keyword
MENU ▼
Read by QxMD icon Read
search

nitro

keyword
https://www.readbyqxmd.com/read/29346079/a-recognition-mechanism-study-luminescent-metal-organic-framework-for-the-detection-of-nitro-explosives
#1
Zhengyan Zhao, Xuedan Song, Lei Liu, Guanglan Li, Shaheen Shah, Ce Hao
This article presents a recognition mechanism for nitro-explosives by the luminescent metal-organic framework 1 (LMOF-1) with the aid of density functional theory (DFT) and time-dependent density functional theory (TDDFT). The behavior of hydrogen bonding between the LMOF-1 and nitro-explosives in the S1 state is closely associated with the fluorescence properties of the LMOF-1. In our research, we calculated the geometric configuration, 1H NMR and IR spectra of the Complex 2 formed by LMOF-1 and nitrobenzene in the S0 and S1 states...
January 5, 2018: Journal of Molecular Graphics & Modelling
https://www.readbyqxmd.com/read/29345139/catalytically-enantioselective-synthesis-of-acyclic-%C3%AE-tertiary-amines-through-desymmetrization-of-2-substituted-2-nitro-1-3-diols
#2
Shan-Shui Meng, Wu-Bang Tang, Wen-Hua Zheng
Highly enantioselective synthesis of acyclic α-tertiary amines through asymmetric desymmetrization is reported. This approach is based on chiral phosphoric acid mediated, enantioselective, oxidative desymmetrization of 2-substituted 2-nitro-1,3-diolbenzylidine acetals in the presence of DMDO as an oxidant. The method allows for the formation of a wide variety of chiral 2-nitro-1,3-diols in high enantioselectivity, which could be transformed into optically pure, unnatural α-alkyl series. The synthetic utility of this method has been further demonstrated by the expedient construction of the core structure of natural products manzacidins enantioselectively...
January 18, 2018: Organic Letters
https://www.readbyqxmd.com/read/29341612/stabilization-of-nabh4-in-methanol-using-a-catalytic-amount-of-naome-reduction-of-esters-and-lactones-at-room-temperature-without-solvent-induced-loss-of-hydride
#3
Prasanth C P, Ebbin Joseph, Abhijith A, Nair D S, Ibrahim Ibnusaud, Jevgenij Raskatov, Bakthan Singaram
Rapid reaction of NaBH4 with MeOH precludes its use as a solvent for large-scale ester reductions. We have now learned that a catalytic amount of NaOMe (5 mol %) stabilizes NaBH4 solutions in methanol at 25 °C and permits the use of these solutions for the reduction of esters to alcohols. The generality of this reduction method was demonstrated using 22 esters including esters of naturally occurring chiral γ-butyrolactone containing dicarboxylic acids. This method permits the chemoselective reductions of esters in the presence of cyano and nitro groups and the reductive cyclization of a pyrrolidinedione ester to a fused five-membered furo[2,3-b]pyrrole and a (-)-crispine A analogue in high optical and chemical yields...
January 17, 2018: Journal of Organic Chemistry
https://www.readbyqxmd.com/read/29340390/ultrafast-stimulated-emission-of-nitrophenolates-in-organic-and-aqueous-solutions
#4
N C Michenfelder, H A Ernst, C Schweigert, M Olzmann, A-N Unterreiner
Early-time dynamics of nitroaromatics and its coressponding bases can give valuable insights into photo-induced reactions relevant to atmospheric and environmental processes. In this work, femtosecond broadband absorption spectroscopy between 350 and 700 nm has been applied to explore the ultrafast dynamics of o-, p- and m-nitrophenol anions (NP-) in basic organic and aqueous solution. Excitation at 400 nm promotes these compounds into the first bright electronic singlet state, which is a charge-transfer state...
January 17, 2018: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/29338975/critical-effects-of-polar-fluorescent-probes-on-the-interaction-of-dha-with-popc-supported-lipid-bilayers
#5
Kiera R Flynn, Alessandra Sutti, Lisandra L Martin, M Leigh Ackland, Angel A J Torriero
The understanding of lipid bilayer structure and function has been advanced by the application of molecular fluorophores. However, the effects of these probe molecules on the physicochemical properties of membranes being studied are poorly understood. A quartz crystal microbalance with dissipation monitoring instrument was used in this work to investigate the impact of two commonly used fluorescent probes, 1-palmitoyl-2-{12-[(7-nitro-2-1,3-benzoxadiazol-4-yl)amino]dodecanoyl}-sn-glycero-3-phosphocholine (NBD-PC) and 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine-N-(lissamine rhodamine-B-sulfonyl) (Lis-Rhod PE), on the formation and physicochemical properties of a 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine supported lipid bilayer (POPC-SLB)...
