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• Rh/NbOPO 4 exhibits higher activity for NO reduction than Pd- or Pt-loaded catalysts. • Rh/NbOPO 4 shows high NO reduction activity in a slightly lean region. • Rh/NbOPO 4 showed high activity for C 3 H 6 oxidation to reactive aldehyde species. • Rh/NbOPO 4 possesses resistance of Rh0 against oxidation. The selective catalytic reduction of NO with C 3 H 6 and CO was investigated over platinum group metal (PGM; Pd, Rh, or Pt) supported on NbOPO 4. Rh/NbOPO 4 exhibits a lower light-off temperature of NO reduction to N 2 compared to Pd- or Pt-loaded NbOPO 4 catalysts and Rh/Al 2 O 3 under stoichiometric conditions. Rh/NbOPO 4 shows superior catalytic activity for NO reduction to Rh/Al 2 O 3 under a wide range of lean conditions. Propylene (C 3 H 6) was partially oxidized to reactive aldehyde species on Rh/NbOPO 4 , whereas less-reactive carboxylate species was generated and adsorbed on Rh/Al 2 O 3. A highly dispersed Rh0 nanoparticles on NbOPO 4 was slowly oxidized by exposure to excess O 2 , but Rh on Al 2 O 3 was readily oxidized to less-active Rh 2 O 3. The high activity of Rh/NbOPO 4 for C 3 H 6 oxidation to reactive aldehyde species and the resistance of Rh0 against oxidation results in the enhancement of NO reduction activity in a slightly lean region. [ABSTRACT FROM AUTHOR]

A novel quantitative and specific method for detection of buckwheat, a known food allergen, in diverse food materials was developed by using a unique internal standard to compensate for the variability in DNA extraction and amplification efficiencies. The method was based on a real-time PCR targeting the internal transcribed spacer region of Fagopyrum spp. and was designed to detect both cultivated and wild buckwheat, because wild buckwheat might be potentially allergenic. As the internal standard material, ground seeds of statice (Limonium sinuatum) were added to food samples prior to DNA ex- traction, and the amount of statice DNA measured by real-time PCR was used to standardize the buckwheat content. Statice, an ornamental plant, was chosen as the internal standard material because it was readily available and was inferred to be least likely to be commingled in foods. The specificity of the PCR system was tested against commonly used food materials of plant origin. Quantitative results expressed in buckwheat protein concentrations (mean ± standard deviation) for various food samples prepared to contain 10 ppm (wt/wt) of buckwheat flour (corresponding to 1.2-µg/g [ppm] buckwheat protein) ranged from 0.7 ± 0.2 (rice) to 0.9 ± 0.4 (wheat) and for 100-ppm (wt/wt) samples (12-µg/g [ppm] buckwheat protein) from 7.7 ± 1.0 (pepper) to 9.8 ± 0.5 (wheat) µg/g (ppm). The method's accuracy, sensitivity, and specificity were considered sufficient for detection of buckwheat contamination at the level required for compliance with the Japanese Food Allergen Labeling Regulation. [ABSTRACT FROM AUTHOR]

• New bisthiolane polysulfides were isolated from a reaction model of tearless onion. • The three compounds were confirmed in authentic tearless onion juice. • The isolated two compounds inhibited COX-1 activity more effectively than aspirin. • Lyophilized forms of the compounds could be stored stably for several months. Two novel bisthiolane polysulfides (compounds 1 and 2), trivially named thiolanotrisulfide and thiolanotetrasulfide, were isolated from a reaction model of tearless onion (in which lachrymatory factor synthase is suppressed), and the presence of another novel bisthiolane polysulfide (3), trivially named thiolanopentasulfide, was confirmed. On the basis of spectroscopic and mass spectrometric analyses, it was found that these bisthiolane polysulfides were bis(5-hydroxy-3,4-dimethylthiolan-2-yl)-tri/tetra/pentasulfide with the general formulas of C 12 H 22 O 2 S 5 (tri-), C 12 H 22 O 2 S 6 (tetra-) and C 12 H 22 O 2 S 7 (penta-), and they were confirmed to exist in authentic tearless onion juice. Thiolanotrisulfide (1) and thiolanotetrasulfide (2) inhibited cyclooxygenase-1 activity with IC 50 values of 720 ± 78 and 464 ± 48 μM respectively, compared with 3282 ± 188 μM for aspirin. [ABSTRACT FROM AUTHOR]

Abstract: In “pinking” of onion, E-(+)-S-(1-propenyl)-l-cysteine sulfoxide is first cleaved by alliinase to yield colour developers (CDs), which react with amino acids, such as valine, to form pigment precursors (PPs). The PPs react with naturally occurring carbonyls (NOCs) to form pigments. By inducing a PP from previously isolated cepathiolanes and l-valine, it was confirmed that cepathiolanes constitute at least a part of the CDs. From the PP and formaldehyde as a NOC, two colourless and two pink compounds were derived. The structure of one of the colourless compounds was established as 2-(2-(1-(1-carboxy-2-methylpropyl)-3,4-dimethyl-1H-pyrrol-2-yl)methyl-3,4-dimethyl-1H-pyrrol-1-yl)-3-methylbutanoic acid. The structures of the other colourless compound and the pink pigments were predicted based on their molecular formula and the MSn spectral data. A trimeric pigment structure was predicted for one of the pink pigments, which was believed to be the first to be reported in the literature. With these, a new reaction scheme for “pinking” of onion is proposed. [Copyright &y& Elsevier]