White Biotechnology applied to the synthesis of emollient esters

The production of bulk and fine chemicals using enzymes and/or microorganisms has been recently labelled as "white biotechnology". Targets of this technology are the development of clean processes, the reduction of greenhouse gas emission and energy costs by means of living cells from yeast, bacteria and plants or enzymes [1]. In other words, it's about Green Chemistry taking advantage of biotechnological tools. For this reason, several chemical industries have started to apply this technology to the production of a variety of pharmaceuticals, agrochemicals and organic compounds in general [2]. Perhaps, the earliest known example of industrial biotechnology concerns the use of a genetically modified Escherichia Coli to produce human insulin. This outstanding achievement was announced at the end of 1978 by researchers at the Genentech Inc., and the industrial production started 4 years later [3]. Similar relevant applications of white biotechnology can be found in the production of cosmetic raw materials among which the most known example is the complex active ingredient ceramide. One the other hand, also relatively cheap cosmetic compounds, such as emollients, can be advantageously produced by enzymatic catalysis. Emollients are basically fatty acid esters such as hexyldecanol and hexyldecyl laurate, propylheptyl caprylate or C12-15 alkyl benzoate. Such materials are widely used in day care and sun creams as solvents for crystalline UV-filters, supporting the absorption of UV rays. We herby present some preliminary results on the application of enzymatic catalysis to the production of two different emollient esters, namely C12-C15 alkyl benzoate and 2 ethylhexyl palmitate. The reactions are carried out at very mild conditions either in the presence of organic solvents or neat. A variety of enzymes have been tested at different reaction conditions and the feasibility of catalyst recycling has been performed.