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heterocyclic amines

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https://www.readbyqxmd.com/read/28545815/succinamide-derivatives-of-melampomagnolide-b-and-their-anti-cancer-activities
#1
Venumadhav Janganati, Jessica Ponder, Shraddha Thakkar, Craig T Jordan, Peter A Crooks
A series of succinamide derivatives of melampomagnolide B have been synthesized by coupling MMB monosuccinate (2) with various heterocyclic amines to afford compounds 3a-3l. MMB monosuccinate was also reacted with terminal diaminoalkanes to afford dimeric succinamido analogs of MMB (4a-4h). These succinamide analogs of MMB were evaluated for their anti-cancer activity against a panel of sixty human cancer cell lines. Analogs 3d-3i and dimers 4f-4g exhibited promising anti-cancer activity with GI50 values ranging from 0...
May 8, 2017: Bioorganic & Medicinal Chemistry
https://www.readbyqxmd.com/read/28537596/unique-physicochemical-and-catalytic-properties-dictated-by-the-b3no2-ring-system
#2
Hidetoshi Noda, Makoto Furutachi, Yasuko Asada, Masakatsu Shibasaki, Naoya Kumagai
The expansion of molecular diversity beyond what nature can produce is a fundamental objective in chemical sciences. Despite the rich chemistry of boron-containing heterocycles, the 1,3-dioxa-5-aza-2,4,6-triborinane (DATB) ring system, which is characterized by a six-membered B3NO2 core, remains elusive. Here, we report the synthesis of m-terphenyl-templated DATB derivatives, displaying high stability and peculiar Lewis acidity arising from the three suitably arranged boron atoms. We identify a particular utility for DATB in the dehydrative amidation of carboxylic acids and amines, a reaction of high academic and industrial importance...
June 2017: Nature Chemistry
https://www.readbyqxmd.com/read/28536864/rabbit-n-acetyltransferase-2-genotyping-method-to-investigate-role-of-acetylation-polymorphism-on-n-and-o-acetylation-of-aromatic-and-heterocyclic-amine-carcinogens
#3
David W Hein, Mark A Doll
The rabbit was the initial animal model to investigate the acetylation polymorphism expressed in humans. Use of the rabbit model is compromised by lack of a rapid non-invasive method for determining acetylator phenotype. Slow acetylator phenotype in the rabbit results from deletion of the N-acetyltransferase 2 (NAT2) gene. A relatively quick and non-invasive method for identifying the gene deletion was developed and acetylator phenotypes confirmed by measurement of N- and O-acetyltransferase activities in hepatic cytosols...
May 23, 2017: Archives of Toxicology
https://www.readbyqxmd.com/read/28529787/crystal-structure-of-2-chloro-1-3-bis-2-6-diiso-propyl-phen-yl-1-3-2-di-aza-phospho-lidine-2-oxide
#4
Alex J Veinot, Arthur D Hendsbee, Jason D Masuda
The title compound, C26H38ClN2OP, was synthesized by reacting phosphoryl chloride with N,N'-bis-(2,6-diiso-propyl-phen-yl)ethane-1,2-di-amine in the presence of N-methyl-morpholine which acted as an auxilliary base to quench the HCl released as a by-product. The resultant N-heterocyclic phosphine five-membered ring adopts a half-chair conformation and features a tetra-coordinate P atom ligated by the chelating di-amine [P-N = 1.6348 (14) and 1.6192 (14) Å], one double-bonded O atom [P1-O1 = 1.4652 (12) Å] and one Cl atom [P1-Cl1 = 2...
May 1, 2017: Acta Crystallographica. Section E, Crystallographic Communications
https://www.readbyqxmd.com/read/28525356/synthesis-biological-activity-and-molecular-modeling-study-of-new-schiff-bases-incorporated-with-indole-moiety
#5
Ahmed H Halawa, Shimaa Mohamed Abd El-Gilil, Ahmed H Bedair, Mohamed Shaaban, Marcel Frese, Norbert Sewald, Essam M Eliwa, Ahmed M El-Agrody
A new series of heterocyclic Schiff bases 2-9 containing indole moiety were synthesized by facile and efficient condensation of indole-3/2/5-carboxaldehyde (1a/1b/1c) with different aromatic and heterocyclic primary amines using conventional and/or microwave irradiation methods. The structures of the obtained compounds were assigned by sophisticated spectroscopic and spectrometric techniques (1D-NMR, 2D-NMR and MS). The synthesized compounds were screened for their cytotoxicity and antibacterial activities...
