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1.
Int Arch Allergy Immunol ; 185(3): 253-259, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38035559

RESUMEN

INTRODUCTION: Asthma is one of the most common chronic diseases and affects around 334 million people worldwide. The estimated prevalence of severe asthma is 3-10% of the asthmatic population. Mepolizumab has demonstrated efficacy in reducing exacerbations, oral corticosteroid use, and improving quality of life, asthma control, and lung function in patients with severe eosinophilic asthma (SEA). Our study aimed to check the response to mepolizumab in a series of severe asthma patients regarding exacerbations, oral corticosteroid use, asthma control, quality of life, and lung function and to compare the response between patients with and without nasal polyps. METHOD: This is a retrospective, multicenter study of RE-ASGRAMUR (Register of Severe Asthma of the Region of Murcia) performed in eight hospitals of the Region of Murcia (Spain) under routine clinical practice conditions. We included patients diagnosed with SEA who completed at least 1 year of treatment with mepolizumab. We analyzed clinical characteristics, drug tolerance, and effectiveness: exacerbations, ACT, miniAQLQ, forced expiratory volume in 1 s (FEV1), and use of oral corticosteroids. We also compared the results between patients with and without nasal polyps. RESULTS: The median of exacerbations before treatment was 3 and decreased to 0 after treatment (mean decrease of 77.4%). The median diary oral prednisone intake was 15 mg before treatment and 5 mg after treatment (mean 56% reduction). We have obtained a significant improvement in other variables: ED visits and hospitalizations, asthma control (ACT), quality of life (miniAQLQ), and lung function (FEV1). Thirty-four out of 70 patients (48.57%) fulfilled the criteria of super-responder, and 17 out of 70 (24.29%) had a complete response. More patients in the group with nasal polyps fulfilled the criteria of super-responder and complete response to mepolizumab. CONCLUSIONS: Mepolizumab is a safe and effective treatment for SEA patients, improving exacerbations, oral corticosteroid intake, asthma control, quality of life, and lung function. In patients with associated nasal polyposis, there is a statistically significant higher proportion of super-responders and complete responders.


Asunto(s)
Antiasmáticos , Anticuerpos Monoclonales Humanizados , Asma , Pólipos Nasales , Eosinofilia Pulmonar , Humanos , Antiasmáticos/uso terapéutico , Calidad de Vida , Pólipos Nasales/complicaciones , Pólipos Nasales/tratamiento farmacológico , Estudios Retrospectivos , Asma/complicaciones , Asma/tratamiento farmacológico , Eosinofilia Pulmonar/tratamiento farmacológico , Corticoesteroides/uso terapéutico , Resultado del Tratamiento , Respuesta Patológica Completa
2.
Chemphyschem ; 25(11): e202400072, 2024 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-38470127

RESUMEN

The structure of isolated 1-chloronaphthalene has been investigated in a supersonic expansion by high-resolution chirped-pulse Fourier transform microwave (CP-FTMW) spectroscopy in the 2-8 GHz frequency range. Accurate values of the rotational, centrifugal distortion, and nuclear quadrupole coupling constants for the only availabe conformer have been determined. The intensity of the spectrum allowed us to observe all the heavy atoms isotopologues in natural abundance, determining their rotational constants. From the extensive experimental dataset we derived accurate structures for 1-chloronaphthalene using different methodologies and compared with related compounds.

