Gallic acid‐based alkyl esters synthesis in a water‐free system by celite‐bound lipase of Bacillus licheniformisSCD11501

Abstract

Gallic acid (3, 4, 5- trihydroxybenzoic acid) is an important antioxidant, anti-inflammatory, and radical scavenging agent. In the present study, a purified thermo-tolerant extra-cellular lipase of Bacillus licheniformis SCD11501 was successfully immobilized by adsorption on Celite 545 gel matrix followed by treatment with a cross-linking agent, glutaraldehyde. The celite-bound lipase treated with glutaraldehyde showed 94.8% binding/retention of enzyme activity (36 U/g; specific activity 16.8 U/g matrix; relative increase in enzyme activity 64.7%) while untreated matrix resulted in 88.1% binding/retention (28.0 U/g matrix; specific activity 8.5 U/g matrix) of lipase. The celite-bound lipase was successfully used to synthesis methyl gallate (58.2%), ethyl gallate (66.9%), n-propyl gallate (72.1%), and n-butyl gallate (63.8%) at 55(o) C in 10 h under shaking (150 g) in a water-free system by sequentially optimizing various reaction parameters. The low conversion of more polar alcohols such as methanol and ethanol into their respective gallate esters might be due to the ability of these alcohols to severely remove water from the protein hydration shell, leading to enzyme inactivation. Molecular sieves added to the reaction mixture resulted in enhanced yield of the alkyl ester(s). The characterization of synthesised esters was done through fourier transform infrared (FTIR) spectroscopy and (1) H NMR spectrum analysis.

Enzymes, In Vivo Biocatalysis, and Metabolic Engineering for Enabling a Circular Economy and Sustainability

“…298 After 10-h incubation at 55 °C, about 58%, 67%, 72%, and 64% yields of methyl gallate, ethyl gallate, propyl gallate, and butyl gallate could be obtained, respectively. 298 Vanilla is an important fragrance for the food and perfume industries, which has been extensively used worldwide. Vanillin (4-hydroxy-3-methoxybenzaldehyde) is the key component in vanilla.…”

“…Various alkyl gallates including methyl gallate, ethyl gallate, propyl gallate, and butyl gallate could also be synthesized using a thermophilic lipase from Bacillus licheniformis SCD11501 (Figure ). After 10-h incubation at 55 °C, about 58%, 67%, 72%, and 64% yields of methyl gallate, ethyl gallate, propyl gallate, and butyl gallate could be obtained, respectively …”

The beauty of biocatalysis: sustainable synthesis of ingredients in cosmetics

“…101 The use of celite bound lipases have been investigated for the synthesis of GA based alkyl esters. 102 Propyl gallate 22 (Fig. 6) is a powerful free radical scavenger along with being an anti-microbial and providing UV-radiation protection and has no reports of allergy issues.…”

Biotransformation of Plant-Derived Phenolic Acids

“…immobilized on N,N-methylenebisacrylamide(N,N-MBAAm) can be used to synthesize aspirin at a lower temperature (45 C) thus requiring less energy consumption than chemical synthesis. [48] Ruchanok Tinikul received her PhD degree in Biochemistry in 2012 from Mahidol University under supervision of Prof. Pimchai Chaiyen. Esterification of GA with 1-propanol can be catalyzed by immobilized Staphylococcus xylosus lipase to generate propyl gallate with a conversion yield of 90% when using a propanol/ GA ratio of 160 with 400 U of enzyme at 52 C. [47] Celite-bound B. licheniformis lipase can esterify GA with various alcohols to generate methyl gallate, ethyl gallate, n-propyl gallate, and nbutyl gallate with production yields of 58.2, 66.9, 72.1, and 63.8%, respectively.…”