Stereochemistry of C18 Monounsaturated Cork Suberin Acids Determined by Spectroscopic Techniques Including 1 H-NMR Multiplet Analysis of Olefinic Protons

2013 ◽  
Vol 25 (3) ◽  
pp. 192-200 ◽  
Author(s):  
Sara Santos ◽  
José Graça
Keyword(s):  
Spectroscopic Techniques ◽  
H Nmr ◽  
Multiplet Analysis

scholarly journals Interactions between 4-thiothymidine and water-soluble cyclodextrins: Evidence for supramolecular structures in aqueous solutions

2016 ◽  
Vol 12 ◽  
pp. 549-563 ◽  
Author(s):  
Vito Rizzi ◽  
Sergio Matera ◽  
Paola Semeraro ◽  
Paola Fini ◽  
Pinalysa Cosma
Keyword(s):  
Inclusion Complexes ◽  
Pyrimidine Ring ◽  
Protective Role ◽  
Supramolecular Structures ◽  
Water Soluble ◽  
Aqueous Environment ◽  
Spectroscopic Techniques ◽  
Guest Molecules ◽  
H Nmr ◽  
Cv Measurements

Since several years the inclusion of organic compounds (guests) within the hydrophobic cavity (host) of cyclodextrins (CDs) has been the subject of many investigations. Interestingly, the formation of inclusion complexes could affect the properties of the guest molecules and, for example, the influence of the delivery system can be a method to improve/change the photochemical behavior of the guest. In particular, very recent studies have shown the protective role of CDs preventing the degradation of the encapsulated guest. Starting from this consideration, in this work, only the structure and complexation mode of the inclusion complexes involving 4-thiothymidine (S4TdR, a known photosensitizer) and five CDs, namely 2-hydroxypropyl-α-cyclodextrin (2-HP-α-CD), 2-hydroxypropyl-β-cyclodextrin (2-HP-β-CD), 2-hydroxypropyl-γ-cyclodextrin (2-HP-γ-CD), heptakis-(2,6-di-O-methyl)-β-cyclodextrin (DIMEB CD) and heptakis-(2,3,6-tri-O-methyl)-β-cyclodextrin (TRIMEB CD) were investigated by different spectroscopic techniques (UV–vis, FTIR–ATR, 1H NMR) and cyclic voltammetry analysis (CV). This work is necessary for a prospective research on the photoreactivity of S4TdR in aqueous environment and in the presence of CDs to prevent its degradation under irradiation. UV–vis, FTIR–ATR and CV measurements suggested the formation of supramolecular structures involving the employed CDs and mainly the pyrimidine ring of S4TdR. 1H NMR analyses confirmed such indication, unveiling the presence of inclusion complexes. The strongest and deepest interactions were suggested when TRIMEB and DIMEB CDs were studied. The S4TdR affinity towards CDs was also evaluated by using the Benesi–Hildebrand (B–H) equation at 25 °C employing CV and 1H NMR methods. The stoichiometry of the interaction was also inferred and it appears to be 1:1 for all examined CDs.

scholarly journals Diorganotin(iv) benzyldithiocarbamate complexes: synthesis, characterization, and thermal and cytotoxicity study

2020 ◽  
Vol 18 (1) ◽  
pp. 453-462
Author(s):  
Jerry O. Adeyemi ◽  
Damian C. Onwudiwe ◽  
Nirasha Nundkumar ◽  
Moganavelli Singh
Keyword(s):  
Cell Lines ◽  
Human Tumor ◽  
Complexation Reaction ◽  
Spectroscopic Techniques ◽  
X Ray Diffraction ◽  
Human Tumor Cell Lines ◽  
H Nmr ◽  
Cytotoxicity Studies ◽  
Final Residue ◽  
Mcf 7

AbstractAmmonium benzyldithiocarbamate, represented as NH4L, was prepared and used in the complexation reaction involving three organotin(iv) salts, represented as R2SnCl2 (R = CH3, C4H9, and C6H5). The structures of the synthesized complexes [(CH3)2SnL2] (1), [(C4H9)2SnL2] (2), and [(C6H5)2SnL2] (3) were established using various spectroscopic techniques (Fourier transform infrared spectroscopy, 1H NMR, 13C NMR, and 119Sn NMR) and elemental analysis. Thermal decomposition of the complexes using thermogravimetric analysis under nitrogen showed no definite pathway in the pattern of the complexes even though they are structurally related. X-ray diffraction studies of the final residue showed a common diffraction pattern for the complexes and confirmed SnS as the product of the thermal treatment. Cytotoxicity studies of these complexes against the human tumor cell lines (HeLa and MCF-7) compared favorably with the used standard 5-fluorouracil drug, with complexes 2 and 3 showing very good activity toward the used cell lines.

