Extraction Conditions Of Polysaccharides Research Articles

Extraction Optimization of Polysaccharides from Wet Red Microalga Porphyridium purpureum Using Response Surface Methodology

Porphyridium is a unicellular marine microalga that is rich in polysaccharides and has excellent biological activities. Optimizing the extraction of polysaccharides can significantly improve the value of Porphyridium biomass. In the present study, response surface methodology was employed to optimize the extraction conditions of polysaccharides, including extraction time, extraction temperature, and biomass-to-water ratio. Furthermore, microwave-assisted extraction was used to improve the yield of polysaccharides further. The results showed that increasing the extraction temperature and extraction time could enhance the yield of polysaccharides. The multiple regression analysis of RSM indicated that the model could be employed to optimize the extraction of polysaccharides. The optimal extraction time, extraction temperature, and biomass-to-water ratio were 45 min, 87 °C, and 1:63 g mL−1, respectively. Under these optimal conditions, the maximum yield of polysaccharides was 23.66% DW, which well matched the predicted yield. The results indicated that the extraction temperature was the most significant condition affecting the yield of polysaccharides. The microwave-assisted extraction could further improve the yield of polysaccharides to 25.48% DW. In conclusion, hot water with microwave-assisted extraction was effective for polysaccharide extraction in P. purpureum.

Optimization of the conditions for microwave-assisted hot-water extraction of polysaccharides from Cordyceps militaris and analysis of their hypoglycemic activity

Optimization of the conditions for microwave-assisted hot-water extraction of polysaccharides from Cordyceps militaris and analysis of their hypoglycemic activity

Ultrasound-assisted ethanol/K2HPO4 aqueous two-phase extraction of polysaccharides from Plantago asiatica L. seeds: Process optimization, physicochemical properties, and antioxidant activity.

The seeds of Plantago asiatica L., a folk herb, are rich in polysaccharides that possess antioxidant, antidiabetic, and anti-inflammatory properties. Polysaccharides with lower molecular weights generally exhibit higher biological activity, so a method to efficiently extract low-molecular-weight polysaccharides from P. asiatica L. seeds (PLPs) is needed. The aim was to establish an efficient method for extracting polysaccharides from P. asiatica L. seeds while preserving their activity. Response surface methodology was applied to determine the optimal polysaccharide extraction conditions. Subsequently, the extracted polysaccharides were characterized to determine their monosaccharide composition, physicochemical properties, and molecular weight. Their antioxidant activity was evaluated by measuring their ability to scavenge DPPH and ABTS free radicals. An extraction yield of 9.17% was achieved under an ethanol concentration of 18.0% (w/w), a K2HPO4 concentration of 27.8% (w/w), a solvent-to-material ratio of 30:1 (mL/g), an ultrasound power of 203 W, and an extraction time of 39 min. Structural analyses indicated that this method might cause physicochemical changes in the conformation of PLPs and induce the degradation of PLP side chains but not the backbone. The antioxidant assay results showed that the DPPH and ABTS radical scavenging rates of PLPs were 48.3% and 49.2%, respectively, while in the control group the radical scavenging rates were 35.5% and 37.1%, respectively. The established method for extracting polysaccharides from P. asiatica L. seeds is efficient and reliable. The polysaccharides could be used as an important resource with antioxidant activity.

Polysaccharide extraction optimization, monosaccharide composition, and antioxidant activity analysis of different varieties of Gastrodia elata Bl aerial parts

