Enhancement of propyl gallate yield in nonaqueous medium using novel cell-associated tannase of Bacillus massiliensis.

Enzymatic synthesis of propyl gallate in organic solvent was studied using cell-associated tannase (EC 3.1.1.20) of Bacillus massiliensis. Lyophilized biomass showing tannase activity was used as the biocatalyst. The effects of solvent, surfactant treatment, and bioimprinting on the propyl gallate synthesis were studied and subsequently optimized. Among various solvents, benzene followed by hexane was found to be the most favorable. Treatment of the biocatalyst with Triton X-100 at a lower concentration (0.2% w/v), before lyophilization, increased the propyl gallate yield by 24.5% compared to the untreated biocatalyst. The biocatalyst was imprinted with various concentrations of gallic acid and tannic acid. Biocatalyst imprinted with tannic acid showed 50% enhancement in the propyl gallate yield compared to the non-imprinted biocatalyst.

Effect of JEZTC, a synthetic compound, on proliferation and phenotype maintenance of rabbit articular chondrocytes in vitro.

Antioxidant may provide anti-arthritic effect that contributes to resolution of inflammation. Gallic acid (GA) and its derivatives were reported to be effective in treatment of arthritis. But GA-suppressed cell proliferation may compromise its effect on chondro-protection. In this study, we synthesized sulfonamido-based gallate-JEZTC and investigated its effect on rabbit articular chondrocytes through examination of the cell proliferation, morphology, viability, glycosaminoglycan (GAG) synthesis, and cartilage-specific gene expression. Results showed that JEZTC could effectively promote chondrocyte growth and enhance secretion and synthesis of cartilage extracellular matrix (ECM) by upregulating expression levels of aggrecan, collagen II, and Sox9 genes. Expression of collagen I which marked chondrocyte dedifferentiation was effectively downregulated by JEZTC. In addition, hypertrophy that may lead to chondrocyte ossification could not be detected in JEZTC groups. The results indicated JEZTC can well preserve the phenotype of chondrocytes. Range of 2.344 to 9.375 µg/ml is the recommended dose of JEZTC, which showed increased cell proliferation. Especially, JEZTC of 4.688 µg/ml showed the best performance. This study might provide a basis for development of a novel agent for the treatment of symptomatic chondral and osteochondral lesions.

Synthesis of antioxidant propyl gallate using tannase from Aspergillus niger van Teighem in nonaqueous media.

Tannase from Aspergillus niger van Teighem has been used for synthesis of food additive antioxidant propyl gallate by direct transesterification of tannic acid. The optimized yield of 86% was obtained by using simultaneously pH tuned enzyme, immobilized on Celite and using the right amount of water in the non aqueous media.