Garlicnins B(1), C(1), and D, from the fraction regulating macrophage activation of Allium sativum

Several novel sulfides from acetone extracts of bulbs of garlic (Allium sativum L.), were identified and investigated. These were named garlicnins B(1) (1), C(1) (2), and D (3), and they were found to have the ability to control macrophage activation. Garlicnins B(1) (1) and C(1) (2) possess a new skeleton of cyclic sulfoxide and their structures of garlicnins B(1) (1) and C(1) (2) were characterized as 3,4-dimethyltetrahydrothiophene-S-oxide derivatives carrying the substitutions of a propenyl and a sulfenic acid, and an allyldithiine and a 1-propene-sulfenic acid (a), respectively. The mechanism of the proposed production of these compounds is discussed. Garlicnin D (3), dithiine-type, was estimated to be derived by addition of (a)+allyl thiosulfenic acid (b) derived from allicin. The identification of these novel sufoxides from onion and garlic accumulates a great deal of new chemistry to the Allium sulfide field, and future pharmacological investigations aid the development of natural, healthy foods and anti-cancer agents that could potentially prevent or combat disease.     

Synthesis,including asymmetric synthesis,of 3-oxabicyclo[3.1.0]hexanes and bicyclo[3.1.0]hexanes by the 1,5-CH insertion of cyclopropylmagnesium carbenoids as the key reaction

The addition reactions of α,β-unsaturated carbonyl compounds with dichloromethyl p-tolyl sulfoxide in the presence of NaHMDS or LDA resulted in the formation of adducts, 1-chlorocyclopropyl p-tolyl sulfoxides bearing a carbonyl group at the 2-position, in almost quantitative yields. The carbonyl group of the adducts was transformed to various ether groups to give 1-chlorocyclopropyl p-tolyl sulfoxides bearing an ether functional group at the 2-position in short steps. Treatment of these products with i-PrMgCl at low temperature afforded cyclopropylmagnesium carbenoids via the sulfoxide-magnesium exchange reaction. 1,5-Carbon–hydrogen insertion (1,5-CH insertion) reaction of the generated magnesium carbenoid intermediates took place to give 3-oxabicyclo[3.1.0]hexanes or bicyclo[3.1.0]hexanes bearing an ether group at the 4-position in moderate to good yields. When this procedure was carried out starting with enantiopure dichloromethyl p-tolyl sulfoxide, enantiopure 3-oxabicyclo[3.1.0]hexanes were obtained in good overall yields. These procedures provide a good way for the synthesis, including asymmetric synthesis, of multisubstituted 3-oxabicyclo[3.1.0]hexanes and bicyclo[3.1.0]hexanes from α,β-unsaturated carbonyl compounds and dichloromethyl p-tolyl sulfoxide in short steps.     

First result from the MTV experiment at TRIUMF searching T-violation in nuclear beta decay

The MTV experiment (Mott Polarimetry for T-Violation Experiment) is running from 2009 at TRIUMF, which aims to search a large non-standard T-Violation in polarized nuclear beta decay. Existence of transverse polarization of electrons emitted from polarized ⁸Li nuclei, which are produced at TRIUMF-ISAC and stopped inside an aluminum stopper, is investigated. We utilize a Mott polarimeter consists of a planer drift chamber, measuring backward scattering left-right asymmetry from a thin lead analyzer foil. In this paper, preliminary results from the first physics run performed in 2010 are described.     

Fuel concentration measurement of premixed mixture using spark-induced breakdown spectroscopy

This study determined the local equivalence ratio of a CH₄/air mixture in a laminar premixed flame using spark-induced breakdown spectroscopy (SIBS) with a fiber-coupled intensified charge coupled device (ICCD) spectrometer. Spectrally resolved emission spectra of plasma generated by a spark plug were investigated for their potential to measure local fuel concentrations in a premixed mixture. The influence of key parameters, such as the camera gate timing and spark energy, on the intensity of radical emission was illustrated. The intensity ratio of CN/NH had a greater sensitivity to the equivalence ratio than did that of CN/OH, and the local equivalence ratio could be obtained with high resolution by measuring the local intensity ratios of CN/NH. Moreover, a spark-plug sensor with an optical fiber was developed for application in spark-ignition engines. The atomic emission intensity during the breakdown and arc phases of spark discharge could be obtained using the fiber-optic spark-plug sensor. The H_α/O intensity showed better linearity than the CN/NH intensity ratio in lean mixtures. The results presented here confirm the use of SIBS as a diagnostic tool for spark-ignition engines.     