scholarly journals Synthesis, Characterization, and BSA Binding Studies of Some New Benzamides Related to Schiff Base

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
M. K. Prashanth ◽  
M. Madaiah ◽  
H. D. Revanasiddappa ◽  
K. N. Amruthesh
Keyword(s):  
Schiff Base ◽  
Antioxidant Activities ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Binding Constants ◽  
Spectral Studies ◽  
Spectroscopic Techniques ◽  
Binding Studies ◽  
Mass Spectral ◽  
H Nmr

Condensation of amine 1 with aldehyde 2 gives Schiff base, N-(4-((benzofuran-2-ylmethylene) amino)phenyl)acetamide 3. Schiff base on N-acylation with different substituted acid chlorides in the presence of triethylamine gives the corresponding benzamides, N-acetyl-N-(4-((benzofuran-2-ylmethylene)amino)phenyl)substitutedbenzamide (NABP) 5a–j. The structures of newly synthesized compounds were characterized by elemental analysis, 1H NMR, 13C NMR FT-IR, and mass spectral studies. Compounds 3 and 5a–j have been screened for their antimicrobial activity using the disc diffusion and minimum inhibitory concentration (MIC) method against the selected bacterial and fungal strain. Compounds 5a, 5e, 5g, and 5h were found to be more active against all tested strains. The antioxidant properties were evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and superoxide radical scavenging methods. Compounds 5i and 5j showed predominant antioxidant activities among the synthesized analogues. The interaction between NABP and bovine serum albumin (BSA) was investigated using fluorescence and ultraviolet spectroscopic techniques at 298 K under imitated physiological conditions. The results revealed that NABP caused the fluorescence quenching of BSA through a static quenching procedure. The binding constants and the number of binding sites were calculated. The binding distance between the donor (BSA) and acceptor (NABP) was determined based on Forster’s theory.

scholarly journals Hydrolysis of Methionine- and Histidine-Containing Peptides Promoted by Dinuclear Platinum(II) Complexes with Benzodiazines as Bridging Ligands: Influence of Ligand Structure on the Catalytic Ability of Platinum(II) Complexes

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Snežana Rajković ◽  
Beata Warżajtis ◽  
Marija D. Živković ◽  
Biljana Đ. Glišić ◽  
Urszula Rychlewska ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Amide Bond ◽  
Spectroscopic Techniques ◽  
X Ray Diffraction ◽  
Bridging Ligands ◽  
Metal Centers ◽  
H Nmr ◽  
Dinuclear Platinum ◽  
Ph Range ◽  
Hydrolysis Of

Dinuclear platinum(II) complexes, [{Pt(en)Cl}2(μ-qx)]Cl2·2H2O (1), [{Pt(en)Cl}2(μ-qz)](ClO4)2(2), and [{Pt(en)Cl}2(μ-phtz)]Cl2·4H2O (3), were synthesized and characterized by different spectroscopic techniques. The crystal structure of1was determined by single-crystal X-ray diffraction analysis, while the DFT M06-2X method was applied in order to optimize the structures of1–3. The chlorido Pt(II) complexes1–3were converted into the corresponding aqua species1a–3a, and their reactions with an equimolar amount of Ac–L–Met–Gly and Ac–L–His–Gly dipeptides were studied by1H NMR spectroscopy in the pH range 2.0 < pH < 2.5 at 37°C. It was found that, in all investigated reactions with the Ac–L–Met–Gly dipeptide, the cleavage of the Met–Gly amide bond had occurred, but complexes2aand3ashowed lower catalytic activity than1a. However, in the reactions with Ac–L–His–Gly dipeptide, the hydrolysis of the amide bond involving the carboxylic group of histidine was observed only with complex1a. The observed disparity in the catalytic activity of these complexes is thought to be due to different relative positioning of nitrogen atoms in the bridging qx, qz, and phtz ligands and consequent variation in the intramolecular separation of the two platinum(II) metal centers.

