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1.
Front Pediatr ; 11: 1102354, 2023.
Article in English | MEDLINE | ID: mdl-37181420

ABSTRACT

Introduction: Epidermal barrier dysfunction in children with atopic dermatitis can cause transcutaneous sensitization to allergens and allergic diseases. We evaluated the effectiveness of an early-intervention algorithm for atopic dermatitis treatment, utilizing pimecrolimus for long-term maintenance therapy, in reducing transcutaneous sensitization in infants. Method: This was a single-center cohort observational study that enrolled children aged 1-4 months with family history of allergic diseases, moderate-to-severe atopic dermatitis, and sensitization to ≥ 1 of the investigated allergens. Patients who sought medical attention at atopic dermatitis onset (within 10 days) were group 1 "baseline therapy with topical glucocorticoids with subsequent transition to pimecrolimus as maintenance therapy"; patients who sought medical attention later were group 2 "baseline and maintenance therapy with topical glucocorticoids, without subsequent use of pimecrolimus". Sensitization class and level of allergen-specific immunoglobulin E were determined at baseline, and 6 and 12 months of age. Atopic dermatitis severity was evaluated using the Eczema Area and Severity Index score at baseline and 6, 9 and 12 months of age. Results: Fifty-six and 52 patients were enrolled in groups 1 and 2, respectively. Compared with group 2, group 1 demonstrated a lower level of sensitization to cow's milk protein, egg white and house dust mite allergen at 6 and 12 months of age, and a more pronounced decrease in atopic dermatitis severity at 6, 9 and 12 months of age. No adverse events occurred. Discussion: The pimecrolimus-containing algorithm was effective in treating atopic dermatitis and prophylaxis of early forms of allergic diseases in infants. Trial registration: https://clinicaltrials.gov/ NCT04900948, retrospectively registered, 25 May 2021.

2.
Nat Commun ; 13(1): 4968, 2022 08 25.
Article in English | MEDLINE | ID: mdl-36008406

ABSTRACT

The Arctic is warming faster than any other region on Earth. Putting this rapid warming into perspective is challenging because instrumental records are often short or incomplete in polar regions and precisely-dated temperature proxies with high temporal resolution are largely lacking. Here, we provide this long-term perspective by reconstructing past summer temperature variability at Yamal Peninsula - a hotspot of recent warming - over the past 7638 years using annually resolved tree-ring records. We demonstrate that the recent anthropogenic warming interrupted a multi-millennial cooling trend. We find the industrial-era warming to be unprecedented in rate and to have elevated the summer temperature to levels above those reconstructed for the past seven millennia (in both 30-year mean and the frequency of extreme summers). This is undoubtedly of concern for the natural and human systems that are being impacted by climatic changes that lie outside the envelope of natural climatic variations for this region.


Subject(s)
Heating , Trees , Arctic Regions , Humans , Seasons , Temperature
3.
J Biomol Struct Dyn ; 40(1): 425-437, 2022 01.
Article in English | MEDLINE | ID: mdl-32897172

ABSTRACT

In this work, we study the adsorption of poly(rA) on graphene oxide (GO) using AFM and UV absorption spectroscopies. A transformation of the homopolynucleotide structure on the GO surface is observed. It is found that an energetically favorable conformation of poly(rA) on GO is achieved after a considerable amount of time (days). It is revealed that GO can induce formation of self-structures of single-stranded poly(rA) including a duplex at pH 7. The phenomenon is analyzed by polymer melting measurements and observed by AFM. Details of the noncovalent interaction of poly(rA) with graphene are also investigated using molecular dynamics simulations. The adsorption of (rA)10 oligonucleotide on graphene is compared with the graphene adsorption of (rC)10. DFT calculations are used to determine equilibrium structures and the corresponding interaction energies of the adenine-GO complexes with different numbers of the oxygen-containing groups. The IR intensities and vibrational frequencies of free and adsorbed adenines on the GO surface are calculated. The obtained spectral transformations are caused by the interaction of adenine with GO.


Subject(s)
Graphite , Adsorption , Computers , Molecular Dynamics Simulation
4.
Mol Divers ; 26(2): 1115-1128, 2022 Apr.
Article in English | MEDLINE | ID: mdl-34086156

ABSTRACT

An efficient and practical synthetic procedure for libraries of diversified 1,2-dihydrochromeno[2,3-c]pyrrole-3,9-diones using a multicomponent process is presented. A convenient synthetic procedure for obtaining functionalized 3-(2-hydroxyphenyl)-4,5-dihydropyrrolo[3,4-c]pyrazol-6(1H)-ones via ring-opening strategy has also been developed. This protocol was found to be compatible with a wide range of substituents and paves the way for the practical synthesis of title compounds with a broad range of substituents under mild condition. The products can be easily isolated by crystallization without the use of chromatography.


