- A uracil nitroso amine based colorimetric sensor for the detection of Cu2+ ions from aqueous environment and its practical applications
-
A simple uracil nitroso amine based colorimetric chemosensor (UNA-1) has been synthesized and screened for its cation recognition ability. Sensor UNA-1 exhibited a high sensitivity and selectivity towards Cu2+ ions in aqueous medium in the presence of a wide range of other competing cations (Ag+, Al3+, Ba2+, Ca2+, Cd2+, Co2+, Cr3+, Cs+, Fe2+, Fe3+, Li+, Mg2+, Mn2+, Na+, Ni2+, Pb2+, Zn2+, Hg2+ and Sr2+). With Cu2+, the sensor UNA-1 gave a distinct color change from colorless to dark yellow by forming a complex of 1:1 stoichiometry. Furthermore, sensor UNA-1 was successfully utilized in the preparation of test strips and supported silica for the detection of Cu2+ ions from aqueous environment.
- Patil, Samadhan R.,Nandre, Jitendra P.,Patil, Prashant A.,Sahoo, Suban K.,Devi, Manisha,Pradeep, Chullikkattil P.,Fabiao, Yu,Chen, Lingxin,Redshaw, Carl,Patil, Umesh D.
-
-
Read Online
- An expedient method for the synthesis of 6-substituted uracils under microwave irradiation in a solvent-free medium
-
Condensation of malonic acid 1 and ureas 2a-f proceeds smoothly in the presence of acetic anhydride 3 under microwave irradiation in solvent-free conditions to give 6-hydroxy-uracils 4 in excellent yields. Under identical conditions, the condensation of cyanoacetic acid 5 and ureas 2a,b,g and h in the presence of acetic anhydride 3, followed by cyclization in the presence of sodium hydroxide affords 6-amino-uracils 6 in high yields. The work-up procedures are simple and products need no purification.
- Devi, Ipsita,Bhuyan, Pulak J.
-
-
Read Online
- Molecular and crystal structure of 5,6-diamino-1-methyluracil and 5,6-diamino-1,3-dimethyluracil monohydrate. Semiempirical calculations (AM1 and PM3) on 5,6-diaminouracil derivatives
-
The crystal and molecular structures of 5,6-diamino-1-methyluracil and 5,6-diamino-1,3-dimethyluracil monohydrate have been determined from X-ray diffraction. Both compounds are planar and the two amino groups have two different conformations. The substituent at the 5 position seems to be a true primary amino group with a strongly sp3 nitrogen, whereas the one at the 6 position is nearly coplanar with the uracil ring, displaying a predominant sp2 character. Semiempirical calculations were made on 5,6-diaminouracil, 5,6-diamino-2-thiouracil and their endocyclic N-methylated derivatives using the AM1 and PM3 hamiltonians. These indicate that the stability decreases on increasing methylation, the 2-thio compounds always being less stable than the 2-oxo ones.
- Hueso-Urena, Francisco,Moreno-Carretero, Miguel N.,Low, John N.,Masterton, Alison G.
-
-
Read Online
- Preparation method of linagliptin for treating type II diabetes mellitus
-
The invention provides a preparation method of linagliptin for treating type II diabetes mellitus, which comprises the following steps: by using methylurea and ethyl cyanoacetate as raw materials, carrying out cyclization reaction to form a compound II, carrying out bromination reaction on the compound II to generate a compound III, carrying out condensation reaction on the compound III and 1-amino-2-butyne to generate a compound IV, making the compound IV, formic acid and an iodine source react in an organic solution to generate a compound V, reacting the compound V and a compound VI under the conditions of DMF and anhydrous potassium carbonate, reacting with (R)-3-Boc-aminopiperidine (VIII), and recrystallizing to obtain a pure target compound I, namely linagliptin. The invention provides a novel preparation method of linagliptin, which has the advantages of simple method, high reaction yield, avoidance of side reaction, cheap raw materials, reduction of the reaction cost, increase of the yield of the target compound, and suitableness for industrial large-scale production.
- -
-
Paragraph 0039-0054
(2021/03/30)
-
- Linagliptin intermediate compound IV
-
The invention belongs to the field of pharmaceutical chemicals, and discloses a linagliptin intermediate IV and a novel route for synthesizing an important linagliptin intermediate from the linagliptin intermediate IV. The linagliptin intermediate IV synthesized in the invention has the advantages of high yield, simple operation, substantial reduction of production cost, suitableness for industrial production; and the synthesis route solves the problems of self-coupling of linagliptin intermediates and generation of large impurities in the prior art.
