Antioxidant Activities Of Polysaccharides Research Articles

Antioxidant activity of polysaccharide from Garcinia mangostana rind and their derivatives

BackgroundPolysaccharide from Garcinia mangostana rind has many biological activities and deserves further research.MethodsThe antioxidant properties of UAEE-GMRP, UAEE-GMRP-1 A, CM-30, and Ac-30 were evaluated through two different antioxidant activity experimental systems.ResultsThe four polysaccharides had a better scavenging effect on hydroxyl radicals, while their inhibitory effect on lipid peroxidation was relatively weak. However, overall, the four polysaccharides showed a certain degree of potential application in the two antioxidant experiments mentioned above, especially the chemically modified polysaccharides from Garcinia mangostana rind, which effectively improved their antioxidant activity. This also indicates that chemical modification is a better method to improve polysaccharide activity. In addition, in these two antioxidant exploration experiments, carboxymethylated polysaccharide showed stronger activity compared to the other three polysaccharides.ConclusionThe carboxymethylation modification may have great potential for application.

Enzyme and Microwave Coassisted Extraction, Physicochemical Properties, and Antioxidant Activity of Polysaccharides from Baijiu Distillers' Grains

AbstractBaijiu distillers' grain is a solid waste after the fermentation of grains, and their high added value and deep processing and utilization require further study. This study uses the enzyme and microwave coassisted method to extract Baijiu distillers' grain polysaccharides (DGPs). Through optimization of the single‐factor test and response surface methodology (RSM), the optimal conditions are solid–liquid ratio 1:30, enzyme time 50 min, enzyme temperature 50 °C, enzyme pH 5.0, microwave time 6 min, and microwave power 480 W, with a maximum DGP yield of 3.98% ± 0.03. DGP is purified by DEAE‐Sepharose cellulose ion exchange chromatography to obtain four fractions, namely DGP‐1, DGP‐2, DGP‐3, and DGP‐4; the molecular weights are 2224.05, 90.99, 1478.16, and 346.19 kDa, respectively, and the main monosaccharide components are Man and Glc. The antioxidant assay shows that the four kinds of DGPs have different free radical scavenging capacities, among which DGP‐2, DGP‐3, and DGP‐4 have good antioxidant activities. Therefore, DGP can be used as a potential natural antioxidant.

Extraction, structural characterization, and antioxidant activity of polysaccharides from three microalgae

Microalgal polysaccharides have received much attention due to their potential value in preventing and regulating oxidative damage. This study aims to reveal the mechanisms of regulating oxidative stress and the differences in the yield, structure, and effect of polysaccharides extracted from three microalgae: Golenkinia sp. polysaccharides (GPS), Chlorella sorokiniana polysaccharides (CPS), and Spirulina subsalsa polysaccharides (SPS). Using the same extraction method, GPS, CPS, and SPS were all heteropoly- saccharides composed of small molecular fraction: the monosaccharides mainly comprised galactose (Gal). Among the three, SPS had a higher proportion of small molecular fraction, and a higher proportion of Gal; thus it had the highest yield and antioxidant activity. GPS, CPS, and SPS all showed strong antioxidant activity in vitro, and showed strong ability to regulate oxidative stress, among which SPS was slightly higher. From the analysis of gene expression, the Nrf2-ARE signalling pathway was an important pathway for GPS, CPS, and SPS to regulate cellular oxidative stress. This study provides a theoretical foundation for further research on the utilization of microalgae polysaccharides and product development.

Construction, characterization, antioxidant activity and effects on properties in vitro digestion of selenium nanoparticles decorated with Cyperus esculentus polysaccharides

In this study, in order to obtain selenium complex with high antioxidant activity and low release rate, selenium nanoparticles (SeNPs) were decorated by chemical reduction with Cyperus esculentus polysaccharides (CEP) as stabilizers (CEP-SeNPs). The characterization, construction mechanism, stability, and effects on properties in vitro digestion of CEP-SeNPs were investigated. CEP-SeNPs were orange-red in color and uniformly distributed in a spherical shape with an average diameter of 138.33 ± 0.57 nm, exhibiting good stability which could be stored at 4 °C. The selenium element in CEP-SeNPs was selenium in a zero-valent amorphous state. The O-H and C=O bonds in CEP were bound to selenium by an inductive effect to construct CEP-SeNPs for infrared analysis, and no new covalent bonds were formed in this process. CEP as stabilizer on selenium nanoparticles were physical combination. At the same time, the synergistic effects at antioxidant activity of polysaccharides and selenium was found which made CEP-SeNPs had a higher antioxidant activity than CEP. Above all, CEP-SeNPs showed better pH and enzyme stability in simulated digestion. The selenium release rate of CEP-SeNPs were only 18.52 % ± 0.17 % after intestinal digestion. The antioxidant activity of CEP-SeNPs were higher than that of CEP in the simulated digestion. It provides a theoretical basis for the development and utilization of rich selenium products.

