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新型原卟啉原氧化酶抑制剂的固相合成及生物活性研究 总被引:1,自引:0,他引:1
采用固相有机合成技术,合成了全新结构的新型原卟啉原氧化酶抑制剂化合物.初步建立了针对特殊靶酶PPO的酶生物活性测定方法,对所合成的化合物进行了生物活性测定,初步结果表明预期有活性的化合物显示出一定的PPO酶抑制活性. 相似文献
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用单晶X射线衍射方法测定了6-苯甲酰基-5-(邻氯苯基)-2,3,3a,4,5,6-六氢-3a-苯基-(1,2,3-三乙酸乙酯基)-1H-吡咯啉[1,2-a][1,5-]苯并二氮杂(艹卓)的晶体结构.单斜晶系,空间群P21/c,a=1.3235(5)nm,b=1.7142(6)nm,c=1.6204(6)nm,β=100.49(3)埃琙=4,最终偏离因子R=0.062,Rw=0.075.晶体结构测定结果表明分子中二氮杂(艹卓)七元环采取船式构象,动力学模拟退火计算结果的最低能量构象为椅式,两者的能量差不大,表明这种船式←→椅式的变化是非常容易发生的. 相似文献
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N-{2-氯-5-[3-甲基-2,6-二氧-4-三氟甲基-2,3-二氢嘧啶-1(6H)-基]苯基}酰胺类化合物的合成及除草活性 总被引:2,自引:0,他引:2
为了寻找高效、安全的除草活性化合物, 合成了12个全新的N-{2-氯-5-[3-甲基-2,6-二氧-4-三氟甲基-2,3-二氢嘧啶-1(6H)-基]苯基}酰胺类化合物, 其化学结构经IR, 1H NMR, LC/MS和元素分析确证. 初步生物活性测定结果表明, 该类化合物具有一定的除草活性, 如7a, 7b, 7c, 7g, 7h, 7i, 7k和7l在有效成分75 g/hm2剂量下, 茎叶处理对苘麻(Abutilon theophrasti)、刺苋(Amaranthus spinosus)等阔叶杂草具有良好的除草活性, 其抑制率达100%. 相似文献
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脲嘧啶类化合物具有显著的除草活性. 设计并合成了10个未见文献报道的N-[2,4-二取代-5-(3-甲基-2,6-二氧-4-三氟甲基-1,2,3,6-四氢嘧啶-1-基)苯基]酰亚胺类化合物, 其化学结构经1H NMR, IR, HPLC/MS和元素分析表征. 初步生物活性测定结果表明, 该类化合物具有一定的除草活性, 如9a, 9b, 9c, 9f, 9g和9h在有效成分75 g/hm2剂量下, 茎叶处理对苘麻(Abutilon theophrasti Medic )、刺苋(Amaranthus spinosus)等双子叶杂草的抑制率达90%以上. 相似文献
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取代苯基吡唑类化合物的合成及其除草活性 总被引:6,自引:0,他引:6
以1′-(4-氯-2-氟-5-甲基苯基)-4′,4′,4′-三氟-1,3-丁二酮为原料,合成了一系列具有取代苯基吡唑结构的新化合物.化合物结构经1HNMR,IR,CIMS和元素分析确认.初步生物活性测试表明,所合成的化合物对阔叶杂草具有较高的活性. 相似文献
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从猪心肌中提取的原肌球蛋白(TM),用2,2,6,6-四甲基-4-(二氯三氮嗪代)氨基哌啶-1-氧基进行自旋标记。产物(SL-TM)的ESR波谱属弱固定型。观察了三种变性手段(热、盐酸胍、脲)对上述波谱的影响。SL-TM经酶解后所得ESR波谱与标记物稀溶液的波谱相似,由此测定SL-TM中标记物的结合量。对SL-TM进行变温测定所得Arrhenius图显示两个转折点(TM的构象转变温度),约为45℃和74—75℃,后一种温度迄今未见文献报道。而SL-TM的酶降解产物在对微波功率饱和与变温的响应中的行为则与之截然不同。 相似文献
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为了发现新型的原卟啉原氧化酶抑制剂,根据生物合理设计方法,设计并合成了一系列的结构新颖的3H-吡唑并[3,4-d][1,2,3]三嗪-4-酮衍生物.利用不同取代的5-氨基-吡唑-4-甲酰氯与取代苯胺反应制得的5-氨基-N-苯基-1H-吡唑-4-甲酰胺衍生物,经进一步重氮化得到目标化合物,并对化合物3f进行衍生化.所得目标化合物的结构均经1HNMR,IR和元素分析确证.生物活性测定结果表明,部分化合物对原卟啉原氧化酶有较高的抑制活性,讨论了其结构与活性的关系. 相似文献
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The flexibility of the bicyclo[2.2.1]heptane-based tricyclic bridged system in longifolene is analysed based on x-ray structural
data. In this context, the molecular structure of three differently substituted longifolenes has been analysed. The highly
substituentdependent conformation provides scope for the synthesis of a variety of commercially oriented products.
