Unlocking the access to oxidized coenzyme A via a single-step green membrane-based purification.

A new membrane-based strategy to purify oxidized coenzyme A ((CoAS)2) from adenosine triphosphate (ATP), adenosine diphosphate (ADP) and adenosine monophosphate (AMP) has been developed. Commercially available membranes were screened and studied (permeate flux and overall compounds retention) which allowed the identification of one efficient membrane (GK from Suez Water Technologies & Solutions). Different total compounds concentrations solutions were used in the system in order to find the following working conditions: 4 bars with a total compounds solution of 5.19 g L-1. Applying these conditions to a dia-filtration set-up allowed us to reach 68% pure (CoAS)2 in 4.8 diafiltration volumes (DV) and a 95% (CoAS)2 purity can be predicted in 8.5 DV. A comparative study of green metrics-i.e. process mass index (PMI)-of the classic chromatography vs the membrane-based one demonstrated the great advantages of the latter in terms of sustainability. This strategy unlocks the access to the essential and central cofactor that is coenzyme A.

Phenolic Compounds Extracted from Cherry Tree (Prunus avium) Branches: Impact of the Process on Cosmetic Properties.

Cherry tree branches (Prunus avium var burlat Rosaceae) are agricultural by-products that are often neglected, yet they are rich in phenolic compounds and highly appreciated for their numerous biological activities. Extracts of cherry tree branches were evaluated for their use in cosmetics, particularly for their antioxidant, anti-tyrosinase, and antimicrobial activities. Samples were obtained by accelerated solvent extraction (ASE) at different ethanol percentages and different temperatures. Fourteen phenolic compounds were identified in the extracts by mass spectrometry. Three major compounds were identified (catechin, genistin, and prunin) representing 84 wt% of the total phenolic compounds. Optimal operating conditions maximizing the content of phenolic compounds were determined using a one factor at a time (OFAT) approach (70% aqueous ethanol, 70 °C). The extract obtained under these conditions also showed the highest antioxidant and anti-tyrosinase activities, certainly due to a high catechin content. Although the antimicrobial activities of extracts are less versatile than those of synthetic molecules, they are nonetheless interesting. According to these results, the extracts of cherry tree branches could be used in cosmetics for their interesting properties.

Implementation of an Enzyme Membrane Reactor to Intensify the α-O-Glycosylation of Resveratrol Using Cyclodextrins.

The O-glycosylation of resveratrol increases both its solubility in water and its bioavailability while preventing its oxidation, allowing a more efficient use of this molecule as a bioactive ingredient in pharmaceutical and cosmetic applications. Resveratrol O-glycosides can be obtained by enzymatic reactions. Recent developments have made it possible to selectively obtain resveratrol α-glycosides from the ß-cyclodextrin-resveratrol complex in water with a yield of 35%. However, this yield is limited by the partial hydrolysis of the resveratrol glycosides produced during the reaction. In this study, we propose to intensify this enzymatic reaction by coupling the enzymatic reactor to a membrane process. Firstly, membrane screening was carried out at the laboratory scale and led to the choice of a GE polymeric membrane with a cut-off of 1 kDa. This membrane allowed the retention of 65% of the ß-cyclodextrin-resveratrol complex in the reaction medium and the transfer of 70% of the resveratrol α-O-glycosides in the permeate. In a second step, this membrane was used in an enzymatic membrane reactor and improved the yield of the enzymatic glycosylation up to 50%.