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In this paper, polysaccharides from the seeds of three species of genus Glycyrrhiza were extracted to investigate the physicochemical properties, structural characteristics and antioxidant activities. The polysaccharides were composed of xylose, mannose, galactose, and glucose with different molar ratio. Fourier transform infrared spectroscopy showed the presence of key functional groups of polysaccharides whereas scanning electron microscopy analysis revealed the characteristic morphology of different polysaccharides, and thermogravimetric analysis exhibited good thermal stability of all samples. The antioxidant activities of polysaccharides were evaluated in vitro. All the three polysaccharides demonstrated strong reducing power, as well as scavenging activity against DPPH, ABTS, and hydroxyl free radicals. Antioxidant assays indicated that all the polysaccharides have obvious antioxidant activities and possess a potential development and application value in food, cosmetics as well as pharmaceutical industries., (Copyright © 2019 Elsevier B.V. All rights reserved.)

To contribute towards effective exploitation and utilization of natural antioxidants, response surface methodology (RSM) was employed to optimize the medium composition for the production of exopolysaccharides from the medicinal mushroom Ganoderma lingzhi (GLEPS). An optimal medium for GLEPS production was gave through Plackett-Burman design, path of steepest ascent, and Box-Behnken design as follows: glucose (59.62 g/L), yeast extract (10.03 g/L), CaCO 3 (0.2 g/L), thiamine (45.13 mg/L), KH 2 PO 4 (1.0 g/L), peptone (1.5 g/L), Tween 80 (10.26 mL/L), ZnSO 4 (0.3 g/L), mannitol (1.5 g/L), MgSO 4 (0.5 g/L), and aspartate (8.86 g/L). The GLEPS yield obtained was 3.57 ± 0.21 g/L-3.16-fold higher than that produced in basal medium alone. The resulting GLEPS rich in uronic acid, d-mannose, l-rhamnose, and d-glucose, was a heteropolysaccharide with high-molecular weights (475,000 kDa and 21.6 kDa, 87.97%). It was demonstrated that the GLEPS with higher carbohydrate and uronic acid contents exhibited strong in vitro antioxidant activities via radical scavenging, reductive capacity, and chelation of transition metal catalysis. These findings indicated that RSM is an efficient tool to predict the composition of culture medium required for maximizing GLEPS yield, and GLEPS had potent antioxidant activities and could be explored as a novel natural antioxidant in functional food or medicine., (Copyright © 2018 Elsevier B.V. All rights reserved.)

A novel polysaccharide named Sorghum Water-Soluble Polysaccharide (SWSP) was purified from Sorghum bicolor (L.) seeds. It was structurally characterized by high performance liquid chromatography (HPLC), thin layer chromatography (TLC), Fourier transform-infrared spectroscopy analysis (FT-IR), X-ray diffraction (XRD) and mass spectroscopy (MS). HPLC and TLC showed that SWSP is a glucose polymer. The FT-IR spectrum proved the polysaccharide characteristic band of SWSP. XRD and microscopy analyses revealed that SWSP is a semi-crystalline polymer. Functional properties of SWSP were determined based on Water Holding Capacity (WHC), Oil Holding Capacity (OHC) and emulsification properties. SWSP showed good WHC and OHC, recorded at 3.01±0.03 and 1.02±0.03g/g, respectively and exhibited excellent emulsion properties even after 168h (61.5±0.02%). The effect of SWSP on oxidative stability of sausage during storage up to 12days at 4°C was investigated. Results showed a high rate (P<0.05) of oxymyoglobin and low lipid oxidation. The antioxidant activities of SWSP were also studied in vitro. Results demonstrated that the polysaccharides exhibited interesting 1,1-diphenyl-2-picrylhydrazyl (DPPH), ABTS radical scavenging, and ß-carotene bleaching inhibition activities. Overall, this natural polysaccharide was proved to enhance the oxidation stability of sausages, since it can efficiently substitute synthetic antioxidants in meat industry., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Lectins are proteins able to interact specifically and reversibly with carbohydrates. They are present in all living beings, particularly in legume seeds, which have many biological functions. The aim of this study was to isolate, characterize and verify antioxidant, anti-hemolytic, antitumor and gastroprotective activities in a lectin present in seeds of Phaseolus lunatus L. var. cascavel (PLUN). The isolation of lectin was performed by size exclusion chromatography on Sephadex G-100, which was isolated from a protein capable of agglutinating only human erythrocytes type A, being this the only inhibited haemagglutination n-acetyl-d-galactosamine. Its weight was estimated by PAGE is 128kDa. The lectin is thermostable up to 80°C and is active between pH 2-11. As 8M urea was able to denature the lectin. PLUN is a glycoprotein consisting of 2% carbohydrate and has antioxidant action with ascorbic acid equivalent antioxidant capacity (μMAA/g) of 418.20, 326 and 82.9 for total antioxidant activity, ABTS radical capture and capture of DPPH radical, respectively. The lectin has antitumor activity against melanoma derived cells at doses of 100 and 50mg/ml, reducing up to 83% tumor cells, and gastroprotective action, reducing up to 63% damaged area of ​​the stomach induced by ethanol., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Purification, preliminary characterization and bioactivity of polysaccharides from Grateloupia livida (GL) were investigated. Three water-soluble sulfated polysaccharide fractions (GLP-1, GLP-2 and GLP-3) were isolated and purified from the edible and medicinal red seaweed, Grateloupia livida (Harv.) Yamada by DEAE Sepharose CL-6B and Sephadex G-100 column chromatography, and chemical characterization was performed by HPGPC, GC-MS, FT-IR and SEM. In addition, anticoagulant activities were determined by activated partial thromboplastin time (APTT), thrombin time (TT) and prothrombin time (PT) using normal human plasma in vitro. The antioxidant activities against DPPH and ABTS + radicals were evaluated and compared. The molecular weights of GLP-1, GLP-2 and GLP-3 were 39.5, 60.4 and 3.36kDa, respectively. Monosaccharide analysis revealed that three polysaccharide fractions were homopolysaccharides and comprised of galactose only. Anticoagulant assays indicated that crude GLP, and purified GLP-1 and GLP-2 effectively prolonged APTT and TT, but not PT. All polysaccharide fractions exhibited significant in vitro antioxidant activities in a dose-dependent manner. GLP-2 showed consistently better anticoagulant and antioxidant activities compared with GLP, GLP-1 and GLP-3. These results demonstrate that sulfated polysaccharides isolated from Grateloupia livida can serve as readily available alternative natural sources of anticoagulant and antioxidant agents., (Copyright © 2016 Elsevier B.V. All rights reserved.)

A water-soluble polysaccharide named as CSP-2 was isolated and purified from Chaenomeles speciosa by DEAE-Sepharose and Sephadex G-100 column chromatography. CSP-2 was composed of galactose (Gal), rhamnose (Rha), glucose (Glc) and xylose (Xyl) with a relative molar ratio of 3.8:1.6:1.2:0.4. The average molecular weight of CSP-2 was estimated to be about 4.6×10 4 Da. The in vitro antioxidant assay showed that CSP-2 exhibited remarkable antioxidant activities to scavenge the DPPH radical, superoxide radical, hydroxyl radical and ABTS radical and significant cytoprotective effects on H 2 O 2 -induced PC12 cells injury in a concentration-dependent manner. Overall, CSP-2 may be useful as a naturally potential antioxidant agent for application in food and medicinal fields., (Copyright © 2016 Elsevier B.V. All rights reserved.)