首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到19条相似文献,搜索用时 445 毫秒
1.
以对硝基苯甲酸为原料,经氯化后,被氨基乙酸取代,得到对硝基苯甲酰氨基乙酸,再经还原,重氮化后,与水杨酸偶合,合成了抗溃疡性结肠炎新药-5[[4-[(羧甲基)甲酰氨]苯]偶氮基]水杨酸(Ipsalazide)。并做了红外光谱鉴定。  相似文献   

2.
荜拔中的新酰胺成分   总被引:1,自引:0,他引:1  
从荜拔地上部分乙醇提取物中分得5个化合物,经波谱分析确定其结构分别为:(α,β,α,β)-1,3-双(3,4-二甲基苯基)-2,4-双[1-(2-羰基-5,6-二氢吡啶)-甲酰基]-环丁烷(1)。  相似文献   

3.
异亮氨酸质量标准①—译自《BP93版》曾祥群江西鹰潭市生物化学制品厂C6H13NO2:131.273-32-5[定义]异亮氨酸是(2S,3S)-2-氨基-3-甲基戊酸,以干燥品计,其含C6H13NO2不得少于98.5%,不得高于101.0%。[特征]...  相似文献   

4.
混合溶剂系统对脂肪酶酯化活性和选择性的影响   总被引:7,自引:0,他引:7  
目前非水介质中的酶促反应主要局限于单一有机溶剂系统。为使非水相酶反应顺利进行,所用反应介质一般必须满足2个条件:(1)具有较高的疏水性(LogP值)[1];(2)易于溶解底物。然而对于一些2芳基丙酸(如酮基布洛芬,以下简称酮洛芬)的酶促酯化反应[2...  相似文献   

5.
ANTIPYRETIC ACTION OF DEXAMETHASONE ON EGTAZIC ACIDINDUCED FEVER IN RABBITS   总被引:2,自引:1,他引:1  
本文用脑室灌注和Fura2测定细胞内游离钙技术观察了地塞米松(dexamethasone,DEX)对家兔乙二醇双(2氨基乙醚)四乙酸性发热效应和下丘脑细胞内游离钙浓度([Ca2+]i)的影响,借此深入探讨地塞米松解热作用的中枢机制。结果发现:脑室灌注乙二醇双(2氨基乙醚)四乙酸(06nmol)引起家兔结肠温度明显升高,静脉注射地塞米松(5mg/kg)显著抑制家兔乙二醇双(2氨基乙醚)四乙酸性发热,地塞米松(60~120μmol/L)并不影响下丘脑细胞内[Ca2+]i,而事先脑室灌注抑制基因转录的放线菌素D(3nmol)则完全取消了地塞米松对乙二醇双(2氨基乙醚)四乙酸性发热的解热作用。这些结果提示:地塞米松显著抑制家兔乙二醇双(2氨基乙醚)四乙酸性发热,其机制与地塞米松激活脑内某些基因的表达有关,而与下丘脑神经细胞跨膜钙离子流无关。  相似文献   

6.
蓝红林  梁笑芳 《蛇志》1996,8(3):29-30
72例糖尿病血清、尿β2微球蛋白临床分析蓝红林梁笑芳高玲桂林医学院附属医院541001血清β2—微球蛋白(β2—M)的测定作为肾病早期肾功能减退是一项较为敏感的指标之一已有大量临床报道[1]。本组资料为住院治疗的老年人糖尿病及非糖尿病的老年人、中年人...  相似文献   

7.
滇重楼地上部分的两个微量皂甙   总被引:10,自引:1,他引:9  
从滇重楼地上部分中分离出两个新的微量的甾体皂甙PolyphyllosideⅢ和Ⅳ,根据化学降解和光谱分析,它们的化学结构分别为27-羟基-偏诺皂皂甙元-3-O[a-L-鼠李吡喃糖基(1→2)][a-L-鼠李吡喃糖基(1→4-a-L鼠李吡喃糖基(1→4)]-β-D-葡萄吡喃糖甙,23β,27-二羟基-偏皂甙元-3-O-[a-鼠李吡喃糖(1→2)]  相似文献   