AbstractThis study investigates the optimal extraction conditions, monosaccharide composition, and antioxidant activity analysis of polysaccharides from the aerial parts of three different varietal varieties of Gastrodia (i.e., G. elata Bl. F. elata, G. elata Bl. F. Viridls MaKino, and G. elata Bl. F. Glauca S Chow). The influence of extraction temperature (30–70 °C), extraction time (15–55 min), and liquid-to-solid ratio (25–65 mL/g) on the yield of polysaccharides was analyzed through single-factor experiments. The response surface methodology was used to optimize the extraction process, and a mathematical model was established to obtain the optimal extraction conditions. The response surface experiment was presented as follows: The optimal extraction conditions for polysaccharides were a liquid-to-solid ratio of 59 mL/g, 56 °C, and 36 min. The polysaccharide yield in G. elata. Bl. F. Glauca S Chow aerial parts under these conditions was 10.90%, which was close to the theoretical value calculated by the model (10.64%). Under the optimal conditions, the yields of polysaccharides followed: G. elata Bl. F. elata (11.32%) > G. elata Bl. F. Glauca S Chow (10.90%) > G. elata Bl. F. Viridls MalKino (10.50%). The polysaccharides were mainly composed of 10 monosaccharides, including glucose, rhamnose, mannose, and xylose. However, the content of monosaccharides in polysaccharides of different varieties of Gastrodia elata Bl aerial parts varied greatly, with glucose and rhamnose being the highest, both exceeding 20%. The polysaccharides in different varieties of Gastrodia elata Bl aerial parts had certain in vitro antioxidant activity. The total reducing power and scavenging rates of 2,2-diphenylpicrylhydrazyl (DPPH) and 2,2′-azinobis-(3-ethylbenzthiazolin-6-sulfonic acid) (ABTS) free radicals increased with the increase of polysaccharide concentration. When the polysaccharide concentration was 1.0 mg/mL, the scavenging rates of DPPH and ABTS free radicals were both over 80%. This study provides a theoretical basis for the further development and utilization of Gastrodia elata Bl aerial part resources. Graphical Abstract Using ultrasound-assisted extraction and response surface methodology to optimize the extraction of polysaccharides from the aerial parts of Gastrodia elata, polysaccharide yields of three different G. elata varieties were all above 10%, and the extracted polysaccharides were composed of 10 monosaccharides, including glucose and galactose, and exhibited good in vitro antioxidant activity.

RSM-optimization of microwave-assisted extraction of R. laevigata polysaccharides with bioactivities

Rosa laevigata Michx. is an edible traditional Chinese medicinal herb that possesses several health benefits. This study optimized the microwave-assisted extraction conditions of polysaccharides from Rosa laevigata fruits and investigated the antimicrobial potency and the antioxidant activity of Rosa laevigata polysaccharides. The microwave power, extraction time, the number of extraction, and the solvent-to-solid ratio were established using a three-factor, three-level Box-Behnken Design (BBD) and Response Surface Methodology (RSM) using screening experiments. Maximum polysaccharides yields were obtained when extraction was done for 18 min at a microwave power of 516 W and using a liquid-solid ratio of 54 mL/g. The polysaccharides yield was 20.37 % under the optimized conditions (predictive value for 20.40 %). This study also determined the antioxidant activity and the antibacterial potency of Rosa laevigata fruits to enhance their functional characterization and medicinal use. The antioxidant experiment showed that when the concentration was 5.0 mg/mL, polysaccharides had the strongest scavenging ability to DPPH free radicals and ABTS free radicals, and the scavenging rate was 83.06 % and 99.38 % respectively. Furthermore, the antibacterial experiment showed that the polysaccharides exhibited prominent inhibition activities, the MIC against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) at 3.13 mg/mL and 1.56 mg/mL, respectively.
 Keywords: Rosa laevigata Michx.; polysaccharides; microwave-assisted extraction; antibacterial activity; antioxidant activity

Statistical optimization and characterization of fucose-rich polysaccharides extracted from pumpkin (Cucurbita maxima) along with antioxidant and antiviral activities

Biologically active phytochemicals from pumpkin reveal versatile medical applications, though little is known about their antiviral activity. The fucose-rich polysaccharide extraction conditions were optimized through Box-Behnken design and purified by column chromatography. The purified fucose-rich polysaccharide was characterized through SEM, FT-IR, 1H NMR, XRD, TGA, and GS-MS. The analysis results revealed an irregular and porous surface of the purified polysaccharide with high fucose, rhamnose, galactose, and glucose contents. The tested fucose-rich polysaccharides revealed significant antioxidant and anti-inflammatory activity at very low concentrations. The purified fucose-rich polysaccharides exerted a broad-spectrum antiviral activity against both DNA and RNA viruses, accompanied by high safety toward normal cells, where the maximum safe doses (EC100) were estimated to be about 3–3.9 mg/mL for both Vero and PBMC cell lines. Treatment of HCV, ADV7, HSV1, and HIV viruses with the purified polysaccharides showed a potent dose-dependent inhibitory activity with IC50 values of 95.475, 20.96, 5.213, and 461.75 μg/mL, respectively. This activity was hypothesized to be through inhibiting the viral entry in HCV infection and inhibiting the reverse transcriptase activity in HIV. The current study firstly reported the antioxidant, anti-inflammatory, and antiviral activities of Cucurbita maxima fucose-rich polysaccharide against several viral infections.

