Advanced Materials Research Vols. 634-638

Abstract: Azetidin-3-ones are important heterocycles in organic synthesis and pharmaceutical chemistry. With gold-catalyzed alkyne intermolecular oxidation, these versatile heterocycles can be prepared in three steps from readily available propargylic alcohols with high efficiencies.

Abstract: Extracion of hemicelluloses from sugarcane bagasse under microwave radiation was studied in this paper. The effects of liquid to solid ratio ( V ( water ) : m ( stover ) ) , alkali consumption ( m( NaOH): m ( stover ) ) , time, microwave power, and temperature on the extraction yield of hemicelluloses were investigated. The optimal parameters were: liquid to solid ratio of 25, alkali consumption of 2.0, time of 20 min, and microwave power of 1200 W. The obtained hemicelluloses was qualitatively analyzed by gas chromatography, and results showed that prepared hemicelluloses is a kind of xylan hemicelluloses, mainly consisting of simple sugars like D-xylose, D- arabinose, L- arabinose, D- galacturonic acid, D-galactose and D-mannose.

Abstract: The processes of biomass growth, hydrogen production and sucrose degradation were systemically investigated about batch anaerobic fermentation which is based on activated sludge for a basic strain and the simulating sucrose wastewater for a substrate. The kinetics of microbial growth, hydrogen production and sucrose degradation were proposed according to the Compertz equation and the Luedeking-Piret equation. The relationship between the biomass, hydrogen and substrate were also evaluated. The results shown that the hydrogen is a main produce of the formation process which is a growth-associated, a high biomass is favorable to increasing the hydrogen yield and shortening lag time. The three kinetic models equation have a good coincidence with the experimental data, and can really reflect the hydrogen production process from wastewater contained sucrose. The results will provide helpful reference for the large-scale production and theory study of hydrogen production.

Abstract: In this study, the effects of the supports morphology on the lipase immobilization were discussed. PVA-MCM-41 with perfect spherical morphology, which was synthesized in the presence of PVA, was introduced to compare with MCM-41 which is irregular in shape and aggregate seriously. The amount of lipase immobilized on PVA-MCM-41 was a little higher than that immobilized on MCM-41. However, the activity of the former is just around 50% of the latter. The lipase immobilized on PVA-MCM-41 exhibited well reusability and storage stability that it remained 27% of its original activity after using for 6 times and 44% after being stored for 33 days. To the lipase immobilized on MCM-41, it declined to 8% by using just 3 times and 35% after 33 days.

Abstract: We developed a HPLC method with high specificity and sensitivity for the limit test of AAA in Yishen Juanbi Pill. In this mothod, the detection limit for AAA was 2.216ng. AAA could not be detected in all the 3 batches of the pill which suggests that the pill prepared by the modified water extraction and ethanol precipitation method is safe for clinical use.This efficient HPLC technique is also proposed for the limit test of AAA in other preparations besides Yishen Juanbi Pill.

Abstract: In order to further improve the corrosion resistance and bioactivity of NiTi alloy, TiO2-SiO2-HAP (hydroxyapatite) composite films with different composition were prepared on NiTi alloy substrate by a sol-gel method. The phase composition, surface morphology, interface adhesive strength and corrosion resistance were studied. The results indicated that the composite film heat-treated at 500°C showed amorphous state, and with increasing of heat-treatment temperature, crystals of CaSiO3, anatase TiO2 and hydroxyapatite (HAP) appeared. The composite film with higher (TiO2-SiO2) content was more uniform and smooth, and had higher interface adhesive strength with the substrate. With the decreasing of (TiO2-SiO2) content, the composite films tended to become irregular, and tiny crack clusters with ringy distribution appeared when the (Ti+Si)/Ca molar ratio was decreased to 25/75, which led to decrease of interface adhesive strength to some extent. The anodic polarization curves indicated that NiTi alloy coated with TiO2-SiO2-HAP composite films had an apparent improvement of corrosion resistance, with an obvious decrease of passivation current.

Abstract: The determination of matrine in compound sophora alopecuroides suppositories was carried out by reversed-phase high-performance liquid chromatography(RP-HPLC). Elite ODS C18(250mm×4.5mm, 5µm) column was used and acetonitrile -anhydrous ethanol-water-triethy lamine (15:22.5:62.5:0.01) was selected as the mobile phase. Meanwhile the detection wavelength 215nm was used. The linearity of matrine was in the range of 0.74-5.18µg，r=0.9991，and the average recovery was 98.52%，RSD was 1.54%. The method was proved to be simple, accurate, sensitive and reliable. It can be used for the quality control of compound sophora alopecuroides suppositories.

Abstract: In the assay of serum PON arylesterase activity using phenyl acetate as a substrate, a number of other serum hydrolases can catalyze the substrate hydrolysis, and so bring high background activity signal. EDTA and 2-hydroxyquinoline (2-HQ) were PON inhibitors. Based on this property, background activity can be determined by adding EDTA or 2-HQ just prior to adding the substrate (phenyl acetate). The specific serum PON activity was obtained by subtracting the background activity from the total serum arylesterase activity. The correlation of the background signals based on different inhibitors and the correlation of the specific serum PON activity were investigated, respectively. The inhibition consistency was analyzed. The correlation analysis of PON activity-age was performed.

Abstract: The crude polysaccharides were extracted by hot water from marine green algae Enteromorpha linza. After that, five polysaccharides were obtained through Q-Sepharose Fast Flow chromatography. Their structures and monosaccharide compositions were analyzed by FTIR and GC-MS. Mannose was the abundant monosaccharide in both ELP-3 and ELP-4. ELP-3 consisted of mannose, L(-)-fucose, D-glucose, D-galactose, D-arabinose and D-xylose in a molar ratio of 1.00:0.66:0.46:0.41:0.27:0.19. In α-glucosidase inhibition assay, the polysaccharides showed significant inhibitory activities. ELP-3 (IC₅₀ =0.36 mg/mL) exhibited much stronger inhibitory effect against α-glucosidase, compared with Acarbose (IC₅₀=0.46 mg/mL), while ELP-4, a similar inhibitory effect (IC₅₀=0.58 mg/mL) as Acarbose. Moreover, it was found that EPLs have moderate antioxidant activities in 1,1-diphenyl-2-picrylhydrazil (DPPH) scavenging experiment.

Abstract: Single factor experiments and orthogonal experiments were successively carried out to optimize the water extraction technology of flavonoids in Emilia sonchifolia (Linn.) DC. The results showed that the influential order of factors was extraction times >solid-liquid ratio >extraction time. The optimum conditions were 15:1 of solid-liquid ratio, 2h of the extraction time and 3 of the extraction times. Under these conditions, the extraction yield of flavonoids from Emilia sonchifolia (Linn.) DC was 3.35%.