Objective:The optimal biosynthesis of L-PAC by immobilized Sc-5 yeast cell was systematically studied in this paper.M ethod:Biosynthesis.Result and Conclusion:The average of L-PAC yield produced by the immobilized Sc-5 yeast cell is≥2 g*L －1 and half life≥240 h.

In this paper， the name， origin， changes of producing area， medicinal parts， quality evaluation and processing methods of Arecae Semen in the famous classical formulas by consulting related herbal medicines， medical books and prescription books. The results showed that the names of Arecae Semen in the past dynasties were mostly derived from its shape， efficacy and producing area. The main base of the past generations was Areca catechu， the medicinal parts were its seeds （Arecae Semen） and pericarps （Arecae Pericarpium）. Arecae Semen is produced in Hainan province of China. Since modern times， it has been concluded that the best quality is large， heavy， firm， and unbreakable. The main processing methods of Arecae Semen in the past dynasties were netting， cutting and frying. Therefore， it is suggested that Arecae Semen should be used in Dayuanyin. If the processing requirements of Arecae Semen are not clearly indicated， it can be processed according to raw products in the 2020 edition of Chinese Pharmacopoeia.