3.
Phys Chem Chem Phys ; 26(3): 1881-1890, 2024 Jan 17.
Artículo en Inglés | MEDLINE | ID: mdl-38175733

RESUMEN

The rotational spectra of 4'-aminoacetophenone, and those of two conformers (Z and E arrangement of the CO and NH2 groups) of 3'-aminoacetophenone and their 13C and 15N isotopologues were investigated both in the microwave (2-8 GHz) and millimetre (59.6-74.4 GHz) frequency regions using chirped pulse Fourier transform and free-jet absorption techniques, respectively. The spectra consist of µa and µb type lines that show a hyperfine structure due to both the nuclear quadrupole coupling of the 14N nucleus and the methyl internal rotation. Relative intensity measurements show that the Z form in 3'-aminoacetophenone is favoured with respect to E and the measured energy difference upper limit is about 5.5(1) kJ mol-1. Barriers to methyl internal rotation are V3 = 7.04(2) and 6.530(6) kJ mol-1 for 3'(Z)- and 4'-aminoacetophenone, respectively. Flexible model analyses of the amino inversion motion based on ab initio potential energy paths, suggest that the corresponding vibrational splitting increases up to 78% from aniline to 3'(E)-, 3'(Z), and 4-aminoacetophenone. However, due to supersonic expansion cooling, no splitting related to amine inversion is observed.

4.
J Chem Phys ; 160(16)2024 Apr 28.
Artículo en Inglés | MEDLINE | ID: mdl-38686817

RESUMEN

Microsolvation of the carbamate moiety delivers precise information on complexation effects on the N-C=O backbone and is of relevance to the peptide bond functionality. In this context, the mono-, di-, and trihydrated complexes of methyl carbamate have been studied in molecular expansion by high-resolution microwave spectroscopy, using chirped-pulse and Fabry-Perot resonator Fourier transform microwave instruments covering the frequency range from 2 to 18 GHz. From the rotational constants of the parent and the 18Ow substituted monoisotopologues, accurate values have been derived for the geometries of the hydrogen bond interactions. The nuclear quadrupole coupling constant χcc of the nitrogen nucleus provides a direct measure of complexation changes and decreases with the degree of hydration, whereas the hindered internal rotation barrier increases slightly with microsolvation. Both tendencies could have a common origin in the π-cooperative inductive effects as the microsolvation series progresses. All transitions are split by the internal rotation of the methyl top and the nuclear quadrupole coupling, and in the largest cluster, they are additionally split by an inversion motion.

5.
Int J Mol Sci ; 25(7)2024 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-38612884

RESUMEN

We present a study of salicylic acid and its hydrates, with up to four water molecules, done by employing chirped-pulse Fourier transform microwave spectroscopy. We employed the spectral data set of the parent, 13C, and 2H isotopologues to determine the molecular structure and characterize the intra- and intermolecular interactions of salicylic acid and its monohydrate. Complementary theoretical calculations were done to support the analysis of the experimental results. For the monomer, we analyzed structural properties, such as the angular-group-induced bond alternation (AGIBA) effect. In the microsolvates, we analyzed their main structural features dominated by the interaction of water with the carboxylic acid group. This work contributes to seeding information on how water molecules accumulate around this group. Moreover, we discussed the role of cooperative effects further stabilizing the observed inter- and intramolecular hydrogen bond interactions.


Asunto(s)
Ácido Salicílico , Agua , Estructura Molecular , Análisis Espectral , Espectrometría de Masas
6.
Curr Issues Mol Biol ; 45(2): 799-819, 2023 Jan 17.
Artículo en Inglés | MEDLINE | ID: mdl-36825998

RESUMEN

Chronic obstructive pulmonary disease (COPD) is the third leading cause of death worldwide; the main risk factors associated with the suffering are tobacco smoking (TS) and chronic exposure to biomass-burning smoke (BBS). Different biological pathways have been associated with COPD, especially xenobiotic or drug metabolism enzymes. This research aims to identify single nucleotide polymorphisms (SNPs) profiles associated with COPD from two expositional sources: tobacco smoking and BBS. One thousand-five hundred Mexican mestizo subjects were included in the study and divided into those exposed to biomass-burning smoke and smokers. Genome-wide exome genotyping was carried out using Infinium Exome-24 kit arrays v. 1.2. Data quality control was conducted using PLINK 1.07. For clinical and demographic data analysis, Rstudio was used. Eight SNPs were found associated with COPD secondary to TS and seven SNPs were conserved when data were analyzed by genotype. When haplotype analyses were carried out, five blocks were predicted. In COPD secondary to BBS, 24 SNPs in MGST3 and CYP family genes were associated. Seven blocks of haplotypes were associated with COPD-BBS. SNPs in the ARNT2 and CYP46A1 genes are associated with COPD secondary to TS, while in the BBS comparison, SNPs in CYP2C8, CYP2C9, MGST3, and MGST1 genes were associated with increased COPD risk.

