关键词: 虎杖, 白藜芦醇, 大黄素, 微波程序控温控压, 双水相萃取

Abstract: Microwave procedure controlled temperature-pressure assisted ethanol-ammonium sulfate aqueous two-phase extraction was used to extract the resveratrol and emodin from Polygonum cuspidatum fruits. The effects on extraction rate and purity of resveratrol and emodin were compared by three extraction methods, microwave assisted extraction, microwave-assisted aqueous two-phase extraction and the above mentioned. The chemical structure was determined using Infrared (IR) spectroscopy. The aqueous two-phase system was made by solid-to-solvent ratio 1:20 (g:mL) and ethanol-(NH₄)₂SO₄ with phase separation coefficient of 0.5. Microwave procedure to controll temperature-pressure conditions were divided into 5 stages, i.e., room temperature, 40, 50, 60 and 70℃, and the corresponding control pressure 137.9, 344.75, 689.5, 1 034.25 and 1 379 kPa. Each upgrading microwave lasted 1.2 min and the interval was 5 min. The results showed that under these conditions, the extraction rate of resveratrol and emodin from the fruits of polygonum cuspidatum were 0.694% and 2.067% with purify of 82.68% and 87.25%, respectively. This significantly improved the extraction rate of resveratrol and emodin from the fruits of P. cuspidatum. This also maintained the biology active and had excellent stability, excellent repeatability, high-precision and high-recovery compared with other two methods. Meanwhile, the method simplified the process of separation and purification and reduced production costs, so it was suitable for the extraction of resveratrol and emodin in the fruits of P. cuspidatum.

Key words: Polygonum cuspidatum, resveratrol, emodin, microwave procedure controlled temperature-pressure assisted, aqueous two-phase extraction