Optimization Of Ultrasonic-assisted Extraction Of Oil From Seed Of Paeonia Lactiflora Pall And Chemical Composition Of The Seed Cake

Paeonia lactiflora(Paeoniaceae), widely distributed in China, Korea, and Russia, is a herb with ornate flowers blooming in spring. The root of P. lactiflora(Chi-Shao and Bai-Shao) is one of the most important crude drugs used as antioxidant, analgesic, and anti-inflammatory agent in Asia. It is commonly used as a remedy for cardiovascular disorders, extravagated blood, and rheumatoid arthritis. Recent phytochemical investigations suggested that seed oil and monoterpene glycosides are rich in seeds of P. lactiflora. In our research, the ultrasonic assistant extraction technique of oil from seed of Paeonia lactiflora Pall was studied, and the chemical composition of the oil was analyzed by GC-MS, the monoterpene glucosides were isolated from the seed of P. lactiflora Pall, and content of the monoterpene glycosides in seed kernel and seed shell of P. lactiflora Pall was also determined.The ultrasonic assistant extraction technique of oil from seed of P. lactiflora Pall was studied, and the chemical composition of the oil was analyzed by GC-MS. The extraction parameters including ultrasonic time, ultrasonic temperature, liquid to solid ratio and ultrasonic power on the extraction rate of Paeonia lactiflora Pall seed oil were optimized. On the basis of single factor tests,the extraction technology of P. lactiflora Pall seed oil was optimized by response surface methodology. Chemical constituents were isolated by silica gel column, Toyopearl HW-40, Sephadex LH-20, and preparative HPLC chromatographies. The structures of the isolated compounds were elucidated on the basis of spectral data analysis. The HPLC was used for simultaneous determination the isolated monoterpene glycosides in seed kernel and seed shell of P. lactiflora Pall.The optimum conditions of extracted with solvent obtained were as follows: extraction time was 18 min, extraction temperature was 35℃, extraction power was 445 W. Under this conditions, the extraction rate values of oil was 28.85%. The optimum conditions of extracted with water obtained were as follows: extraction time was 56 min, extraction temperature was 54℃, liquid to solid ratio was 8:1(m L/g), extraction power was 885 W. Under this conditions, the extraction rate values of oil was 27.99%. The predominant fatty acids in Paeonia lactiflora Pall seed oil were α-Linolenic acid), 9,12-linoleic acid, and so on. The percentage of unsaturated fatty acids relative to total fatty acids was over 85 %. Six monoterpene glucosides, 4"-hydroxylalbiflorin(1), oxypaeoniflorin(2),abiflofin(3), paeoniflorin(4), paeonidanin(5), abiflofin R1(6) were isolated from the seed of P. lactiflora. A HPLC method for simultaneously determining the contents of six monoterpene glucosides in seed kernel and seed shell of P. lactiflora Pall was established. The separation was performed on an Agilent Zorbax SB C18 column, using acetonitrile and potassium dihydrogen phosphate solution(p H 3.0) as the mobile phase, with a gradient elution. The flow rate was 1.0 m L·min-1; Detection wavelength was set at 260 nm(0-7.5 min) for the detection of 4′′-hydroxyl abiflofin, oxypaeoniflorin, and 232 nm(7.5-22 min) for the detection of abiflofin, paeoniflorin, Paeonidanin, abiflofin R1. Column temperature was set at 30℃.Organic solvent extraction process is more effective than aqueous extraction process under the ultrasonic assistant conditions. All the isolated compounds were isolated from the seed of P. lactiflora for the first time. The HPLC method is simple, accurate and can be used for quality control of the seed cake of P. lactiflora.