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 (X 1 ), ratio of water to raw material (X 2 ) and extraction time (X 3 ), 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.

Physicochemical Characterisation of Polysaccharides from the Seeds and Leaves of Miracle Fruit (Synsepalum dulcificum) and Their Antioxidant and α-Glucosidase Inhibitory Activities In Vitro

“…This result is consistent with its almost single monosaccharide composition with glucose (Figure 2(b)). Li et al [25] reported a similar HPGFC profile for polysaccharide. MFP-L consisted of three major fractions with Mw of 92093, 1496, and 237 Da (Mp: 54038, 1267, and 200 Da) in proportion of 34%, 62%, and 4%, respectively (Figure 3(b)).…”

“…Weight. The molecular weight (Mw) of MFPs was determined by high-performance gel-filtration chromatography (HPGFC), according to the method of Li et al [25]. A Waters 1525 HPLC system was equipped with an Ultrahydrogel6 Linear 300 mm × 7.8 mm inner diameter × 2 (Waters Corp., Milford, MA), a Waters 2414 Refractive Index Detector (RI), and an Empower3 workstation.…”

Purification, Characterization, and Antioxidant Activity of Polysaccharides Isolated from Cortex Periplocae

“…Overall, the antioxidant activity order of the CPPs in the present study was CPP3 > CPP2 > CPP1. Based on the published literatures, the antioxidant activity of natural polysaccharides might be related to their composition, molecular weight, water solubility, monosaccharide component, structure of chain conformation, polarity, and intramolecular hydrogen bonds [ 43 , 45 ]. Therefore, the antioxidant activity of polysaccharides is not a single factor but a combination of many factors.…”

“…Therefore, the antioxidant activity of polysaccharides is not a single factor but a combination of many factors. Some researchers have reported that polysaccharides with lower molecular weights present stronger reducing power [ 5 , 45 ], but Huang et al reported that polysaccharides with larger molecular weights possessed higher reducing power [ 46 ]. In the present work, the results indicated that there was no obvious relationship between molecular weight and antioxidant activity, which was also consistent with reported results [ 47 , 48 ].…”

Compared extraction methods on the physicochemical properties, antioxidant activity, and optimization of enzyme‐assisted extraction of polysaccharides from Gynura medica

“…The HWE method was performed according to our previous work (Li, Gao, Xue, Yu, & Shao, ). The dried powder 5.0 g was extracted with 150 ml of distilled water at 80°C for 3 hr.…”