8.
目的:探讨营养干预对肾衰竭维持性血液透析患者营养状况和钙磷代谢的影响。方法:选取100例2018年2月—2020年9月在我院进行维持性血液透析的肾衰竭患者,采用随机数字表法,将100例患者随机均分为观察组和对照组,两组患者间年龄、性别、原发疾病、已接受血液透析治疗时间均无差异(P>0.05),具有可比性。其中,对观察组患者实施为期3个月的营养干预,对照组进行常规临床治疗和护理。比较维持性血液透析前后两组营养状况和钙磷代谢的变化,以及透析后两组患者外周血营养指标和钙磷代谢的变化情况。结果:两组患者经维持性血液透析后,血清TP、ALB、PA、HGB水平均较透析前高,且透析后,营养干预组患者血清TP[(66.28±2.65)vs(63.26±2.84)g/L]、ALB[(33.96±1.14)vs(32.22±1.33)g/L]、PA[(206.58±13.90)vs(191.38±12.95)mg/L]及HGB[(99.56±3.20)vs(96.60±3.46)g/L]水平均高于对照组患者,差异有统计学意义(P<0.05)。经维持性血液透析后,两组患者血清血钙水平均较透析前高,血清血磷、钙磷乘积及iPTH水平均较透析前降低,且透析后,营养干预组患者血清血钙[(1.48±0.17)vs(1.19±0.18)mmol/L]显著高于对照组患者,血清血磷[(2.77±0.34)vs(3.67±0.25)mmol/L]、钙磷乘积[(4.06±0.59)vs(4.38±0.75)mmol2/L2]及iPTH[(260.30±53.72)vs(282.12±57.18)ng/L]水平均显著低于对照组患者,差异有统计学意义(P<0.05)。结论:营养干预可改善肾衰竭患者营养状况,使得钙磷代谢紊乱得到更好的纠正,值得临床推广应用。  相似文献   

9.
除草剂阿特拉津生物降解研究进展   总被引:1,自引:0,他引:1  
阿特拉津(Atrazine)又称氯乙异丙嗪[2-氯-4(乙基)-6-(异丙氨基)-1,3,5-三嗪],商品名莠去津,是一种广泛使用的三嗪类除草剂,用于阔叶杂草和禾草的防除,如玉米、高梁、甘蔗和库区杂草等。阿特拉津虽然是一种低毒除草剂,但由于它被微生物矿化的过程十分缓慢,在土壤中的半存留期长达4-57周,所以在施用过这种除草剂的土壤中以及地下水和表面水中,其浓度远远超过3ppb的最大允许值,造成对环境的污染[1]。阿特拉津在世界范围内已经使用了近40年,其在环境中的扩散引起广泛重视,因此研究这种化合物的生物降解机理十分必要。虽然自1982年以来先后在诺卡氏菌属(Nocardia)[2,3]、红球菌属(Rhodococus)[4,5]、不动杆菌属(Acinetobacter)[6]、土壤杆菌属(Agrobacterium)[7]和假单胞菌属(Pseudomonas)[1,8,9]等多个细菌属中分离到降解阿特拉津的菌株,但直到90年代中期,对这一生物降解过程所涉及到的基因、酶和中间代谢物仍知之甚少。自1995年Wacket实验室从施用过阿特拉津的土壤中分离到假单胞菌ADP菌株以后[1],阿特拉津的生物降解机理研究获得了迅速发展。此后,又从根瘤菌属(Rhizobium)[10]以及棍状杆菌属(Clavibacter)、产碱杆菌属(Alcaligens)[11]和Ralstonia等多个细菌属中分离到降解阿特拉津的细菌。本文主要对假单胞菌ADP菌株降解阿特拉津的酶学、遗传学和生物工程研究概况作简要介绍 。  相似文献   

10.
合成了4-[(R,S)-1-氨基(2’,4’-二甲氧苄基)]苯氧乙酸以及4个中间体,其结构分别通过红外光谱、核磁共振、折光率、熔点等测试手段得到确证。  相似文献   

11.
1. Streptomyces griseus was grown in a medium containing l-[Me-(14)C]methionine, and the labelled products from an ethanolic extract of the cells were examined. 2. Acid hydrolysis of one of the products gave a compound identified as 3-O-[Me-(14)C]-methylmannose by a series of degradative reactions. 3. Reduction of the radioactive compound gave 3-O-methyl-d-mannitol, indistinguishable from a synthetic sample.  相似文献   

