Advanced Materials Research Vols. 550-553

Abstract: The separation and purification of resveratrol in wine grape residue with aqueous two phase extraction method were studied in this paper. Used identified ethanol - ammonium sulfate - water as the aqueous two-phase system, the wine grape residue extract substances separated well. By TLC and HPLC analysis, resveratrol content (13.3μg/ml) in aqueous two-phase extraction was higher than the results (2.342μg/ml) in organic solvent extraction. The results showed that the aqueous two phase extraction method could be used in primary separation and purification of resveratrol in wine grape residue.

Abstract: Limit dextrinase is one of three main amylases in malted barley, which plays a significant role during the mashing stage of brewing. Due to very low content and similar properties compared to other amylases in malted barley, limit dextrinase is hard to separate effectively. Our work had been directed towards the extraction and purification of limit dextrinase from malted barley. Final products were obtained through fraction precipitation with ammonium sulfate and column chromatography, and purified limit dextrinase acquired a high purity of 31.23 times as much as that of crude extracts. The previous results were also confirmed by sodiumdodecyl sulphate poly-acrylamide gel electrophoresis (SDS-PAGE) revealing a single band of protein (~97KDa). Effect of temperature, pH value, and metal ion on hydrolysis characterization of limit dextrinase was investigated. The results indicated that the maximum activity of purified samples changed significantly compared with that of crude extracts. The activity of purified limit dextrinase could be activated by lower concentration of Mg2+、Ca2+、Mn2+ and inhibited by the action of Zn2+、Fe2+. But this influence was not so obvious for K+.

Abstract: Abstract. The natural rubber latex (NRL) concentrate was mixed with 10～50 parts per hundred rubber (phr) of methyl methacrylate-grafted-natural rubber latex having a methyl methacrylate content of 49% (MGL49), prevulcanized, and then cast to obtain prevulcanized NRL/MGL49 films. The leached films of prevulcanized NRL/MGL49 were aged in an hot-air oven for comparison of the mechanical properties before and after aging, whereas the thermal decomposition of these films in an atmosphere of air was carried out in a thermo-gravimetric analyzer, and the films were also immersed into water to obtain water absorption. Results showed that the incorporation of MGL49 improved the thermal-oxidative aging resistance of natural rubber latex film when the MGL49 content was less than 50 phr, the water absorption increased with the increment of MGL49 content, and the NRL/MGL49 film containing 10phr of MGL 49 has a best thermal-oxidative stability and highest water absorption also.

Abstract: Objective: Studies on the chemical constituents of the Baphicacanthus plants, Baphicacanthus cusia (Nees) Bremek root. Methods: Using Column chromatography to separation and purification. Identify the compounds structures through the Physicochemical properties and spectral analysis methods. Result: Isolated 9 compounds from the Baphicacanthus cusia (Nees) Bremek roots. They were identified as Stigmasterol-3-O-β-D–glucoside(I), Spinasterol-3-O-β-D– glucoside(Ⅱ),2-(3,4-dihydroxyphenylacetic phenylethyl)]-3O-α-L-rhamnosyl-(1 → 4)-(4-O-caffeoyl)-β-D-pyran-glucosidase(III), Lupeol(Ⅳ), Indigo(Ⅴ), Indirubin (VI), Sucrose (Ⅶ), Adenosine (VIII), β-sitosterol(IX). Among them, compound I and compound II are compounds that at the first time isolated from this plant.

Abstract: To optimize the conditions of supercritical CO2 extraction of carotenoid, a single factorial experiment was used to study the extracting temperature, time and pressure. A three-level Box–Behnken factorial design was used with response surface methodology (RSM) to optimize the three conditions. A mathematical model was then developed to show the effect of each factor and their interactions on the carotenoid yield. The single factorial experiment shows that the best extracting temperature, time and pressure are 50 0C,50 min and 25 MPa, respectively. The model estimates that a maximal caroteniod yield (0.624 mg/g) can be obtained when the conditions of temperature, time and pressure are set at 51.9 0C,61 min and 25.6MPa,repectively. The yield of carotenoid (0.621± 0.009 mg/g) from validation experiments agree with the predicted one.

