Xiong Fu

Optimization for ultrasound extraction of polysaccharides from mulberry fruits with antioxidant and hyperglycemic activity in vitro

Single-factor experiment and Box-Behnken design (BBD) were applied to optimize the ultrasound-assisted extraction of mulberry fruits polysaccharides (MFP). Under optimum conditions: ratio of water to raw material 40.25, extraction temperature 69°C, ultrasonic power 190W and extraction time 75 min, the MFP yield was 3.13% (±0.07%), in accordance to the predicted value of 3.04%. The mulberry fruits polysaccharides fractions was obtained by deproteinization (MFP-1), followed by decolorization and deionization (MFP-2). Carbohydrate content in MFP, MFP-1 and MFP-2 was 58.61% (±1.47%), 69.98% (±0.91%), 81.18% (±1.29%), as well as proteins was estimated 16.50% (±0.86%), 1.57% (±0.63%), 1.02% (±0.18%), respectively. The FT-IR indicated that MFP, MFP-1 and MFP-2 were acidic polysaccharides. The MFP-1 exhibited the strongest antioxidant activity, while MFP-2 showed the strongest hyperglycemic activity in vitro. This may be caused by their different compositions and physical properties in the different mulberry fruit polysaccharides fractions.

Characterization, antioxidant and immunomodulatory activities of polysaccharides from Prunella vulgaris Linn

Water-soluble polysaccharides from Prunella vulgaris Linn (P. vulgaris) were fractionated using DEAE-Sepharose fast-flow column to obtain several eluents of water (PV-P1), 0.1M NaCl (PV-P2) and 0.2M NaCl (PV-P3). Structural analyses showed that PV-P1 had a higher molecular weight and degree of branching as compared to PV-P2 and PV-P3. Tertiary structure analyses indicated that PV-P1, PV-P2 and PV-P3 did not have triple-helical conformation. PV-P2 and PV-P3 showed stronger antioxidant activities than PV-P1, as measured radical scavenging capacities. PV-P1 showed stronger immunomodulatory activities than PV-P2 and PV-P3 in term of stimulation of the production of pro-inflammatory cytokines, including nitric oxide (NO), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) in murine macrophage RAW 264.7 cells. PV-P1, PV-P2 and PV-P3 did not exhibit cytotoxicities against RAW 264.7 at the concentrations tested. These results suggest that P. vulgaris polysaccharides could be explored as potential antioxidant and immunomodulatory agents for the complementary medicine or functional foods.

Properties and extraction of pectin-enriched materials from sugar beet pulp by ultrasonic-assisted treatment combined with subcritical water

Pectin-enriched material (PEM) was extracted from sugar beet pulp using subcritical water combined with ultrasonic-assisted treatment. Optimisation of the reaction parameters for maximum extraction yield of PEM was carried out using response surface methodology. Optimum modification conditions were as follows: liquid/solid ratio 44.03, extraction temperature 120.72°C, extraction time 30.49min and extraction pressure 10.70MPa. Under optimal conditions, the maximum yield of PEM was 24.63%. The composition of the PEM was determined. The data showed that the contents of galacturonic acid and arabinose were 59.12% and 21.66%, respectively. The flow behaviours were investigated by a rheometer. The effects of PEM on the pasting and thermal properties of maize starch were also conducted. The results showed that the addition of PEM increased pasting temperature and decreased other pasting parameters. Increasing PEM concentrations resulted in increased gelatinisation temperature and enthalpy.

Comparison of phytochemical profiles, antioxidant and cellular antioxidant activities of different varieties of blueberry (Vaccinium spp.)

Numerous reports have demonstrated that the consumption of fruits and vegetables is beneficial for the human health. Blueberries, in particular, are rich in phytochemicals including free and bound forming. Phytochemical profiles of 14 varieties of blueberry were compared in this study. 12 compounds were analyzed and had significant changes in blueberry fruits. Total antioxidant activities in different blueberry varieties varied about 2.6times by oxygen radical absorbance capacity (ORAC) assay, and 2times by peroxyl radical scavenging capacity (PSC) assay. The cellular antioxidant activities (CAA) in different varieties varied about 3.9times without phosphate buffer saline (PBS) wash, and 4.7times with PBS wash by CAA assay. Blueberry extracts had potent antiproliferative activities against HepG2 human liver cancer cells, indicating the potential protective benefits associated with their use as functional foods. The anti-proliferative activity was observed to be dose-dependent in blueberry extracts.