NCL Communication Number 3459 相似文献
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Dr. Anastasia Hager Dr. Mingxuan Wu Dr. Huanchen Wang Nathaniel W. Brown Jr. Prof. Stephen B. Shears Prof. Nicolás Veiga Prof. Dorothea Fiedler 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(35):12406-12414
The inositol pyrophosphate messengers (PP‐InsPs) are emerging as an important class of cellular regulators. These molecules have been linked to numerous biological processes, including insulin secretion and cancer cell migration, but how they trigger such a wide range of cellular responses has remained unanswered in many cases. Here, we show that the PP‐InsPs exhibit complex speciation behaviour and propose that a unique conformational switching mechanism could contribute to their multifunctional effects. We synthesised non‐hydrolysable bisphosphonate analogues and crystallised the analogues in complex with mammalian PPIP5K2 kinase. Subsequently, the bisphosphonate analogues were used to investigate the protonation sequence, metal‐coordination properties, and conformation in solution. Remarkably, the presence of potassium and magnesium ions enabled the analogues to adopt two different conformations near physiological pH. Understanding how the intrinsic chemical properties of the PP‐InsPs can contribute to their complex signalling outputs will be essential to elucidate their regulatory functions. 相似文献
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《Analytical letters》2012,45(4):989-997
Abstract Results for an integration method of enzymatic analysis are directly compared to concurrently-achieved fixed-time rate data. Two to fiftyfold enhancement of signal-to-noise ratios are obtained for the integration method vs. the fixed-time method for theoretically-calculated response vs. time data. the signal-to-noise ratio improves substantially as the number of increments increases for estimating the integral of changes in product concentration over time. Also, advantages of the integration method are enchanced as enzyme activities increase and as instrument noise decreases. 相似文献
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Alberto Lesarri Prof. Dr. Emilio J. Cocinero Dr. Luca Evangelisti Richard D. Suenram Dr. Walther Caminati Prof. Dr. Jens‐Uwe Grabow Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(33):10214-10219
The conformational landscape of the alkaloid anabasine (neonicotine) has been investigated by using rotational spectroscopy and ab initio calculations. The results allow a detailed comparison of the structural properties of the prototype piperidinic and pyrrolidinic nicotinoids (anabasine vs. nicotine). Anabasine adopts two most stable conformations in isolation conditions, for which we determined accurate rotational and nuclear quadrupole coupling parameters. The preferred conformations are characterized by an equatorial pyridine moiety and additional N–H equatorial stereochemistry at the piperidine ring (eq‐eq; eq=equatorial). The two rings of anabasine are close to a bisecting arrangement, with the observed conformations differing by an approximately 180° rotation of the pyridine subunit, denoted either syn or anti. The preference of anabasine for the eq‐eq‐syn conformation has been established by relative intensity measurements (syn/anti~5(2)). The conformational preferences of free anabasine are directed by a weak N???H? C hydrogen bond interaction between the nitrogen lone pair at piperidine and the closest C? H bond in pyridine, with N???H distances ranging from 2.686 (syn) to 2.667 Å (anti). Supporting ab initio calculations by using MP2 and the recent M05‐2X density functional are provided, evaluating the predictive performance of both methods. 相似文献
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Nataliya Kiriy Evelin Jähne Anton Kiriy Hans-Juergen Adler 《Macromolecular Symposia》2004,210(1):359-367
Diverse conformational transitions and aggregations of regioregular poly (3-alkylthiophene)s (PATs) in different environment have been studied by means of AFM and UV-vis-spectroscopy. In methanol, which is a non-solvent for both alkyl side groups and aromatic backbone at low polymer concentration, PATs chains fold into compact poorly ordered flat structures. At higher polymer concentration PATs molecules undergo 3D aggregation into near spherical particles. In hexane, which is a selective solvent for alkyl side chains, PATs molecules undergo ordered main-chain collapse followed by 1D aggregation. Concentration-independent red shift of λmax and good resolved fine vibronic structure in the electronic absorption spectra indicate that planarization occurs on the single-molecule level. 相似文献
