Phenolic profile and antioxidant activity of thermally processed sponge gourd (Luffa cylindrica) as studied by using high performance thin layer chromatography (HPTLC)

The effect of different extracting solvents (methanol, ethanol and butanol) and cooking treatments such as pressure cooking, microwave cooking and frying was studied in regards to phenolic profile and antioxidant activity of Sponge gourd (L. cylindrica). The antioxidant activity was investigated using different assays, namely, ferric thiocyanate test (FTC), thiobarbituric acid test (TBA), ferric reducing antioxidant power (FRAP) and DPPH free radicals scavenging test. A densitometric HPTLC analysis was performed for the analysis of phenolic acids and flavonoids. The inconsistent effect of cooking treatments on antioxidant potential was observed. In general, frying was most potent cooking treatments to retain the maximum antioxidant capacity. Correlation studies indicated that the phenolic compounds including flavonoids were mainly responsible for ferric reducing power, free radical scavenging activity and percent inhibition activity.     

Effect of intake of sponge gourd (Luffa cylindrica) seed oil and Yukdomok (Chionanthus retusa L.) seed oil on lipid levels of blood and organs of a mice

In this study, the effects of sponge gourd (Luffa cylindrical) seed oil and yukdomok (Chionanthus retusa L.) seed oil intake on lipid levels of blood and organs in mice were compared with those of commercially available vegetable oils. In this study, the group treated with sponge gourd seed oil showed the highest final weight, kidney weight, and content of intra-abdominal fat. The group treated with sponge gourd seed oil showed the highest total cholesterol level of 171.75±27.15 mg/dL in the blood, whereas the group treated with yukdomok seed oil showed the highest triacylglycerol level of 234.00±50.52 mg/dL. Further, the group treated with sponge gourd seed oil showed a significantly higher HDL-cholesterol level of 142.75±16.32 mg/dL compared to the other groups (p<0.05). These results suggest that oils extracted from sponge gourd and yukdomok seeds have health-related effects.     

脂肪酶固定化载体材料研究进展

该文综述固定化脂肪酶载体材料研究进展,对固定化用材料发展前景予以展望。     

磷脂酶固定化载体材料的研究进展

游离磷脂酶价格昂贵且稳定性差限制了其应用,固定化技术使酶稳定性增强,可以反复使用,降低了成本,极大地拓宽了酶的应用范围。性能优良的固定化酶应具备成本低、稳定性高和催化活性高等特性。载体材料不仅是固定化酶的重要组成部分,还是影响固定化酶性能的因素之一。对磷脂酶固定化载体材料主要从无机材料、有机材料、复合材料以及无载体4个方面进行综述,并对磷脂酶固定化载体材料发展方向予以展望,为固定化磷脂酶研究在载体材料上的选择提供了参考依据。     

细胞固定化技术-聚氨酯泡沫颗粒作为载体研究进展

该文概述了以聚氨酯泡沫颗粒作为载体进行细胞固定化技术的特点,分析了影响其固定化的各主要因素,探讨了聚氨酯作为细胞固定化载体材料的应用现状、存在的问题、解决办法及其发展前景,以期为聚氨酯载体材料进行细胞固定化研究提供思路。     

丝瓜花不同溶剂提取物抗氧化活性及其酚类成分分析

以无水乙醇、70%乙醇、40%乙醇和水分别对丝瓜花进行提取,并测定各提取物中总酚、总黄酮含量,采用DPPH·清除能力、超氧化物自由基清除能力、FRAP抗氧化能力和亚铁离子螯合能力等方法评价其抗氧化活性,通过HPLC分析其中酚类成分。结果表明,70%和40%乙醇提取物总酚及总黄酮含量较高,而且DPPH·清除活性、FRAP还原力最强,40%乙醇提取物、水提物分别具有最强的超氧阴离子自由基清除活性和亚铁离子螯合能力。总酚含量与DPPH·清除活性之间存在较强的相关性(R²=0.8688)。HPLC分析检出提取物中9种酚类化合物,其中含量最高的为杨梅素。试验结果说明,70%乙醇、40%乙醇可能是丝瓜花抗氧化性物质提取的较好溶剂。结果表明丝瓜花是一种较好的抗氧剂资源。     

Treatment capability of an up-flow anammox column reactor using polyethylene sponge strips as biomass carrier