Optimization of the Extraction Process and Antioxidant Activity of Polysaccharide Extracted from Centipeda minima.

The purpose of this study is to optimize the extraction process and study antioxidant activity of Polysaccharide extracted from Centipeda minima. The Box-Behnken design-response surface methodology was adopted to optimize the extraction process of polysaccharides from Centipeda minima. We purified the crude polysaccharides from Centipeda minima, as well as determined the purity, monosaccharide composition, and molecular weight of the purified fraction. Fourier transform infrared spectrometer (FT-IR) and scanning electron microscopy (SEM) were used to analyze the structural features of the polysaccharides. Further, we investigated the antioxidant activities of different fractions of polysaccharides. Consequently, the results showed that the optimum extraction conditions for polysaccharides were: a liquid-solid ratio of 26 mL/g, extraction temperature of 85.5 °C, and extraction time of 2.4 h. Moreover, the yield of polysaccharides measured under these conditions was close to the predicted value. After purification, we obtained four components of Centipeda minima polysaccharides (CMP). The purity, monosaccharide composition, molecular weight, and structural characteristics of CMP were different, but with similar infrared absorption spectra. CMP exhibited a typical infrared absorption characteristic of a polysaccharide. Besides, CMP displayed good antioxidant activity, with potential to scavenge DPPH radical, hydroxyl radical, and superoxide radical. Therefore, this study provides a reference for future research on the structure and biological activity of CMP, and lays a theoretical foundation for food processing and medicinal development of CMP.

Optimized Isolation and Characterization of the Major Polysaccharide from Grape Pomace

Grape pomace is the major component in grape fruits and is mostly wasted after wine and juice making processes. To recycle the residual biomass in grape pomace, extraction conditions of polysaccharides from grape pomace (GPP) were investigated. Three parameters affecting the crude GPP extraction, material to solvent ratio, extraction time, and extraction temperature were determined through single parameter optimization and then further optimized by orthogonal test. Results showed that the optimum extraction conditions were material to solvent ratio of 1:25, extraction temperature of 75 °C, and extraction time of 40 min, with extraction time as the most significant factor among them. Crude GPP was purified by gel column chromatography and chemically characterized. UV-Vis spectra analysis indicated that the GPP fraction did not contain any proteins or nucleic acids. FT-IR analysis implied that GPP consisted of α- and β-pyranose with carboxyl groups. Monosaccharide composition analysis indicated that GPP was composed of arabinose, glucose, galactose, and mannose with a molar ratio of 18.4:14.1:10.8:3.0. These results provide a theoretic basis for the production and utilization of GPP.

Optimization of Extraction Process, Structure Characterization, and Antioxidant Activity of Polysaccharides from Different Parts of Camellia oleifera Abel

The flowers, leaves, seed cakes and fruit shells of Camellia oleifera are rich in bioactive polysaccharides, which can be used as additives in food and other industries. In this study, a Box−Behnken design was used to optimize the extraction conditions of polysaccharides from C. oleifera flowers (P-CF), leaves (P-CL), seed cakes (P-CC), and fruit shells (P-CS). Under the optimized extraction conditions, the polysaccharide yields of the four polysaccharides were 9.32% ± 0.11 (P-CF), 7.57% ± 0.11 (P-CL), 8.69% ± 0.16 (P-CC), and 7.25% ± 0.07 (P-CS), respectively. Polysaccharides were mainly composed of mannose, rhamnose, galacturonic acid, glucose, galactose, and xylose, of which the molecular weights ranged from 3.31 kDa to 128.06 kDa. P-CC had a triple helix structure. The antioxidant activities of the four polysaccharides were determined by Fe2+ chelating and free radical scavenging abilities. The results showed that all polysaccharides had antioxidant effects. Among them, P-CF had the strongest antioxidant activity, of which the highest scavenging ability of DPPH•, ABTS•+, and hydroxyl radical could reach 84.19% ± 2.65, 94.8% ± 0.22, and 79.97% ± 3.04, respectively, and the best chelating ability of Fe2+ could reach 44.67% ± 1.04. Overall, polysaccharides extracted from different parts of C. oleifera showed a certain antioxidant effect, and could be developed as a new type of pure natural antioxidant for food.