Ultrasonic-Assisted Extraction, Structural Characteristics, and Antioxidant Activities of Polysaccharides from Alpinia officinarum Hance.

Alpinia officinarum Hance, a well known agricultural product in the Lei Zhou peninsula, is generally rich in polysaccharides. In order to enhance the use of A. officinarum Hance polysaccharides (AOP) in functional food, AOP was extracted using an ultrasonic-assisted extraction method, and the ultrasonic extraction parameters of AOP was optimized. Furthermore, this study investigated the physicochemical and antioxidant activities of AOPs. In addition, the structural properties were preliminarily determined using Fourier-transform infrared spectroscopy (FTIR), high performance size exclusion chromatography, and a Zetasizer. Ultimately, this study explored the mechanism underlying the antioxidant activities of AOP. The results showed that the optimal ultrasonic-assisted extraction parameters were as follows: ultrasonic time, 6 min; ratio of water to material, 12 mL/g; and ultrasonic power, 380 W. Under these conditions, the maximum yield of AOPs was 5.72%, indicating that ultrasonic-assisted extraction technology is suitable for extracting AOPs due to the reduced time and water usage. Additionally, AOPs were purified using graded alcohol precipitation, resulting in three fractions (AOP30, AOP50, and AOP70). AOP30 had the lowest molecular weight of 11.07 kDa and mainly consisted of glucose (89.88%). The half inhibitory concentration (IC50) value of AOP30 and AOP70 was lower than that of AOP50 in the ability to scavenge the ABTS radical, while a reverse trend was observed in reducing ferric ions. Notably, the antioxidant activities of AOPs were highly correlated with their polydispersity index (Mw/Mn) and Zeta potential. AOP30, a negatively charged acidic polysaccharide fraction, exhibited electron donating capacities. Additionally, it displayed strong antioxidant abilities through scavenging 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) radicals and reducing ferric ions. In conclusion, the present study suggests that AOP30 could be developed as an antioxidant ingredient for the food industry.

Comparison of Antioxidant effects of Polysaccharides of Mixed Microalgae Isolates Glagah Beach Yogyakarta and East Java, Indonesia

Indonesia is a country with a large marine and has a very high biodiversity of microalgae. Previous research has identified mixed microalgae from Glagah Beach, Yogyakarta, and several beaches in East Java. This study aims to extract polysaccharides and assessed the antioxidant activity of polysaccharides from those microalgae. Polysaccharides of Spirulina platensis, a mixed microalgae Glagah, and a mixed microalgae East Java were extracted by the alkaline method. The extraction rate and protein and carbohydrate content of polysaccharides of each of microalgae were calculated. The antioxidant activity of polysaccharides was observed in vitro using the DPPH assay method. The highest extraction rate was obtained from Glagah microalgae followed by S. platensis and East Java microalgae with values of 13.575%, 9.75%, and 2.375%, respectively. On the other hand, the carbohydrate content of the polysaccharides from Glagah microalgae was the lowest, followed by S. platensis and East Java microalgae, 1.2 mg/mL, 13.33 mg/mL, and 21.925 mg/mL, respectively. The protein content in polysaccharides from Glagah microalgae was the highest, followed by East Java microalgae and S. platensis the lowest, 2.23 mg/mL, 1.01 mg/mL, and 0.67 mg/mL, respectively. Based on the results of IC50 values, the antioxidant activity of mixed microalgae polysaccharides from Glagah and East Java was included in the active/moderate category, 125.21 µg/mL and 127.11 µg/mL, respectively, while the antioxidant activity of polysaccharide S. platensis was low, 171.82 µg/mL. In conclusion, Glagah and East Java Microalgae Polysaccharides have the opportunity to be promoted as health ingredients to overcome free radicals.

