Microwave-Assisted Extraction of Tanning in Potentilla Discolor Bunge

The single factor experiment and orthogonal experiment has been used to optimize the process for microwave-assisted extraction of tanning in potentilla discolor bunge, using the extractant concentration, pH, liquid-solid ratio, microwave time and extraction temperature as the investigation factors. As the assessment index, the extraction rates of tanning were detected by the phosphotungstomolybdate acid-casein spectrophotometry. The optimum conditions for the process were as follows: 70% methanol (pH=8.0) was used as the extraction agent, the liquid-solid ratio was 1:40, and extraction time was 10 min at 40℃. The contents of tannins in different parts of potentilla discolor bunge were also determined, showing that the content of tannins in the root was the highest, and followed by the stem and leaf. HPLC is also used in the qualitative analysis of type of tanning in potentilla discolor bunge.