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The bis(calix [4] arene)3 was synthesized in moderate yield by the reaction of p-tert-butylcalix [4] arene (1) with 1,4-bis(chloromethyl) benzene (2). The conformation of all alkylated product 4 was investigated by the variable-temperature ^1H-NMR. 相似文献
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Chatterjee J Mierke DF Kessler H 《Chemistry (Weinheim an der Bergstrasse, Germany)》2008,14(5):1508-1517
Systematic N-methylation of all peptide bonds in the cyclic pentapeptide cyclo(-D-Ala-Ala(4)-) has been performed yielding 30 different N-methylated derivatives, of which only seven displayed a single conformation on the NMR time scale. The conformation of these differentially N-methylated peptides was recently reported by us (J. Am. Chem. Soc. 2006, 128, 15 164-15 172). Here we present the conformational characterization of nine additional N-methylated peptides from the previous library which are not homogeneous but exist as a mixture in which at least one conformation is preferred by over 80 %. The structures of these peptides are investigated employing various 2D-NMR techniques, distance geometry calculations and further refined by molecular dynamics simulations in explicit DMSO. The comparison of the conformation of these nine peptides and the seven conformationally homogeneous peptides allow us to draw conclusions regarding the influence of N-methylation on the peptide backbone of cyclic pentapeptide of the class cyclo(-D-Ala-Ala(4)-). Here we present the different conformational classes of the peptides arising from the definitive pattern of N-methylation which can eventually serve as templates for the design of bioactive peptides. 相似文献
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Chinnappan Raja 《European Polymer Journal》2006,42(3):495-506
The copolymers of methacrylic acid with protoporphyrin IX (PPIX) and the metal complexes, zinc protoporphyrin IX and magnesium protoporphyrin IX were synthesised and characterised. Corresponding acrylic acid copolymers were also synthesised. The steady state absorption and fluorescence spectral properties of the macromolecular bound fluorophores PPIX, Zn-PPIX and Mg-PPIX were investigated. Poly(methacrylic acid) bound protoporphyrin IX, zinc protoporphyrin IX and magnesium protoporphyrin IX show an increase in the fluorescence intensity and lifetime with increase in the pH in the range 2-8 with a marked transition around pH 6.0-7.0. The fluorophore concentration in the dilute solution of the copolymers is micromolar and the fluorophore to the carboxylic acid monomer ratios in the copolymer is around 10−3. The molecular weight of the copolymers is 100 ± 10 kD. The fluorescence decay curves of all the fluorophore bound polymers follow biexponential decay fit independent of pH. Poly(MAA-co-PPIX) and poly(MAA-co-MgPPIX) undergo well marked pH induced structural transitions in the pH range of 6.0-7.0 whereas poly(MAA-co-ZnPPIX) undergoes pH induced structural transitions in the pH range of 4.0. In the case of polyacrylic acid copolymers the changes observed in the steady state and time resolved fluorescence studies are less marked. The distinct hydrophobic and hydrophilic environments experienced by the fluorophore bound to PMMA are attributed to the dynamics of the macromolecules in dilute aqueous solutions manifested by the α-methyl group present in the copolymer. The studies carried out using the fluorophores in the time windows from 2 ns to 12 ns indicate evolving trends in the dynamic coiling and reverse coiling of poly methacrylic acid chain. 相似文献
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《Analytical letters》2012,45(14):2341-2349
A simple, label-free fluorescence method was developed for the sensitive determination of lead(II) using a nitrocellulose membrane biosensor. The surface of the nitrocellulose membrane was modified by glutaraldehyde to conjugate streptavidin, followed by the immobilization of a DNA probe via a biotin modifier. The biotinylated DNA probe can fold into a G-quadruplex structure in the presence of potassium ion that selectively binds to N-methyl mesoporphyrin IX and yields a strong fluorescence signal. The presence of lead(II) can induce a conformational change of the G-quadruplex to a more compact structure, which results in the release of potassium ion and N-methyl mesoporphyrin IX with a concomitant reduction of the fluorescence signal. The biosensor displayed a detection limit as low as 10 nM with excellent selectivity for lead(II) over other metal ions. The developed biosensor was employed for the determination of lead(II) in spiked river water. 相似文献