7.
Chemistry ; 29(25): e202300064, 2023 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-36827623

RESUMEN

The combination of atropisomerism and chirality in flurbiprofen is shown to be relevant concerning its pharmacological activity. The two most stable conformers of a total of eight theoretically predicted for each R- or S- flurbiprofen enantiomers have been isolated in the cooling conditions of a supersonic jet and structurally characterized by laser ablation Fourier transform microwave spectroscopy. The detected conformers, whose structure is mainly defined by three dihedral angles, only differ in the sign of the phenyl torsion angle giving rise to Sa and Ra atropisomers. A comparison with the structures available for the R- and S- enantiomers complexed to COX isoforms reveals that the enzymes select only the Sa atropisomers, resulting in a diastereoisomer-specific recognition. The most stable gas phase conformer is exclusively selected when using the S- enantiomer while the second is recognized only for the R- enantiomer. These experimental results highlight the importance of atropisomerism in drug design.


Asunto(s)
Flurbiprofeno , Terapia por Láser , Conformación Molecular , Análisis Espectral/métodos , Rayos Láser
8.
Inorg Chem ; 62(35): 14411-14421, 2023 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-37616569

RESUMEN

Unsymmetrical dicarboxylato complexes [Pt(tpy)2(O2CR)2] [tpy = cyclometalated 2-(p-tolyl)pyridine, R = Me, CF3] react with the terminal alkynes 4-methoxyphenylacetylene, phenylacetylene, 4-(trifluoromethyl)phenylacetylene or 3,5-difluorophenylacetylene in the presence of a base to produce complexes mer-[Pt(tpy)2(O2CR)(CCAr)], in which the metalated carbon atoms are in a meridional arrangement. Irradiation of the trifluoroacetato derivatives with a 365 nm LED source leads to isomerization to the facial complexes, which can be converted to chlorido derivatives upon reaction with NH4Cl. In contrast, irradiation of the acetato derivatives leads to four different processes, namely, reduction to cis-[Pt(tpy)2], annulations involving one of the tpy ligands and the Cα and Cß atoms of the alkynyl to give benzoquinolizinium derivatives, isomerization to the facial geometry, or C-O couplings between the acetato ligand and one tpy. The first two processes are favored by the presence of electron-donating groups on the alkynyl, whereas electron-withdrawing groups favor the last two. Irradiation of complexes fac-[Pt(tpy)2(O2CCF3)(CCAr)] with a medium-pressure Hg UV lamp leads to a reductive C-C coupling involving the alkynyl Cα atom and one of the tpy ligands to give pyridoisoindolium derivatives, except for the methoxyphenylacetylide derivative, which is photostable. On the basis of TDDFT calculations, the photoreactivity of the mer complexes is attributed to 3LLCT [π(alkynyl) → π*(tpy)] excited states for annulations or 3LMCT [π(alkynyl) → dσ*] excited states for the rest of the processes, which are accessible through thermal population from 3LC(tpy) states. The C-C couplings from the fac complexes are attributed to photoreactive pentacoordinate intermediates.

