title: Extraction Optimization, Purification and Physicochemical Properties of Polysaccharides from Gynura medica.
abstract: Extraction of polysaccharides from Gynura medica (GMPs) was optimized by response surface methodology (RSM). A central composition design including three parameters, namely extraction temperature (X₁), ratio of water to raw material (X₂) and extraction time (X₃), was used. The best conditions were extraction temperature of 91.7 °C, extraction time of 4.06 h and ratio of water to raw material of 29.1 mL/g. Under the optimized conditions, the yield of GMPs was 5.56%, which was similar to the predicted polysaccharides yield of 5.66%. A fraction named GMP-1 was obtained after isolation and purification by DEAE-52 and Sephadex G-100 gel chromatography, respectively. GMP-1, with a molecular weight of 401 kDa, mainly consisted of galacturonic acid (GalA), xylose (Xyl), glucose (Glu). Infrared spectroscopy was used to characterize the major functional groups of GMP-1 and the results indicated that it was an acidic polysaccharide. The antioxidant and α-glucosidase inhibitory activities of GMPs and GMP-1 were determined in vitro. The results indicated that GMPs and GMP-1 show potential for use in functional foods or medicines.
authors.affiliation: College of Prataculture Science, Nanjing Agricultural University, Nanjing 210095, China. lifengwei1980@126.com.|School of Marine and Bioengineering, Yan Cheng Institute of Technology, Yan Cheng 224051, China. lifengwei1980@126.com.
authors.forename: Fengwei
authors.initials: F
authors.lastname: Li
authors.affiliation: School of Marine and Bioengineering, Yan Cheng Institute of Technology, Yan Cheng 224051, China. gaojian@ycit.cn.
authors.forename: Jian
authors.initials: J
authors.lastname: Gao
authors.affiliation: School of Marine and Bioengineering, Yan Cheng Institute of Technology, Yan Cheng 224051, China. coldsun_xf@163.com.
authors.forename: Feng
authors.initials: F
authors.lastname: Xue
authors.affiliation: School of Marine and Bioengineering, Yan Cheng Institute of Technology, Yan Cheng 224051, China. yxh1127@163.com.
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Yu
authors.affiliation: College of Prataculture Science, Nanjing Agricultural University, Nanjing 210095, China. taoshaolan@163.com.
authors.forename: Tao
authors.initials: T
authors.lastname: Shao
mesh_terms: D000975:Antioxidants / Q000737:chemistry* / Q000302:isolation & purification; D019659:Asteraceae / Q000737:chemistry*; D005947:Glucose / Q000737:chemistry / Q000302:isolation & purification; D065089:Glycoside Hydrolase Inhibitors / Q000737:chemistry / Q000494:pharmacology; D006603:Hexuronic Acids / Q000737:chemistry / Q000302:isolation & purification; D008970:Molecular Weight; D011134:Polysaccharides / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D014994:Xylose / Q000737:chemistry / Q000302:isolation & purification; D000520:alpha-Glucosidases / Q000187:drug effects
chemical_list: D000975:Antioxidants; D065089:Glycoside Hydrolase Inhibitors; D006603:Hexuronic Acids; D011134:Polysaccharides; C007819:galacturonic acid; D014994:Xylose; D000520:alpha-Glucosidases; D005947:Glucose
keywords: Gynura medica; activity; extraction optimization; polysaccharides; purification