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1.
Luteolin and apigenin are naturally occurring flavones with a wide spectrum of pharmacological properties. In the present study, enzyme assisted extraction of luteolin and apigenin from pigeonpea leaves using commercial plant cell wall degrading enzyme preparations including cellulase, beta-glucosidase and pectinase were examined. We found that pectinase offered a better performance in enhancement of the extraction yields of luteolin and apigenin than cellulase and beta-glucosidase. The pectinase assisted extraction process was further optimized by varying different parameters such as pectinase concentration, time of incubation, pH of pectinase solution, and incubation temperature. The optimum parameters were obtained as follows: 0.4 mg/ml pectinase, incubation for 18 h at 30–35 °C, pH of pectinase solution 3.5–4. Under the optimum conditions, the extraction yields of luteolin and apigenin achieved 0.268 and 0.132 mg/g in pectinase treated sample, which increased 248% and 239%, respectively, compared with the untreated ones.  相似文献   
2.
花生壳中木犀草素等抑菌活性成分的提取、纯化与研究   总被引:22,自引:2,他引:20  
本实验以甲醇粗提、溶剂梯度萃取、配合抑菌活性跟踪检测,得到了抑菌活性较强、富含黄酮类的花生壳乙酸乙配组分,并用酸碱沉淀、柱层析等法纯化得到三种化合物(1^#,2^#,3^#)。其中2^#从紫外光谱法确认为木犀草素,得率为0.53%。它对金黄色葡萄球菌和枯草杆菌有一定的抑制效果。实验还发现30对金黄色葡萄球菌、酿酒酵母有一定的抑菌活性;1^#则具有更广的抑菌谱,它对金黄色葡萄球菌、酿酒酵母、枯草杆菌和青霉均有较强的抑制作用。它的紫外图谱具有二氢黄酮的特点,其结构有待进一步实验认证。  相似文献   
3.
乐薇  锁进猛  徐文广  杨立  龚乃超 《精细化工》2019,36(9):1795-1802
采用沉淀聚合法,结合Zn2+的配位作用,在水溶液中制备了木犀草素配位印迹聚合物(LUT-CIPs),并考察了LUT-CIPs的吸附性能。结果表明,LUT-CIPs的最佳制备条件为:n〔模板分子(木犀草素-Zn2+)〕∶n〔功能单体(丙烯酰胺)〕∶n〔交联剂(N,N?-亚甲基双丙烯酰胺)〕=1∶4∶30。在该条件下聚合物对醇相中的木犀草素的吸附量达36.45 mg/g、对芹菜素和芸香叶苷竞争底物的选择性系数分别达到5.09和3.35;木犀草素在LUT-CIPs的吸附过程符合Freundlich等温吸附模型和准二级动力学方程;吸附液中加入的14种金属盐均可提高LUT-CIPs的吸附容量,金属离子和酸根离子种类对吸附有影响,其中加入Pb(Ac)2后吸附容量提高最明显,为加入Zn(Ac)2的2.48倍、未加金属盐的5.20倍。  相似文献   
4.
This study was designed to evaluate the mutagenic and antimutagenic activities of luteolin derivatives (luteolin 7-O-glucoside, luteolin 7-O-rutinoside and luteolin 7-O-glucuronide) isolated from Mentha longifolia (L.) Huds. subsp. longifolia by using Ames Salmonella test (TA 1535 and TA1537 strains). In the antimutagenicity assays, luteolin 7-O-glucoside, luteolin 7-O-rutinoside and luteolin 7-O-glucuronide showed antimutagenic effects on TA1537 and TA1535 strains. The highest inhibition rates for luteolin 7-O-glucoside, luteolin 7-O-rutinoside and luteolin 7-O-glucuronide on TA1537 strain were 84.03%, 87.63% and 67.77%, respectively. Similarly, in the antimutagenicity assays performed with the TA1535 strain, the inhibition rates for luteolin 7-O-glucoside and luteolin 7-O-rutinoside were 23.86% and 23.76% respectively. Our findings showed that the antimutagenic properties of luteolin derivatives on TA1537 and TA1535 strains have been found to be structure dependent. The clarification of differences in antimutagenic potency of these luteolin derivatives based on their structures has been demonstrated in this study.  相似文献   
5.