The feasibility of applying a polyethylene (PE) sponge as a biomass carrier in an anaerobic ammonium oxidation (anammox) reactor and its nitrogen removal performance were also investigated. Experiments were carried out in an up-flow column reactor with synthetic inorganic wastewater. Experimental results indicate that reactor containing PE sponge biomass carriers showed a high nitrogen removal capability and exhibited stable performance. In addition, the reactor with 8 strips PE sponge as biomass carrier exhibited greater adaptation capacity compared to that with 6 strips and could achieve a high TN removal rate within a very short period. The ratio of NO₂-N removal and NO₃-N production to NH₄-N removal for the reactor was 1.26:0.21. Furthermore, to investigate the bacterial composition of the mature community, 16S rRNA sequences were amplified by PCR and analyses were conducted using DNA databases. Results showed that a new kind of anammox microorganism (Kumadai-1) was the dominant species in the reactor when using PE sponge as a biomass carrier.     

Deformation and Dehulling of Sponge Gourd (Luffa aegyptiaca) Seeds

This work presents the compressive strength properties of sponge gourd (Luffa aegyptica) seeds to facilitate the design or adaptation of an appropriate dehuller. The sizes and shape indices of the seed and kernel, and the clearance of the kernel from the seed coat were determined. The seed samples were subjected to uni-axial quasi-static compression tests at 1.0 mm min^?1 along the minor and the major axes. The fracture resistance, stiffness modulus, modulus of elasticity, toughness, and maximum elastic deformation of the seed were obtained from the force-deformation curve. The geometric mean diameters varied from 4.0 to 4.5 mm for the seed and 1.6 to 3.9 mm for the embedded kernel; while their corresponding sphericities were 0.64 and 0.62, respectively. The compressive strength of the seed varied with loading orientation. The seed exhibited larger deformation but lower stiffness along the major axis than the minor axis. The force required for rupturing the hull were 95 N along the major axis and 81 N along the minor axis; while the corresponding energy required were 95 and 40 mJ.     

一种新的酶载体的制备及其在脂肪酶固定化中的应用

聚乙二醇(PEG)是一种用途极为广泛的聚醚高分子化合物,它可应用于医药、卫生、食品、化工等众多领域.研究合成末端含有环氧基的聚乙二醇(环氧聚醚)的过程,讨论了反应物配比、反应时间、反应温度、分子量等因素对环氧聚醚的影响,结果表明,该反应的最佳反应条件:分子量为1000,在-OHmol:ECHmol:OH-mol=1:5:2,60%的条件下,反应5h,所得产物的转化率可达95%;并用该环氧聚醚作为接枝链,以壳聚糖为栽体,对脂肪酶进行固定化,得到活力较高的固定化脂肪酶,酶活力回收率约为36.5%,最适反应温度由游离酶的36℃上升至55℃,最适pH由8.0升至8.5,固定化酶的Km值由游离酶的51me/mL下降至45mg/mLo环氧聚醚接枝壳聚糖后固定化脂肪酶在较宽的温度和pH范围内稳定性高.     

Characterization of polystyrene-binding peptides (PS-tags) for site-specific immobilization of proteins

In this study, we characterized polystyrene-binding peptides (PS-tags) that possess a specific binding affinity for hydrophilic polystyrene (phi-PS) plates. Both the FITC-labeled PS19-1 (RAFIASRRIKRP) and PS19-6 (RIIIRRIRR) peptides showed strong binding affinity for commercially available hydrophilic, but not hydrophobic, PS plates in the presence of the non-ionic surfactant Tween 20. The dissociation constants (K_d) of the PS19-1 and PS19-6 peptides for the hydrophilic PS-A plate were 169 and 86 nM, respectively, and the K_d of both peptides increased with the concentration of NaCl or urea. Based on adsorption yield and residual activity of glutathione S-transferase (GST) after fusion with the PS19-6 peptide or its variants, it was found that the basic amino acid in the PS-tags, i.e., Arg was essential for the strong binding affinity of PS-tags in both the peptide and peptide-fused protein forms The aliphatic amino acids in PS19-6 and PS19-6L, such as Ile or Leu, were also effective. Thus, a series of PS-tags that possess this unusual feature, especially the peptides PS19-6 (RIIIRRIRR) and PS19-6L (RLLLRRLRR), are potential candidate affinity peptide tags for site-specific immobilization of proteins onto hydrophilic PS plates, which show potential as solid supports for protein-based biochips.     