Abstract: Mirabilis jalapa L. (Nyctaginaceae) is a traditional specie and widely distributed in most parts of China. Its leaves, roots, seed and flowers are used as drugs pharmacological activity. This is the first report on the biological activity against activities of scavenging free radical and ferric reducing antioxidant power (FRAP). Mirabilis jalapa L. seed epicarp (MJSE) was immersed with ethanol (or methanol, ethyl acetate, water) in the ultrasonic instrument, then determination of total phenolic content (TPC) and total flavonoid content (TFC) of these extracts were performed. Furthermore, antioxidant activities of these extracts were evaluated by using DPPH radical scavenging, hydroxyl radical scavenging and FRAP. The TPC, TFC, FRAP and scavenging activities against DPPH and OH radical were in the following order ethyl acetate >ethanol>methanol>water. The TPC of ethyl acetate extract is 4.24 mg GAE /g of dry power weight (DPW), and TFC 0.39 mg RE/ g DPW. ethyl acetate extract exhibit high free radical scavenging rate, IC50 of DPPH and OH assay were 6.62 mg DPW/ml and 3.49 mg DPW/ml, respectively. The TPC values, IC50 obtained from DPPH assay and FRAP assay were highly correlated with correlation of determination (R2 = 0.9878, R2 = 0.9419). The present study confirmed that MJSE has a strong antioxidant activity and can be considered to be safe and an inexpensive source of natural antioxidants and drugs.

Abstract: A main active component cordycepin was extracted and purified from cultured Cordyceps militaris. The crude extract was microwave extracted and then purified using a cation exchange resin (CER) of LSD-001. The adsorption ability of the resin was investigated using equilibrium adsorption isotherm including Langmuir and Freundlich model, and the equilibrated relationship between cordycepin and LSD-001 could be well described by Langmuir equation. The influential factors of desorption experiments, such as NH3 concentration, pH value and ethanol content of desorption solution, along with desorption time and temperature were successively investigated. The optimal desorption conditions were confirmed as: 0.2 mol L-1 NH3 combined with 80% ethanol (v/v), desorbed for 2 h at 25 °C and pH 14. Compared with the content in crude C. militaris (2.5 mg g-1), cordycepin in the final purified products (144.6 mg•g-1) was increased 58-fold after one cycle of dynamic adsorption and desorption on resin LSD-001.

Abstract: The reduction ratio was compared between the Pidgeon process and the aluminothermic reduction process with CA₂, CA, C₁₂A₇ as the main production in the residue. The results of XRD show that the main phase in the reduction residue is CA₂, CA, C₁₂A₇ and Ca₂SiO₄, respectively. Consideration of the efficiency of extracting magnesium, the aluminothermic reduction process which is CA₂ as the main phase in the reduction residue, is the best one.

Abstract: This study aimed at evaluating the antioxidative activity of crude hsian-tsao extracted by acetone and the Fraction E purified by AB-8 macroporous resin chromatography column. The antioxidative activities, including the DPPH radical-scavenging effects, Fe2+-chelating ability, and reducing power as well as the inhibition of lipid peroxidation, were studied. Results demonstrated that both crude extract and Fraction E were more effective in the inhibition of lipid peroxidation and the DPPH radical-scavenging ability than that in the Fe2+-chelating ability. Based on the inhibition of lipid peroxidation, the order of the antioxidant activities was follows: Fraction E >GA> crude extract >Vc. Fraction E seemed to be a promising product of natural antioxidants enriched with phenolic compounds

Abstract: Extraction and purification of polyphenolic compounds from Hsian-tsao (Mesona procumbens Hemsl.) were investigated. The polyphenolic compounds were extracted by using acetone, ethanol or methanol at three different concentrations. The polyphenolic concentration and the inhibition of lipid peroxidation were determined. The results showed that, among solvents tested, 75% acetone solvent extracted a maximum amount of polyphenolic compounds from Hsian-tsao. The 75% acetone extract was purified further by AB-8 adsorption column chromatography and eight fractions, A~H, were obtained. Among eight fractions, Fraction E had the highest polyphenolic content and inhibition(76%). Moreover, Fraction E was separated into four polyphenolic compounds (1~4) by HPLC and each compound reached a purity of more than 98%. The structure of the compound was identified by LC-MS and NMR, and the compound-4 was determined to be astragalin (a flavonol glycoside) which was obtained from HT for the first time.