- -
-
Paragraph 0188-0189
(2020/09/09)
-
- Synthesis, radiolabelling and initial biological characterisation of 18F-labelled xanthine derivatives for PET imaging of Eph receptors
-
Eph receptor tyrosine kinases, particularly EphA2 and EphB4, represent promising candidates for molecular imaging due to their essential role in cancer progression and therapy resistance. Xanthine derivatives were identified to be potent Eph receptor inhibitors with IC50 values in the low nanomolar range (1-40 nm). These compounds occupy the hydrophobic pocket of the ATP-binding site in the kinase domain. Based on lead compound 1, we designed two fluorine-18-labelled receptor tyrosine kinase inhibitors ([18F]2/3) as potential tracers for positron emission tomography (PET). Docking into the ATP-binding site allowed us to find the best position for radiolabelling. The replacement of the methyl group at the uracil residue ([18F]3) rather than the methyl group of the phenoxy moiety ([18F]2) by a fluoropropyl group was predicted to preserve the affinity of the lead compound 1. Herein, we point out a synthesis route to [18F]2 and [18F]3 and the respective tosylate precursors as well as a labelling procedure to insert fluorine-18. After radiolabelling, both radiotracers were obtained in approximately 5% radiochemical yield with high radiochemical purity (>98%) and a molar activity of >10 GBq μmol-1. In line with the docking studies, first cell experiments revealed specific, time-dependent binding and uptake of [18F]3 to EphA2 and EphB4-overexpressing A375 human melanoma cells, whereas [18F]2 did not accumulate at these cells. Since both tracers [18F]3 and [18F]2 are stable in rat blood, the novel radiotracers might be suitable for in vivo molecular imaging of Eph receptors with PET.
- Belter, Birgit,Caflisch, Amedeo,K?ckerling, Martin,Kinski, Elisa,Mamat, Constantin,Neuber, Christin,Pietzsch, Jens,Pretze, Marc,Steinbach, J?rg
-
p. 3104 - 3116
(2020/05/08)
-
- Linagliptin intermediate compound V
-
The invention belongs to the field of pharmaceutical chemicals, and provides a linagliptin intermediate compound V and an important intermediate for synthesizing linagliptin by using the intermediateV. The method solves the problems of self-coupling of linagliptin intermediates and generation of large impurities in the prior art, and the synthesized novel intermediate compound V has the advantages of high yield, simple operation, significantly reduced production cost, and suitableness for industrial production.
- -
-
Paragraph 0185-0186
(2020/09/09)
-
- Xanthine compound and pharmaceutical composition and application thereof
-
The invention discloses a xanthine derivative as shown in the formula (I) and a pharmaceutical composition and application thereof. The xanthine derivative is prepared from a compound as shown in theformula (I) or a stereoisomer, a geometrical isomer, a hydrate or a solvate thereof, or a pharmaceutically acceptable salt or prodrug as shown in the description. The invention also relates to application of the compound as shown in the formula (I) and the pharmaceutical composition thereof as a DPP-4 inhibitor, and especially application in preparation of medicines for treating and/or preventingmetabolic disorder diseases such as diabetes.
- -
-
Paragraph 0142-0144
(2019/07/11)
-
- HYDROXYL PURINE COMPOUNDS AND USE THEREOF
-
Disclosed are a series of hydroxyl purine compounds and the use thereof as PDE2 or TNFα inhibitors, in particular, the compounds as shown in formula (I), or tautomers thereof or pharmaceutically acceptable salts thereof.
- -
-
Paragraph 0587; 0588
(2018/04/05)
-
- HYDROXYL PURINE COMPOUNDS AND USE THEREOF
-
Disclosed are a series of hydroxyl purine compounds and the use thereof as PDE2 or TNFα inhibitors, in particular, the compounds as shown in formula (I), or tautomers or pharmaceutically acceptable salts thereof.
- -
-
Paragraph 0331; 0332
(2018/06/09)
-
- Synthesis and evaluation of antitumour activities of novel fused tri-And tetracyclic uracil derivatives
-
Simple one-pot syntheses of indenopyrrolopyrimidines and indolopyrrolopyrimidines were achieved via the cyclocondensation of 6-Aminouracils and, respectively, ninhydrin and isatin in the presence of catalytic amounts of glacial acetic acid. Similarly, 5,6-diaminouracil derivatives were used as starting materials for the synthesis of indenopteridines and indolopteridines via their reaction with ninhydrin and isatin, respectively. The synthesised compounds were evaluated for antitumour activity against a human hepatocellular carcinoma cell line (HepG2), some showing antitumour activity comparable with 5-fluorouracil and imatinib.