Subject(s)
Pyrroles , Molecular Structure
5.
Comput Biol Chem ; 90: 107407, 2021 Feb.
Article in English | MEDLINE | ID: mdl-33191110

ABSTRACT

Natural products as well as their derivatives play a significant role in the discovery of new biologically active compounds in the different areas of our life especially in the field of medicine. The synthesis of compounds produced from natural products including cytisine is one approach for the wider use of natural substances in the development of new drugs. QSAR modeling was used to predict and select of biologically active cytisine-containing 1,3-oxazoles. The eleven most promising compounds were identified, synthesized and tested. The activity of the synthesized compounds was evaluated using the disc diffusion method against C. albicans M 885 (ATCC 10,231) strain and clinical fluconazole-resistant Candida krusei strain. Molecular docking of the most active compounds as potential inhibitors of the Candida spp. glutathione reductase was performed using the AutoDock Vina. The built classification models demonstrated good stability, robustness and predictive power. The eleven cytisine-containing 1,3-oxazoles were synthesized and their activity against Candida spp. was evaluated. Compounds 10, 11 as potential inhibitors of the Candida spp. glutathione reductase demonstrated the high activity against C. albicans M 885 (ATCC 10,231) strain and clinical fluconazole-resistant Candida krusei strain. The studied compounds 10, 11 present the interesting scaffold for further investigation as potential inhibitors of the Candida spp. glutathione reductase with the promising antifungal properties. The developed models are publicly available online at http://ochem.eu/article/120720 and could be used by scientists for design of new more effective drugs.


Subject(s)
Alkaloids/pharmacology , Antifungal Agents/pharmacology , Candida/drug effects , Glutathione Reductase/antagonists & inhibitors , Molecular Docking Simulation , Oxazoles/pharmacology , Alkaloids/chemical synthesis , Alkaloids/chemistry , Antifungal Agents/chemical synthesis , Antifungal Agents/chemistry , Azocines/chemical synthesis , Azocines/chemistry , Azocines/pharmacology , Candida/enzymology , Glutathione Reductase/metabolism , Microbial Sensitivity Tests , Molecular Structure , Oxazoles/chemical synthesis , Oxazoles/chemistry , Quantitative Structure-Activity Relationship , Quinolizines/chemical synthesis , Quinolizines/chemistry , Quinolizines/pharmacology
7.
Chaos ; 30(5): 053108, 2020 May.
Article in English | MEDLINE | ID: mdl-32491916

ABSTRACT

Large-amplitude oscillations of turning operations are investigated, which can be modelled by a one degree-of-freedom damped oscillator subjected to the regenerative effect that introduces a relevant time delay in the system. In the case of large oscillations, when the cutting tool loses contact with the surface of the workpiece, the time delay is switched off, leading to a non-smooth delay differential equation. To explore the geometric structure of the global dynamics of the system, the mathematical model is approximated by means of the essential part of the spectrum in the region where the stationary cutting process may lose its stability. The trajectories embedded in the infinite-dimensional phase space are interpreted in a three-dimensional subspace and then analyzed by means of a discrete Lorenz-map. The bifurcation diagrams of the non-smooth system include chaotic windows, which are presented by numerical and semi-analytical tools and compared to the existing results in the literature.

8.
Comput Biol Chem ; 74: 294-303, 2018 Jun.
Article in English | MEDLINE | ID: mdl-29698921

ABSTRACT

Based on modern literature data about biological activity of E7010 derivatives, a series of new sulfonamides as potential anticancer drugs were rationally designed by QSAR modeling methods Сlassification learning QSAR models to predict the tubulin polymerization inhibition activity of novel sulfonamides as potential anticancer agents were created using the Online Chemical Modeling Environment (OCHEM) and are freely available online on OCHEM server at https://ochem.eu/article/107790. A series of sulfonamides with predicted activity were synthesized and tested against 60 human cancer cell lines with growth inhibition percent values. The highest antiproliferative activity against leukemia (cell lines K-562 and MOLT-4), non-small cell lung cancer (cell line NCI-H522), colon cancer (cell lines NT29 and SW-620), melanoma (cell lines MALME-3M and UACC-257), ovarian cancer (cell lines IGROV1 and OVCAR-3), renal cancer (cell lines ACHN and UO-31), breast cancer (cell line T-47D) was found for compounds 4-9. According to the docking results the compounds 4-9 induce cytotoxicity by the disruption of the microtubule dynamics by inhibiting tubulin polymerization via effective binding into colchicine domain, similar the E7010.


