Impact of the Acetyl Group on Cysteine: A Study of N-Acetyl-Cysteine through Rotational Spectroscopy.

Herein, we report a spectroscopic study of N-acetyl-L-cysteine, an important antioxidant drug, using Fourier-transform microwave techniques and in isolated conditions. Two conformers are observed, where most stable structure adopts a cis disposition, and the second conformer has a lower abundance and adopts a trans disposition. The rotational constants and the barriers to methyl internal rotation are determined for each conformer, allowing a precise conformation identification. The results show that the cis form adopts an identical structure in the crystal, solution, and gas phases. Additionally, the structures are contrasted against those of cysteine.

Fumadores y riesgo de muerte hospitalaria por COVID calculado con el procesamiento de lenguaje natural de SAVANA en el ámbito de Castilla-La Mancha / Smokers and risk of hospital death by COVID calculated with SAVANA's natural language processing in the Castilla-La Mancha area

Introducción Durante la pandemia de COVID se especuló que los pacientes con el virus que tenían relación con el tabaco podrían tener una menor probabilidad de agravamiento de la enfermedad o muerte. Para evaluar si existe una asociación entre el tabaquismo y el riesgo de mortalidad intrahospitalaria se utiliza la tecnología de Big Data y Procesamiento del Lenguaje Natural (PLN) de SAVANA. Método Se llevó a cabo un estudio de cohortes retrospectivo, observacional y sin intervención basado en datos de vida real extraídos de registros médicos de toda Castilla-La Mancha utilizando las técnicas de PLN e inteligencia artificial desarrolladas por SAVANA. El estudio abarcó toda la población de esta Comunidad con historia clínica electrónica en SESCAM que presentara diagnóstico de COVID desde el 1 de marzo de 2020 al 28 de febrero de 2021. Resultados Los fumadores tienen mayor porcentaje de factores de riesgo cardiovascular (hipertensión arterial, dislipemia y diabetes), EPOC, asma, EPID, CI, ECV, TEP, cáncer en general y cáncer de pulmón en particular, bronquiectasias, insuficiencia cardíaca y antecedentes de neumonía, de forma significativa (p<0,0001). Los pacientes exfumadores, fumadores y no fumadores tienen una diferencia de edad significativa. En cuanto a las muertes hospitalarias, fueron más frecuentes en el caso de los exfumadores, siguiendo los fumadores y luego los no fumadores (p<0,0001). Conclusión Existe un mayor riesgo de mortalidad intrahospitalaria en los pacientes infectados por SARS-CoV-2 que sean fumadores activos o hayan fumado en el pasado. (AU)

Introduction During the COVID pandemic, it was speculated that patients with the virus who were smoking-related might have a lower likelihood of disease exacerbation or death. To assess whether there is an association between smoking and risk of in-hospital mortality, SAVANA's big data and natural language processing (NLP) technology is used. Method A retrospective, observational, non-interventional cohort study was conducted based on real-life data extracted from medical records throughout Castilla-La Mancha using natural language processing and artificial intelligence techniques developed by SAVANA. The study covered the entire population of this region with Electronic Medical Records in SESCAM presenting with a diagnosis of COVID from March 1, 2020 to February 28, 2021. Results Smokers had a significantly higher percentage of cardiovascular risk factors (hypertension, dyslipidemia and diabetes), COPD, asthma, IDP, IC, CVD, PTE, cancer in general and lung cancer in particular, bronchiectasis, heart failure and a history of pneumonia (P<.0001). Former smokers, current smokers and non-smokers have a significant age difference. As for in-hospital deaths, they were more frequent in the case of ex-smokers, followed by smokers and then non-smokers (P<.0001). Conclusion There is an increased risk of dying in hospital in SARS-CoV-2-infected patients who are active smokers or have smoked in the past. (AU)