In order to selectively separate luteolin from its crude solution, we synthesized imprinted porous materials with high recognition specificity for luteolin, using an imprinting technique. Modified luteolin was used as template, vinyltriethoxysilane as the functional monomer, and tetraethyl orthosilicate (TEOS) as the cross‐linking agent. The results showed the following optimum reaction conditions: The reaction ratio between luteolin and acryloyl chloride was 1 : 2 (0.10 g/0.20 g), adding 1.0 g precursor; the feasible elution time was 12 h; when the molar quantity of modified template molecule was 0.01 mol and ethenyltriethyloxy‐silane (VTEO) was 0.04 mol, the maximum yield reached 91.6 %. All samples were tested by Brunauer‐Emmett‐Teller method, Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy, equilibrium adsorption experiments and selective adsorption experiments. It was found that the imprinted porous materials showed excellent selectivity for luteolin in aqueous solution. Characterization by FTIR suggested that an addition reaction had occurred between the modified template molecule and VTEO while forming ester bonds in the functional precursor. Results from pore structure analysis indicated that the imprinted porous materials had good channels, and the average pore size of the prepared porous materials was between 35.85 and 95.82 Å. Adsorption dynamics analysis suggested that, when the adsorption time reached 3 h, the adsorption process had reached balance and the adsorption capacity was at steady state. These porous materials had highly selective recognition properties and high equilibrium adsorption capacity for the template molecule. The equilibrium adsorption capacity of the imprinted porous materials to the template molecule was 11.4 times that of the blank porous materials.  相似文献   
6.
利用月桂酰氯酯化制备了脂溶性木犀草素。利用正交实验研究了反应物配比、反应温度及反应时间对制备木犀草素酯化物的影响。通过红外光谱对酯化物进行结构表征,并考察木犀草素酯化物在大豆油中的溶解性和抗氧化活性。制备木犀草素酯化物的最佳反应条件是:反应物配比n(木犀草素)∶n(月桂酰氯)=1∶2、反应温度50℃、反应时间5h,其在大豆油中的溶解度为2.02×104μg/mL,且在相同浓度下,抗氧化活性优于二丁基羟基甲苯(BHT)。结果表明:木犀草素酯化物在大豆油中的溶解度明显提高,并具有良好的抗氧化性能。  相似文献   
7.
Origanum vulgare L. (oregano) is a flavoring herb widely used around the world. In the present study, crude extract of O. vulgare L. (oregano) and its petroleum ether, chloroform, ethyl acetate, n-butanol, water fractions were prepared in order to isolate and investigate antimutagenic compounds from the active extract through the bacterial genotoxicity assay guided fractionation procedures. The methanol extract and its n-butanol fraction showed significant antimutagenic activity. In the end of sub-fractionation process of the n-butanol extract, luteolin 7-O-glucuronide and luteolin 7-O-xyloside were isolated. These compounds showed significant antimutagenic activity against 9-Aminoacridine and N-Methyl-N′-nitro-N-nitrosoguanidine mutagenicity. The inhibition rates ranged from 22.1% (luteolin 7-O-xyloside: Salmonella typhimurium TA1537 – 0.4 mM/plate) to 67.8% (luteolin 7-O-glucuronide: S. typhimurium TA1537 – 0.8 μM/plate). In conclusion, the results revealed that luteolin 7-O-glucuronide and luteolin 7-O-xyloside are two of the antimutagenic compounds of O. vulgare L. ssp. vulgare.  相似文献   
8.
Buddleia officinalis Maxim, commonly used as rice dye for festivals, was extracted with ethanol using microwave-assisted extraction and Soxhlet extraction. The antioxidant activities of microwave-assisted extract of B. officialis (MEB) and Soxhlet extract of B. officianils (SEB) at the optimum extraction conditions were evaluated and compared with synthetic antioxidant butylated hydroxytoluene (BHT) employing DPPH free radical assay, ABTS assay, total antioxidant activity and reducing power. MEB and SEB had stronger antioxidant activities than BHT in all assays except reducing power, and the effects decreased as follows: MEB > SEB > BHT. The total phenolic contents of MEB and SEB reached 113.56 mg/g and 100.94 mg/g dry weight of extract, respectively, expressed as pyrocatechol equivalents, while the total flavonoids contents were 75.33 mg/g and 62.56 mg/g dry weight of extract, respectively, expressed as catechin equivalents (P < 0.05). Higher phenolic and flavonoids compounds may be major contributors to their higher antioxidant activities. Following activity-oriented separation, luteolin was isolated as an active principle, which exhibited excellent free radical scavenging activities with DPPH IC50 3.09 μg/ml and ABTS IC50 2.20 μg/ml.  相似文献   
9.
10.
In this study, we aimed to examine the mutagenic and antimutagenic potencies of three luteolin derivatives (luteolin-7-O-glucoside, luteolin-7-O-rutinoside and luteolin-7-O-glucuronide) by using a eukaryotic cell system, Saccharomyces cerevisiae (RS112).  相似文献   
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