Conformational Study of Catecholamines in Solution

Abstract Conformations of noradrenaline, dopamine and ephedrine have been studied in aqueous solutions using high resolution PMR spectroscopy. We found that for dopamine the mole fraction of trans rotamer is increased if pH is changed from acidic to basic while for noradrenaline and ephedrine the opposite trend is observed: gauche rotamer forms of the side chain become more populated. These changes are discussed in relation to the role of the benzylic hydroxyl group for conformation and/or binding to a receptor site in the biophase.

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Study of the Interaction of Zinc Cation with Azithromycin and its Significance in the COVID-19 Treatment: A Molecular Approach

The Open Biochemistry Journal ◽

10.2174/1874091x02014010033 ◽

2020 ◽

Vol 14 (1) ◽

pp. 33-40

Author(s):

Jacques H. Poupaert ◽

Blanche Aguida ◽

Codjo Hountondji

Keyword(s):

Quantum Mechanics ◽

Hydroxyl Group ◽

Side Chain ◽

Molecular Approach ◽

Direct Role ◽

Zinc Cation ◽

Pm3 Method ◽

Chaotropic Agent ◽

Semi Empirical

Introduction: On account of the current COVID-19 pandemic, we have explored the importance of azithromycin and zinc in the treatment of the coronavirus disease by studying the interaction between the cation Zn++ and azithromycin with the tools of the semi-empirical quantum mechanics PM3 method. Methods: By this approach, the niche in which Zn++ is located was determined. Zn++ creates a strong clastic binding between an amine and a hydroxyl group located on the amino-hexose side-chain. Such an interaction serves as a shuttle and allows zinc cation to invade endocellular structures. Results: In this triple collaborative association, the role of hydroxychloroquine would be more that of a chaotropic agent at plasmic membranes, which facilitates access to the azithromycin-Zn++ equipage into key internal compartments. Conclusion: Finally, we show that both azithromycin and Zn++ are susceptible to play a direct role against the replication and the assembly of SARS-CoV-2 particles.

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Equilibria between pyranoses and furanoses. III. Deoxyaldoses. The stability of furanoses

Australian Journal of Chemistry ◽

10.1071/ch9721711 ◽

1972 ◽

Vol 25 (8) ◽

pp. 1711 ◽

Cited By ~ 41

Author(s):

SJ Angyal ◽

VA Pickles

Keyword(s):

Aqueous Solutions ◽

Hydroxyl Group ◽

Side Chain ◽

The Stability ◽

The One

The proportion of the pyranose and furanose forms in aqueous solutions of deoxyaldoses has been determined by p.m.r. spectroscopy. Removal of a hydroxyl group from C2 or C3 of an aldose causes an increase in the furanose content, particularly if the group was cis to another group. The strongest unfavourable interaction in the furanose ring appears to be the one between the side-chain and a neighbouring cis hydroxyl group.

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The role of secondary interactions on the preferred conformers of the fenchone–ethanol complex

Physical Chemistry Chemical Physics ◽

10.1039/c8cp06970k ◽

2019 ◽

Vol 21 (6) ◽

pp. 2938-2945 ◽

Cited By ~ 3

Author(s):

Donatella Loru ◽

Isabel Peña ◽

M. Eugenia Sanz

Keyword(s):

Hydrogen Bond ◽

High Resolution ◽

Weak Interactions ◽

Side Chain ◽

Rotational Spectroscopy ◽

Secondary Interactions ◽

Relative Arrangement

Three conformers of the complex formed between fenchone, a natural common odorant, and ethanol, a mimic of serine's side chain, have been identified using high resolution rotational spectroscopy. All conformers show a main O⋯H–O hydrogen bond and C–H⋯O secondary weak interactions, which drive the relative arrangement of the two moieties.