9.
Inorg Chem ; 62(43): 17843-17850, 2023 Oct 30.
Artículo en Inglés | MEDLINE | ID: mdl-37845787

RESUMEN

In this work, we present a series of luminescent platinum acetylide complexes with acetylides that are electronically modified and/or π-extended. Six isocyanide-supported complexes with the general formula cis-[Pt(CNAr)2(C≡CR)2] and six acyclic diaminocarbene (ADC) complexes of the form trans-[Pt(ADC)2(C≡CR)2], all using the same five acetylide ligands, are described. The compounds are characterized by multinuclear NMR, FT-IR, and single-crystal X-ray diffraction. In most cases, the phosphorescence arises from an acetylide-centered 3(π → π*) excited state, although in one of the isocyanide compounds there is evidence for a charge-transfer excited state. The photoluminescence wavelength depends strongly on the substitution pattern and extent of the π conjugation on the acetylide, with maxima spanning the range of ca. 460-540 nm. Most photoluminescence lifetimes are long, beyond 50 µs, and quantum yields are low to moderate, 0.043-0.27. The photoluminescence quantum yields and lifetimes in these compounds do not systematically improve in the ADC complexes compared to the isocyanide versions, suggesting the neutral ligand σ-donor character does not play a large role in the excited-state dynamics when the triplet excited state is delocalized over a large π system.

10.
Environ Res ; 239(Pt 2): 117376, 2023 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-37832766

RESUMEN

Most of methane (CH4) emissions contain low CH4 concentrations and typically occur at irregular intervals, which hinders the implementation and performance of methane abatement processes. This study aimed at understanding the metabolic mechanisms that allow methane oxidizing bacteria (MOB) to survive for long periods of time under methane starvation. To this aim, we used an omics-approach and studied the diversity and metabolism of MOB and non-MOB in bioreactors exposed to low CH4 concentrations under feast-famine cycles of 5 days and supplied with nutrient-rich broth. The 16S rRNA and the pmoA transcripts revealed that the most abundant and active MOB during feast and famine conditions belonged to the alphaproteobacterial genus Methylocystis (91-65%). The closest Methylocystis species were M. parvus and M. echinoides. Nitrifiers and denitrifiers were the most representative non-MOB communities, which likely acted as detoxifiers of the system. During starvation periods, the induced activity of CH4 oxidation was not lost, with the particulate methane monooxygenase of alphaproteobacterial MOB playing a key role in energy production. The polyhydroxyalkanoate and nitrification metabolisms of MOB had also an important role during feast-famine cycles, maintaining cell viability when CH4 concentrations were negligible. This research shows that there is an emergence and resilience of conventional alphaproteobacterial MOB, being the genus Methylocystis a centrepiece in environments exposed to dilute and intermittent methane emissions. This knowledge can be applied to the operation of bioreactors subjected to the treatment of dilute and discontinuous emissions via controlled bioaugmentation.


Asunto(s)
Reactores Biológicos , Metano , ARN Ribosómico 16S/genética , Oxidación-Reducción , Microbiología del Suelo
11.
Arch Virol ; 167(12): 2795-2800, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36085531

RESUMEN

Human papillomavirus 31 (HPV31) is the fourth most frequent high-risk HPV (HR-HPV) genotype identified in cervical cancer (CC) worldwide and in Mexico. It has been recently classified into three lineages (A, B, and C) and eight sublineages (A1, A2, B1, B2, and C1 - C4). Here, we report the complete genomic sequences of 14 HPV31 isolates from cervical samples, and these were compared with viral genome sequences from the GenBank database for phylogenetic and genetic distance analysis. The formation of two novel clades within the C lineage (proposed as C5 and C6) was observed, with a well-defined variant-specific mutational pattern. The smallest average pairwise distance was 0.71% for lineages A and B, 0.94% for lineages A and C, and 1.01% for lineages B and C, and between sublineages, these values were 0.21% for clade A, 0.29% for clade B, and 0.24% for clade C. The isolates were grouped into the sublineages A1, B2, C1-C3, and C6. This is the first report on the whole-genome diversity of HPV31 in Mexico.