Phenolic contents and cellular antioxidant activity of Chinese hawthorn “Crataegus pinnatifida”

It is evident from various epidemiological studies that consumption of fruits and vegetables is essential to maintain health and in the disease prevention. Present study was designed to examine phenolic contents and antioxidant properties of three varieties of Crataegus pinnatifida (Chinese hawthorn). Shanlihong variety exhibited elevated levels of total phenolics and flavonoid contents, including free and bond phenolics. Procyanidin B2 was most abundant phenolic compound in all samples, followed by epicatechin, chlorogenic acid, hyperoside, and isoquercitrin. The free ORAC values, and free hydro-PSC values were 398.3-555.8 μmol TE/g DW, and 299.1-370.9 μmol VCE/g DW, respectively. Moreover, the free cellular antioxidant activity (CAA) values were 678-1200 μmol of QE/100 g DW in the no PBS wash protocol, and 345.9-532.9 μmol of QE/100 g DW in the PBS wash protocol. C. pinnatifida fruit could be valuable to promote consumer health.

Fractionation, preliminary structural characterization and bioactivities of polysaccharides from Sargassum pallidum

Sargassum pallidum polysaccharides were fractioned using a DEAE-Sepharose fast-flow column and four polysaccharide fractions (SP-P1, SP-P2, PV-P3 and SP-P4) were obtained. Structural analyses indicated that SP-P2 and SP-P4 had higher molecular weights than SP-P1 and SP-P3. SP-P2, SP-P3 and SP-P4 comprised of fucose, rhamnose, arabinose, galactose, glucose, xylose, and mannose in a similar molar ratio, while SP-P1 did not contain arabinose. SP-P2 and SP-P4 had a similar number of (1→6) or (1→) glycosidic linkages (1→2) or (1→4) glycosidic linkages and (1→3) glycosidic linkages, while SP-P1 and SP-P3 contained a small number of (1→3) glycosidic linkages. SP-P2 exhibited better bioactivities than SP-P1, SP-P3 and SP-P4, including antioxidant, anti-hemolysis inhibitory, α-amylase and α-glucosidase inhibitory and antiproliferative activities. These data suggest that S. pallidum has four polysaccharide fractions with different structural features and bioactivities and SP-P2 has potential to be explored as a functional food or complementary medicine.

Preparation of starch nanoparticles in a water-in-ionic liquid microemulsion system and their drug loading and releasing properties.

An ionic liquid microemulsion consisting of 1-butyl-3-methylimidazolium hexafluorophosphate ([Bmim]PF₆), surfactant TX-100, 1-butanol, and water was prepared. The water-in-[Bmim]PF₆ (W/IL), bicontinuous, and [Bmim]PF₆-in-water (IL/W) microregions of the microemulsion were identified by conductivity measurements. Starch nanoparticles with a mean diameter of 91.4 nm were synthesized with epichlorohydrin as cross-linker through W/IL microemulsion cross-linking reaction at 50 °C for 4 h. Fourier transform infrared spectroscopy (FTIR) data demonstrated the formation of cross-linking bonds in starch molecules. Scanning electron microscopy (SEM) revealed that starch nanoparticles were spherical and that some particles showed aggregation formation. Furthermore, drug loading and releasing properties of starch nanoparticles were investigated with mitoxantrone hydrochloride as a drug model. This work provides an efficient and environmentally friendly approach for the preparation of starch nanoparticles, which is beneficial to their further application.

Ethnomedicinal values, phenolic contents and antioxidant properties of wild culinary vegetables.