Optimization of High Hydrostatic Pressure-Assisted Extraction of Polysaccharides from Lycium ruthenicum Murr. by Response Surface Methodology and Their Antioxidant Activity

This study aimed to optimize the extraction conditions of polysaccharides with high hydrostatic pressure-assisted extraction (HHPE) from Lycium ruthenicum Murr (LRM) and evaluate the antioxidant activity of polysaccharides from LRM (PLR). Effects of pressure HHPE, HHPE time, and the ratio of water to LRM (RWL) of HHPE on the extraction yield of PLR were examined with the method of response surface methodology (RSM). 3 kinds of antioxidant activity of PLR were measured. The optimal HHPE conditions were as follows: HHPE pressure was 380 MPa, HHPE time was 8 min and RWL was 25 (mL/g). Under these HHPE conditions, the PLR yield was (8.35±0.12)%, which was almost identical to the predicted value 8.33% of the RSM. Also, PLR demonstrated stronger antioxidant activity in vitro. HHP was a suitable method for the extraction of PLR. PLR can be used as a good antioxidant.

Valorisation of harmful algae bloom (Enteromorpha prolifera) for polysaccharide and crude bio-oil production

The excessive growth of Enteromorpha prolifera (EP) could lead to the harmful algae bloom, making the disposal of EP (millions of tons) an inevitable problem. This study aimed to extract water-soluble polysaccharide from EP, followed by utilizing an emerging thermochemical technique (hydrothermal liquefaction, HTL) to generate crude bio-oil from residual EP. 2 k factorial design with replicated center points were employed to evaluate the necessity of using response surface methodology (RSM) to optimize polysaccharide extraction conditions. The curvature effect was identified to be temperature*temperature in this study, and the interaction effects (solid/water ratio*time & temperature*time) were also crucial for EP polysaccharide extraction. The maximal polysaccharide yield of 12.1 wt% was achieved under the optimal conditions (1:55 g/mL solid/water ratio, 70 °C, 60 min). The polysaccharide solution acquired under the optimal conditions had a DPPH radical scavenging rate of 24.3% and reducing power of 0.28. The residual EP after polysaccharide extraction was commonly discarded as waste, which was used as HTL feedstock for biocrude production in this study. HTL of residual EP resulted in a biocrude yield of 26.6 wt%, dry-ash free (daf) and a hydro-char yield of 22.4 wt%, daf, which were comparable with that of raw EP, suggesting the viability of obtaining value-added polysaccharide and biocrude simultaneously. We also co-liquified residual EP with microalgae (Chlorella sp.) under various mixing ratios, and satisfactory biocrude yield, chemical composition, higher heating value, energy recovery, and carbon recovery were achieved. The valorisation route developed in this study is of importance for full utilization of EP, thereby improving the economic viability and sustainability for EP biorefinery.

Extraction and Antioxidant Activities of Polysaccharides Produced by Submerged Mycelia Culture of Oudemansiella raphanipes

Oudemansiella raphanipes is a commercially popular edible medicinal mushroom. The polysaccharides from O. raphanipes are the natural therapy for various metabolic diseases. Therefore, we have developed the optimal extraction conditions for extraction of polysaccharides from the mycelia of O. raphanipes and investigated their antioxidant activities. The optimal conditions of extracting polysaccharides from the mycelia of O. raphanipes were 85°C for 3.5 h, and the material-to-liquid ratio of 1:31. Under these conditions, the polysaccharides recovery was 91.89 mg/g, which was close to the predicted value (92.49 mg/g). In vitro antioxidant activity assays exhibited that the polysaccharides from the mycelia of O. raphanipes could effectively scavenge the 1,1-diphenyl-2-picrylhydrazyl, 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid), and hydroxyl radicals, and it also exhibited the reducing power against K3Fe (CN)6. These results suggested that the polysaccharides from the mycelia of O. raphanipes could be used as the source of natural antioxidants.

Optimisation of enzyme-assisted extraction of Erythronium sibiricum bulb polysaccharide and its effects on immunomodulation.

