Solvent‐free synthesis of hydrophobic and amphiphilic esters using a chemically modified lipase from Thermomyces lanuginosus: a comparative study with native and immobilized forms

Abstract

Using lipases to catalyze the synthesis of the most differentiated type of compounds remains one of the major challenges among scientists. Seeking more economic and advantageous catalysts is a current goal of green chemistry. In this work, we demonstrate the potential of a chemically modified form of lipase from Thermomyces lanuginosus (cmLTL) for the synthesis of both hydrophobic (heptyl heptanoate, heptyl octanoate, heptyl decanoate, decyl heptanoate, decyl octanoate and decyl decanoate) and amphiphilic (2‐(2‐ethoxyethoxy)ethyl oleate and 2‐(2‐ethoxyethoxy)ethyl linoleate) esters, in bulk. The results were compared with its native (LTL) and immobilized (imLTL) forms. The data revealed that LTL showed poor activity for all reactions performed with n‐heptane (h<20%). ImLTL was able to synthesize all hydrophobic esters (h>60%), with exception of the short ester, heptyl heptanoate. cmLTL was the only form of LTL capable of producing hydrophobic and amphiphilic esters, without compromising the yield when the reactions were performed under solvent‐free conditions (>50%). Molecular modeling showed that the active pocket of cmLTL is able to deeply internalize transcutol, with stronger interactions, justifying the outstanding results obtained. Furthermore, owing to the possibility of cmLTL filtration, the reusability of the catalyst is ensured for at least 6 cycles, without compromising the reaction yields.

Physicochemical Properties of New Silicone Alternatives Unraveled by Experimental and Molecular Modeling Techniques

“…For this purpose, three commercial silicones� cyclopentasiloxane, dimethicone 5, and dimethicone 10 cst� and three commercial alternatives to silicones�cetiol CC, cetiol sensoft, and cetiol C5�are used to compare their effect and properties against a small collection of esters, previously produced by us. 13 The formulations were characterized, mainly regarding rheologic properties, texture analysis, spreadability contact angle, and physical−chemical properties.…”

“…Because synthetic silicones are highly insoluble molecules, they have been a target for replacement due to concerns about bioaccumulation in wastewater and, more importantly, the use of aggressive surfactants to incorporate them into these formulations or to cleanse the product from the hair or skin. , The present study aimed to evaluate the effect of various esters as silicone alternatives in a cosmetic-based formulation. For this purpose, three commercial siliconescyclopentasiloxane, dimethicone 5, and dimethicone 10 cstand three commercial alternatives to siliconescetiol CC, cetiol sensoft, and cetiol C5are used to compare their effect and properties against a small collection of esters, previously produced by us . The formulations were characterized, mainly regarding rheologic properties, texture analysis, spreadability contact angle, and physical–chemical properties.…”