- Elkalyoubi, Samar,Fayed, Eman
-
p. 771 - 777
(2017/01/03)
-
- Synthesis and lipid-lowering evaluation of 3-methyl-1 H-purine-2,6-dione derivatives as potent and orally available anti-obesityagents
-
Obesity accompanied with metabolic disorder is often complicated with a strong link of dyslipidemia and insulin resistance, whose indicator is the excess accumulation of triglycerides (TG) in cells. Consideration the idea of lipid-lowering and improving insulin resistance, 34 novel compounds by combination the xanthine scaffold with the chain of Rosiglitazone have been synthesized. Among them, several compounds showed efficiency on reducing TG in 3T3-L1 adipoctyes, and 11c exhibited the most optimal capacity in lipid-lowering and improving obese clinical symptoms in DIO mice. Furthermore, the hydrochloride of 11c (11c·HCl) showed excellent bioavailability, 58.94%, over 2 folds than that (28.03%) of 11c, and the anti-obesity effect of 11c·HCl at 50 mg/kg dose was better than that of Metformin at 150 mg/kg dose in DIO mice, almost reversed HFD to a normal level. Thus, 11c·HCl might be a potent and orally available anti-obesity agent via alleviating the obese clinical symptoms, body fat, improving serum parameters and insulin resistance and TG clearance in liver.
- He, Linhong,Pei, Heying,Ma, Liang,Pu, Yuzhi,Chen, Jinying,Liu, Zhuowei,Ran, Yan,Lei, Lei,Fu, Suhong,Tang, Minghai,Peng, Aihua,Long, Chaofeng,Chen, Lijuan
-
p. 595 - 610
(2014/12/11)
-
- Synthesis and biological evaluation of xanthine derivatives on dipeptidyl peptidase 4
-
A series of xanthine derivatives in which a methylene was inserted at position 8 of xanthine scaffold was synthesized and evaluated as inhibitors of dipeptidyl peptidase 4 (DPP-4) for the treatment of type 2 diabetes. As the results of structure-activity relationship (SAR) study of the series, the compounds with 4-methylquinazoline- 2-yl-methyl group at N-1 position and 2-aminoethylaminomethyl group gave better activities. Compounds H4 and H9 showed good DPP-4 inhibition and more than 100-fold selectivity over DPP-7 and DPP-8.
- Lin, Kuaile,Cai, Zhengyan,Wang, Fei,Zhang, Wei,Zhou, Weicheng
-
p. 477 - 482
(2013/05/22)
-
- Ionic liquid mediated one-pot synthesis of 6-aminouracils
-
A novel, one-pot synthesis of 6-aminouracils via in situ generated ureas and cyanoacetylureas in the presence of an ionic liquid catalyst, 1,1,3,3-tetramethylguanidine acetate, is described. The catalyst can be recycled for five consecutive runs without loss of activity. The mechanism for the ring closure of cyanoacetylurea to 6-aminouracil is also discussed.
- Chavan, Sunil S.,Degani, Mariam S.
-
supporting information; experimental part
p. 296 - 299
(2012/03/26)
-
- PROCESS FOR STRAIGHTENING KERATIN FIBRES WITH A HEATING MEANS AND DENATURING AGENTS
-
The invention relates to a process for straightening keratin fibres, comprising: (i) a step in which a straightening composition containing at least two denaturing agents is applied to the keratin fibres, (ii) a step in which the temperature of the keratin fibres is raised, using a heating means, to a temperature of between 110 and 250° C.
- -
-
-
- Approach to the library of fused pyridine-4-carboxylic acids by combes-type reaction of acyl pyruvates and electron-rich amino heterocycles
-
A library of fused pyridine-4-carboxylic acids (including pyrazolo[3,4-b]pyridines, isoxazolo[5,4-b]pyridines, furo[2,3-b]pyridines, thieno[2,3-b]pyridines, and pyrido[2,3-d]pyrimidines) was generated by Combes-type reaction of acyl pyruvates and electron-rich amino heterocycles followed by hydrolysis of the ester. The library members were also demonstrated to undergo the standard combinatorial transformations including amide coupling and esterification, as well as less common heterocyclizations to 1,2,4-triazoles and 1,2,4-oxadiazoles.