In this study, polysaccharides of Erythronium sibiricum bulb were extracted using enzyme-assisted extraction technology and then optimised by response surface methodology. The characteristics and immunomodulatory activities of the polysaccharide (E1P) were investigated. Setting the yield of polysaccharides as the index, the effects of amylase content, zymolytic time, extraction pH and zymolytic temperature were investigated. The optimal extraction conditions for polysaccharides were as follows: amylase content, 1% weight of pre-treated powder; zymolytic time, 2h; extraction pH, 7.5; and zymolytic temperature, 55°C. The yield was predicted to be 61.10%, which agreed with the value obtained in confirmatory experiments (59.71% ± 2.72%). Further research indicated that the primary component of E1P is glucose; however, it also contains a small quantity of galactose and arabinose. In vitro assays showed that E1P and ESBP (another kind of E. sibiricum bulb polysaccharide extracted by water decoction in our previous study) could significantly promote the cellular viability and phagocytosis of RAW264.7 cells without cytotoxicity. Moreover, they could enhance the ability to secrete nitric oxide and cytokines such as TNF-α and IL-1β. However, the immunomodulatory activities of E1P were better than those of ESBP. According to the results of this study, enzyme-assisted extraction represents a new strategy for extracting E. sibiricum bulb polysaccharides with higher yield and better immune activity.

Ultrasonic and Microwave Co-Extraction Optimization of Polysaccharide of Portulaca oleracea L. Technology and its Effect on Ulcerative Colitis

The extraction conditions of polysaccharides from Portulaca oleracea L.（POP） were optimized and its effects on the colonic mucosa of mice with ulcerative colitis were studied. In this study, POP were extracted by ultrasonic and microwave synergism. The extraction process of POP was optimized by a single factor experiment and orthogonal design. HE staining was used to evaluate the pathological changes of colon tissues in mice. The results showed that the optimal extraction conditions were as follows: extraction time was 550 s, microwave power was 40 W, solid-liquid ratio (W/V) was 1:35, and extraction times were 3. Under these conditions, the extraction rate of POP was 3.80%. POP could improve the disease state of UC mice, and the high dose group could significantly reduce the DAI index. The results of the HE experiment showed that POP could reduce inflammatory infiltration and tissue damage of the colon in UC mice. This study provided a theoretical basis for the preparation of POP and its clinical application in the treatment of ulcerative colitis.

Optimization of Ultrasonic-assisted Extraction Polysaccharide from Cynanchum auriculatum Royle ex Wight by Response Surface Methodology and Its Characterization

In order to improve the extraction yield of Cynanchum auriculatum Royle ex Wight , ultrasonic-assisted extraction was used to extract polysaccharide from Cynanchum auriculatum Royle ex Wight. The response surface method was used to optimize the ultrasonic-assisted extraction conditions of polysaccharide from Cynanchum auriculatum Royle ex Wight. The optimized ultrasonic-assisted extraction conditions of polysaccharide from Cynanchum auriculatum Royle ex Wight were the following: Solvent to material ratio 22: 1 mL/g, extraction time 44 min, ultrasonic power 350 W and temperature 52 ℃. Under these conditions, polysaccharide yield was 1.35%±0.02%. The average molecular weight of polysaccharides was mainly composed of 1.71×107, 1.15×106, 5.93×104 Da, and the polysaccharides mainly consisted of fucose, rhamnose, arabinose, galactose, galactose, xylose, mannose, ribose, galacturonic acid and glucuronic acid, with contents of 0.17%, 1.66%, 7.40%, 10.51%, 74.41%, 0.79%, 0.85%, 0.36%, 3.28%, 0.57%, respectively. FTIR spectrum showed characteristic absorptions of polysaccharide was observed in polysaccharides of Cynanchum auriculatum Royle ex Wight. The polysaccharides had good solubility. The study could provide some reference for structure analysis and industrial application of polysaccharides from Cynanchum Auriculatum Royle ex Wight.