Fumadores y riesgo de muerte hospitalaria por COVID calculado con el procesamiento de lenguaje natural de SAVANA en el ámbito de Castilla-La Mancha / Smokers and risk of hospital death by COVID calculated with SAVANA's natural language processing in the Castilla-La Mancha area

Introducción Durante la pandemia de COVID se especuló que los pacientes con el virus que tenían relación con el tabaco podrían tener una menor probabilidad de agravamiento de la enfermedad o muerte. Para evaluar si existe una asociación entre el tabaquismo y el riesgo de mortalidad intrahospitalaria se utiliza la tecnología de Big Data y Procesamiento del Lenguaje Natural (PLN) de SAVANA. Método Se llevó a cabo un estudio de cohortes retrospectivo, observacional y sin intervención basado en datos de vida real extraídos de registros médicos de toda Castilla-La Mancha utilizando las técnicas de PLN e inteligencia artificial desarrolladas por SAVANA. El estudio abarcó toda la población de esta Comunidad con historia clínica electrónica en SESCAM que presentara diagnóstico de COVID desde el 1 de marzo de 2020 al 28 de febrero de 2021. Resultados Los fumadores tienen mayor porcentaje de factores de riesgo cardiovascular (hipertensión arterial, dislipemia y diabetes), EPOC, asma, EPID, CI, ECV, TEP, cáncer en general y cáncer de pulmón en particular, bronquiectasias, insuficiencia cardíaca y antecedentes de neumonía, de forma significativa (p<0,0001). Los pacientes exfumadores, fumadores y no fumadores tienen una diferencia de edad significativa. En cuanto a las muertes hospitalarias, fueron más frecuentes en el caso de los exfumadores, siguiendo los fumadores y luego los no fumadores (p<0,0001). Conclusión Existe un mayor riesgo de mortalidad intrahospitalaria en los pacientes infectados por SARS-CoV-2 que sean fumadores activos o hayan fumado en el pasado. (AU)

Introduction During the COVID pandemic, it was speculated that patients with the virus who were smoking-related might have a lower likelihood of disease exacerbation or death. To assess whether there is an association between smoking and risk of in-hospital mortality, SAVANA's big data and natural language processing (NLP) technology is used. Method A retrospective, observational, non-interventional cohort study was conducted based on real-life data extracted from medical records throughout Castilla-La Mancha using natural language processing and artificial intelligence techniques developed by SAVANA. The study covered the entire population of this region with Electronic Medical Records in SESCAM presenting with a diagnosis of COVID from March 1, 2020 to February 28, 2021. Results Smokers had a significantly higher percentage of cardiovascular risk factors (hypertension, dyslipidemia and diabetes), COPD, asthma, IDP, IC, CVD, PTE, cancer in general and lung cancer in particular, bronchiectasis, heart failure and a history of pneumonia (P<.0001). Former smokers, current smokers and non-smokers have a significant age difference. As for in-hospital deaths, they were more frequent in the case of ex-smokers, followed by smokers and then non-smokers (P<.0001). Conclusion There is an increased risk of dying in hospital in SARS-CoV-2-infected patients who are active smokers or have smoked in the past. (AU)

Identification of Cryptosporidium parvum and Blastocystis hominis subtype ST3 in Cholga mussel and treated sewage: Preliminary evidence of fecal contamination in harvesting area.

Cryptosporidium parvum and Blastocystis hominis are foodborne parasites known for causing diarrhea. They accumulate in mussels grown on contaminated water bodies, due to the discharge of treated sewage from sewage treatment plants (STP). Despite this, some countries like Chile do not include these parasites in the control or monitoring of sewage water. The objective of this research was to evaluate the contamination of C. parvum. and B. hominis from treated sewage (disinfected by chlorination) and Cholga mussels in a touristic rural cove from the bay of Concepción. Cholga mussels from commercial stores and a treated sewage sample were analyzed. Cryptosporidium spp. was identified by Ziehl-Neelsen-Staining (ZNS) and C. parvum by direct-immunofluorescence assay (IFA) from ZNS-positive samples. Blastocystis hominis was identified by PCR using locus SSU rDNA. C. parvum and B. hominis subtype ST3 were found in 40% and 45% of Cholga mussel samples, respectively, and both parasites were identified in the treated sewage. Blastocystis hominis SSU rDNA gene alignment from Cholga mussels and treated sewage showed 89% of similarity, indicating that could be the same parasite in both samples. We describe the first evidence of possible contamination with these parasites from treated sewage to Cholga mussel suggesting an environmental contamination with high human risk. Based on these results, further studies will consider all the rural coves and STP from the bay to prevent possible contamination of these parasites.