- Volochnyuk, Dmitriy M.,Ryabukhin, Sergey V.,Plaskon, Andrey S.,Dmytriv, Yuri V.,Grygorenko, Oleksandr O.,Mykhailiuk, Pavel K.,Krotko, Dmitriy G.,Pushechnikov, Alexei,Tolmachev, Andrey A.
-
scheme or table
p. 510 - 517
(2010/09/05)
-
- Synthesis of 8-(cyclopentyloxy)phenyl substituted xanthine derivatives as adenosine A2A ligands
-
The present paper describes the synthesis of a series of 8-(cyclopentyloxy)phenyl-xanthines and their evaluation for affinity for A 1 and A2 adenosine receptors using radioligand binding assays. The effects of moving the cyclopentyloxy substituent with or without an ortho methoxy group on the various positions of the 8-phenyl ring have been studied. The vanilloid based xanthines 8-[4-(cyclopentyloxy)-3-methoxyphenyl]-1, 3-dimethylxanthine (6a) (Ki = 100 nM) and 8-[(4-cyclopentyloxy)-3- methoxyphenyl]-3-methyl-1-propylxanthine (12) (Ki = 150 nM) displayed the highest affinity at A2A receptors as well as over 1000 fold selectivity over the A1 adenosine receptor subtype. ECV · Editio Cantor Verlag, Aulendorf (Germany).
- Bansal, Ranju,Kumar, Gulshan,Gandhi, Deepika,Yadav, Rakesh,Young, Louise C.,Harvey, Alan L.
-
scheme or table
p. 131 - 136
(2011/07/30)
-
- Structure-based optimization of potent and selective inhibitors of the tyrosine kinase erythropoietin producing human hepatocellular carcinoma receptor B4 (EphB4)
-
The tyrosine kinase EphB4 is an attractive target for drug design because of its recognized role in cancer-related angiogenesis. Recently, a series of commercially available xanthine derivatives were identified as micromolar inhibitors of EphB4 by high-throughput fragment-based docking into the ATP-binding site of the kinase domain. Here, we have exploited the binding mode obtained by automatic docking for the optimization of these EphB4 inhibitors by chemical synthesis. Addition of only two heavy atoms, methyl and hydroxyl groups, to compound 4 has yielded the single-digit nanomolar inhibitor 66, with a remarkable improvement of the ligand efficiency from 0.26 to 0.37 kcal/(mol per non-hydrogen atom). Compound 66 shows very high affinity for a few other tyrosine kinases with threonine as gatekeeper residue (Abl, Lck, and Src). On the other hand, it is selective against kinases with a larger gatekeeper. A 45 ns molecular dynamics (MD) simulation of the complex of EphB4 and compound 66 provides further validation of the binding mode obtained by fragment-based docking. 2009 American Chemical Society.
- Lafleur, Karine,Huang, Danzhi,Zhou, Ting,Caflisch, Amedeo,Nevado, Cristina
-
supporting information; experimental part
p. 6433 - 6446
(2010/03/31)
-
- Selective, high affinity A2B adenosine receptor antagonists: N-1 monosubstituted 8-(pyrazol-4-yl)xanthines
-
A series of N-1 monosubstituted 8-pyrazolyl xanthines have been synthesized and evaluated for their affinity for the adenosine receptors (AdoRs). We have discovered two compounds 18 (CVT-7124) and 28 (CVT-6694) that display good affinity for the A2B AdoR (Ki = 6 nM and 7 nM, respectively) and greater selectivity for the human A1, A2A, and A3 AdoRs (>1000-, >830-, and >1500-fold; >850-, >700-, and >1280-fold, respectively). CVT-6694 has been shown to block the release of interleukin-6 and monocyte chemotactic protein-1 from bronchial smooth muscle cells (BSMC), a process believed to be promoted by activation of A2B AdoR.
