows, and is schematically pictured in Figure 1 .…”

“…Lanolin, FAs standards (lauric (FA 12:0), myristic (FA 14:0), palmitic (FA 16:0), stearic (FA 18:0), arachidic (FA 20:0), behenic (FA 22:0), lignoceric (FA 24:0), myristoleic (FA 14:1), palmitoleic (FA 16:1), linoleic (FA 18:2), and oleic (FA 18:1) acids), internal standard (IS, heptadecanoic acid (FA17:0)), methanol, cyclohexane, potassium hydroxide, hydrochloric acid, N-Trimethylsilyl-N-methyl trifluoroacetamide (MSTFA), trimethylanilinium hydroxide (MethElute™, TMPAH), and deuterated chloroform (CDCl 3 ) were acquired from Sigma-Aldrich (Milan, Italy). α-Hydroxy fatty acids (myristic (α-HFA 14:0), palmitic (α-HFA 16:0), and stearic (α-HFA 18:0) were synthetized from the corresponding FAs (FA 14:0, FA 16:0, and FA 18:0) according to recently reported procedures based on the chlorination of FAs with trichloroisocyanuric acid, a versatile green chlorinating agent [ 19 , 20 ], and successive α-hydroxylation [ 18 ] or, alternatively, on the enzyme catalysed α-hydroxylation of FAs [ 21 ]. The synthetic procedure for α-hydroxy arachidic acid (α-HFA 20:0) can be found in the supporting information (Procedure S1) .…”

Design of a H2O2‐generating P450SPα fusion protein for high yield fatty acid conversion

“…Wool grease (also known as lanolin or wool wax) is usually obtained as a raw wool processing derivative, consisting mainly of esters, polyesters of high molecular weight fatty acids and alcohols, along with hydrocarbons and free fatty acids 2 . As previously reported, a possible approach to enhance the value of waste fat biomass is the conversion of lanolin fatty acids to α‐hydroxy fatty acids 3 . The hydroxylated products of fatty acids, indeed, find widespread use in chemical, food and cosmetic industry 4 as well as in medical research and medicine 5 .…”

“…2 As previously reported, a possible approach to enhance the value of waste fat biomass is the conversion of lanolin fatty acids to α-hydroxy fatty acids. 3 The hydroxylated products of fatty acids, indeed, find widespread use in chemical, food and cosmetic industry 4 as well as in medical research and medicine. 5 Although the biocatalytic conversion of fatty acids to hydroxy fatty acids has been reported using, among the other, lipoxygenase, hydratase, and diol synthase, 6 to date the efficient enzymatic production of α-hydroxy fatty acids has not been achieved, leading to the low commercial availability of these compounds.…”

Sustainable Routes for Wool Grease Removal Using Green Solvent Cyclopentyl Methyl Ether in Solvent Extraction and Biosurfactant Wool Protein Hydrolyzate in Scouring

“…This process is carried out to obtain crude lanolin or reduce the chemical oxygen demand (COD) and the biological oxygen demand (BOD) of effluents. Wool grease extracted from wool scouring liquors is refined into value-added products ranging from rust-proof coatings, lubricants, and personal and healthcare creams [3][4][5]. Lanolin is a mixture of esters, diesters, and hydroxy esters of high molecular weight, free fatty alcohols, and fatty acids [2,[6][7][8].…”