Subject(s)
Antineoplastic Agents/pharmacology , Drug Design , Sulfonamides/pharmacology , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Cell Line, Tumor , Cell Proliferation/drug effects , Drug Screening Assays, Antitumor , Humans , Machine Learning , Models, Molecular , Molecular Structure , Quantitative Structure-Activity Relationship , Sulfonamides/chemical synthesis , Sulfonamides/chemistry
9.
Proc Math Phys Eng Sci ; 473(2207): 20170502, 2017 Nov.
Article in English | MEDLINE | ID: mdl-29225502

ABSTRACT

The single-degree-of-freedom model of orthogonal cutting is investigated to study machine tool vibrations in the vicinity of a double Hopf bifurcation point. Centre manifold reduction and normal form calculations are performed to investigate the long-term dynamics of the cutting process. The normal form of the four-dimensional centre subsystem is derived analytically, and the possible topologies in the infinite-dimensional phase space of the system are revealed. It is shown that bistable parameter regions exist where unstable periodic and, in certain cases, unstable quasi-periodic motions coexist with the equilibrium. Taking into account the non-smoothness caused by loss of contact between the tool and the workpiece, the boundary of the bistable region is also derived analytically. The results are verified by numerical continuation. The possibility of (transient) chaotic motions in the global non-smooth dynamics is shown.

10.
Oecologia ; 183(2): 571-586, 2017 02.
Article in English | MEDLINE | ID: mdl-27904966

ABSTRACT

Climate warming is shifting the elevational boundary between forests and tundra upwards, but the related belowground responses are poorly understood. In the pristine South and Polar Urals with shifts of the treeline ecotone documented by historical photographs, we investigated fine root dynamics and production of extramatrical mycorrhizal mycelia (EMM) along four elevational transects reaching from the closed forest to the treeless tundra. In addition, we analysed elevational differences in climate and vegetation structure, and excavated trees to estimate related changes in the partitioning between below- and aboveground biomass. Fine root biomass of trees (<2 mm) increased by 13-79% with elevation, paralleled by a 35-72% increase in ground vegetation fine roots from the closed forest to the tundra. During the first year of decomposition, mass loss of fine root litter from different vegetation types was greater at lower elevations in the forest-tundra ecotone. The ratio between fine roots of trees and stem biomass largely increased with elevation in both regions, but these increases were not accompanied by a distinct production of EMM. Production of EMM, however, increased with the presence of ectomycorrhizal trees at the transition from the tundra to the forest. Our results imply that the recorded upward expansion of forest into former tundra in the Ural Mountains by 4-8 m per decade is decreasing the partitioning of plant biomass to fine roots. They further suggest that climate-driven forest advances will alter EMM production rates with potential feedbacks on soil carbon and nutrient cycling in these ecosystems.


Subject(s)
Forests , Tundra , Biomass , Ecosystem , Plant Roots , Soil/chemistry , Trees
11.
J Mol Graph Model ; 70: 77-84, 2016 11.
Article in English | MEDLINE | ID: mdl-27684527

ABSTRACT

Placing electrical charges on nanomaterials is a means to extend their functional capabilities in nanoelectronics and sensoring applications. This paper explores the effect of charging nitrogen bases cytosine (Cyt) and adenine (Ade) via protonation on their noncovalent interaction with carbon nanotubes (CNT) using quantum chemical calculations performed at the M05-2X/6-31++G** level of theory alongside with a molecular graphics method. It is shown that the protonation of the bases causes threefold increase of the interaction energy in the CNT·Cyt·H+ and СNT·Ade·H+ complexes as compared to the CNT complexes formed with neutral bases. There is also some shortening of the base-CNT distance by ca 0.13Ǻ. The visualization of the electrostatic potential distribution with the molecular graphics reveals that the positive potential due to the protonated bases extends to a cylindrical domain of the nanotube segment adjacent to the base binding site. Furthermore, subtraction of the electrostatic potential maps of the protonated bases from the maps of their complexes with CNTs reveals an area of negative potential on the CNT surface, which reflects the location of the adsorbed base. The positive charge transfer of ca 0.3 e from the protonated bases to the CNT strengthens the interaction in the CNT·Cyt·H+ and СNT·Ade·H+ complexes. The analysis of the frontier orbitals shows that the LUMOs of the complexes mainly reside on the CNT, while the HOMOs spread over both components of each complex. The observed effects may facilitate the design of nanomaterials involving nitrogen bases and CNTs.