- Kalla, Rao V.,Elzein, Elfatih,Perry, Thao,Li, Xiaofen,Gimbel, Art,Yang, Ming,Zeng, Dewan,Zablocki, Jeff
-
p. 1397 - 1401
(2008/09/21)
-
- Discovery of a novel A2B adenosine receptor antagonist as a clinical candidate for chronic inflammatory airway diseases
-
Recently, we have reported a series of new 1,3-symmetrically (R1 = R3) substituted xanthines (3 and 4) which have high affinity and selectivity for the human adenosine A2B receptors (hA 2B-AdoR). Unfortunately, this class of compounds had poor pharmacokinetic properties. This prompted us to investigate the effect of differential alkyl substitution at the N-1 and N-3 positions (N1-R ≠ N3-R) on A2B-AdoR affinity and selectivity; we had the dual objectives of enhancing affinity and selectivity for the A 2B-AdoR, as well as improving oral bioavailability. This effort has led to the discovery of compound 62, that displayed high affinity and selectivity for the hA2B-AdoR (Ki = 22 nM). In addition, compound 62 showed high functional potency in inhibiting the accumulation of cyclic adenosine monophosphate induced by 5′-N-ethylcarboxamidoadenosine in HEK-A2B-AdoR and NIH3T3 cells with KB values of 6 and 2 nM, respectively. In a single ascending-dose phase I clinical study, compound 62 had no serious adverse events and was well tolerated.
- Elzein, Elfatih,Kalla, Rao V.,Li, Xiaofen,Perry, Thao,Gimbel, Art,Zeng, Dewan,Lustig, David,Leung, Kwan,Zablocki, Jeff
-
p. 2267 - 2278
(2008/12/21)
-
- XANTHINE DERIVATIVES AS A2B ADENOSINE RECEPTOR ANTAGONISTS
-
Disclosed are compounds that are A2B adenosine receptor antagonists, useful for treating various disease states, including asthma and diarrhea.
- -
-
-
- A2B adenosine receptor antagonists
-
Disclosed are novel compounds that are A2B adenosine receptor antagonists, useful for treating various disease states, including asthma and diarrhea.
- -
-
-
- A novel ring closure reaction for the preparation of 6-aminouracils with an α-branched 1-substituent
-
The preparation of 6-aminouracil derivatives is described involving a novel, silicon-promoted ring closure reaction. Condensation of N-substituted urea with cyanoacetic acid yields cyanoacetylureas, which are heated in hexamethyldisilazane/trimethylchlorosilane to afford N-substituted 6- aminouracils. Previously unaccessible derivatives bearing an α-branched 1- substituent, including 6-amino-1-(1-phenylethyl)uracil were obtained.
- Fuelle, Friederike,Mueller, Christa E.
-
p. 347 - 351
(2007/10/03)
-
- Molecular modeling and synthesis of inhibitors of herpes simplex virus type 1 uracil-DNA glycosylase
-
We recently reported the properties of the first selective inhibitors of herpes simplex virus type 1 (HSV1) uracil-DNA glycosylase (UDG), an enzyme of DNA repair that has been proposed to be required for reactivation of the virus from latency. 6-(4-Octylanilino)uracil (octAU) was the most potent inhibitor among a series of 6-(4-alkylanilino)uracils, acting in the micromolar range and without effect against human UDG. A 28.5-kDa catalytic fragment of HSV1 UDG has been crystallized in the presence of uracil, and the structure was recently solved. We have used the coordinates of this structure in order to study interaction of our inhibitors with the enzyme, and a model of binding between octAU and UDG has been derived. Starting with the optimized model, the activity of several octAU analogues was predicted, and the values compared favorably with experimental results found for the synthetic compounds. Several hydrophilic derivatives were predicted and found to be active as UDG inhibitors. These compounds will be useful to determine if UDG, like the viral thymidine kinase, is required for reactivation of HSV1 from latency in nerve cells.
- Sun, Hongmao,Zhi, Chengxin,Wright, George E.,Ubiali, Daniela,Pregnolato, Massimo,Verri, Annalisa,Focher, Federico,Spadari, Silvio
-
p. 2344 - 2350
(2007/10/03)
-
- Structure-activity relationships in a series of xanthine derivatives with antibronchoconstrictory and bronchodilatory activities
-
Thirty-one 1,3,7,8-substituted xanthine derivatives have been synthesized and evaluated for bronchodilator and anti-bronchoconstrictory activities in in vitro tracheal relaxation and in vivo bronchospasm inhibition models. Activity tests have been complemented with phosphodiesterase inhibition and toxicological data. Structure-activity relationships are discussed. Compound 21 (1,3-diisobutyl-8-methylxanthine) has been selected for further pharmacological development because of its good activity profile and favourable therapeutic index, which is 14- and 38-fold greater than that of theophylline and IBMX, respectively.
- Merlos,Gomez,Vericat,Bartroli,Garcia-Rafanell,Forn
-
p. 653 - 658
(2007/10/02)
-