Direct proline catalyzed asymmetric α-aminooxylation of aldehydes

The direct catalytic enantioselective α-aminooxylation of aldehydes has been developed using nitrosobenzene as the oxygen source and l-proline as catalyst, affording versatile α-aminooxylated aldehydes in high yield with excellent enantioselectivities.     

Comparison between quantitative and subjective assessments of chemotherapy-induced peripheral neuropathy in cancer patients: A prospective cohort study

Objective: Chemotherapy-induced peripheral neuropathy (CIPN) is a common adverse event experienced by cancer patients. In general, CIPN is evaluated subjectively based on patient self-assessment or clinician-reported scales; evidence supporting the utility and validity of quantitative sensory tests (QST) is lacking in this patient population. The aim of this study was to objectively assess CIPN of lower extremities by QSTs, and to evaluate the concordance between QSTs and subjective assessments. Methods: In this prospective cohort study, outpatients with cancer receiving chemotherapy were recruited at a single university hospital. We assessed CIPN at the lower extremities at baseline and three months after baseline. The QSTs were performed by applying a monofilament and a tuning fork to determine touch and vibration thresholds, respectively, at the affected site. Subjective assessments were performed based on the visual analog scale (VAS) and the National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE) toxicity grade. Kappa coefficients were calculated to evaluate the concordance between QSTs and subjective assessments. Results: After exclusion and drop-outs during follow-up, nineteen patients were included in the analysis. The prevalence of patients with abnormal sensation was 37% based on QSTs, 32% based on the VAS, and 14% based on CTCAE grading, respectively. Kappa coefficients were 0.32 between QSTs and VAS, and 0.28 between QSTs and CTCAE. Conclusions: The concordance rates between quantitative and subjective assessments were low. CIPN should be assessed using both quantitative and subjective assessments.     

Potent Th2 Cytokine Bias of Natural Killer T Cell by CD1d Glycolipid Ligands: Anchoring Effect of Polar Groups in the Lipid Component

Th2‐biasing CD1d ligands are attractive potential candidates for adjuvants and therapeutic drugs. However, the number of potent ligands is limited, and their biasing mechanism remain unclear. Herein, a series of novel Th2‐biasing CD1d glycolipid ligands, based on modification of their lipid part, have been identified. These have shown high binding affinities and efficient Th2 cytokine production. Importantly, the truncated acyl chain containing variants still retain their binding affinities and agonistic activities, which can be associated with an “anchoring effect,” that is, formation of a buried hydrogen bond between a polar group on the acyl chain and the CD1d lipid‐binding pocket. The analysis indicated that the appearance rates of ligand–CD1d complexes on the cell surface were involved in Th2‐biasing responses. The designed ligands, having the anchor in the shorter lipid part, are one of the most potent Th2‐biasing ligands among the known ligands.     

Solid-state electrochemical CO2 sensor by coupling lithium ion conductor (Li2CO3-Li3PO4-Asl2O3) with oxide ion-electron mixed conductor (La0.9Sr0.1MnO3)

A solid-state electrochemical cell of the type O₂(air), PtLa_0.9Sr_0.1MnO₃/Li₂CO₃(+5 mol% Li₃PO₄ + 6 mol% Al₂O₃)/Au, CO₂, O₂ was composed to determine CO₂ concentration, where Li₂CO₃, a lithium ion conductor, was used as an electrolyte, and the perovskite-type oxide (La_0.9Sr_0.1MnO₃)/O₂-electrode as a reference electrode. The electromotive force (EMF) of the cell was found to be proportional to the logarithm of CO/₂ partial pressure in CO₂/O₂/N₂ gas mixtures at temperatures between 300 and 400 °C. The EMF responded to changes of CO₂ partial pressure within 1 min at 400 °C. The sensitivity to CO₂ of this cell was not affected by coexistence of O₂, and the EMF remained constant after the first 15 days. The mechanism for sensing CO₂ is discussed.     

Characterization of a d-Stereoselective Aminopeptidase (DamA) Exhibiting Aminolytic Activity and Halophilicity from Aspergillus oryzae

β-Aminopeptidases exhibit both hydrolytic and aminolytic (peptide bond formation) activities and have only been reported in bacteria. We identified a gene encoding the β-aminopeptidase homolog from a genome database of the filamentous fungus Aspergillus oryzae. The gene was overexpressed in A. oryzae, and the resulting recombinant enzyme was purified. Apart from bacterial homologs [β-Ala-para-nitroanilide (pNA)], the enzyme preferred d-Leu-pNA and d-Phe-pNA as substrates. Therefore, we designated this gene as d-stereoselective aminopeptidase A (damA). The purified recombinant DamA was estimated to be a hexamer and was composed of two subunits with molecular masses of 29.5 and 11.5 kDa, respectively. Optimal hydrolytic activity of DamA toward d-Leu-pNA was observed at 50 °C and pH 8.0. The enzyme was stable up to 60 °C and from pH 4.0–11.0. DamA also exhibited aminolytic activity, producing d-Leu-d-Leu-NH₂ from d-Leu-NH₂ as a substrate. In the presence of 3.0 M NaCl, the amount of pNA liberated from d-Leu-pNA by DamA was 3.1-fold higher than that in the absence of NaCl. Thus, DamA is a halophilic enzyme. The enzyme was utilized to synthesize several hetero-dipeptides containing a d-amino acid at the N-terminus as well as physiologically active peptides.