Subject(s)
Adenine/chemistry , Cytosine/chemistry , Nanotubes, Carbon/chemistry , Protons , Models, Molecular , Static Electricity , Thermodynamics
12.
Glob Chang Biol ; 20(11): 3530-43, 2014 Nov.
Article in English | MEDLINE | ID: mdl-24756980

ABSTRACT

High-altitude treelines are temperature-limited vegetation boundaries, but little quantitative evidence exists about the impact of climate change on treelines in untouched areas of Russia. Here, we estimated how forest-tundra ecotones have changed during the last century along the Ural mountains. In the South, North, Sub-Polar, and Polar Urals, we compared 450 historical and recent photographs and determined the ages of 11,100 trees along 16 altitudinal gradients. In these four regions, boundaries of open and closed forests (crown covers above 20% and 40%) expanded upwards by 4 to 8 m in altitude per decade. Results strongly suggest that snow was an important driver for these forest advances: (i) Winter precipitation has increased substantially throughout the Urals (~7 mm decade(-1) ), which corresponds to almost a doubling in the Polar Urals, while summer temperatures have only changed slightly (~0.05°C decade(-1) ). (ii) There was a positive correlation between canopy cover, snow height and soil temperatures, suggesting that an increasing canopy cover promotes snow accumulation and, hence, a more favorable microclimate. (iii) Tree age analysis showed that forest expansion mainly began around the year 1900 on concave wind-sheltered slopes with thick snow covers, while it started in the 1950s and 1970s on slopes with shallower snow covers. (iv) During the 20th century, dominant growth forms of trees have changed from multistemmed trees, resulting from harsh winter conditions, to single-stemmed trees. While 87%, 31%, and 93% of stems appearing before 1950 were from multistemmed trees in the South, North and Polar Urals, more than 95% of the younger trees had a single stem. Currently, there is a high density of seedlings and saplings in the forest-tundra ecotone, indicating that forest expansion is ongoing and that alpine tundra vegetation will disappear from most mountains of the South and North Urals where treeline is already close to the highest peaks.


Subject(s)
Climate Change , Forests , Plant Dispersal , Trees/growth & development , Tundra , Altitude , Russia , Seasons , Snow , Temperature
13.
J Phys Chem A ; 113(15): 3621-9, 2009 Apr 16.
Article in English | MEDLINE | ID: mdl-19320448

ABSTRACT

In this work, we have used Raman spectroscopy and quantum chemical methods (MP2 and DFT) to study the interactions between nucleic acid bases (NABs) and single-walled carbon nanotubes (SWCNT). We found that the appearance of the interaction between the nanotubes and the NABs is accompanied by a spectral shift of the high-frequency component of the SWCNT G band in the Raman spectrum to a lower frequency region. The value of this shift varies from 0.7 to 1.3 cm(-1) for the metallic nanotubes and from 2.1 to 3.2 cm(-1) for the semiconducting nanotubes. Calculations of the interaction energies between the NABs and a fragment of the zigzag(10,0) carbon nanotube performed at the MP2/6-31++G(d,p)[NABs atoms]|6-31G(d)[nanotube atoms] level of theory while accounting for the basis set superposition error during geometry optimization allowed us to order the NABs according to the increasing interaction energy value. The order is: guanine (-67.1 kJ mol(-1)) > adenine (-59.0 kJ mol(-1)) > cytosine (-50.3 kJ mol(-1)) approximately = thymine (-50.2 kJ mol(-1)) > uracil (-44.2 kJ mol(-1)). The MP2 equilibrium structures and the interaction energies were used as reference points in the evaluation of the ability of various functionals in the DFT method to predict those structures and energies. We showed that the M05, MPWB1K, and MPW1B95 density functionals are capable of correctly predicting the SWCNT-NAB geometries but not the interaction energies, while the M05-2X functional is capable of correctly predicting both the geometries and the interaction energies.