Medium composition optimization and characterization of polysaccharides extracted from Ganoderma boninense along with antioxidant activity

Ganoderma is a well-known medicinal macrofungal genus, of which several species have been thoroughly studied from the medicinal perspective, but most species are rarely involved in. In this study, we focus on the polysaccharides extracted from Ganoderma boninense and their antioxidant activity. Ganoderma boninense is a serious pathogen of oil palms that are cultivated commercially in Southeast Asia. Response surface methodology was conducted to optimize the liquid medium composition, and the mycelia biomass reached 7.063 g/L, that is, 1.4-fold compared with the seed medium. The crude and purified polysaccharides extracted from the fermentation broth showed well 1,1-diphenyl-2-picrylhydrazyl and 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid radical scavenging abilities, and the scavenging abilities of purified polysaccharides reached 94.47 % and 99.88 %, respectively. Six fractions of polysaccharides were extracted and purified from fruiting bodies, mycelia and fermentation broth separately with the elution buffers of distilled water and 0.1 M NaCl solution. Generally, the polysaccharides from fruiting bodies showed stronger protective effect on H2O2-induced HepG2 cell oxidative damage than other fractions. A total of five to seven monosaccharides were identified in the six fractions of polysaccharides. The correlation analysis revealed that the content of fucose was significantly correlated with the antioxidant activity of polysaccharides, while xylose showed negative correlation results. In summary, the polysaccharides from G. boninense have a potential to be used as natural antioxidants.

Optimization of Three Extraction Methods and Their Effect on the Structure and Antioxidant Activity of Polysaccharides in Dendrobium huoshanense.

Dendrobium huoshanense is a famous edible and medicinal herb, and polysaccharides are the main bioactive component in it. In this study, response surface methodology (RSM) combined with a Box-Behnken design (BBD) was used to optimize the enzyme-assisted extraction (EAE), ultrasound-microwave-assisted extraction (UMAE), and hot water extraction (HWE) conditions and obtain the polysaccharides named DHP-E, DHP-UM, and DHP-H. The effects of different extraction methods on the physicochemical properties, structure characteristics, and bioactivity of polysaccharides were compared. The differential thermogravimetric curves indicated that DHP-E showed a broader temperature range during thermal degradation compared with DHP-UM and DHP-H. The SEM results showed that DHP-E displayed an irregular granular structure, but DHP-UM and DHP-H were sponge-like. The results of absolute molecular weight indicated that polysaccharides with higher molecular weight detected in DHP-H and DHP-UM did not appear in DHP-E due to enzymatic degradation. The monosaccharide composition showed that DHPs were all composed of Man, Glc, and Gal but with different proportions. Finally, the glycosidic bond types, which have a significant effect on bioactivity, were decoded with methylation analysis. The results showed that DHPs contained four glycosidic bond types, including Glcp-(1→, →4)-Manp-(1→, →4)-Glcp-(1→, and →4,6)-Manp-(1→ with different ratios. Furthermore, DHP-E exhibited better DPPH and ABTS radical scavenging activities. These findings could provide scientific foundations for selecting appropriate extraction methods to obtain desired bioactivities for applications in the pharmaceutical and functional food industries.

Structural characterization of a polysaccharide derived from Saposhnikovia divaricatee (Turcz.) Schischk with anti-allergic and antioxidant activities

Ethnopharmacological relevanceSaposhnikoviae Radix, the dry root of Saposhnikovia divaricatee (Turcz.) Schischk, is a traditional chinese medicine used for the treatment of cold, headache, and skin pruritus. Aim of the studyThis study aimed to identify novel active polysaccharides from Saposhnikovia divaricatee (Turcz.) Schischk and clarify their structures and bioactivities. Materials and methodsThe structure of polysaccharides was clarified by PMP-HPLC, methylation analysis, particle acid hydrolysis analysis and NMR analysis. The anti-allergic and antioxidant activities of polysaccharides were evaluated on allergic reaction model in RBL-2H3 cells and oxidative damage model of C. elegans. ResultsWe purified a novel homogenous polysaccharide named SP-3 from Saposhnikovia divaricatee (Turcz.) Schischk and its molecular weight was determined as 3.096 × 104 Da. Monosaccharide composition analysis revealed that SP-3 was composed of mannose, rhamnose, galacturonic acid, glucose, galactose, and arabinose (1.85: 5.22: 38.06: 2.36: 23.25: 29.26). The main linkage type of SP-3 was a repeat unit of →4,6)-β-D-Galp-(1 → 4)-α-D-GalpA-(1 → . The branches of SP-3 contained T-linked-α-L-Araf and 1,3,4-linked-α-L-Rhap. It was observed that SP-3 inhibited β-HEX release and inflammatory factors in RBL-2H3 cells subject to IgE stimulant. Meanwhile, SP-3 increased the mean lifespan of Caenorhabditis elegans under oxidative stress, reduced ROS content and increased antioxidant enzyme activities of C. elegans, potentially through activating the SOD-3. ConclusionsA novel homogenous polysaccharide was identified from Saposhnikovia divaricatee (Turcz.) Schischk, and this polysaccharide SP-3 played key roles for the anti-allergic and antioxidant activities.

