| Polygonum cuspidatum, a perennial herbaceous plant, it's rich with resveratrol. Resveratrol accounted for 0.1~0.2%, polydatin accounted for 2%, the polydatin can be decomposed into resveratrol under the action of intestinal hydrolase to play a role of pharmacology, including anti-inflammatory, cardiovascular protection, antitumor, antiviral, anti-aging,anti-Alzheimer's disease and other biological activity.With means of ultrasonic assisted extraction, enzymatic conversion, column chromatography, preparative HPLC, mass spectrometry and NMR experimental technique, this subject successfully isolated and identified resveratrol. Then we studied and discussed the Alzheimer's disease related biological activity. The results were summarized as follows:Combined with the UV absorption spectrum display of polydatin and resveratrol as standard substance, we concluded that both had maximum absorption at about 305 nm. The suitable conditions by ultrasonic waves of polydatin was identified by orthogonal tests. The optimum extraction parameters were the concentration of ethanol was 60%, ratio of solid to liquid was 1:20, ultrasonic time was 60 min, and the extraction temperature was 40 ?, the extraction ratio of polydatin was up to 1.83%.Considering yield of total resveratrol as index, based on single factor experiments, response surface methodology was adopted to optimize transformation process by taking the amount of enzyme, the percentage enzyme, temperature, p H,time as factors. Optimum technological conditions were as follows: 463 ?L enzyme dosage, temperature 43 ?, p H=5.0, conversion time 153 min, the yield of resveratrol was 16.46 mg.g-1, whose deviation was small by comparing with the theoretical value of 16.52 mg.g-1, which was 3.58 times to before optimization and 1.66 times of the best enzyme hydrolysis process(251 ?L enzyme dosage,temperature 46 ?,p H=4.4,conversion time 133 min). Response surface analysis used inoptimization of total resveratrol was feasible, which was a beneficial reference for the industrialized production to reduce the cost of resveratrol.This experiment used the ultrasonic assisted extraction, microbial fermentation to produce ?-glycosidase and cellulase transformed polydatin into resveratrol, pre-process the extracts by using both physical and chemical means, finally purified resveratrol by silica gel column and preparative liquid chromatography.Culturing Neuro-2a-sw mouse brain tumor cells, we tested the proliferation of this cell at resveratrol using the CCK kit. In conclusion, resveratrol at 10~40 ?mol.L-1 had no inhibition on proliferating activity of Neuro-2a-sw mouse brain tumor cells at one hour. So we choosed these concentration as appropriate ones for the following activity experiment.Inflammatory reaction accelerates the formation of senile plaques in Alzheimer 's disease brain. Resveratrol at 10~40 ?mol.L-1 showed concentration dependent inhibition of Neuro-2a-sw cell induced by glutamate to release NO, suggesting that resveratrol had anti-inflammatory effect.The coagulation of A? protein oligomers was one of the important mechaninsms causing Alzheimer's disease. The Th T model in vitro experiments showed that resveratrol at 100 ?mol.L-1 inhibition rate for A?42 protein aggregation was 33.77%.Experiments proved that resveratrol could resist Alzheimer's disease related biological activity through the cell and molecular levels. Polygonum cuspidatum had the advantages of low cost, abundant, polydatin was transformed into resveratrol improve the yield, so it was expected to separate and develop safe, effective, inexpensive drug anti-Alzheime's disease. |
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