Process development and multikilogram synthesis of the monocyclic β-lactam core 17 for a novel pyridone-conjugated monobactam antibiotic is described. Starting with commercially available ...2-(2,2-diethoxyethyl)isoindoline-1,3-dione, the five-step synthesis features several telescoped operations and direct isolations to provide significant improvement in throughput and reduced solvent usage over initial scale-up campaigns. A particular highlight in this effort includes the development of an efficient Staudinger ketene–imine 2 + 2 cycloaddition reaction of N-Boc-glycine ketene 12 and imine 9 to form racemic β-lactam 13 in good isolated yield (66%) and purity (97%). Another key feature in the synthesis involves a classical resolution of racemic amine 15 to afford single enantiomer salt 17 in excellent isolated yield (45%) with high enantiomeric excess (98%).
An efficient process to synthesize Monobactam 1 from intermediates 2, 3, and 4 was developed. The process was initially enabled to deliver 500 g of 1 for exploratory toxicity studies and further ...improved to facilitate kilogram-scale production of the active pharmaceutical ingredient with enhanced quality and throughput. Highlights of the process encompass utilizing 1,1′-carbonyldiimidazole to construct a urea linker with good selectivity, oxidative cleavage to remove a 2,4-dimethoxybenzyl protecting group, two activation methods to form an amide bond, a high yielding reaction to introduce N-sulfonic moiety, and a global deprotection to remove all protecting groups. Practical procedures were developed to isolate intermediates en route by adding a concentrated substrate to antisolvents to obtain filterable amorphous solids with partial purification. Amberchrom CG161M resin was applied not only as a “resin-capture–release” tool to remove the bulk amount of water but also as an effective method to purify 1. Finally, a process isolating 1 pentahydrate (1·5H 2 O) as a crystalline solid from the acidic aqueous solution was developed based on zwitterionic crystallization methodology.
A practical large-scale synthesis was developed for 1, a DGAT-1 inhibitor, involving an aza-Michael reaction, amidation, Dieckman cyclization, and conjugate addition of cyanamide followed by ...cyclization, to form the fused 4-amino-7,8-dihydropyrido4,3-dpyrimidin-5-one scaffold. The enabled process presented here substantially improved safety (in particular, due to eliminating a nitration step and optimizing a high-energy intermediate step), reproducibility, and scalability, resulting in delivery of a multikilogram quantity of the API with high purity. The controls of API quality and particle size were also discussed.
Understanding humoral responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is critical for improving diagnostics, therapeutics, and vaccines. Deep serological profiling of 232 ...coronavirus disease 2019 (COVID-19) patients and 190 pre-COVID-19 era controls using VirScan revealed more than 800 epitopes in the SARS-CoV-2 proteome, including 10 epitopes likely recognized by neutralizing antibodies. Preexisting antibodies in controls recognized SARS-CoV-2 ORF1, whereas only COVID-19 patient antibodies primarily recognized spike protein and nucleoprotein. A machine learning model trained on VirScan data predicted SARS-CoV-2 exposure history with 99% sensitivity and 98% specificity; a rapid Luminex-based diagnostic was developed from the most discriminatory SARS-CoV-2 peptides. Individuals with more severe COVID-19 exhibited stronger and broader SARS-CoV-2 responses, weaker antibody responses to prior infections, and higher incidence of cytomegalovirus and herpes simplex virus 1, possibly influenced by demographic covariates. Among hospitalized patients, males produce stronger SARS-CoV-2 antibody responses than females.
A novel 16-membered-ring macrolide agent (CP-163, 505, a reductive amination derivative of repromicin) was identified as an antibacterial against Pasteurella haemolytica, P. multocida and ...Actinobacillus pleuropneumoniae, important etiological agents of livestock respiratory disease. In vitro MIC50/90 analysis revealed that CP-163, 505 was more potent (4×) than tilmicosin against P. multocida, and equivalent to tilmicosin against P. haemolytica and A. pleuropneumoniae. In time kill kinetic studies, CP-163, 505 showed bactericidal activity against P. haemolytica, P. multocida and A. pleuropneumoniae and bacteriostatic activity against E. coli at 8 times its MIC. In vitro, CP-163, 505 was more potent in alkaline pH (16∼32×) and less potent in the presence of excess cations (Mg+2 and Ca+2, 4×). EDTA and PMBN increased CP-163, 505 potency against E. coli (4×) but not against the other species. Similar results were obtained with erythromycin A and tilmicosin, which were used as controls. From our data, we hypothesize that Pasteurella and Actinobacillus have an outer membrane significantly different from that of the typical enteric Gram-negative bacterium E. coli.