12.
1.1. Lysosome-enriched fractions were prepared by differential centrifugation of homogenates of luteinized rats ovaries. Acid phospholipase A activities were characterized with [U-14C]diacyl-sn-glycero-3-phosphocholine and 1-palmitoyl-2-[9,10-3H]- or [1-14C]oleoyl-sn-glycero-3-phosphocholine as substrates. Acid phospholipase A1 activity had properties similar to other hydrolases of lysosomal origin; subcellular distribution, latency and acidic pH optimum. Acid phospholipase A2 activity with similar characteristics was also tentatively identified. We were unable to exclude the possibility that the combined action of phospholipase A1 and lysophospholipase contributed to the release of acyl moieties from the 2-position of the synthetic substrates. 2. Lysophospholipase activity was present in the lysosome-enriched fractions. This activity had an alkaline pH optimum. 3. Phospholipase A1 and A2 activities solubilized from lysosome fractions by freeze-thawing were inhibited by Ca2+ and slightly activated by EDTA. A Ca2+- stimulated phospholipase A2 activity, with an alkaline pH optimum, remained in the particulate residue of freeze-thawed lysosome preparations. This activity is believed to represent mitochondrial contamination. 4. Activities of acid phospholipase A, as well as other acid hydrolases, increased approx. 1.5-fold between 1 and 4 days following induction of luteinizatin, suggesting a hormonal influence on lysosomal enzyme activities.  相似文献   

13.
Microbial treatment of environmental pollutants including dyes with white rot fungi has received wide attention as a potential alternative for conventional methods in wastewater treatment. The degradation products from dyes and mechanism underlying fungal degradation of dyes is desirable to be understood. Capillary electrophoresis coupled with mass spectrometry (CE-MS) was used in this study to determine biodegradation products of 4-[(4-hydroxyphenyl)azo]-benzenesulfonic acid, sodium salt (4HABA) and Acid Orange 7 (C.I. 15510), produced by a white rot fungus, Pleurotus ostreatus. Two major degradation products, benzenesulfonic acid and 4-hydroxy-benzenesulfonic acid, from both sulfonated compounds, were identified and their kinetic profiles in biodegradation were followed by CE-MS. Another product, 1,2-naphthoquinone, from Acid Orange 7 was identified using HPLC. Formation of these products in fungal degradation is discussed.Revisions requested 8 October 2004; Revision received 12 November 2004  相似文献   

14.
Summary Hepatic-FABP was labelled at cysteine-69 with the fluorescent environmentally sensitive reporter group AEDANS. The labelled protein had an emission maximum at 465 nm indicating that cysteine-69 was buried in a non-polar environment. The modified protein was still able to bind ligands such as oleic acid, oleoyl CoA and haem. The affinity of AEDANS-FABP for haem was unaltered as compared with the native protein indicating that cysteine-69 must be remote from the ligand binding site. The binding of oleic acid did not significantly perturb the fluorescence emission spectrum of the fluorescent reporter group suggesting that there are not large conformational changes in the region of cysteine-69 on fatty acid binding. The binding of stoichiometric amounts of oleoyl CoA was accompanied by a small fluorescence enhancement which suggests that fatty acyl CoAs may interact with other regions of the FABP molecule not involved in fatty acid binding.Abbreviations FABP Fatty Acid-Binding Protein - AEDANS 5-[2-(Acetyl)aminoEthyl]Aminonaphthalene-1-Sulphonic Acid - AAEDANS 5-[2-(Iodoacetyl-AminolEthyl] aminonaphthalene-1-Sulphonic Acid - DTNB 5,5Dithiobis-(2-Nitrobenzoic acid)  相似文献   

15.
Yang Y  Jin D  Wang G  Wang S  Jia X  Zhao Y 《Bioresource technology》2011,102(16):7429-7436
The performance of unmodified and cetyldimethylethyl ammonium bromide (CDAB) modified nonviable Aspergillus oryzae for removal of Acid Blue 25 (AB 25) and Acid Red 337 (AR 337) was investigated in single and binary systems. In single system, the biosorption capacities of CDAB-modified biosorbent reached 160.36 and 280.39 mg g−1 for AB 25 and AR 337, respectively, which were 1.52 and 1.66 times higher than that of unmodified biosorbent. In binary system, the biosorption capacities of unmodified and CDAB-modified biosorbents for both dyes decreased significantly compared to that in single system. Relative competitiveness analysis demonstrated that there existed critical initial concentration ratio which determined the predominance of dyes during biosorption process. The biosorption of AB 25 was found to be in dominant position at initial concentration ratio of [AB 25]/[AR 337] above 0.63. Kinetic analysis indicated that intraparticle diffusion was the limiting step for biosorption of two dyes onto biosorbents.  相似文献   

16.
O-specific polysaccharide has been isolated on mild hydrolysis of lipopolysaccharide from Yersinia aldovae and shown to consist of 2-acetamido-2-deoxy-D-glucose, D-glucose, 2-acetamido-2-deoxy-D-galactose, and 3,6-dideoxy-3- [(R)-3-hydroxybutyramido]-D-galactose in molar ratio 2:2:1:1. Acid hydrolysis, methylation, solvolysis with anhydrous hydrogen fluoride, 1H and 13C NMR studies indicated the polysaccharide to be composed of hexasaccharide repeating units of the following structure: [formula see text].  相似文献   