Antitumor and antioxidant activities of polysaccharides from the seaweed Durvillaea antarctica.

The present study was carried out to determine the antitumor and antioxidant activities of the seaweed Durvillaea antarctica. Extraction and purification of polysaccharides from D. antarctica were performed. They were characterized by FT-IR and GC-MS, identifying isomers of arabinose, fucose, mannose, and galactose. The antioxidant capacity of polysaccharides was analyzed using the ABTS method (14.3 ± 0.5 μmol TE g-1 PS) and the DPPH method (21.82 ± 0.32 μmol TE g-1 PS). The antitumor capacity of polysaccharides was studied by MTT colorimetric assays in human leukemia, colon, breast, and lung cancer cell lines, obtaining the lowest IC50 in colon cancer (19.99 μg mL-1 ). In the line of healthy human gingival fibroblasts (HGF-1), an IC50 of 444.39 μg mL-1 was obtained. Flow cytometry in the HL60 cell line showed that polysaccharides at concentrations higher than IC50 inhibited cell proliferation, demonstrating a possible antitumor capacity invitro. In the proteomic analysis with HGF-1, nine proteins involved in different biological processes were identified. In conclusion, polysaccharides from D. antarctica could be considered powerful nutraceuticals, mainly against colon cancer.

Purification, characterization, and antioxidant activity of polysaccharides from Grifola frondosa by hydrogen peroxide/ascorbic acid-assisted extraction

Purification, characterization, and antioxidant activity of polysaccharides from Grifola frondosa by hydrogen peroxide/ascorbic acid-assisted extraction

Characterization and antioxidant activities of polysaccharides from Hippophae rhamnoides L

Characterization and antioxidant activities of polysaccharides from Hippophae rhamnoides L

Optimization of Polysaccharides and Essential Oils Extraction from Artemisia argyi Leaves and the Antioxidant Activity of Polysaccharides

Artemisia argyi leaves (AL) are a common traditional Chinese herbal medicine that possess significant biological activities, including antioxidant, antibacterial, anticancer, promoting blood circulation and reducing inflammation. AL contains many natural bioactive substances. In this study, Soxhlet extraction method was implemented to extract polysaccharides and essential oils (EOs) from AL, and the process was optimized by multi-response optimization. To explorer the best extraction conditions, three experimental parameters, soaking time (2–10 h), extraction time (1–3 h), and material liquid ratio (1:12–1:24 g/mL), were investigated in single-factor experiments. The Box-Behnken design of response surface analysis was used to optimize the extraction conditions. Further, the antioxidant ability of polysaccharides was evaluated using DPPH clearance rate. The results showed that the optimum extraction parameters of soaking time, extraction time and ratio of material to liquid were: 10 h, 2.5 h, and 1:27, respectively. The extraction rate of crude polysaccharides from AL reached 11.21% under the optimized conditions. The polysaccharide content in crude polysaccharides was about 50% according to anthrone-sulfuric acid method. Moreover, the crude polysaccharides from AL exhibited good antioxidant activity, with the ability of scavenging DPPH free radical being about 60% of that of L-ascorbic acid (Vc). These findings indicated that crude polysaccharides extracted from AL showed good free radical scavenging ability and possess potential for developed as natural antioxidanst. This study aims to provide a basic reference for the optimization of extracting process of polysaccharides from AL and further development and utilization.

Impact of Six Extraction Methods on Molecular Composition and Antioxidant Activity of Polysaccharides from Young Hulless Barley Leaves.

