Enhancement of the selective enzymatic biotransformation of rutin to isoquercitrin using an ionic liquid as a co-solvent.

An ionic liquid (IL)-containing buffer system was first applied in the conversion of rutin to isoquercitrin. High substrate solubility was achieved to enhance the selectivity and efficiency of hesperidinase-catalyzed reaction. Ten ILs were selected as co-solvents to assist catalytic reactions in this biotransformation process. The transformed products of rutin were identified by LC-MS. The [Bmim][BF(4)]-glycine-sodium hydroxide buffer (pH 9) (10:90, v/v) was found to be the best medium for the biotransformation of isoquercitrin from rutin with higher selectivity and efficiency. The reaction time was reduced by 0.33-fold while the conversion of rutin and the yield of isoquercitrin were increased by 1.67-fold and 2.33-fold. The results suggest that IL co-solvents have great potential to enhance the selectively enzymatic hydrolysis of rutin for isoquercitrin production.

The early phase response of rat alveolar bone to traumatic occlusion.

OBJECTIVES: Occlusal trauma is an important factor to influence alveolar bone remodelling, the effect of which includes many cytokines and signalling pathways. However, the exact mechanism of the traumatic stimulus for alveolar remodelling is still unclear. The purpose of the present study was to investigate the early responses of alveolar osteocytes to occlusal trauma through genome-wide microarray. METHODS: The occlusal surface of the upper left first molar of rat was raised by placing a stainless steel wire to induce occlusal trauma in the lower left first molar. After 24 h, we took out the alveolar bone tissue of the first molars at the both sides of rats' lower jaws under anaesthesia. The different gene expressions were showed by genome-wide microarray, which comprises about 27,000 genes and the results were examined by quantitative RT-PCR. RESULT: Of the approximately 27,000 genes, the expression of 586 genes was strongly changed. These findings clearly demonstrated that in the early response of the alveolar bone to occlusal trauma, the expression of osteoblast, collagens, bone mineralization, bone remodelling and WNT, TGF-ß pathway related cytokines decreased, and osteoclast-specific cytokines have no significant changes in expression. CONCLUSION: These results suggested that at early phase of the occlusal trauma, osteogenesis in rat's alveolar bone was inhibited, and osteoclastogenesis was not significant.