Protozoan parasites and free-living amoebae contamination in organic leafy green vegetables and strawberries from Spain.

In this study, the presence of Acanthamoeba spp., Blastocystis sp., Cryptosporidium spp., Cyclospora cayetanensis, Entamoeba histolytica, Giardia sp., Toxoplasma gondii and Vermamoeba vermiformis was assessed in organic leafy green vegetables (lettuce, spinach, cabbage) and fruits (strawberry), which are usually consumed raw. A total of 110 organic samples were collected in Valencia (Spain). Protozoa were concentrated before detection by immunofluorescence (Cryptosporidium spp. and Giardia sp.) or real-time qPCR (Acanthamoeba spp., Blastocystis sp., C. cayetanensis, E. histolytica, T. gondii and V. vermiformis). The most abundant protozoa in organic vegetables and berry fruits were Acanthamoeba (65.5%), followed by T. gondii (37.2%), V. vermiformis (17.3%), C. cayetanensis (12.7%), Cryptosporidium spp. (6.8%), Blastocystis sp. (1.8%) and Giardia sp. (1.7%). E. histolytica was not found in any of the organic samples. Thus, results showed that consumers can be exposed to protozoan parasites by consuming organic vegetables and berry fruits. This is the first report in Spain describing the presence of the protozoan pathogens Acanthamoeba spp., Blastocystis sp., C. cayetanensis, T. gondii and V. vermiformis, Cryptosporidium spp. and Giardia sp. in organic fresh produce. The results of this research will help determine the risk of foodborne protozoan parasites on organic leafy greens and strawberries that are available at local markets.

Hemorrhagic cystitis following allogeneic hematopoietic stem cell transplantation: experience in a pediatric oncological institution. / Cistitis hemorrágica tras trasplante alogénico de progenitores hematopoyéticos: experiencia en un centro oncológico pediátrico.

OBJECTIVE: To analyze the risk factors associated with hemorrhagic cystitis (HC) severity and the treatment strategies available in HC patients following allogeneic hematopoietic stem cell transplantation (AHSCT). MATERIALS AND METHODS: A retrospective study of medical records was carried out. Patients with HC following AHSCT treated from 2017 to 2021 were divided into two groups according to severity -mild and severe. Demographic data, disease-specific characteristics, urological sequelae, and overall mortality were compared between both groups. The hospital's protocol was used for patient management. RESULTS: 33 episodes of HC were collected in 27 patients, 72.7% of whom were male. HC incidence following AHSCT was 23.4% (33/141). 51.5% of HCs were severe (grades III-IV). Severe graft host disease (GHD) (grades III-IV) and thrombopenia at HC onset were associated with severe HC (p= 0.043 and p= 0.039, respectively). This group had longer hematuria times (p< 0.001) and required more platelet transfusions (p= 0.003). In addition, 70.6% required bladder catheterization, but only 1 case needed percutaneous cystostomy. None of the patients with mild HC required catheterization. No differences were found in terms of urological sequelae or overall mortality. CONCLUSIONS: Severe HC could be predicted thanks to the presence of severe GHD or thrombopenia at HC onset. Severe HC can be managed with bladder catheterization in most of these patients. A standardized protocol may help reduce the need for invasive procedures in patients with mild HC.