Subject(s)
Nanotubes, Carbon/chemistry , Nucleic Acids/chemistry , Quantum Theory , Dimerization , Models, Molecular , Sensitivity and Specificity , Spectrum Analysis, Raman , Thermodynamics
15.
J Phys Chem B ; 110(32): 15769-75, 2006 Aug 17.
Article in English | MEDLINE | ID: mdl-16898724

ABSTRACT

IR spectra of photopolymerized fullerene films obtained by simultaneous deposition and UV irradiation were measured in the range of 1500-450 cm(-1). The degree of the polymerization of the C60 films was estimated to be about 95%. To assist the assignment of the experimental IR spectra of the films, quantum chemical calculations of the equilibrium structures of the C60 dimers and trimers were performed at the DFT(B3LYP)/3-21G level of theory. Next, IR frequencies and intensities for those structures were calculated. For the five-trimer structures found in the calculations, the relative stabilities were determined at the B3LYP/4-31G and B3LYP/6-31G levels and used to select the lowest-energy trimers, which are Trimer A (angle between monomer centers is 90 degrees ) and Trimer B (angle between monomer centers is 120 degrees). Next, the IR spectra of the polymerized fullerene films were compared with the calculated frequencies of the lowest-energy dimer and the two lowest-energy trimers. On the basis of this analysis and on the comparison of the film spectra with the IR spectra of the C60 dimer and trimer spectra obtained by other methods, it was shown that the main components of the films are C60 dimers and the orthorhombic (O) polymer phase. The tetragonal (T) and rhombohedral (R) polymers, as well as small amounts of monomers, were also found. Although vibrational frequencies of different C60 phases are similar in most cases, we found several unique spectral features of the C60 dimer and other polymers that may be used to determine the composition of the polymerized C60 film.


Subject(s)
Fullerenes/chemistry , Membranes, Artificial , Models, Chemical , Fullerenes/radiation effects , Photochemistry , Quantum Theory , Sensitivity and Specificity , Spectrophotometry, Infrared/methods , Surface Properties , Ultraviolet Rays
16.
J Mass Spectrom ; 41(1): 113-23, 2006 Jan.
Article in English | MEDLINE | ID: mdl-16382482

ABSTRACT

Satellite [M + 2](+*) and [M + 3](+) peaks accompanying the common peak of the protonated molecule [M + H](+) that are known to indicate the occurrence of a reduction process were observed in the fast atom bombardment (FAB) mass spectra of imidazophenazine dye derivatives in glycerol matrix. The distribution of the abundances in the [M + nH](+) peak group varied noticeably for different derivatives. This indicated different levels of the reduction depending on the different structure variations of the studied molecules. In the search for correlations between the mass spectral pattern and the structural features of the dyes, ab initio HF/6-31++G** quantum chemical calculations were performed. They revealed that the abundances of the [M + 2](+*) and [M + 3](+) ions show growth proportional to the decrease of the energy of the lowest unoccupied molecular orbital, i.e. proportional to the increase of the electron affinity of the dye molecule. A method for rapid screening of reductive properties of sets of dye derivatives on the basis of the FAB mass spectral data is discussed.

17.
Phys Rev Lett ; 94(15): 153004, 2005 Apr 22.
Article in English | MEDLINE | ID: mdl-15904140

ABSTRACT

Precision measurements using the Rydberg charge-exchange and electric field-detachment methods find that the dipole-bound electron affinity (EA) of acetone (C3H6O) is 55+/-10 mueV greater than for deuterated acetone (C3D6O). The result agrees well with a theoretical prediction obtained with high-level electronic-structure and anharmonic vibrational calculations. The dipole moments calculated for the vibrationally averaged structures of C3H6O and C3D6O show that the isotope effect (2% reduction) on the EA of acetone is mainly due to a slight reduction (0.5%) of the average dipole moment upon deuteration.