January 12, 2018: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/29338819/in-vitro-efficacy-of-continuous-mild-high-temperature-on-the-biofilm-formation-of-aspergillus-niger
#6
Rong Zeng, Jian Bo Tong, Yu Zhen Liu, Qing Chen, Tong Lin, Min Li, Gui Xia Lü
Objective To investigate whether continuous mild high temperature (increased temperature without causing significant damage to host cells) can inhibit the biofilm formation of Aspergillus niger (A.niger) and its vitality.Methods A.niger biofilms were formed on a coverslip in 24-well tissue culture plate and were checked at the time points 4,8,10,16,24,48 and 72 hours.Confocal laser scanning microscopy (CLSM) was used to image and quantify A.niger biofilm formation under three different continuous mild high temperatures at 37℃,39℃,and 41℃...
December 20, 2017: Zhongguo Yi Xue Ke Xue Yuan Xue Bao. Acta Academiae Medicinae Sinicae
https://www.readbyqxmd.com/read/29338200/solid-phase-synthesis-of-oligopeptides-containing-sterically-hindered-amino-acids-on-non-swellable-resin-using-3-nitro-1-2-4-triazol-1-yl-tris-pyrrolidin-1-yl-phosphonium-hexafluorophosphate-pyntp-as-the-condensing-reagent
#7
Rintaro Iwata Hara, Yuta Mitsuhashi, Keita Saito, Yuske Maeda, Takeshi Wada
Peptides are still difficult to synthesize when they contain sterically hindered amino acids such as α,α-di-substituted amino acids and N-substituted amino acids. In this study, solid-phase syntheses of oligopeptides containing multiple α-aminoisobutyric acid (Aib) residues were performed in high yields by using a non-swellable resin as the solid-support and 3-nitro-1,2,4-triazol-1-yl-tris(pyrrolidin-1-yl)phosphonium hexafluorophosphate (PyNTP) as the condensing reagent.
January 17, 2018: ACS Combinatorial Science
https://www.readbyqxmd.com/read/29335865/beneficial-effect-of-berberis-amurensis-rupr-on-penile-erection
#8
Rui Tan, Yun Jung Lee, Kyung Woo Cho, Dae Gill Kang, Ho Sub Lee
OBJECTIVE: To investigate whether the methanol extract of Berberis amurensis Rupr. (BAR) augments penile erection using in vitro and in vivo experiments. METHODS: The ex vivo study used corpus cavernosum strips prepared from adult male New Zealand White rabbits. In in vivo studies for intracavernous pressure (ICP), blood pressure, mean arterial pressure (MAP), and increase of peak ICP were continuously monitored during electrical stimulation of Sprague-Dawley rats...
January 15, 2018: Chinese Journal of Integrative Medicine
https://www.readbyqxmd.com/read/29334104/one-pot-cascade-synthesis-of-azabicycles-via-the-nitro-mannich-reaction-and-n-alkylation
#9
Wannaporn Disadee, Somsak Ruchirawat
A one-pot, metal-free process for the synthesis of azabicycles is developed. The key transformations involved a cascade of double intramolecular cyclizations via the nitro-Mannich reaction and N-alkylation, providing various ring systems of azabicycles in yields up to 81% and an isomeric ratio of 62 : 1. This approach offers considerable advantages in terms of the handling of small molecules, the flexibility to introduce a functionalized side chain, and gives direct access to various azabicycles.
January 15, 2018: Organic & Biomolecular Chemistry
https://www.readbyqxmd.com/read/29333618/age-associated-urethral-dysfunction-in-urethane-anesthetized-rats
#10
Ryu Kimura, Minoru Miyazato, Asuka Ashikari, Takuma Oshiro, Seiichi Saito
AIMS: We aimed to investigate the age-associated changes in movement coordination between the urinary bladder and the urethra in rats. METHODS: A total of 17 female Sprague-Dawley rats were used. The rats were divided into young (3 months old) and middle-aged (12-15 months old) groups. In both groups, isovolumetric cystometry and urethral perfusion pressure (UPP) measurements were performed under urethane anesthesia. After the rhythmic bladder contractions stabilized, L-arginine, a nitric oxide (NO) substrate (100 mg/kg), was administered intravenously in both groups...