OBJETIVO: Analizar factores de riesgo asociados a la gravedad de la cistitis hemorrágica (CH) y estrategias de tratamiento en pacientes con CH tras trasplante alogénico de progenitores hematopoyéticos (TAPH). MATERIAL Y METODOS: Estudio retrospectivo de historias clínicas. Los pacientes con CH tras TAPH tratados entre 2017 y 2021 se dividieron en dos grupos según la gravedad del cuadro (leve y grave). Se compararon datos demográficos, características específicas de la enfermedad, secuelas urológicas y mortalidad global entre ambos grupos. Se utilizó el protocolo del hospital para el manejo de los pacientes. RESULTADOS: Se recogieron 33 episodios de CH en 27 pacientes, de los cuales el 72,7% fueron varones. La incidencia de CH tras TAPH fue del 23,4% (33/141). El 51,5% de las CH fueron graves (grados III-IV). La enfermedad de injerto contra huésped (EICH) grave (grados III-IV) y la trombopenia al inicio se asociaron a CH grave (p= 0,043 y p= 0,039, respectivamente). Este grupo tuvo mayor tiempo de hematuria (p< 0,001) y necesitó más transfusiones de plaquetas (p= 0,003). Además, el 70,6% precisó sondaje vesical, pero solo un caso cistostomía percutánea. Ningún paciente con CH leve precisó sondaje. No hubo diferencias en las secuelas urológicas ni en la mortalidad global. CONCLUSIONES: Una CH más grave podría predecirse por la presencia de EICH grave o trombopenia al inicio del cuadro. La CH grave puede manejarse con sondaje vesical en la mayoría de estos pacientes. Seguir un protocolo estandarizado puede reducir la necesidad de procedimientos invasivos en pacientes con CH leve.

Bringing Machine-Learning Enhanced Quantum Chemistry and Microwave Spectroscopy to Conformational Landscape Exploration: the Paradigmatic Case of 4-Fluoro-Threonine.

A combined experimental and theoretical study has been carried out on 4-fluoro-threonine, the only naturally occurring fluorinated amino acid. Fluorination of the methyl group significantly increases the conformational complexity with respect to the parent amino acid threonine. The conformational landscape has been characterized in great detail, with special attention given to the inter-conversion pathways between different conformers. This led to the identification of 13 stable low-energy minima. The equilibrium population of so many conformers produces a very complicated and congested rotational spectrum that could be assigned through a strategy that combines several levels of quantum chemical calculations with the principles of machine learning. Twelve conformers out of 13 could be experimentally characterized. The results obtained from the analysis of the intra-molecular interactions can be exploited to accurately model fluorine-substitution effects in biomolecules.

Unveiling the Shape of N-Acetylgalactosamine: A Cancer-Associated Sugar Derivative.

In the present work, we report the first rotational study of N-acetylgalactosamine, a cancer-associated sugar derivative, by means of high-resolution rotational spectroscopy. Two different conformers have been conclusively characterized using broadband Fourier transform microwave spectroscopy coupled with a laser ablation vaporization system. Additionally, we performed a comprehensive analysis of the intramolecular interactions that govern these structures, which allowed us to both characterize the existence of intramolecular hydrogen bond networks that drive the intrinsic conformation panorama of N-acetylgalactosamine and further rationalize the biological role of this aminosugar derivative as part of the Tn antigen.

Understanding the abundance of the rare sugar ß-D-allose.

The conformational landscape of ß-D-allose, a rare sugar, was investigated using laser ablation in combination with high-resolution rotational spectroscopy. Altogether, three species are identified, exhibiting a counter-clockwise intramolecular hydrogen bond network. The effect of epimerization on the main aldohexose is also studied and, despite the main conformers being very similar, the position of the hydroxyl groups in allose allows the formation of considerably stronger intramolecular hydrogen bonds than in glucose, and this could explain the low abundance of ß-D-allose in Nature.

Intrinsic cell rheology drives junction maturation.