May 18, 2017: Zeitschrift Für Naturforschung. C, A Journal of Biosciences
https://www.readbyqxmd.com/read/28523442/catalytic-properties-and-heat-stabilities-of-novel-recombinant-human-n-acetyltransferase-2-allozymes-support-existence-of-genetic-heterogeneity-within-the-slow-acetylator-phenotype
#6
David W Hein, Mark A Doll
Human N-acetyltransferase 2 (NAT2) catalyzes the N-acetylation of numerous aromatic amine drugs such as sulfamethazine (SMZ) and hydrazine drugs such as isoniazid (INH). NAT2 also catalyzes the N-acetylation of aromatic amine carcinogens such as 2-aminofluorene and the O- and N,O-acetylation of aromatic amine and heterocyclic amine metabolites. Genetic polymorphism in NAT2 modifies drug efficacy and toxicity as well as cancer risk. Acetyltransferase catalytic activities and heat stability associated with six novel NAT2 haplotypes (NAT2*6C, NAT2*14C, NAT2*14D, NAT2*14E, NAT2*17, and NAT2*18) were compared with that of the reference NAT2*4 haplotype following recombinant expression in Escherichia coli...
May 18, 2017: Archives of Toxicology
https://www.readbyqxmd.com/read/28513160/formation-of-free-and-protein-bound-heterocyclic-amines-in-roast-beef-patties-assessed-by-uplc-ms-ms
#7
Jing Chen, Zhiyong He, Fang Qin, Jie Chen, Maomao Zeng
The effect of different roasting temperatures on the amounts of 17 heterocyclic amines (HAs) from seven categories of both free and protein-bound states in roast beef patties was assessed using an ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method. There were increased amounts and more types of HAs detected at higher roasting temperatures. Nine free HAs were detected at 250 °C, including PhIP (14.34 ± 0.36 ng/g), DMIP (1.02 ± 0.07 ng/g), 1,5,6-TMIP (1.70 ± 0.08 ng/g), MeIQ (0...
May 25, 2017: Journal of Agricultural and Food Chemistry
https://www.readbyqxmd.com/read/28509884/one-flask-synthesis-of-pyrazolo-3-4-d-pyrimidines-from-5-aminopyrazoles-and-mechanistic-study
#8
Wan-Ping Yen, Shuo-En Tsai, Naoto Uramaru, Hiroyuki Takayama, Fung Fuh Wong
A novel one-flask synthetic method was developed in which 5-aminopyrazoles were reacted with N,N-substituted amides in the presence of PBr₃. Hexamethyldisilazane was then added to perform heterocyclization to produce the corresponding pyrazolo[3,4-d]pyrimidines in suitable yields. These one-flask reactions thus involved Vilsmeier amidination, imination reactions, and the sequential intermolecular heterocyclization. To study the reaction mechanism, a series of 4-formyl-1,3-diphenyl-1H-pyrazol-5-yl-N,N-disubstituted formamidines, which were conceived as the chemical equivalent of 4-(iminomethyl)-1,3-diphenyl-1H-pyrazol-5-yl-formamidine, were prepared and successfully converted into pyrazolo[3,4-d]pyrimidines...
May 16, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28507694/a-convergent-synthesis-of-1-3-4-oxadiazoles-from-acyl-hydrazides-under-semiaqueous-conditions
#9
Kazuyuki Tokumaru, Jeffrey N Johnston
The 1,3,4-oxadiazole is an aromatic heterocycle valued for its low-lipophilicity in drug development. Substituents at the 2- and/or 5-positions can modulate the heterocycle's electronic and hydrogen bond-accepting capability, while exploiting its use as a carbonyl bioisostere. A new approach to 1,3,4-oxadiazoles is described wherein α-bromo nitroalkanes are coupled to acyl hydrazides to deliver the 2,5-disubstituted oxadiazole directly, avoiding a 1,2-diacyl hydrazide intermediate. Access to new building blocks of oxadiazole-substituted secondary amines is improved by leveraging chiral α-bromo nitroalkane or amino acid hydrazide substrates...
April 1, 2017: Chemical Science
https://www.readbyqxmd.com/read/28493705/quantification-of-hemoglobin-and-white-blood-cell-dna-adducts-of-the-tobacco-carcinogens-2-amino-9h-pyrido-2-3-b-indole-and-4-aminobiphenyl-formed-in-humans-by-nanoflow-liquid-chromatography-ion-trap-multistage-mass-spectrometry
#10
Tingting Cai, Medjda Bellamri, Xun Ming, Woon-Puay Koh, Mimi C Yu, Robert J Turesky
Aromatic amines covalently bound to hemoglobin (Hb) as sulfinamide adducts at the cysteine 93 residue of the Hb β chain have served as biomarkers to assess exposure to this class of human carcinogens for the past 30 years. In this study, we report that 2-amino-9H-pyrido[2,3-b]indole (AαC), an abundant carcinogenic heterocyclic aromatic amine formed in tobacco smoke and charred cooked meats, also reacts with Hb to form a sulfinamide adduct. A novel nanoflow liquid chromatography/ion trap multistage mass spectrometry (nanoLC-IT/MS(3)) method was established to assess exposure to AαC and the tobacco-associated bladder carcinogen 4-aminobiphenyl (4-ABP) through their Hb sulfinamide adducts...