Asunto(s)
Infecciones por Papillomavirus , Neoplasias del Cuello Uterino , Femenino , Humanos , Virus del Papiloma Humano , Filogenia , Variación Genética , Papillomavirus Humano 31/genética , Genotipo , Genoma Viral
12.
Phys Chem Chem Phys ; 24(25): 15484-15493, 2022 Jun 29.
Artículo en Inglés | MEDLINE | ID: mdl-35713114

RESUMEN

Complexes formed by pyridine and small ketones such as acetone and 2-butanone have been generated in a supersonic jet and characterized by broadband Fourier transform microwave spectroscopy combined with high-level theoretical computations. The spectra of the complexes show a quadrupole coupling hyperfine structure due to the presence of a nitrogen atom and the splittings owing to the low barriers of the internal rotation of the methyl groups bonded to the carbonyl group. The corresponding barriers have been determined from the analysis of the spectra. We show in both complexes that pyridine closes a cycle with a ketone carbonyl group through an N⋯CO n→π* tetrel interaction and a C-H⋯O contact. The n→π* tetrel bond involves the pyridine N atom lone pair and the ketone carbonyl group with a geometry approaching the Bürgi-Dunitz trajectory for the nucleophilic attack to a carbonyl group.

13.
Allergol Immunopathol (Madr) ; 50(6): 163-168, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36335460

RESUMEN

INTRODUCTION: Clinical trials and real-life studies have been published showing effectiveness of benralizumab in severe eosinophilic asthmatic patients. The aim of the present study is to describe super-responders to benralizumab in a series of 79 patients who completed at least 1 year of treatment, and to compare super-responders with non super-responders. METHODS: This is a multicenter study of the Register of Severe Asthma of the Region of Murcia (RE-ASGRAMUR) Group performed in eight hospitals under the conditions of routine clinical practice. Patients with zero exacerbations and no oral corticosteroid therapy for asthma were considered super-responders. We analyzed clinical, functional, and inflammatory parameters of selected patients. RESULTS: In all, 50 of the 79 patients (63%) met the super-responder criteria. In addition, 36% of the patients (26/71) were considered as complete responders to treatment (super--responder + Asthma Control Test [ACT] ≥ 20 + forced expiratory volume in 1 s [FEV1] ≥ 80%). The super--responders were significantly older in age (P = 0.0029), had higher eosinophils count (P = 0.0423), higher proportion of nasal polyps (P = 0.036), and they had less severe disease at baseline. After 1 year of treatment, the super-responders had higher levels of ACT questionnaire (23 vs 19, P = 0.0007) and better percentage of FEV1 (83 vs 75, P = 0.0359). CONCLUSION: Almost two of the three patients treated with benralizumab were super--responders after 1 year of treatment and 36% had a complete response. Super-responders were associated with older age, higher eosinophils count, had nasal polyposis as comorbidity, and had less severe disease at baseline. This data illustrated the good real-life response of patients with severe eosinophilic asthma to the treatment with benralizumab.


Asunto(s)
Antiasmáticos , Asma , Pólipos Nasales , Eosinofilia Pulmonar , Humanos , Antiasmáticos/uso terapéutico , Eosinófilos , Asma/tratamiento farmacológico , Eosinofilia Pulmonar/tratamiento farmacológico , Progresión de la Enfermedad
14.
Sensors (Basel) ; 22(19)2022 Oct 09.
Artículo en Inglés | MEDLINE | ID: mdl-36236738

RESUMEN

Hyperspectral imaging opens up new opportunities for masked face recognition via discrimination of the spectral information obtained by hyperspectral sensors. In this work, we present a novel algorithm to extract facial spectral-features from different regions of interests by performing computer vision techniques over the hyperspectral images, particularly Histogram of Oriented Gradients. We have applied this algorithm over the UWA-HSFD dataset to extract the facial spectral-features and then a set of parallel Support Vector Machines with custom kernels, based on the cosine similarity and Euclidean distance, have been trained on fly to classify unknown subjects/faces according to the distance of the visible facial spectral-features, i.e., the regions that are not concealed by a face mask or scarf. The results draw up an optimal trade-off between recognition accuracy and compression ratio in accordance with the facial regions that are not occluded.