ETHNOPHARMACOLOGICAL RELEVANCE Traditional medicines comprise a variety of health practices, approaches, knowledge, and beliefs. Documentation of traditional knowledge, estimation of total phenolics and antioxidant properties of plant species used as wild vegetables and in traditional medicines by the local communities of Lesser Himalayas-Pakistan are targeted. MATERIALS AND METHODS Interviews, questionnaires, and focus group conversation with local informants were carried out to record ethno-medicinal values. Used value, percentage of people who have traditional knowledge, preference ranking and informant consensus factors were also measured. Standard analytical methods were applied to estimate phenolic contents and antioxidant properties in water and acetone extracts. RESULTS A total of 39 plant species used as culinary vegetables and to treat 44 different health disorders are investigated. Significant levels of use value (0.571) and preference ranking (58% PPK, PR-5) are calculated for Ficus palmata, Ficus carica and Solanum nigrum. Elevated levels of total phenolics (144.5 mg GAE/100 g, FW), and flavonoid contents (142.5 mgRtE/100 g, FW) were measured in the water extracts of Origanum vulgare, while Ficus palmata exhibits the highest flavonol contents (142.7 mg RtE/100 g, FW). Maximum DPPH activity is noted in the flowering buds of Bauhinia variegata (85.34%). However, highest values for OH(-) radical scavenging activity (75.12%), Fe(3+) reducing antioxidant power (54.50 µM GAE/100 g, FW), and total antioxidant capacity (180.8 µM AAE/100 g, FW) were measured in the water extracts of Origanum vulgare. CONCLUSION Lesser Himalayas is a rich source of traditional cultural heritage, and plant biodiversity, which are under threat and necessitate urgent documentation. Present study is focused on the plant species used in traditional medicines and culinary vegetables as well. Preliminary determinations of phenoloic contents and antioxidant properties of various plant species were carried out. Present work will introduce new resource of medicinal and food plants, which could be used as functional food. Furthermore, phytochemical profiles, cellular based antioxidant properties, and isolation of active ingredients will be useful for consumers, and in the pharmaceutical and nutraceutical industries of the country.

Optimization of microwave-assisted extraction of Sargassum thunbergii polysaccharides and its antioxidant and hypoglycemic activities

In the present work, optimization of microwave-assisted extraction of polysaccharides from Sargassum thunbergii was investigated. The physicochemical properties, structural characteristics, and in vitro antioxidant and hypoglycemic activities were determined. The optimal extraction conditions with a yield of 2.84±0.09% for extraction of polysaccharides (STP-1) were extraction time 23min, microwave power 547W, extraction temperature 80°C, and the ratio of raw material to water 1:27g/mL. STP-1 contained 32.7% of total carbohydrate, 1.86% of protein, and 15.2% of sulfates. STP-1 had a major molecular weight of 190.4kDa, and comprised of arabinose, galactose, glucose, xylose, mannose, galacturonic acid, and glucuronic acid with molar percentages of 1.94, 30.7, 4.54, 23.2, 17.6, 8.11, and 13.9%, respectively. In addition, STP-1 showed strong antioxidant and α-glucosidase inhibitory activities, and could improve the glucose uptake in insulin-resistant HepG2 cells, suggesting that STP-1 can be exploited as a promising natural antioxidant and hypoglycemic agent.

Two-Step Method of Enzymatic Synthesis of Starch Laurate in Ionic Liquids

Enzymatic esterification of starch with long-chain fatty acid was investigated by using ionic liquids 1-butyl-3-methylimidazolium choride ([BMIm]Cl) and 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIm][BF4]) as reaction media. An industrial lipase produced by Candida rugosa was used to modify starch with lauric acid. The effect of reaction parameters such as the lipase dosage, the molar ratio of lauric acid/anhydroglucose unit (AGU) in starch, and the reaction temperature as well as the reaction time on the degree of substitution (DS) of long-chain fatty acid starch esters was studied. The maximum DS value was 0.171 under the given conditions. The maximum solubility of high-amylose starch measured by turbidity was 11.0/100 g of [BMIm]Cl. The esterification products were confirmed according to Fourier transform infrared (FT-IR) and nuclear magnetic resonance (NMR) analysis. The morphological and crystallographic properties of native starch were largely disrupted during modification process as indicated by scanning electron microscopy (SEM) and X-ray diffraction (XRD) data. The thermal stability of the starch laurates was found to decrease compared to native starch. After reaction, the ionic liquid was effectively recycled and reused. This paper explores the potential of ionic liquids as solvent for the enzymatic synthesis of long-chain fatty acid starch esters.