scholarly journals Two New Glycosides from Conyza bonariensis

2010 ◽  
Vol 5 (7) ◽  
pp. 1934578X1000500 ◽  
Author(s):  
Aqib Zahoor ◽  
Imran Nafees Siddiqui ◽  
Afsar Khan ◽  
Viqar Uddin Ahmad ◽  
Amir Ahmed ◽  
...  
Keyword(s):  
2D Nmr ◽  
Mass Spectrometric ◽  
Spectroscopic Techniques ◽  
H Nmr ◽  
Alkyl Glycoside ◽  
Conyza Bonariensis ◽  
C Nmr

Studies on Conyza bonariensis (L.) Cronq. led to the isolation of two new glycosides trivially named as erigeside E and F (1–2), along with two new source compounds; benzyl-β-D-glucopyranoside (3) and 2-phenylethyl-β-D-glucopyranoside (4). Compounds 1, 3, and 4 are aromatic glycosides, while compound 2 is an alkyl glycoside. Their structures were elucidated through mass spectrometric, and 1D- and 2D-NMR spectroscopic techniques, including 1H NMR, 13C NMR, HMQC, HSQC and HMBC.

Microwave-assisted synthesis of zinc 5-(4-carboxyphenyl)-10,15,20-triphenylporphyrin and zinc 5-(4-carboxyphenyl)-10,15,20-triphenylchlorin

2015 ◽  
Vol 19 (04) ◽  
pp. 595-600 ◽  
Author(s):  
Rima Chouikrat ◽  
Aymeric Champion ◽  
Régis Vanderesse ◽  
Céline Frochot ◽  
Albert Moussaron
Keyword(s):  
Reaction Times ◽  
Microwave Assisted Synthesis ◽  
Spectroscopic Techniques ◽  
H Nmr ◽  
Microwave Assisted ◽  
Experimental Protocols ◽  
Time Of Reaction

The microwave-assisted synthesis of zinc 5-(4-carboxyphenyl)-10,15,20-triphenylporphyrin and zinc 5-(4-carboxyphenyl)-10,15,20-triphenylchlrorin are described and compared to classic conditions of synthesis in terms of time of reaction and yields obtained. The new experimental protocols are easy to implement required small amounts of reagents and solvents and lead to short reaction times. All compounds have been characterized by 1 H NMR, MS and spectroscopic techniques.

scholarly journals Synthesis of compounds related to the anti-migraine drug eletriptan hydrobromide

2012 ◽  
Vol 8 ◽  
pp. 1400-1405 ◽  
Author(s):  
Suri Babu Madasu ◽  
Nagaji Ambabhai Vekariya ◽  
M N V D Hari Kiran ◽  
Badarinadh Gupta ◽  
Aminul Islam ◽  
...  
Keyword(s):  
Mass Spectroscopy ◽  
Acute Treatment ◽  
Selective Serotonin ◽  
Spectroscopic Techniques ◽  
Active Pharmaceutical Ingredients ◽  
Pharmaceutical Ingredients ◽  
H Nmr ◽  
Related Compounds ◽  
C Nmr ◽  
Anti Migraine Drug

Eletriptan hydrobromide (1) is a selective serotonin (5-HT1) agonist, used for the acute treatment of the headache phase of migraine attacks. During the manufacture of eletriptan hydrobromide the formation of various impurities were observed and identified by LC–MS. To control the formation of these impurities during the preparation of active pharmaceutical ingredients, the structure of the impurities must be known. Major impurities of the eletriptan hydrobromide synthesis were prepared and characterized by using various spectroscopic techniques, i.e., mass spectroscopy, FTIR , 1H NMR, 13C NMR/DEPT, and further confirmed by co-injection in HPLC. The present study will be of great help in the synthesis of highly pure eletriptan hydrobromide related compounds.

Photoluminescent Tetrazolate-based Eu(III) Complexes: An Outstanding Impact of Aromatic Phosphine Oxide Co-ligands on the Photoluminescence Quantum Yields

2014 ◽  
Vol 69 (2) ◽  
pp. 239-247 ◽  
Author(s):  
Marek Pietraszkiewicz ◽  
Suraj Mal ◽  
Oksana Pietraszkiewicz ◽  
Krzysztof Górski ◽  
Nitin Chelwani
Keyword(s):  
Phosphine Oxide ◽  
Elemental Analysis ◽  
Analytical Data ◽  
Quantum Yields ◽  
Spectroscopic Techniques ◽  
Ancillary Ligands ◽  
H Nmr ◽  
Luminescence Efficiency ◽  
The Eu ◽  
Oxygen Atoms

New ternary Eu(III) 5-(2-pyridyl-1-oxide)tetrazolate complexes with phosphine oxide co-ligands have been synthesized and characterized by elemental analysis, and IR and 1H NMR spectroscopic techniques. The analytical data revealed that these complexes are mononuclear, and the central Eu(III) ion is coordinated by three oxygen and three nitrogen atoms of the tetrazolate and two oxygen atoms from the phosphine oxide ligands. The ancillary ligands increased remarkably the luminescence efficiency of the Eu(III) tetrazolate.