A fundamental property of higher eukaryotes that underpins their evolutionary success is stable cell-cell cohesion. Yet, how intrinsic cell rheology and stiffness contributes to junction stabilization and maturation is poorly understood. We demonstrate that localized modulation of cell rheology governs the transition of a slack, undulated cell-cell contact (weak adhesion) to a mature, straight junction (optimal adhesion). Cell pairs confined on different geometries have heterogeneous elasticity maps and control their own intrinsic rheology co-ordinately. More compliant cell pairs grown on circles have slack contacts, while stiffer triangular cell pairs favour straight junctions with flanking contractile thin bundles. Counter-intuitively, straighter cell-cell contacts have reduced receptor density and less dynamic junctional actin, suggesting an unusual adaptive mechano-response to stabilize cell-cell adhesion. Our modelling informs that slack junctions arise from failure of circular cell pairs to increase their own intrinsic stiffness and resist the pressures from the neighbouring cell. The inability to form a straight junction can be reversed by increasing mechanical stress artificially on stiffer substrates. Our data inform on the minimal intrinsic rheology to generate a mature junction and provide a springboard towards understanding elements governing tissue-level mechanics.

Simultaneous detection of less frequent waterborne parasitic protozoa in reused wastewater using amplicon sequencing and qPCR techniques.

Waterborne parasitic protozoa (WPP) infections have a worldwide distribution and are a source for epidemic and endemic human diseases. Although a variety of protozoa are commonly detected in wastewater and cited as causative agents of outbreaks, effluents from wastewater treatment plants (WWTPs) used for irrigation can contain other pathogenic protozoa that are not currently being controlled. The lack of control on a routine basis using rapid and sensitive methods to detect these parasites in water may keep them under-recognized. This study focused on using molecular tools, 18 S rRNA amplicon-based sequencing and qPCR, to characterize WPP distribution in wastewater samples from urban WWTPs used for irrigation. A total of eight wastewater samples (from secondary and tertiary disinfection treatment effluents) were collected. Potentially pathogenic protozoa identified by 18 S rRNA sequencing and/or qPCR in the analyzed samples included Acanthamoeba spp., Blastocystis sp., Entamoeba coli, Entamoeba dispar, Entamoeba hartmanni, Giardia intestinalis assemblage A and Toxoplasma gondii Positive results by qPCR were in non-quantifiable levels. Blastocystis sp. was the most represented protozoa among the sequences retrieved from the amplicon sequencing. Blastocystis ST1 and ST2 were the most abundant subtypes among the obtained OTUs. Moreover, Blastocystis sp. ST3, ST4, ST6 and ST8 were also detected, although in lower abundances. Results of this study showed that WWTP effluents used for irrigation can provide a source of WPP.

The eight structures of caffeic acid: a jet-cooled laser ablated rotational study.

This work reports a complete conformational analysis of caffeic acid, an exceptionally versatile pharmacophore, using laser ablation chirped-pulse Fourier transform microwave spectroscopy. The whole conformational space consisting of eight distinct species has been fully deciphered based on the trend of the rotational constants supported by theoretical computations. We show how rotational spectroscopy can be confidently used to distinguish between conformers even when the structural differences are minimal, such as those involved in the conformational panorama of caffeic acid. Additionally, the structural information here provided, such as the planarity observed in all the conformers, could help to elucidate the mechanisms underlying the biological and pharmacological activity of hydroxycinnamic acids.

[Oral antibiotic treatment of exacerbation of COPD. Beyond COVID-19]. / Tratamiento antibiótico oral de la exacerbación de la EPOC. Más allá de la COVID-19.