17.
The present study deals with the decolorization of Acid Black 210 by a bioluminescent bacterium, Vibrio harveyi TEMS1, isolated from coastal seawater of Izmir Bay, Turkey. Maximum rate of decolorization of Acid Black 210 was observed when Luria Bertani medium was used. Decolorization of Acid Black 210 was 38.9% and 93.9% at 24 h under shaking and static conditions, respectively. The optimum dye-decolorizing activity of the culture was obtained at 100 ppm initial dye concentration and incubation temperature of 20°C. Vibrio harveyi TEMS1 was also tested for its ability to decolorize four azo dyes (Acid Black 24, Acid Blue 7, Acid Green 20, Acid Yellow 36) in addition to Acid Black 210.  相似文献   

18.
Purification and partial characterization of the poliovirus RNA-linked protein (VPg) are described. VPg has been freed from the RNA by ribonuclease digestion and phenol extraction. Gel filtration chromatography of VPg-pUp (labeled with 32P) in 0.5% sodium dodecyl sulfate or 6 M guanidine HCl indicates that it has a molecular weight of about 12,000. VPg is bound to the 5' end of poliovirion RNA by a phosphodiester bond between a tyrosine residue in the VPg molecule and the 5'-terminal uridine. After acid hydrolysis of [3H]tyrosine-labeled VPg-pU, free tyrosine can be released by venom phosphodiesterase. Acid hydrolysis of VPg-p labeled with either 32P or [3H] tyrosine yields tyrosine-phosphate. There appears to be only 1 tyrosine residue per VPg molecule.  相似文献   

19.
匙吻鲟仔稚鱼消化酶发育的研究   总被引:3,自引:0,他引:3  
对出膜后0—53d匙吻鲟的酸性蛋白酶、碱性蛋白酶、α-淀粉酶、脂肪酶以及磷酸酶的活性变化进行了测定。匙吻鲟出膜后饲养于室内水泥培育池中,从第3天开始投喂枝角类,之后于第40天将试验鱼转移至池塘。试验材料为受精卵及出膜后第3、第6、第12、第20、第30、第40、第44、第47、第53天仔稚鱼样品。研究发现主要消化酶在出膜时或卵黄期即可检测出活力。碱性蛋白酶和酸性蛋白酶分别在出膜后3d(3DAH)和刚出膜时(0DAH)检测出活力。碱性蛋白酶活力在44DAH达到最大值[(1.96±0.09)U/fish],47DAH出现下降,但在53DAH开始上升,比活力在53DAH达到最大值[(8.84±0.59)U/mg protein]。酸性蛋白酶在44DAH达到最大值[(0.52±0.05)U/fish],比活力在6DAH出现第一个峰值[(2.08±0.09)U/mg protein],并在30DAH出现最小值[(0.83±0.06)U/mg protein]。试验期间碱性蛋白酶活力高于酸性蛋白酶。在12DAH—40DAH期间α-淀粉酶活力相对稳定,并在47DAH达到最大值[(0.42±0.03)U/fish],比活力在12DAH出现一个峰值[(1.18±0.12)U/mg protein],并于47DAH出现最大值[(1.94±0.16)U/mg protein]。发育早期脂肪酶活力较高,活力和比活力分别在30DAH[(0.20±0.02)U/fish]和6DAH[(2.28±0.22)U/mg protein]出现最大值。碱性磷酸酶活力变化趋势与比活力变化趋势相似,但是最大值分别出现在44DAH[(0.08±0.00)U/fish]和30DAH[(1.96±0.15)U/mg protein]。酸性磷酸酶活力在3DAH出现一个峰值[(0.01±0.00)U/fish],之后显著升高,并在44DAH达到最大值[(0.05±0.00)U/fish],其比活分别在30DAH[(1.19±0.10)U/mg protein]和44DAH[(1.10±0.08)U/mg protein]出现两个峰值。结果表明,蛋白酶、α-淀粉酶和磷酸酶随个体发育活力增加,碱性蛋白酶在个体发育早期对蛋白质的消化具有重要作用。养殖环境发生改变时,酸性蛋白酶、α-淀粉酶、碱性磷酸酶和酸性磷酸酶活力在生长减慢时增加,生长加快时降低,而脂肪酶活力则维持稳定。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号