A matrix of photobioreactors integrated with metabolic sensors was used to examine the combined impact of light and temperature variations on the growth and physiology of the biofuel candidate ...microalgal species Nannochloropsis oculata. The experiments were performed with algal cultures maintained at a constant 20 °C versus a 15 °C to 25 °C diel temperature cycle, where light intensity also followed a diel cycle with a maximum irradiance of 1920 µmol photons m(-2) s(-1). No differences in algal growth (Chlorophyll a) were found between the two environmental regimes; however, the metabolic processes responded differently throughout the day to the change in environmental conditions. The variable temperature treatment resulted in greater damage to photosystem II due to the combined effect of strong light and high temperature. Cellular functions responded differently to conditions before midday as opposed to the afternoon, leading to strong hysteresis in dissolved oxygen concentration, quantum yield of photosystem II and net photosynthesis. Overnight metabolism performed differently, probably as a result of the temperature impact on respiration. Our photobioreactor matrix has produced novel insights into the physiological response of Nannochloropsis oculata to simulated environmental conditions. This information can be used to predict the effectiveness of deploying Nannochloropsis oculata in similar field conditions for commercial biofuel production.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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Air trapping is an obstructive phenotype that has been associated with more severe and unstable asthma in children. Air trapping has been defined using pre- and postbronchodilator ...spirometry. The causes of air trapping are not completely understood. It is possible that environmental exposures could be implicated in air trapping in children with asthma.
We investigated the association between indoor exposures and air trapping in urban children with asthma.
Children with asthma aged 5 to 17 years living in Baltimore and enrolled onto the Environmental Control as Add-on Therapy for Childhood Asthma study were evaluated for air trapping using spirometry. Aeroallergen sensitization was assessed at baseline, and spirometry was performed at 0, 3, and 6 months. Air trapping was defined as an FVC z score of less than −1.64 or a change in FVC with bronchodilation of ≥10% predicted. Logistic normal random effects models were used to evaluate associations of air trapping and indoor exposures.
Airborne and bedroom floor mouse allergen concentrations were associated with air trapping but not airflow limitation (odds ratio 1.19, 95% confidence interval 1.02-1.37, P = .02 per 2-fold increase in airborne mouse allergen; odds ratio 1.23, 95% confidence interval 1.07-1.41, P = .003 per 2-fold increase in bedroom floor mouse allergen). Other indoor exposures (cockroach, cat, dog, dust mite, particulate matter, and nicotine) were not associated with air trapping or airflow limitation.
Mouse allergen exposure, but not other indoor exposure, was associated with air trapping in urban children with asthma.
Mouse allergen exposure was associated with air trapping, an obstructive phenotype associated with more severe and unstable asthma, possibly explaining some of the excess asthma burden in urban ...populations.
Proteomics is a rapidly transforming interdisciplinary field of research that embraces a diverse set of analytical approaches to tackle problems in fundamental and applied biology. This viewpoint ...article highlights the benefits of interlaboratory studies and standardization initiatives to enable investigators to address many of the challenges found in proteomics research. Among these initiatives, we discuss our efforts on a comprehensive performance standard for characterizing PTMs by MS that was recently developed by the Association of Biomolecular Resource Facilities (ABRF) Proteomics Standards Research Group (sPRG).
In April 2019, the Alberta Newborn Screening Program expanded to include screening for classic galactosemia using a two-tier screening approach. This approach secondarily identifies infants with ...glucose-6-phosphate dehydrogenase (G6PD) deficiency. The goals of this study were (i) to evaluate the performance of a two-tier galactosemia screening protocol, (ii) to explore the impact on and acceptability to families of reporting G6PD deficiency as a secondary finding, and (iii) assess the communication and follow-up process for positive G6PD deficiency screening results. The two-tiered galactosemia approach increased the positive predictive value (PPV) for galactosemia from 8% to 79%. An additional 119 positive newborn screen results were reported for G6PD deficiency with a PPV of 92%. The results show that there may be utility in reporting G6PD deficiency results. Most parents who participated in the study reported having some residual worry around the unexpected diagnosis; however, all thought it was helpful to know of their child's diagnosis of G6PD deficiency. Finally, the communication process for reporting G6PD deficiency newborn screen results was determined to result in appropriate follow up of infants.
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