May 25, 2017: Chemical Research in Toxicology
https://www.readbyqxmd.com/read/28490740/presence-of-heterocyclic-amine-carcinogens-in-home-cooked-and-fast-food-camel-meat-burgers-commonly-consumed-in-saudi-arabia
#11
Mohammad Rizwan Khan, Mu Naushad, Zeid Abdullah Alothman
Heterocyclic amines (HCAs) are formed by cooking protein-rich foods, for instance, meat and fish, and are listed as possible human carcinogens. In the present study, the presence of five potential HCAs (IQ, MeIQ, MeIQx, 4,8-DiMeIQx, and PhIP) in cooked camel meat burgers was analyzed for the first time. The analysis was performed in home-cooked and fast-food burger samples containing food additives. The applied cooking technique for the home-cooked samples was pan frying for a controlled cooking time and temperature...
May 10, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28485602/metal-free-sequential-c-sp-2-h-oh-and-c-sp-3-h-aminations-of-nitrosoarenes-and-n-heterocycles-to-ring-fused-imidazoles
#12
Anisha Purkait, Subhra Kanti Roy, Hemant Kumar Srivastava, Chandan K Jana
Hydrogen bond assisted ortho-selective C(sp(2))-H amination of nitrosoarenes and subsequent α-C(sp(3))-H functionalization of aliphatic amines is achieved under metal-free conditions. The annulation of nitrosoarenes and 2-hydroxy-C-nitroso compounds with N-heterocycles provides a facile excess to a wide range of biologically relevant ring-fused benzimidazoles and structurally novel polycyclic imidazoles, respectively. Nucleophilic aromatic hydrogen substitution (SNArH) was found to be preferred over classical SNAr reaction during the C(sp(2))-H amination of halogenated nitrosoarenes...
May 9, 2017: Organic Letters
https://www.readbyqxmd.com/read/28474720/aerobic-catalytic-systems-inspired-by-copper-amine-oxidases-recent-developments-and-synthetic-applications
#13
REVIEW
Martine Largeron
Recent efforts to design synthetic quinone-based catalysts for the efficient aerobic oxidation of amines to imines have been inspired by copper amine oxidases (CuAOs), a family of metalloenzymes which selectively converts primary amines into aldehydes, using molecular oxygen through the cooperation of a quinone-based cofactor, 2,4,5-trihydroxyphenylalanine quinone (TPQ) and a copper ion. Two distinct classes of bioinspired quinone-based catalytic systems have been developed. The first class consists of catalytic systems, which mimic the activity of CuAOs by exhibiting exquisite selectivity for primary amines...
May 5, 2017: Organic & Biomolecular Chemistry
https://www.readbyqxmd.com/read/28464765/functional-chemical-groups-that-may-likely-become-source-for-synthesis-of-novel-central-nervous-system-cns-acting-drugs
#14
Saganuwan Alhaji Saganuwan
Central nervous system (CNS) disorders are on increase perhaps due to genetic, enviromental, social and dietetic factors. Unfortunately, a large number of CNS drugs have adverse effects such as addiction, tolerance, psychological and physical dependence. In view of this, literature search was carried out with a view to identifying functional chemical groups that may serve as lead molecule for synthesis of compounds that may have CNS activity. The search revealed that heterocycles that have heteroatoms such as nitrogen (N), sulphur (S) and oxygen (O) form the largest class of organic compounds...
May 2, 2017: Central Nervous System Agents in Medicinal Chemistry
https://www.readbyqxmd.com/read/28443521/synthesis-anticancer-screening-and-molecular-docking-studies-of-new-heterocycles-with-trimethoxyphenyl-scaffold-as-combretastatin-analogues
#15
Korany A Ali, Naglaa A Abdel Hafez, Mohamed A Elsayed, Manal M Elshahawi, Salwa M El-Hallouty, Abd El-Galil E Amr
In this study, synthesis, molecular docking and anticancer screening of new series of substituted heterocycles with trimethoxy phenyl scaffold as Combretastatin analogues were described. Substituted pyridines were synthesized via reaction of (E)-3-(dimethylamino)-1-(3,4,5-trimethoxyphenyl)prop-2-en-1-one (2)with active methylene reagents. Substituted pyrimidines were prepared by the reaction of the enaminone (2) with heterocyclic amines and 6-amino thiouracil. Furthermore, a series of pyrazoles substituted with trimethoxyphenyl scaffold were prepared by reaction of the enaminone 2, with selected examples of hydrazonoyl halides...