Young hulless barley leaves are gaining recognition for potential health benefits, and the method of extracting polysaccharides from them is critical for potential food industry applications. This study delves into a comparative analysis of six distinct fiber extraction techniques: hot water extraction; high-pressure steam extraction; alkaline extraction; xylanase extraction; cellulase extraction; and combined xylanase and cellulase extraction. This analysis included a thorough comparison of polysaccharide-monosaccharide composition, structural properties, antioxidant activities (DPPH, ABTS, and FRAP), and rheological properties among fibers extracted using these methods. The results underscore that the combined enzymatic extraction method yielded the highest extraction yield (22.63%), while the rest of the methods yielded reasonable yields (~20%), except for hot water extraction (4.11%). Monosaccharide composition exhibited divergence across methods; alkaline extraction yielded a high abundance of xylose residues, whereas the three enzymatic methods demonstrated elevated galactose components. The extracted crude polysaccharides exhibited relatively low molecular weights, ranging from 5.919 × 104 Da to 3.773 × 105 Da across different extraction methods. Regarding antioxidant activities, alkaline extraction yielded the highest value in the ABTS assay, whereas enzymatically extracted polysaccharides, despite higher yield, demonstrated lower antioxidant capacity. In addition, enzymatically extracted polysaccharides exerted stronger shear thinning behavior and higher initial viscosity.

Extraction, purification and antioxidant activity of polysaccharides from different parts of Hibiscus manihot L.

The goal of this study was to elucidate the characteristics and properties of polysaccharides from different parts of cultivated Hibiscus manihot L. (HM). Polysaccharides were extracted with hot-water from the flowers, leaves, roots, stems and epidermis of HM. Two purified fractions having high content, HMPS-F2 and HMPS-F4, were isolated from floral polysaccharides. The results showed that HMPS-F2 was a homopolysaccharide composed of glucose residues with an average molecular weight of 8.59 × 104 Da, which might have a backbone structure of →1)-α-d-Glcp (4→. HMPS-F4 was a natural acetylated heteropolysaccharide with a complex structure and an average molecular weight of 1.63 × 105 Da. It was mainly composed of Rha(rhamnose), GalA(galacturonic acid), and Gal(galactose) with a molar ratio of 3.06:1.00:1.62. The results of antioxidant experiments showed that HM polysaccharides (0.125–4.0 mg/L) had certain inhibitory effects on DPPH radicals, hydroxyl radicals and lipid peroxidation, among which the scavenging effect on hydroxyl radicals was the best. These results suggest that HM polysaccharide is a potent active ingredient that may play an active role in the medicinal activity of HM.

Preparation, structural characteristics and antioxidant activity of polysaccharide and its metal chelates from the peel of Dioscorea oppositifolia L

Two metal chelates of Dioscorea oppositifolia L. peel polysaccharides (DTP) were prepared: iron chelate (DTP-Fe) and zinc chelate (DTP-Zn). The physicochemical properties of the polysaccharide and its metal chelates were assessed by UV-Vis absorption spectroscopy, Fourier-transform infra-red spectroscopy, scanning electron microscopy, and thermogravimetric analysis. Antioxidant activities were evaluated by DPPH, ABTS + and hydroxyl radical scavenging assays. According to ICP-MS, the iron content of DTP-Fe was 9.47%, while the zinc content of DTP-Zn was 4.02%. The antioxidant capacity of DTP-Fe increased with the increase of concentration, and its overall activity was higher than that of DTP and DTP-Zn. This polysaccharide-iron chelate can be developed and utilised as an antioxidant and multifunctional iron supplement. DTP-Zn showed the potential to be a natural antioxidant and zinc supplement food.

Physicochemical characterization and antioxidant activity of polysaccharides from Chlorella sp. by microwave-assisted enzymatic extraction.

Microwave-assisted enzymatic extraction (MAEE) was used for the separation of polysaccharides from micro-Chlorella. The extraction condition of MAEE was optimized by Box-Behnken design and response surface methodology. Results showed that the optimal condition for the extraction of Chlorella sp. crude polysaccharides (CSCP) was at 50°C for 2.3h with 380W of microwave power and 0.31% of enzyme dosage. Under the optimal extraction condition, the extraction yield of CSCP reached 0.72%. Similarly, the α-amylase modification conditions of the CSCP were also optimized, in which the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging rate was used as the response value. The scavenging rate of DPPH free radicals was 17.58% when enzyme dosage was 271 U/g at 51°C for 14min. Moreover, the enzyme-modified CSCP presented a typical heteropolysaccharide mainly including glucose (48.84%), ribose (13.57%) and mannose (11.30%). MAEE used in this work achieved a high extraction yield of CSCP, which provides an efficient method for the extraction of CSCP from Chlorella sp.