Langmur monolayers of cerebroside with different head groups originated from sea cucumber: Binary systems with dipalmitoylphosphatidylcholine (DPPC)

Surface properties (Langmuir monolayer) of two different cerebrosides which are extracted from the sea cucumber (Bohadschia argus) were investigated. A main difference in chemical structure of cerebroside between BAC-2a and BAC-4 is their head groups (glucose and galactose, respectively). Furthermore, miscibility and interaction between dipalmitoylphosphatidylcholine (DPPC) and cerebrosides (BAC-2a and BAC-4) in the monolayer have been systematically examined. The surface pressure (π)−area (A), the surface potential (ΔV)−A, and the dipole moment (μ)−A isotherms for monolayers of DPPC, cerebrosides, and their binary combinations have been measured using the Wilhelmy method and the ionizing electrode method. BAC-4 forms a stable liquid-expanded (LE) monolayer, whereas BAC-2a has a first-order phase transition from the LE phase to the liquid-condensed (LC) state on 0.15 M NaCl at 298.2 K. The fundamental properties for each cerebroside monolayer were elucidated in terms of the surface dipole moment based on the three-layer model [R.J. Demchak, T. Fort Jr., J. Colloid Interface Sci. 46 (1974) 191–202] for both cerebrosides and the apparent molar quantity change (Δs^γ, Δh^γ, and Δu^γ) for BAC-2a. In addition, their miscibility with DPPC was examined by the variation of the molecular areas and the surface potentials as a function of cerebroside mole fractions, the additivity rule. The miscibility was also confirmed by constructing the two-dimensional phase diagrams. The phase diagrams for the both binary systems were of negative azeotropic type. That is, the two-component DPPC/BAC-2a and DPPC/BAC-4 monolayers are miscible. Furthermore, the Joos equation for the analysis of the collapse pressure of binary monolayers allowed calculation of the interaction parameter and the interaction energy between the DPPC and cerebroside monolayers. The miscibility in the monolayer state was also confirmed by the morphological observation with Brewster angle microscopy (BAM), fluorescence microscopy (FM), and atomic force microscopy (AFM).     

Enhancement of peroxyoxalate chemiluminescence intensity by surfactants and its application to detect detergent

Enhancement of peroxyoxalate chemiluminescence (PO-CL) intensity by a surfactant in the H₂O₂/bis(2,4,6-trichlorophenyl)oxalate (TCPO)/rhodamine B system was described. The effects of 15 surfactants were evaluated by comparing the ratio of a relative CL intensity (RCI) with surfactant to that of the blank in each system. In preliminary study, H₂O₂/imidazole-HNO₃ buffer/TCPO/rhodamine B system was used to study the effects of surfactants on PO-CL intensity. Fourteen surfactants reduced the CL intensity at the 2% concentration, where their relative CL intensities ranged from 0.6 to 93.5%. Some of these phenomena may be caused by a notable change of pH that was occurred by adding the surfactant.Additionally, enhancement of PO-CL intensity was studied by using system (1) H₂O₂/TCPO/rhodamine B and (2) H₂O₂/imidazole-HNO₃ buffer/TCPO/systems. In the system 1, the favorable enhancement of CL intensity (ranged from 124 to 472%) was observed with 9 surfactants at the 0.5% concentration. This result suggested that several surfactants might play a role as a catalyst in the PO-CL reaction. There was no tendency to enhance CL intensity among the surfactant types. In the system 2, the enhancement of CL intensity was also observed by adding with 11 surfactants, which might be mainly caused by the fluorescent impurities of surfactants used.Furthermore, detection of detergent commercially available was applied by using the system 1.     

Hg2+-sensing system based on structures of complexes

The first example of a new Hg(2+)-sensing system based on the structures of complexes is reported. The system uses a combination of a new chiral bidentate ligand and CD spectroscopy. Significant CD spectral changes are observed when Hg(2+) is added, whereas no CD spectral changes are observed in the cases of Li(+), Na(+), K(+), Mg(2+), Ca(2+), Mn(2+), Fe(2+), Co(2+), Ni(2+), Cu(2+), Zn(2+), Rb(+), Ag(+), Cd(2+), La(3+), Gd(3+), and Pb(2+).