April 24, 2017: Mini Reviews in Medicinal Chemistry
https://www.readbyqxmd.com/read/28443179/inhibition-of-carcinogen-activating-cytochrome-p450-enzymes-by-xenobiotic-chemicals-in-relation-to-antimutagenicity-and-anticarcinogenicity
#16
REVIEW
Tsutomu Shimada
A variety of xenobiotic chemicals, such as polycyclic aromatic hydrocarbons (PAHs), aryl- and heterocyclic amines and tobacco related nitrosamines, are ubiquitous environmental carcinogens and are required to be activated to chemically reactive metabolites by xenobiotic-metabolizing enzymes, including cytochrome P450 (P450 or CYP), in order to initiate cell transformation. Of various human P450 enzymes determined to date, CYP1A1, 1A2, 1B1, 2A13, 2A6, 2E1, and 3A4 are reported to play critical roles in the bioactivation of these carcinogenic chemicals...
April 2017: Toxicological Research
https://www.readbyqxmd.com/read/28440656/heteroannulation-of-3-nitroindoles-and-3-nitrobenzo-b-thiophenes-a-multicomponent-approach-toward-pyrrole-fused-heterocycles
#17
P V Santhini, Sheba Ann Babu, Akhil Krishnan R, E Suresh, Jubi John
A simple, efficient, and general multicomponent reaction involving an enolizable ketone, a primary amine, and an N-protected 3-nitroindole was developed for the synthesis of a range of functionalized pyrrolo[3,2-b]indoles. The methodology was efficaciously utilized for the "pyrroloindoliztion" of natural products, the pyrrolization of 3-nitrobenzo[b]thiophene, and the gram-scale synthesis of pyrroloindole. Furthermore, a "one-pot" approach for accessing indolo[3,2-b]indoles was realized.
May 5, 2017: Organic Letters
https://www.readbyqxmd.com/read/28430203/photoredox-activation-of-carbon-dioxide-for-amino-acid-synthesis-in-continuous-flow
#18
Hyowon Seo, Matthew H Katcher, Timothy F Jamison
Although carbon dioxide (CO2) is highly abundant, its low reactivity has limited its use in chemical synthesis. In particular, methods for carbon-carbon bond formation generally rely on two-electron mechanisms for CO2 activation and require highly activated reaction partners. Alternatively, radical pathways accessed via photoredox catalysis could provide new reactivity under milder conditions. Here we demonstrate the direct coupling of CO2 and amines via the single-electron reduction of CO2 for the photoredox-catalysed continuous flow synthesis of α-amino acids...
May 2017: Nature Chemistry
https://www.readbyqxmd.com/read/28428996/development-of-emissive-aminopentaazaphenalene-derivatives-employing-a-design-strategy-for-obtaining-luminescent-conjugated-molecules-by-modulating-the-symmetry-of-molecular-orbitals-with-substituent-effects
#19
Hiroyuki Watanabe, Masataka Hirose, Kazuo Tanaka, Yoshiki Chujo
This communication describes the transformation of a non-emissive heterocycle into a luminophore via modulation of molecular orbitals by employing a dialkylamine-substituted pentaazaphenalene (A5AP) skeleton. It was presumed that the introduction of the amine group changed the symmetry-forbidden HOMO-LUMO (H-L) transition to an allowed one. According to optical measurements and theoretical calculations, the H-L transition was turned into the symmetry-allowed one because of the lone pair on the nitrogen atom in the dialkylamine substituent...
April 21, 2017: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/28418184/b-c6-f5-3-catalyzed-cascade-reduction-of-pyridines
#20
Zhi-Yun Liu, Zhi-Hui Wen, Xiao-Chen Wang
B(C6 F5 )3 has been found to be an effective catalyst for reduction of pyridines and other electron-deficient N-heteroarenes with hydrosilanes (or hydroboranes) and amines as the reducing reagents. The success of this development hinges upon the realization of a cascade process of dearomative hydrosilylation (or hydroboration) and transfer hydrogenation. The broad functional-group tolerance (e.g. ketone, ester, unactivated olefins, nitro, nitrile, heterocycles, etc.) implies high practical utility.
April 18, 2017: Angewandte Chemie
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