Study on Process Optimization and Antioxidant Activity of Polysaccharide from Bletilla striata Extracted via Deep Eutectic Solvents.

Taking the extraction yield of Bletilla striata polysaccharide (BSP) as the index and taking the type of deep eutectic solvents (DESs), extraction time, extraction temperature, DES water content, and solid-liquid ratio as the investigation factors, single-factor and Box-Behnken response surface tests were carried out to optimize the extraction process of BSP. Thus, the antioxidant activity of BSP on DPPH radicals, ABTS radicals and ferric reducing antioxidant power were determined. The results showed that the most suitable deep eutectic solvent was DES-2, namely choline chloride-urea. The optimal extraction conditions for BSP were an extraction time of 47 min, extraction temperature of 78 °C, water content of 35%, and solid-liquid ratio of 1:25. Under this optimized condition, the extraction yield of BSP was able to reach (558.90 ± 8.83) mg/g, and recycling studies indicated the good cycle stability of the DES. Antioxidant results showed that BSP had superior antioxidant activity and had a dose-response relationship with drug concentration. Compared with Bletilla striata polysaccharide obtained via conventional hot water extraction (BSP-W), the extraction yield of BSP obtained through this method (BSP-2) increased by 36.77%, the scavenging activity of DPPH radicals increased by 24.99%, the scavenging activity of ABTS radicals increased by 41.16%, and the ferric reducing antioxidant power increased by 49.19%. Therefore, DESs as new green reagents and BSP extracted with DESs not only had a high yield but also had strong antioxidant activity.

Effects of different processing (Paozhi) on structural characterization and antioxidant activities of polysaccharides from Cistanche deserticola

In this study, five polysaccharides were extracted from processed Cistanche deserticola. The processing included crude product, enzymatic hydrolysis, hot air drying, stir-baking with wine and high-pressure steaming, and these polysaccharides were named as CP-CDPs, EH-CDPs, HAD-CDPs, SBW-CDPs and HPS-CDPs, respectively. The structural characteristics and biological activities were explored. The results showed that processing changed properties of C. deserticola polysaccharides. CP-CDPs had the highest brightness value L*(93.84) and carbohydrate content (61.27 %). EH-CDPs had minimum Mw (1531.50 kDa), while SBW-CDPs had maximum Mw (2526.0 kDa). Glucose was major predominant monosaccharide in CP-CDPs (89.82 %), HAD-CDPs (79.3 %), SBW-CDPs (59.41 %) and HPS-CDPs (63.86 %), while galactose was major monosaccharide in EH-CDPs (29.44 %). According to SEM, SBW-CDPs showed compact structures, while HPS-CDPs and HAD-CDPs had similar looser structure than SBW-CDPs; meanwhile, CP-CDPs showed irregular agglomeration shape and EH-CDPs was dense blocky shape. The AFM showed SBW-CDPs had the largest molecular chain than other polysaccharides. When scavenging activity reaching 50 %, the concentrations of CP-CDPs, EH-CDPs, HAD-CDPs, SBW-CDPs, HPS-CDPs are 2.25, 0.25, 0.75, 1.8 and 1.5 mg/mL, respectively. This study sheds light on the effects of traditional Chinese medicine processing on characteristics, bioactivities of C. deserticola polysaccharides, and provides the basis for applications in food and pharmaceutical industries.

Ultrasound-assisted extraction, analysis and antioxidant activity of polysaccharide from the rinds of Garcinia mangostana L.

According to response surface methodology (RSM), the extraction conditions of ultrasound-assisted extraction of polysaccharide from the rinds of Garcinia mangostana L. (GMRP) were optimized and determined. The optimal conditions obtained through optimization were: the liquid to material ratio was 40 mL/g, ultrasonic power was 288 W and extraction time was 65 min. The average extraction rate of GMRP was 14.73%. Ac - GMRP was obtained by acetylation of GMRP, and the antioxidant activities of the two polysaccharides were compared in vitro. The results indicated that the antioxidant capacity of polysaccharide obtained after acetylation was significantly improved compared with that of GMRP. In conclusion, chemical modification of polysaccharide is an effective measure to improve its properties to a certain extent. Meanwhile, it implies that GMRP has great research value and potential.