Microwave-Assisted Synthesis of (±)-Mandelic Acid-5 , ��tical Resolution, and A�solute Con�guration Deter�ination

An efficient microwave-assisted synthesis of (±)-mandelic acid-5 was developed. e racemic mixture was resolved by diastereomeric salt formation using 1-phenylethylamine enantiomers as resolving agents. At each step, the resolution process was checked by determining mandelic acid-5 enantiomer ee values directly on fractional crystallized diastereomeric salts by chiral capillary electrophoresis analysis. Highly enriched (−)-and (+)-mandelic acid-5 (95% and 90% ee, resp.) were obtained and their absolute con�gurations-and , respectively-were determined by correlation of the (−)-mandelic acid-5 circular dichroism spectrum to the (R)-mandelic acid one

Elective cancer surgery in COVID-19-free surgical pathways during the SARS-CoV-2 pandemic: An international, multicenter, comparative cohort study

PURPOSE As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19–free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19–free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19–free surgical pathways. Patients who underwent surgery within COVID-19–free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19–free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score–matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19–free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION Within available resources, dedicated COVID-19–free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

Elective Cancer Surgery in COVID-19-Free Surgical Pathways During the SARS-CoV-2 Pandemic: An International, Multicenter, Comparative Cohort Study.

PURPOSE: As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19-free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS: This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19-free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS: Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19-free surgical pathways. Patients who underwent surgery within COVID-19-free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19-free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score-matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19-free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION: Within available resources, dedicated COVID-19-free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

Preparation of (–)-(R)-2-(2,3,4,5,6-pentafluorophenoxy)-2-(phenyl-d5)acetic acid: an efficient 1H NMR chiral solvating agent for direct enantiomeric purity evaluation of quinoline-containing antimalarial drugs

The title compound was prepared as a racemate from (±)-mandelic acid-d5 in one step. The corresponding ()-(R)-enantiomer (98% ee) was obtained by resolution with ()-(R)-1-phenylethylamine and evaluated as a chiral solvating agent (CSA) for direct 1H NMR enantiomeric excess determination of mefloquine (Lariam), chloroquine (Chloroquine Bayer), and hydroxychloroquine (Plaquenil) enantiomers. The displayed non-equivalence was high for signals in the aromatic region of all three antimalarials. Thus, the mandelic acid derivative described herein may be considered as the first efficient CSA ‘invisible’ in the aromatic region, useful for direct 1H NMR ee value determination of chiral quinoline-containing antimalarial drugs

The Crystal Structure of N-[(2E)-3-(4-Chlorophenyl)prop-2-en-1-yl]-4-methoxy-N-methylbenzenesulfonamide

The title compound C17H18ClNO3S crystallizes in the monoclinic P21/c space group with unit cell parameters a = 15.040 (3) Å, b = 9.151 (6) Å, c = 13.868 (7) Å, β = 116.38 (5)°. Chlorophenyl and methoxyphenyl ring planes are approximately perpendicular and the two moieties form an angle of 82.2°. The crystal packing is stabilized by π–π and Cl–π interactions, which occur between parallel methoxyphenyl and chlorophenyl moieties. Dipolar intermolecular contacts, mainly involving the oxygen atoms and C–H, also contribute to the crystal network. Graphical Abstract: The title compound is formed in the synthetic route for the production of potent inhibitors of calmodulin. Its crystal structure shows the chlorophenyl and methoxyphenyl moieties forming an angle of 82.2°. The crystal packing is stabilized by π–π, Cl–π and dipolar intermolecular contacts. [Figure not available: see fulltext.]

Synthesis and evaluation of berberine derivatives and analogues as potential anti-acetylcholinesterase and antioxidant agents

Two known berberine derivatives and novel N-benzyl phenethylamines as open models of berberine were synthesized and evaluated as acetylcholinesterase (AChE) inhibitors and antioxidant agents. While being less potent than the parent compound (IC50 = 0.70± 0.04 μM), both berberine derivatives performed as good AChE inhibitors (IC50 = 2.30 ± 0.29 μM and 7.8 ± 0.8 μM, respectively) and were at least 36 and four times more potent than berberine as radical scavengers. Among the synthesized compounds, demethyleneberberine bromide (2) was the most interesting because it showed both anticholinesterase and radical scavenging activities with the lowest IC50 values. As expected, catechol rings appeared as fundamental for antioxidant properties. Indeed, the most active scavenging compound in the simplified analog series was the one bearing two catechol moieties, which displayed higher potency than gallic acid

The chemosensitizing agent lubeluzole binds calmodulin and inhibits Ca2+/calmodulin-dependent Kinase II

An affinity capillary electrophoresis (ACE) method to estimate apparent dissociation constants between bovine brain calmodulin (CaM) and non-peptidic ligands was developed. The method was validated reproducing the dissociation constants of a number of well-known CaM ligands. In particular, the potent antagonist 125-C9 was ad hoc synthesized through an improved synthetic procedure. The ACE method was successfully applied to verify CaM affinity for lubeluzole, a well-known neuroprotective agent recently proved useful to potentiate the activity of anti-cancer drugs. Lubeluzole was slightly less potent than 125-C9 (Kd Combining double low line 2.9 ± 0.7 and 0.47 ± 0.06 1/4M, respectively) and displayed Ca2+/calmodulin-dependent kinase II (CaMKII) inhibition (IC50 Combining double low line 40 ± 1 1/4M). Possible binding modes of lubeluzole to CaM were explored by docking studies based on the X-ray crystal structures of several trifluoperazine-CaM complexes. An estimated dissociation constant in good agreement with the experimental one was found and the main aminoacidic residues and interactions contributing to complex formation were highlighted. The possibility that interference with Ca2+ pathways may contribute to the previously observed chemosensitizing effects of lubeluzole on human ovarian adenocarcinoma and lung carcinoma cells are discussed. © 2016 Elsevier Masson SAS

Nitro-substituted tetrahydroindolizines and homologs: Design, kinetics, and mechanism of α-glucosidase inhibition

A series of 1-[(methylsulfonyl)methyl]-2-nitro-5,6,7,8-tetrahydroindolizines and homologs were designed, prepared, and evaluated as non-sugar-type α-glucosidase inhibitors. The inhibitory activity appeared to be related to cyclo homologation with the best congeners being tetrahydroindolizines. The introduction of a methoxycarbonyl group as an additional hydrogen bond acceptor into the exocyclic methylene group was beneficial affording the most potent congener 3e (half maximal inhibitory concentration, IC50 = 8.0 ± 0.1 μM) which displayed 25-fold higher inhibitory activity than 1-deoxynojirimycin (2, IC50 = 203 ± 9 μM)â\u80\u94the reference compound. Kinetic analysis indicated that compound 3e is a mixed inhibitor with preference for the free enzyme over the α-glucosidaseâ\u80\u93substrate complex (Ki,free = 3.6 μM; Ki,bound = 7.6 μM). Molecular docking experiments were in agreement with kinetic results indicating reliable interactions with both the catalytic cleft and other sites. Circular dichroism spectroscopy studies suggested that the inhibition exerted by 3e may involve changes in the secondary structure of the enzyme. Considering the relatively low molecular weight of 3e together with its high fraction of sp3 hybridized carbon atoms, this nitro-substituted tetrahydroindolizine may be considered as a good starting point towards new leads in the area of α-glucosidase inhibitors