January 15, 2018: Neurourology and Urodynamics
https://www.readbyqxmd.com/read/29333036/autonomic-receptors-and-nitric-oxide-involvements-in-mediating-vasorelaxation-effect-induced-by-syzygium-polyanthum-leaves-extract
#11
Azlini Ismail, Wan Amir Nizam Wan Ahmad
Context: Syzygium polyanthum (Wight) Walp leaves are traditionally used by Malays for treating hypertension. Our previous study showed that aqueous extract of S. polyanthum (AESP) and methanolic extract of S. polyanthum (MESP) extracts of S. polyanthum leaves significantly reduced blood pressure of normotensive Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR). Aims: This study aimed to investigate their vasorelaxation potential and the possible involvement of autonomic receptors and nitric oxide in mediating their effect...
December 2017: Pharmacognosy Research
https://www.readbyqxmd.com/read/29332392/transfer-hydrogenation-of-aldehydes-and-ketones-with-isopropanol-under-neutral-conditions-catalyzed-by-a-metal-ligand-bifunctional-catalyst-cp-ir-2-2-bpyo-h2o
#12
Rongzhou Wang, Yawen Tang, Meng Xu, Chong Meng, Feng Li
A Cp*Ir complex bearing a functional bipyridonate ligand [Cp*Ir(2,2'-bpyO)(H2O)] was found to be a highly efficient and general catalyst for transfer hydrogenation of aldehydes and chemoselective transfer hydrogenation of unsaturated aldehydes with isopropanol under neutral conditions. It was noteworthy that many readily reducible or labile functional groups such as nitro, cyano, ester and halide did not undergo any change under the reaction conditions. Furthermore, this catalytic system exhibited highly activity for transfer hydrogenation of ketones with isopropanol...
January 13, 2018: Journal of Organic Chemistry
https://www.readbyqxmd.com/read/29329462/silibinin-from-silybum-marianum-stimulates-embryonic-stem-cell-vascular-differentiation-via-the-stat3-pi3-k-akt-axis-and-nitric-oxide
#13
Enas Hussein Ali, Fatemeh Sharifpanah, Maria Wartenberg, Heinrich Sauer
Silibinin, the bioactive compound of milk thistle (Silybum marianum), exerts tissue protective and regenerative effects that may include stem cell differentiation toward vascular cells. The purpose of the present study was to investigate whether silibinin stimulates blood vessel formation from mouse embryonic stem (ES) cells and to unravel the underlying signaling cascade. Vascular branching points were assessed by confocal laser scanning microscopy and computer-assisted image analysis of CD31-positive cell structures...
January 12, 2018: Planta Medica
https://www.readbyqxmd.com/read/29329229/chemical-composition-and-evaluation-of-the-biological-properties-of-the-essential-oil-of-the-dietary-phytochemical-lippia-citriodora
#14
Eleni Fitsiou, Gregoria Mitropoulou, Katerina Spyridopoulou, Manolis Vamvakias, Haido Bardouki, Alex Galanis, Katerina Chlichlia, Yiannis Kourkoutas, Mihalis Ι Panayiotidis, Aglaia Pappa
The aim of the study was to characterize the chemical composition and biological properties of the essential oil from the plant Lippia citriodora grown in Greece. The essential oil volatiles were analyzed by gas chromatography-mass spectrometry GC-MS indicating citral as the major component. Τhe antimicrobial properties were assayed using the disk diffusion method and the minimum inhibitory and non-inhibitory concentration values were determined. Listeria monocytogenes, Staphylococcus epidermidis, Staphylococcus aureus, Saccharomyces cerevisiae, and Aspergillus niger were sensitive to Lippia citriodora oil, but not Escherichia coli, Salmonella Enteritidis, Salmonella typhimurium, and Pseudomonas fragi...
January 12, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/29327141/theoretical-study-on-benzoheterocycle-based-energetic-materials-effect-of-heterocyclic-fused-conjugation-hydrogen-bond-and-substitutional-group-on-the-detonation-performance
#15
Cheng Shen, Pengcheng Wang, Ming Lu
In this paper, four series of benzoheterocycle based energetic materials (EMs) have been designed to plan out a strategy to improve the density and safety of EMs, such as combining the insensitive group with aminobenzene ring and the high energetic nitramine explosives, benzo-heterocycle mother ring, designing multi-nitrogen heterocycles with a conjugated system containing N-N and C-N high energy bonds, and hydrogen bonding. Their optimized structure and detonation properties were first calculated and discussed using DFT methods...