Preparation of Cu(II) adsorbed chitosan beads for catalase immobilization

Glutaraldehyde pretreated crosslinked chitosan beads (Ch) were used for Cu(II) adsorption (Cu-Ch). The amount of adsorbed copper was determined using atomic absorption spectroscopy.     

Bifunctionalized mesoporous silicas for Cr(VI) reduction and concomitant Cr(III) immobilization

Surfactant-templated thiol-functionalized mesoporous silica adsorbents have been prepared by cocondensation of mercaptopropyltrimethoxysilane and tetraethoxysilane in the presence of cetyltrimethylammonium bromide, which were then partially oxidized to get bifunctionalized materials containing both thiol and sulfonic acid moieties (MCM-41-SH/SO3H). The resulting organic-inorganic hybrid was applied to the uptake of chromium species according to a reduction-sorption mechanism involving reduction of Cr(VI) by thiol groups and immobilization of Cr(III) onto sulfonic acid moieties. These processes were strongly affected by pH, and the optimal conditions for effective chromium sequestration resulted from a compromise between pH values low enough to ensure quantitative reduction of Cr(VI) and not too low to enable Cr(III) binding to sulfonate groups, which was best achieved at pH 2-3. The effect of the solid-to-solution ratio and the relative amounts of -SH and -SO3H groups was also discussed. Even if Cr(VI) reduction by thiol groups resulted in the formation of sulfonic acid moieties, their contentwas not high enough to ensure quantitative Cr(III) immobilization, which was only attained with materials containing already some sulfonic acid groups prior to contacting Cr(VI) solutions. Redox speciation of sulfur and chromium species was analyzed by X-ray photoelectron spectroscopy (XPS) and used to support the proposed mechanism.     

Compositional,Mass-Volume-Area Related and Mechanical Properties of Sponge Gourd (Luffa aegyptiaca) Seeds

Some physical, mechanical and compositional properties of sponge gourd seeds were determined according to standard methods. The length, width, thickness and equivalent diameter were 9.6, 6.17, 1.59 and 4.53 mm for whole seeds and 6.99, 4.31, 0.79 and 2.84 mm for the dehulled seeds respectively. Sphericity, surface area, seed mass, bulk density, apparent density and porosity were 0.47, 0.57 cm², 0.079 g, 0.43, 0.50 g/cm³ and 0.14 for whole seeds and 0.41, 0.33 cm², 0.044 g, 0.57, 0.93 g/cm³ and 0.39 for dehulled seeds, respectively. Coefficient of friction against wood, aluminum, galvanized steel and mild steel surfaces were 0.50, 0.59, 0.64 and 0.70 for the whole seeds and 0.55, 0.66, 0.67, and 0.76 for the dehulled seeds, respectively. Sponge gourd seeds contain 33.38 and 39.11 g of protein and fat per 100 g of sample, respectively, the fat being largely made up of 50.1% linoleic and 31.03 % stearic acids.     

Control of speargrass (Imperata cylindrica (L) Raeuschel) with glyphosate and fluazifop‐butyl for soybean (Glycine max (L) Merr) production in savanna zone of Nigeria

A field trial was conducted in 1996 and 1997 to control speargrass (Imperata cylindrica (L) Raeuschel) for soybean production. The treatments comprised four levels of glyphosate, 1.08, 1.44, 1.80 and 2.16 kg ha⁻¹, applied pre‐tillage and followed by one hoe‐weeding (HW) at 6 weeks after planting (WAP); fluazifop‐butyl, 0.125, 0.25 and 0.375 kg ha⁻¹, at 3WAP; 1HW at 3WAP; 2HW at 3 and 6WAP; and an unweeded control. Glyphosate and fluazifop‐butyl controlled 57–85% and 51–83% respectively of I cylindrica compared with 64–67% by traditional hoe‐weeding. The highest grain yield (1.88 t ha⁻¹) was obtained from plots treated with glyphosate (1.44 kg ha⁻¹) + 1HW. The highest profit, however, was obtained with fluazifop‐butyl. It was unprofitable to apply glyphosate at rates higher than 1.44 kg ha⁻¹ to control I cylindrica at 30 cm foliage. © 2000 Society of Chemical Industry     