Asunto(s)
Reconocimiento Facial , Algoritmos , Máquina de Vectores de Soporte
15.
Int J Mol Sci ; 23(17)2022 Aug 29.
Artículo en Inglés | MEDLINE | ID: mdl-36077225

RESUMEN

Anxiety is the most prevalent psychiatric disorder worldwide, causing a substantial economic burden due to the associated healthcare costs. Given that commercial anxiolytic treatments may cause important side effects and have medical restrictions for prescription and high costs, the search for new natural and safer treatments is gaining attention. Since lupin protein hydrolysate (LPH) has been shown to be safe and exert anti-inflammatory and antioxidant effects, key risk factors for the anxiety process and memory impairment, we evaluated in this study the potential effects of LPH on anxiety and spatial memory in a Western diet (WD)-induced anxiety model in ApoE-/- mice. We showed that 20.86% of the 278 identified LPH peptides have biological activity related to anxiolytic/analgesic effects; the principal motifs found were the following: VPL, PGP, YL, and GQ. Moreover, 14 weeks of intragastrical LPH treatment (100 mg/kg) restored the WD-induced anxiety effects, reestablishing the anxiety levels observed in the standard diet (SD)-fed mice since they spent less time in the anxiety zones of the elevated plus maze (EPM). Furthermore, a significant increase in the number of head dips was recorded in LPH-treated mice, which indicates a greater exploration capacity and less fear due to lower levels of anxiety. Interestingly, the LPH group showed similar thigmotaxis, a well-established indicator of animal anxiety and fear, to the SD group, counteracting the WD effect. This is the first study to show that LPH treatment has anxiolytic effects, pointing to LPH as a potential component of future nutritional therapies in patients with anxiety.


Asunto(s)
Ansiolíticos , Animales , Ansiolíticos/farmacología , Ansiolíticos/uso terapéutico , Ansiedad/tratamiento farmacológico , Ansiedad/psicología , Apolipoproteínas E/genética , Apolipoproteínas E/farmacología , Conducta Animal , Dieta Occidental/efectos adversos , Humanos , Aprendizaje por Laberinto , Ratones , Hidrolisados de Proteína/farmacología , Hidrolisados de Proteína/uso terapéutico
16.
Molecules ; 28(1)2022 Dec 24.
Artículo en Inglés | MEDLINE | ID: mdl-36615353

RESUMEN

The rotational spectrum of laser-ablated gallic acid has been recorded using CP-FTMW spectroscopy. Two rotamers have been detected, and their rotational spectra have been assigned and analyzed to obtain the molecular spectroscopic parameters. The observed rotamers have been unambiguously identified in the light of theoretical computations, based on the comparison of the experimental line intensities and rotational parameters with the rotational constants and electric dipole moments predicted from theoretical calculations. The values of the planar inertial moments confirm that the observed conformers are planar, and their relative stability and population have been determined from relative intensity measurements. The B3LYP-D3/6-311++G(2d,p) level has been shown to be the best method among a series of levels normally used to predict the rotational parameters in rotational spectroscopy. In the observed conformers, the three adjacent OH groups are arranged in a sequential form, and the only difference between them lies in the orientation of the COOH group. Although weak attractive OH···O interactions seem to exist, the analysis of the electron density topology does not show the existence of any critical point corresponding to these interactions.


Asunto(s)
Terapia por Láser , Conformación Molecular , Análisis Espectral , Rayos Láser
17.
Entropy (Basel) ; 24(7)2022 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-35885099

RESUMEN

Density-Based Spatial Clustering of Applications with Noise (DBSCAN) is a widely used algorithm for exploratory clustering applications. Despite the DBSCAN algorithm being considered an unsupervised pattern recognition method, it has two parameters that must be tuned prior to the clustering process in order to reduce uncertainties, the minimum number of points in a clustering segmentation MinPts, and the radii around selected points from a specific dataset Eps. This article presents the performance of a clustering hybrid algorithm for automatically grouping datasets into a two-dimensional space using the well-known algorithm DBSCAN. Here, the function nearest neighbor and a genetic algorithm were used for the automation of parameters MinPts and Eps. Furthermore, the Factor Analysis (FA) method was defined for pre-processing through a dimensionality reduction of high-dimensional datasets with dimensions greater than two. Finally, the performance of the clustering algorithm called FA+GA-DBSCAN was evaluated using artificial datasets. In addition, the precision and Entropy of the clustering hybrid algorithm were measured, which showed there was less probability of error in clustering the most condensed datasets.