January 11, 2018: Journal of Molecular Modeling
https://www.readbyqxmd.com/read/29326996/organocatalytic-3-2-cycloaddition-of-oxindole-based-azomethine-ylides-with-3-nitrochromenes-a-facile-approach-to-enantioenriched-polycyclic-spirooxindole-chromane-adducts
#16
Shiqi Wu, Guodong Zhu, Shiqiang Wei, Hongbo Chen, Jingping Qu, Baomin Wang
An organocatalytic asymmetric [3 + 2] cycloaddition of oxindole-based azomethine ylides with 3-nitro-2H-chromenes has been developed. This reaction provides a facile approach to densely functionalized polycyclic spirooxindole-chromane adducts featuring four contiguous stereogenic centers, including two tetrasubstituted carbon centers. The products were obtained in high yields with good to excellent stereoselectivities (up to 99% yields, 96% ee and >20 : 1 dr). In addition, the spiro[pyrrolidine-2,3'-oxindole]-chromane adducts could be readily derivatized via simple oxidation and reduction treatment...
January 12, 2018: Organic & Biomolecular Chemistry
https://www.readbyqxmd.com/read/29319921/enantioselective-and-simultaneous-determination-of-lactate-and-3-hydroxybutyrate-in-human-plasma-and-urine-using-a-narrow-bore-online-two-dimensional-hplc-system
#17
Chin-Ling Hsieh, Reiko Koga, Aogu Furusho, Takeyuki Akita, Masashi Mita, Tomomi Ide, Jen-Ai Lee, Kenji Hamase
For the enantioselective and simultaneous analysis of lactate and 3-hydroxybutyrate, a validated online two-dimensional high-performance liquid chromatography system using 4-nitro-7-piperazino-2,1,3-benzoxadiazole as a fluorescent derivatization reagent has been developed. For the reversed-phase separation in the first dimension, a Capcell Pak C18 ACR column (1.5 × 250 mm, particle size 3 μm) was used, and the target fractions were isolated by their hydrophobicity. In the second dimension, a polysaccharide-coated enantioselective column, Chiralpak AD-H (2...
January 10, 2018: Journal of Separation Science
https://www.readbyqxmd.com/read/29315228/contribution-of-secondary-metabolites-to-the-gastroprotective-effect-of-aqueous-extract-of-ximenia-americana-l-olacaceae-stem-bark-in-rats
#18
Ticiana Parente Aragão, Lady Dayane Kalline Travassos Dos Prazeres, Samara Alves Brito, Pedro José Rolim Neto, Larissa Araújo Rolim, Jackson Roberto Guedes da Silva Almeida, Germana Freire Rocha Caldas, Almir Gonçalves Wanderley
Ximenia americana L. (Olacaceae) is used in ethnomedicine as cicatrizant and for the treatment of gastric disorders. This study identified the chemical constituents of the aqueous extract of X. americana (XaAE) and evaluated its antiulcerogenic activity. After lyophilization, XaAE was analyzed by liquid chromatography-mass spectrometry (LC-MS) and its antiulcerogenic effect was evaluated in acute gastric lesions induced by ethanol, acidified ethanol, and indomethacin. Antisecretory action, mucus production and the participation of sulfhydryl groups (-SH) and nitric oxide (NO) were also investigated...
January 9, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/29314291/chemistry-of-the-8-nitroguanine-dna-lesion-reactivity-labelling-and-repair
#19
Katie J Alexander, Matthew McConville, Kathryn R Williams, Konstantin V Luzyanin, Ian A O'Neil, Richard Cosstick
The 8-nitroguanine lesion in DNA is increasingly associated with inflammation-related carcinogenesis, whilst the same modification on guanosine 3',5'-cyclic monophosphate generates a second messenger in NO-mediated signal transduction. Very little is known about the chemistry of 8-nitroguanine nucleotides, despite the fact that their biological effects are closely linked to their chemical properties. To this end, a selection of chemical reactions have been performed on 8-nitroguanine nucleosides and oligodeoxynucleotides...
January 3, 2018: Chemistry: a European Journal
https://www.readbyqxmd.com/read/29310209/highly-fluorescent-sensing-of-nitroaromatic-explosives-in-aqueous-media-using-pyrene-linked-pbema-microspheres
#20
Hamza Turhan, Ece Tukenmez, Bunyamin Karagoz, Niyazi Bicak
Crosslinked 2-bromoethyl methacrylate polymer (PBEMA) was prepared in micro-spherical form (2-5µm) by precipitation polymerization methodology. The bromide substituent was substituted with an azide group, which was then coupled with 1-[(2-Propynyloxy)methyl]pyrene] via alkyne-azide click chemistry. The pyrene-linked microspheres showed an intense green-blue excimer emission with a maximum at 480nm, implying π-π stacking between the pyrene moieties on the microsphere surfaces. This fluorescence emission is extremely sensitive to the aromatic nitro compounds...
March 1, 2018: Talanta
keyword
keyword
54943
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"