COPD (chronic obstructive pulmonary disease) includes patients with chronic bronchitis and / or emphysema who have in common the presence of a chronic and progressive airflow obstruction, with symptoms of dyspnea and whose natural history is modified by acute episodes of exacerbations. Exacerbation (EACOPD) is defined as an acute episode of clinical instability characterized by a sustained worsening of respiratory symptoms. It is necessary to distinguish a new EACOPD from a previous treatment failure or a relapse. EACOPD become more frequent and intense over time, deteriorating lung function and quality of life. The diagnosis of EACOPD consists of 3 essential steps: a) differential diagnosis; b) establish the severity, and c) identify its etiology. The main cause of exacerbations is infection, both bacterial and viral. Antibiotics are especially indicated in severe EACOPD and the presence of purulent sputum. Beta-lactams (amoxicillin-clavulanate and cefditoren) and fluoroquinolones (levofloxacin) are the most widely used antimicrobials. This review updates the problem of acute exacerbation with infectious origin from the perspective of etiology, antimicrobial resistance, microbiological studies, risk stratification, and antimicrobial management. The risk, prognosis and characteristics of COPD patients who develop COVID19 are analyzed.

Rotational spectroscopic study and astronomical search for propiolamide in Sgr B2(N).

CONTEXT: For all the amides detected in the interstellar medium (ISM), the corresponding nitriles or isonitriles have also been detected in the ISM, some of which have relatively high abundances. Among the abundant nitriles for which the corresponding amide has not yet been detected is cyanoacetylene (HCCCN), whose amide counterpart is propiolamide (HCCC(O)NH2). AIMS: With the aim of supporting searches for this amide in the ISM, we provide a complete rotational study of propiolamide from 6 GHz to 440 GHz. METHODS: Time-domain Fourier transform microwave (FTMW) spectroscopy under supersonic expansion conditions between 6 GHz and 18 GHz was used to accurately measure and analyze ground-state rotational transitions with resolved hyperfine structure arising from nuclear quadrupole coupling interactions of the 14N nucleus. We combined this technique with the frequency-domain room-temperature millimeter wave and submillimeter wave spectroscopies from 75 GHz to 440 GHz in order to record and assign the rotational spectra in the ground state and in the low-lying excited vibrational states. We used the ReMoCA spectral line survey performed with the Atacama Large Millimeter/submillimeter Array toward the star-forming region Sgr B2(N) to search for propiolamide. RESULTS: We identified and measured more than 5500 distinct frequency lines of propiolamide in the laboratory. These lines were fitted using an effective semi-rigid rotor Hamiltonian with nuclear quadrupole coupling interactions taken into consideration. We obtained accurate sets of spectroscopic parameters for the ground state and the three low-lying excited vibrational states. We report the nondetection of propiolamide toward the hot cores Sgr B2(N1S) and Sgr B2(N2). We find that propiolamide is at least 50 and 13 times less abundant than acetamide in Sgr B2(N1S) and Sgr B2(N2), respectively, indicating that the abundance difference between both amides is more pronounced by at least a factor of 8 and 2, respectively, than for their corresponding nitriles. CONCLUSIONS: Although propiolamide has yet to be included in astrochemical modeling networks, the observed upper limit to the ratio of propiolamide to acetamide seems consistent with the ratios of related species as determined from past simulations. The comprehensive spectroscopic data presented in this paper will aid future astronomical searches.

Interstellar glycolamide: A comprehensive rotational study and an astronomical search in Sgr B2(N).