High-efficiency separation and analysis of monosaccharides in Pueraria polysaccharides by pressurized capillary electrochromatography

Pueraria polysaccharides have been proven to possess biological activities such as bacteriostasis, anti-oxidative, anti-tumor, and immunity boosting activities. The variation in the structure, composition, and amount of monosaccharides in these polysaccharides may lead to different spatial structures and biological activities. Therefore, extraction of Pueraria polysaccharides and determination of the monosaccharide composition are of great significance for activity analysis and quality control. Direct detection of saccharides is difficult because they are strongly polar and do not show absorption in the ultraviolet region. At present, the commonly used methods for saccharide detection are liquid chromatography-ultraviolet detection, gas chromatography-ultraviolet detection, and mass spectrometry. Pressurized capillary electrochromatography is a high-efficiency microseparation technology. In this study, two kinds of Pueraria polysaccharides were extracted by an ultrasonic-assisted method, and response surface methodology was performed to explore the conditions for ultrasonic-assisted extraction of polysaccharides from Pueraria. The interaction effects of four factors, the liquid-solid ratio, ultrasonic extraction time, ultrasonic extraction temperature, and ultrasonic power, on the extraction rate of the polysaccharides were analyzed. By combining the optimal conditions predicted by the software and the actual equipment conditions, the optimal extraction conditions for Pueraria polysaccharides were chosen as follows:ultrasonic extraction temperature, 90℃; liquid-solid ratio of Pueraria thomsonii Benth, 20 mL/g; liquid-solid ratio of Pueraria lobata Ohwi, 40 mL/g; ultrasonic extraction time, 30 min; ultrasonic power, 180 W. Through data fitting, the multiple quadratic regression equation of the four factors on the extraction rate of Pueraria polysaccharides was established. A novel method based on pressurized capillary electrochromatography for the separation and analysis of eight neutral monosaccharides has been established. The monosaccharides were derivatized by the 1-phenyl-3-methyl-5-pyrazolone pre-column derivatization method. The separation conditions for these monosaccharides were explored, and the buffer concentration, buffer pH, applied voltage, type of chromatographic column, and mobile phase ratio were optimized. Finally, the established pressurized capillary electrochromatography-ultraviolet detection method was applied to the detection and identification of two kinds of actual Pueraria polysaccharide samples. The results of response surface analysis showed that among the four experimental factors, ultrasonic extraction temperature had the greatest influence on the extraction rate of polysaccharides from the two kinds of Pueraria, followed by the liquid-solid ratio; the influence of the ultrasonic extraction time and ultrasonic power was relatively weak. The experimental conditions were determined as follows:the separation of eight neutral monosaccharide derivatives could be realized within 24 min on a Halo-2.7 μm core-shell C18 capillary column with acetonitrile-50 mmol/L ammonium acetate aqueous solution (18:82, v/v, pH 4.1) as the mobile phase, by detection at 250 nm under an applied voltage of-20 kV. The separation and detection speeds and the column efficiency achieved with this method were much better than those obtained with the traditional liquid chromatography method. The results show that the proposed method has a good linear relationship and good repeatability. The separation and identification results for the actual samples showed that the polysaccharides of Pueraria thomsonii Benth were mainly composed of glucose, mannose, rhamnose, and fucose in the molar ratio 1.00:0.16:0.14:0.07. The polysaccharides of Pueraria lobata Ohwi were mainly composed of glucose and mannose in the molar ratio 1.00:0.70. This study provides a novel method for the rapid and efficient separation and detection of neutral monosaccharides, and serves as a reference for analyzing the monosaccharide composition of Pueraria polysaccharides.

Extraction optimization, physicochemical properties and antioxidant and hypoglycemic activities of polysaccharides from roxburgh rose (Rosa roxburghii Tratt.) leaves

The optimum extraction conditions of polysaccharides from roxburgh rose (Rosa roxburghii Tratt.) leaves (RLP) were obtained by response surface methodology (RSM), which were a liquid to solid ratio of 21.16 mL/g, an extraction temperature of 81.32 °C, and an extraction time of 90.49 min. An RLP yield of 11.04% was obtained under these conditions. DEAE-52 cellulose and Sepharose CL-6B columns were used to purify the RLP, and the purified polysaccharide components RLP-1.2 and RLP-2.1 were obtained. Both RLP-1.2 and RLP-2.1 were composed of galacturonic acid (GalA), glucose (Glc), galactose (Gal), and arabinose (Ara). However, the molar ratios of GalA, Glc, Gal, and Ara in RLP-1.2 and RLP-2.1 were different. At a concentration of 10 mg/mL, the α-amylase inhibitory activities of RLP-1.2 and RLP-2.1 reached 80.74% and 89.85% that of acarbose, respectively, and the α-glucosidase inhibitory activity of RLP-1.2 reached 87.91% that of acarbose. In addition, both RLP-1.2 and RLP-2.1 showed good antioxidant activity. These results suggested that RLP-1.2 and RLP-2.1 possess potential as natural hypoglycemic agents or natural antioxidants.