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STEROID TRANSFORMATIONS IN VITRO BY TESTICULAR TISSUE FROM TWO CASES OF TESTICULAR FEMINISATION

Acta Endocrinologica ◽

10.1530/acta.0.0490177 ◽

1965 ◽

Vol 49 (2) ◽

pp. 177-192 ◽

Cited By ~ 13

Author(s):

R. Neher ◽

F. W. Kahnt ◽

G. D. Roversi ◽

A. Bompiani

Keyword(s):

Qualitative Difference ◽

Testicular Tissue ◽

Hydroxyl Group ◽

Side Chain ◽

Ample Evidence ◽

Adenoma Tissue ◽

Testicular Feminisation ◽

Transformation Pattern

ABSTRACT Cryptorchid testicular and testicular adenoma tissue obtained from two patients with the testicular feminisation syndrome was incubated with 3Hor 14C-labelled pregnenolone, 17-hydroxy-pregnenolone, progesterone and androstenedione. In the tissue of both patients a similar steroid transformation pattern was observed. There was abundant biosynthesis of testosterone from androstenedione but rather little from the other precursors. Oestrone and oestradiol were formed only from androstenedione. There is ample evidence of both 17-hydroxylation and side-chain splitting, in particular with the δ5-precursors. From the ratio of the δ5- and δ4-steroids identified, it is concluded that there was, however, little dehydrogenation of the 3β-hydroxyl group. Though there seems to be no qualitative difference as compared with what is known about the possible pathways in testicular tissue from various species, our findings contrast to some extent with those reported previously by other investigators in a few cases of testicular feminisation. The possible role of anti-androgens is discussed.

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Noncovalent Complexes of an Inactive Mutant of CTX-M-9 with the Substrate Piperacillin and the Corresponding Product

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00245-11 ◽

2011 ◽

Vol 55 (12) ◽

pp. 5660-5665 ◽

Cited By ~ 5

Author(s):

David Leyssene ◽

Julien Delmas ◽

Frédéric Robin ◽

Antony Cougnoux ◽

Lucie Gibold ◽

...

Keyword(s):

Crystal Structure ◽

High Resolution ◽

Catalytic Process ◽

Side Chain ◽

Noncovalent Complexes

ABSTRACTWe determined the crystal structure of an inactive Ser70Gly mutant of CTX-M-9 in complex with the bulky penicillin piperacillin at precovalent and posthydrolytic stages in the catalytic process. The structures obtained at high resolution were compared with the corresponding structures for the small penicillin benzylpenicillin and the bulky cephalosporin cefotaxime. The findings highlight the key role of the configuration of the carbon adjacent to the acylamino group of the side chain of β-lactams in the precovalent recognition of substrates.

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Supplemental Material for High Resolution Examination of the Role of Sleep Disturbance in Predicting Functioning and Psychotic Symptoms in Schizophrenia: A Novel Experience Sampling Study

Journal of Abnormal Psychology ◽

10.1037/abn0000180.supp ◽

2016 ◽

Keyword(s):

High Resolution ◽

Sleep Disturbance ◽

Experience Sampling ◽

Psychotic Symptoms

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Quantitative accuracy of serotonergic neurotrans-mission imaging with high-resolution 123I SPECT

Nuklearmedizin ◽

10.1055/s-0038-1623914 ◽

2004 ◽

Vol 43 (06) ◽

pp. 185-189 ◽

Cited By ~ 4

Author(s):

J. T. Kuikka

Keyword(s):

High Resolution ◽

Scatter Correction ◽

Region Of Interest ◽

Binding Potential ◽

Partial Volume ◽

Therapeutic Drugs ◽

Quantitative Accuracy ◽

Critical Error ◽

Statistical Noise

Summary Aim: Serotonin transporter (SERT) imaging can be used to study the role of regional abnormalities of neurotransmitter release in various mental disorders and to study the mechanism of action of therapeutic drugs or drugs’ abuse. We examine the quantitative accuracy and reproducibility that can be achieved with high-resolution SPECT of serotonergic neurotransmission. Method: Binding potential (BP) of 123I labeled tracer specific for midbrain SERT was assessed in 20 healthy persons. The effects of scatter, attenuation, partial volume, mis-registration and statistical noise were estimated using phantom and human studies. Results: Without any correction, BP was underestimated by 73%. The partial volume error was the major component in this underestimation whereas the most critical error for the reproducibility was misplacement of region of interest (ROI). Conclusion: The proper ROI registration, the use of the multiple head gamma camera with transmission based scatter correction introduce more relevant results. However, due to the small dimensions of the midbrain SERT structures and poor spatial resolution of SPECT, the improvement without the partial volume correction is not great enough to restore the estimate of BP to that of the true one.

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