CONTEXT: Glycolamide is a glycine isomer and also one of the simplest derivatives of acetamide (e.g., one hydrogen atom is replaced with a hydroxyl group), which is a known interstellar molecule. AIMS: In this context, the aim of our work is to provide direct experimental frequencies of the ground vibrational state of glycolamide in the centimeter-, millimeter- and submillimeter-wavelength regions in order to enable its identification in the interstellar medium. METHODS: We employed a battery of state-of-the-art rotational spectroscopic techniques in the frequency and time domain to measure the frequencies of glycolamide. We used the spectral line survey named Exploring Molecular Complexity with ALMA (EMoCA), which was performed toward the star forming region Sgr B2(N) with ALMA to search for glycolamide in space. We also searched for glycolamide toward Sgr B2(N) with the Effelsberg radio telescope. The astronomical spectra were analyzed under the local thermodynamic equilibrium approximation. We used the gas-grain chemical kinetics model MAGICKAL to interpret the results of the astronomical observations. RESULTS: About 1500 transitions have been newly assigned up to 460 GHz to the most stable conformer, and a precise set of spectroscopic constants was determined. Spectral features of glycolamide were then searched for in the prominent hot molecular core Sgr B2(N2). We report the nondetection of glycolamide toward this source with an abundance at least six and five times lower than that of acetamide and glycolaldehyde, respectively. Our astrochemical model suggests that glycolamide may be present in this source at a level just below the upper limit, which was derived from the EMoCA survey. We could also not detect the molecule in the region's extended molecular envelope, which was probed with the Effelsberg telescope. We find an upper limit to its column density that is similar to the column densities obtained earlier for acetamide and glycolaldehyde with the Green Bank Telescope.

Entropy and canonical ensemble of hybrid quantum classical systems.

In this work we generalize and combine Gibbs and von Neumann approaches to build, for the first time, a rigorous definition of entropy for hybrid quantum-classical systems. The resulting function coincides with the two cases above when the suitable limits are considered. Then, we apply the MaxEnt principle for this hybrid entropy function and obtain the natural candidate for the hybrid canonical ensemble (HCE). We prove that the suitable classical and quantum limits of the HCE coincide with the usual classical and quantum canonical ensembles since the whole scheme admits both limits, thus showing that the MaxEnt principle is applicable and consistent for hybrid systems.

A rotational study of the AlaAla dipeptide.

Herein, we present the first rotational study of the AlaAla dipeptide, brought into the gas phase by laser ablation. Two different structures have been unveiled in the isolated environment of a supersonic expansion by Fourier transform microwave spectroscopy. These structures have been identified through their rotational and 14N quadrupole coupling constants. The flexibility of the -NH2 and -COOH ends allows the formation of strong intramolecular interactions giving rise to five- and seven-membered ring configurations.

Gas-Phase Conformational Map of the Amino Acid Isovaline.

Four conformers of the non-proteinogenic α-amino acid isovaline, vaporized by laser ablation, are characterized by Fourier-transform microwave techniques in a supersonic expansion. The comparison between the experimental rotational and 14 N nuclear quadrupole coupling constants and the ab initio calculated ones provides conclusive evidence for the identification of the conformers. The most stable species is stabilized by an N-H⋅⋅⋅O =C intramolecular hydrogen bond and a cis-COOH interaction, whereas the higher-energy conformers exhibit an N⋅⋅⋅H-O intramolecular hydrogen bond and trans-COOH, as in other aliphatic amino acids. The spectroscopic data herein reported can be used for the astrophysical purpose in a possible detection of isovaline in space.

Formation of interstellar cyanoacetamide: a rotational and computational study.

CONTEXT: Cyanoacetamide is a -CN bearing molecule that is also an amide derivative target molecule in the interstellar medium. AIMS: The aim of our investigation is to analyze the feasibility of a plausible formation process of protonated cyanoacetamide under interstellar conditions and to provide direct experimental frequencies of the ground vibrational state of the neutral form in the microwave region in order to enable its eventual identification in the interstellar medium. METHODS: We used high-level theoretical computations to study the formation process of protonated cyanoacetamide. Furthermore, we employed a high-resolution laser-ablation molecular beam Fourier transform spectroscopic technique to measure the frequencies of the neutral form. RESULTS: We report the first rotational characterization of cyanoacetamide, and a precise set of the relevant rotational spectroscopic constants have been determined as a first step to identifying the molecule in the interstellar medium. We fully explored the potential energy surface to study a gas-phase reaction on the formation process of protonated cyanoacetamide. We found that an exothermic process with no net activation barrier is initiated by the high-energy isomer of protonated hydroxylamine, which leads to protonated cyanoacetamide.