Extraction, purification, emulsifying property, hypoglycemic activity, and antioxidant activity of polysaccharides from comfrey

Performing the researches on extraction conditions, purification and activities of polysaccharides are of great significance to the development of comfrey (Symphytum officinale L.) resources. In this study, the optimum extraction conditions of polysaccharides from comfrey (CPs) were obtained by response surface methodology (RSM), which were liquid to solid ratio 25 mL/g, extraction temperature 89 °C, and extraction time 155 min. A CPs yield of 19.20 % was obtained under these conditions. DEAE-52 cellulose and Sepharose CL-6B columns were used to purify CPs, and the purified polysaccharide component CPs-1.2 was obtained. The characteristics, emulsifying property, and hypoglycemic activity of CPs-1.2 were analyzed. The monosaccharide compositions of CPs-1.2 were galacturonic acid, arabinose, glucose, and galactose with the molar ratio of 1.00:0.88:2.28:1.13. CPs-1.2 showed notable DPPH and ABTS radical scavenging abilities, which could reach 95.00 % and 96.71 % of those of ascorbic acid at the determination concentrations of 0.4 mg/mL and 1.5 mg/mL, respectively. The α-glucosidase inhibitory activity of CPs-1.2 (10 mg/mL) could reach 80.00 % of that of acarbose. In addition, CPs-1.2 showed good emulsifying properties for olive oil, benzene, xylene and methylbenzene. These results suggested that CPs possessed potential as a hypoglycemic agent, an antioxidant or a polysaccharide-based emulsifier.

Ultrasound-assisted extraction of phlorotannins and polysaccharides from Silvetia compressa (Phaeophyceae)

Silvetia compressa is a brown seaweed native to the coast of Baja California, Mexico. It is a rich source of phlorotannins and polysaccharides, two compound families with important nutraceutical applications. Optimal conditions for obtaining highly concentrated phlorotannin and polysaccharide extracts from S. compressa were determined using Box-Behnken experimental design combined with response surface methodology (RSM). The effect of extraction temperature (X1: 50–65 °C), ultrasound power density (X2: 1.2–3.8 W cL−1), solvent/seaweed ratio (X3: 10–30 mL g−1 seaweed meal), and ethanol concentration (X4: 25–100% ethanol in water) on phlorotannin and polysaccharide yield was explored. Experimental results were fitted to a second-degree polynomial model, while model fitness was assessed using analysis of variance (ANOVA). From this analysis, optimal phlorotannin and polysaccharide extraction conditions were determined for the evaluated parameters (X1 = 50 °C, X2 = 3.8 W cL−1, X3 = 30 mL g−1 seaweed meal, and X4 = 32.33%). Under these conditions, experimental phlorotannin and polysaccharide yields were 0.73% and 23% (w/w), respectively. Phlorotannin extraction was significantly enhanced by ultrasound power density, while polysaccharide extraction improved when using low ethanol concentration in the solvent, therefore both families of compounds were obtained combining those parameters. Experimental data agreed with predictions from the RSM model, indicating suitability of the obtained model and the success of RSM in optimizing the extraction conditions. In addition, the identification of the main compounds in the phlorotannin extract was carried out by HPLC-MS-TOF; 8 of the 12 identified phenolic compounds belonged to the phlorotannin family, 4 from the fuhalol group, 3 being eckol derivatives, and 1 being a phloroglucinol subunit.

Polysaccharides from Pyracantha fortuneana and its biological activity

This study used response surface methodology to determine the optimal conditions for extraction of polysaccharides from Pyracantha. fortuneana (PSPF), and studied the mechanism of PSPF-inducing apoptosis in human ovarian carcinoma Skov3 cells. Response surface methodology (RSM) were adopted to extract PSPF. The maximum value of polysaccharide yield was obtained under these optimal conditions. PSPF had good potential as an antioxidant. Exposure of cells to PSPF resulted in cytotoxicity through the induction of apoptosis, and the reactive oxygen species were increased, mitochondrial membrane potential decreased, DNA damage (detected as γ- H2AX and RAD51 foci) was observed in Skov3 cells. In addition, PSPF could induce apoptosis of cancer cells. Therefore, PSPF should be explored as novel potential antioxidants and an anti-tumor drug in a clinical setting.