高速逆流色谱(HSCCC)在丝瓜苷类化合物提取中的应用

丝瓜正丁醇相采用AB-8大孔树脂,利用水和30%、50%、70%和95%的乙醇溶液洗脱提纯得总糖苷。30%洗脱部分以氯仿-甲醇-异丙醇-水(5:6:1:4)为溶剂系统采用高速逆流色谱分离得到4个酯苷类化合物和一个酸,分别为:阿魏酰-β-D-葡萄糖(Ⅰ);1-O-p-香豆酰-β-D-葡萄糖(Ⅱ);对羟基苯甲酰葡萄糖(Ⅲ);咖啡酰-β-D-葡萄糖(Ⅳ);香豆酸(Ⅴ)。50%洗脱部分以氯仿-甲醇-水(13:7:8)为溶剂系统采用高速逆流色谱分离得到2个黄酮苷类化合物,分别为:香叶木素-7-O-β-D-葡萄醛酸苷甲酯(Ⅵ);芹菜素-7-O-β-D-葡萄醛酸苷甲酯(Ⅶ)。70%洗脱部分以氯仿-甲醇-水(13:7:8)为溶剂系统采用高速逆流色谱分离得到1个皂苷化合物丝瓜皂苷H(Ⅷ)。化合物Ⅰ-Ⅶ都是首次从该植物中分离得出。     

Immunomodulatory and antioxidative potential of herb (Pueraria tuberosa) in mice using milk as the carrier

Eighteen healthy male mice were divided into three equal groups and given specific diets for a period of 28 days: Group M were fed a normal synthetic diet (NSD) and milk; Group P were fed NSD and Pueraria tuberosa (PT) extract (0.4%), while the diet of group PM was NSD supplemented with PT extract (0.4%) and milk. The phagocytic activity and immunoglobulin A (in intestines) and immunoglobulin G (serum) levels increased significantly in comparison with group M in PT supplemented groups after a period of 28 days. Group P and Group PM showed significantly higher reduced glutathione level and significantly lowered thiobarbituric acid reactive substances levels in liver and red blood cells as compared to control.     

DNS法检测灰略红链霉菌JSD-1产纤维素酶的CMC酶活条件的优化

为研究3,5-二硝基水扬酸法（DNS）检测纤维素酶的CMC酶活条件,采用单因素实验探讨了波长、酶促反应温度与时间、p H、粗酶液和底物添加量、底物浓度、显色时间及空白实验对测定结果的影响,并通过响应面（BoxBehnken）实验设计及方差分析确定了一种较优的CMC酶活检测条件组合。结果表明,CMC酶活检测最佳条件为:波长520nm、酶促反应温度和时间分别为45℃和30min、p H7.0、底物浓度12g/L、显色15min。      

DNS法检测灰略红链霉菌JSD-1产纤维素酶的CMC酶活条件的优化

为研究3,5-二硝基水扬酸法(DNS)检测纤维素酶的CMC酶活条件,采用单因素实验探讨了波长、酶促反应温度与时间、p H、粗酶液和底物添加量、底物浓度、显色时间及空白实验对测定结果的影响,并通过响应面(BoxBehnken)实验设计及方差分析确定了一种较优的CMC酶活检测条件组合。结果表明,CMC酶活检测最佳条件为:波长520nm、酶促反应温度和时间分别为45℃和30min、p H7.0、底物浓度12g/L、显色15min。     

Arsenic(V) removal with polymer inclusion membranes from sulfuric acid media using DBBP as carrier

Polymer inclusion membranes (PIMs) based on cellulose triacetate (CTA) and dibutyl butyl phosphonate (DBBP) were tested for arsenic(V) separation from H2SO4 for its recovery from copper electrolytes. Solvent extraction experiments allowed the determination of the As(V)-DBBP and H2SO4-DBBP complexes formed in the organic phase. Application of a transient model to membrane transport experiments in solutions containing only arsenic or H2SO4 indicated that it occurred under a kinetically controlled regime by formation of H3AsO4[DBBP]2 and H2SO4[DBBP] species, respectively. When arsenic and H2SO4 are simultaneously present, the existence of a third species, H3AsO4[DBBP][H2SO4], explains well the fact that As(V) flux decreases and that H2SO4 flux increases. In both cases, a limiting 50% recovery value was obtained. However, active arsenic transport (>50%) is achieved if the H2SO4 concentration gradient is assured (e.g., using a triple-cell configuration). In this way, high arsenic recovery factors (90% in 800 min) were obtained with initial concentrations of 5000 mg/L As(V) and 220 g/L H2SO4. In all membrane systems tested, good As(V) selectivity over copper (up to 30000 mg/L) was attained.