18.
Rapid Commun Mass Spectrom ; 19(6): 785-97, 2005.
Article in English | MEDLINE | ID: mdl-15714596

ABSTRACT

In the course of a liquid secondary ion mass spectrometric (SIMS) investigation on a bisquaternary ammonium antimicrobial agent, decamethoxinum, unusual pathways of fragmentation of the organic dication M2+ of this bisquaternary salt, with preservation of the doubly charged state of the fragments, were observed. To reveal the structural and electronic parameters of decamethoxinum, which are responsible for the stabilization of its organic dication in the gas phase, a comprehensive SIMS study using metastable decay, collision-induced dissociation and kinetic energy release techniques complemented by ab initio quantum chemical calculations was performed. Pathways of fragmentation of two main precursors originating from decamethoxinum-organic dication M2+ and its cluster with a Cl- counterion [M.Cl]+-and a number of their primary fragments were established and systematized. Differences in the pathways of fragmentation of M2+ and [M.Cl]+ were revealed: the main directions of [M.Cl]+ decay involve dequaternization similar to thermal degradation of this compound, while in M2+ fragmentation via loss of one and two terminal radicals with preservation of the doubly charged state of the fragments dominates over charge separation processes. It was shown that pairing of the dication with a Cl- anion does not preserve the complex from fragmentation via separation of two positively charged centers or neutralization (dequaternization) of one such center. At the same time the low abundance of M2+ in the SIMS spectra is to a larger extent controlled by a probability of M2+ association with an anion than by the decay of the dication per se. Quantum chemical calculations of the structural and electronic parameters of the decamethoxinum dication have revealed at least three features which can provide stabilization of the doubly charged state. Firstly, in the most energetically favorable stretch conformation the distance between the quaternary nitrogens (rN1-N2=1.39 nm) is relatively large. Secondly, an intramolecular solvation of quaternary groups by carbonyl oxygens of the adjacent groups of the dication occurs, which contribute to structural stabilization. Thirdly, an important feature of the electronic structure of the dication is the presence of a partial negative charge on the nitrogen atoms and smearing of a positive charge mainly over the hydrogens of alkyl groups attached to the quaternary nitrogens, which reduces the net repulsion between the quaternary groups. The possible influence of charge smearing on the kinetic energy released on the dication fragmentation is discussed.


Subject(s)
Chromatography, Liquid/methods , Esters/analysis , Esters/chemistry , Models, Chemical , Models, Molecular , Organic Chemicals/chemistry , Quaternary Ammonium Compounds/analysis , Quaternary Ammonium Compounds/chemistry , Spectrometry, Mass, Electrospray Ionization/methods , Anti-Infective Agents/analysis , Anti-Infective Agents/chemistry , Cations, Divalent , Computer Simulation , Reproducibility of Results , Salts/analysis , Salts/chemistry , Sensitivity and Specificity
19.
Radiat Prot Dosimetry ; 116(1-4 Pt 2): 109-12, 2005.
Article in English | MEDLINE | ID: mdl-16604608

ABSTRACT

The developmental version of MCNP5 has recently been extended to provide for continuous-energy transport of high-energy protons. This enhancement involves the incorporation of several significant new physics models into the code. Multiple Coulomb scattering is treated with an advanced model that takes account of projectile and nuclear target form factors. In the next version, this model will provide a coupled sampling of both angular deflection and collisional energy loss, including straggling. The proton elastic scattering model is also new, based on recent theoretical work. Charged particle transport in the presence of magnetic fields is accomplished either by using transfer maps from the COSY INFINITY code (in void regions) or by using an algorithm adapted from the MARS code (in void regions or in scattering materials). Work is underway to validate and implement the latest versions of the Cascade-Exciton Model and the Los Alamos Quark-Gluon String Model, which will process inelastic nuclear interactions and generate secondary particles.


Subject(s)
Monte Carlo Method , Protons , Radiation Protection/methods , Radiographic Image Interpretation, Computer-Assisted/methods , Radiography/methods , Radiometry/methods , Software , Algorithms , Computer Simulation , Computer-Aided Design , Linear Energy Transfer , Models, Statistical , Radiation Dosage , Scattering, Radiation , Software Design , User-Computer Interface
20.
Chem Phys Lipids ; 130(2): 117-26, 2004 Jul.
Article in English | MEDLINE | ID: mdl-15172828

ABSTRACT

Total synthesis of (5Z,8Z,11Z,14Z)-18- and 19-azidoeicosa-5,8,11,14-tetraenoic acids and their [5,6,8,9,11,12,14,15-3H8]-analogues via the corresponding p-toluenesulphonates is reported. This synthetic approach allows the preparation of radioactively labelled arachidonic acid derivatives following a common synthetic route. Activity assays indicated that 15-lipoxygenases may tolerate the azido group in the substrate binding pocket and thus, radioactively labelled azido compounds may be used as photo-affinity probes to investigate mechanistic features of eicosanoid biosynthesis.


Subject(s)
Arachidonic Acid/chemistry , Arachidonic Acid/chemical synthesis , Animals , Arachidonate 15-Lipoxygenase/metabolism , Arachidonic Acid/metabolism , Kinetics , Molecular Structure , Oxidation-Reduction , Rabbits , Reticulocytes/enzymology , Glycine max/enzymology
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