Synthesis and photophysical studies of non-covalently linked porphyrin dyads and triads

2007 ◽  
Vol 11 (02) ◽  
pp. 85-94 ◽  
Author(s):  
Punidha Sokkalingam ◽  
Sangita Santra ◽  
Ravikanth Mangalampalli
Keyword(s):  
Ring Current ◽  
Singlet State ◽  
Photophysical Properties ◽  
Spectroscopic Techniques ◽  
Current Effect ◽  
H Nmr ◽  
Nmr Study ◽  
Photophysical Studies ◽  
Ring Current Effect ◽  
Covalently Linked

Non-covalent porphyrin dyads and triads containing N 3 S porphyrin and RuN 4 porphyrin subunits were synthesized by treating meso-pyridyl-21-thiaporphyrin with RuTPP(CO)(EtOH) in toluene at refluxing temperature. The dyads and triads were characterized by various spectroscopic techniques and the properties were compared with the reported dyad containing N 4 and RuN 4 porphyrin subunits. The 1 H NMR study of dyads and triads indicated that the inner NH , β-heterocycle and meso-pyridyl protons of the 21-thiaporphyrin unit experienced large upfield shifts as compared to their corresponding monomeric meso-pyridyl-21-thiaporphyrins due to the ring current effect of RuTPP(CO) subunit. The singlet state photophysical properties of N 3 S porphyrin subunit in dyads and triads showed 50-80% quenching of fluorescence as observed previously for N 4- RuN 4 dyad due to heavy ruthenium ion(s).

scholarly journals Characterization of some compounds isolated from Sweet Basil (Ocimum basilicum L.) leaf extract

2016 ◽  
Vol 2 (7) ◽  
pp. 159
Author(s):  
Hadush Gebrehiwot ◽  
Aman Dekebo ◽  
Rakesh Kumar Bachheti
Keyword(s):  
Crude Extract ◽  
Ocimum Basilicum ◽  
Spectroscopic Techniques ◽  
Traditional Medicines ◽  
Sweet Basil ◽  
H Nmr ◽  
The Family ◽  
Pure Compounds ◽  
Chloroform Methanol

<p class="abstract"><strong>Background: </strong>For thousands of years, several people depend on traditional medicines from flowers, bark, leaves and fruits of plants. Sweet Basil (<em>Ocimum basilicum L.</em>) is a medicinal herb which belongs to the family of Labiatae and it is the most abundant of the genus <em>Ocimum.</em> The present study aimed to isolate pure compounds from chloroform/methanol (1:1) crude extract of the leaves of <em>O. basilicum </em>herb and characterize them using infra-red (IR) and nuclear magnetic resonance (NMR) spectroscopic techniques.</p><p class="abstract"><strong>Methods:</strong> The sample of powdered leaves of <em>O. basilicum </em>was extracted using a mixture of chloroform and methanol (1:1) and the crude extract was investigated for its chemical composition using spectroscopic techniques.</p><p class="abstract"><strong>Results:</strong> Only one fraction designated as <em>O. basilicum </em>-14 (OB-14) displayed a single spot on TLC plate. Results showed that two isomeric compounds named <em>(1-(2-vinylcyclohexa-1,4-dienyl) propan-2-ol and 2-(2-vinylcyclohexa-1,5-dienyl) propan-1-ol) </em>were isolated as a mixtures using column chromatography over silica gel. The structures of these compounds were identified using IR and one dimensional NMR spectroscopic techniques such as proton NMR (<sup>1</sup>H NMR), carbon-13 NMR (<sup>13</sup>C NMR) and distortionless enhancement by polarization transfer (DEPT).</p><p class="abstract"><strong>Conclusions:</strong> So, more compounds can be isolated from the plant using different chromatographic techniques.</p>

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