18.
Chemistry ; 27(55): 13870-13878, 2021 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-34347915

RESUMEN

The rotational spectrum of the weakly bound complex pentafluoropyridine⋅⋅⋅formaldehyde has been investigated using Fourier transform microwave spectroscopy. From the analysis of the rotational parameters of the parent species and of the 13 C and 15 N isotopologues, the structural arrangement of the adduct has been unambiguously established. The full ring fluorination of pyridine has a dramatic effect on its binding properties: It alters the electron density distribution at the π-cloud of pyridine creating a π-hole and changing its electron donor-acceptor capabilities. In the complex, formaldehyde lies above the aromatic ring with one of the oxygen lone pairs, as conventionally envisaged, pointing toward its centre. This lone pair⋅⋅⋅π-hole interaction, reinforced by a weak C-H⋅⋅⋅N interaction, indicates an exchange of the electron-acceptor roles of both molecules when compared to the pyridine⋅⋅⋅formaldehyde adduct. Tunnelling doublets due to the internal rotation of formaldehyde have also been observed and analysed leading to a discussion on the competition between lone pair⋅⋅⋅π-hole and π⋅⋅⋅π stacking interactions.

19.
Chemistry ; 27(5): 1680-1687, 2021 Jan 21.
Artículo en Inglés | MEDLINE | ID: mdl-32976672

RESUMEN

The water adducts of triacetone triperoxide (TATP) have been observed by using broadband rotational spectroscopy. This work opens a new way for the gas-phase detection of this improvised explosive. The observed clusters exhibit unusual water dynamics and rarely observed multicenter interactions. TATP-H2 O is formed from the D3 symmetry conformer of TATP with water lying close to the C3 axis. Water rotation around this axis with a very low barrier gives rise to the rotational spectrum of a symmetric top. The main interaction of the monohydrate is a four-center trifurcated donor Ow -H⋅⋅⋅O hydrogen bond, not observed previously in the gas phase, reinforced by a weak four-center trifurcated acceptor C-H⋅⋅⋅Ow interaction. Surprisingly, all structural signatures show the weakness of these interactions. The complex TATP-(H2 O)2 is formed from the monohydrated TATP by the self-association of water.

20.
Phys Chem Chem Phys ; 23(24): 13705-13713, 2021 Jun 23.
Artículo en Inglés | MEDLINE | ID: mdl-34128013

RESUMEN

Thalidomide is a drug that presents two enantiomers with markedly different pharmacological and toxicological activities. It is sadly famous due to its teratogenic effects mostly caused by the preferential docking of the (S)-enantiomer to the target protein cereblon (CRBN). To compare the structure of the bound CRBN thalidomide enantiomers with that of the isolated molecule, the rotational spectrum of laser-ablated thalidomide has been studied by chirp-pulsed Fourier transform microwave spectroscopy in supersonic jets complemented by theoretical computations. A new setup of the laser ablation nozzle used is presented. Two stable equatorial and axial conformers of thalidomide have been predicted corresponding to the two possible bent conformations exhibited by the glutarimide moiety. Only the most stable equatorial conformer has been detected. The comparison of its structure with those of the (S)- and (R)-enantiomers bound to CBRN shows that the bound (S) species is only slightly distorted. On the contrary, the bound (R)-enantiomer exhibits a highly distorted structure which affects the degree of puckering of the glutarimide ring and especially to the orientation of the phtalimide and glutarimide subunits. This is consistent with a less stable (R)-enantiomer and the known preference of (S)-thalidomide to bind CRBN, which starts the process leading to teratogenic effects.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/antagonistas & inhibidores , Rayos Láser , Talidomida/farmacología , Ubiquitina-Proteína Ligasas/antagonistas & inhibidores , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Humanos , Conformación Molecular , Rotación , Estereoisomerismo , Talidomida/química , Talidomida/aislamiento & purificación , Ubiquitina-Proteína Ligasas/metabolismo
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