title: Optimization of ultrasound extraction of Alisma orientalis polysaccharides by response surface methodology and their antioxidant activities.
abstract: Rhizoma alismatis (the rhizome of Alisma orientalis) polysaccharides (RAP) have been reported to have a variety of important biological activities. However, effective extraction of RAP has been an unsolved issue. In this study, we used an ultrasound method for high yield extraction of RAP and optimized the conditions using the response surface methodology (RSM). Following multiple regression analyses of the experimental results, we applied the 3-D response surface and the contour plots to determine the optimal conditions, which were found to be ultrasound treatment at 76.1°C for 75.2 min, and water to material ratio at 30.1 ml/g. Under such conditions, the yield was 6.90% which was much higher than traditional hot water extraction yield (3.41%). The fractionated RAPs following stepwise ethanol precipitation showed strong antioxidant activities. The results indicated that ultrasound extraction was a very effective method for the extraction of RAP and the polysaccharides could be explored as a potential antioxidant agent for use in medicine or functional food.
authors.affiliation: College of Pharmacy, Harbin Medical University, Harbin 150081, China.
authors.forename: Zhan-Yi
authors.initials: ZY
authors.lastname: Zhao
authors.affiliation: Harbin Medical University Library, Harbin 150081, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: College of Pharmacy, Harbin Medical University, Harbin 150081, China.
authors.forename: Ya-Fang
authors.initials: YF
authors.lastname: Li
authors.affiliation: College of Pharmacy, Harbin Medical University, Harbin 150081, China. Electronic address: Zhanyi_Zhao@163.com.
authors.forename: Lu-Lu
authors.initials: LL
authors.lastname: Dong
authors.affiliation: College of Pharmacy, Harbin Medical University, Harbin 150081, China; Genomics Research Center, Harbin Medical University, Harbin 150081, China. Electronic address: slliu@ucalgary.ca.
authors.forename: Shu-Lin
authors.initials: SL
authors.lastname: Liu
mesh_terms: D034902:Alisma / Q000737:chemistry*; D000704:Analysis of Variance; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D001713:Biphenyl Compounds / Q000737:chemistry; D004912:Erythrocytes / Q000187:drug effects; D016166:Free Radical Scavengers / Q000737:chemistry; D006461:Hemolysis / Q000187:drug effects; D006358:Hot Temperature; D008297:Male; D008970:Molecular Weight; D010851:Picrates / Q000737:chemistry; D010936:Plant Extracts / Q000494:pharmacology*; D011134:Polysaccharides / Q000302:isolation & purification* / Q000494:pharmacology; D017208:Rats, Wistar; D015203:Reproducibility of Results; D013055:Spectrophotometry, Infrared; D017550:Spectroscopy, Fourier Transform Infrared; D013997:Time Factors; D014465:Ultrasonics / Q000379:methods*; D014867:Water / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D016166:Free Radical Scavengers; D010851:Picrates; D010936:Plant Extracts; D011134:Polysaccharides; D014867:Water; C004931:1,1-diphenyl-2-picrylhydrazyl
keywords: Antioxidant activity; Polysaccharides; Response surface methodology; Rhizoma alismatis; Ultrasound extraction