A quick and simple method for the identification of meat species and meat products by PCR assay

The polymerase chain reaction (PCR) was applied to identify six meats (cattle, pig, chicken, sheep, goat and horse) as raw materials for products. By mixing seven primers in appropriate ratios, species-specific DNA fragments could be identified by only one multiplex PCR. A forward primer was designed on a conserved DNA sequence in the mitochondrial cytochrome b gene, and reverse primers on species-specific DNA sequences for each species. PCR primers were designed to give different length fragments from the six meats. The products showed species-specific DNA fragments of 157, 227, 274, 331, 398 and 439 bp from goat, chicken, cattle, sheep, pig and horse meats, respectively. Identification is possible by electrophoresis of PCR products. Cattle, pig, chicken, sheep and goat fragments were amplified from cooked meat heated at 100 or 120°C for 30 min, but horse DNA fragments could not be detected from the 120°C sample. Detection limits of the DNA samples were 0.25 ng for all meats.     

Hydroxylation of fatty acids and alcohols by hepatic microsomal cytochrome P-450 system from the Mongolian gerbil

The liver microsomes of the Mongolian gerbilMeriones unguiculatus catalyzed the hydroxylation of various saturated fatty acids (C₈−C₁₈), alcohols (C₁₂ and C₁₆) and hydrocarbon (C₁₂) to the corresponding ω- and (ω-1)-hydroxy derivatives. Lauric acid was hydroxylated most effectively among saturated fatty acids and the order of activity as hydroxylation substrates was C₁₂>C₁₄>C₁₃>C₁₆>C₁₀>C₁₈>C₈. The specific activity of laurate hydroxylation (5.99 nmol/mg microsomal protein/min) in gerbil liver microsomes was higher than that observed in other species. 1-Dodecanol was also hydroxylated very effectively (4.58 nmol/mg microsomal protein/min) by gerbil liver microsomes, but in general the hydroxylation rates for fatty alcohols were much lower than those for the corresponding acids. It was found from both inhibitor and cofactor studies that the enzyme catalyzing the hydroxylation of fatty acids and alcohols in the liver microsomes of the Mongolian gerbil was a typical cytochrome P-450-linked monooxygenase, and at least two different cytochrome P-450 species were involved in the hydroxylation. Presented in part at the AOCS annual meeting (a joint meeting with the Japan Oil Chemists' Society), Honolulu, Hawaii, May 1986.     

Contrasting diurnal variations in fossil and nonfossil secondary organic aerosol in urban outflow, Japan

Diurnal variations of fossil secondary organic carbon (SOC) and nonfossil SOC were determined for the first time using a combination of several carbonaceous aerosol measurement techniques, including radiocarbon (1?C) determinations by accelerator mass spectrometry, and a receptor model (chemical mass balance, CMB) at a site downwind of Tokyo during the summer of 2007. Fossil SOC showed distinct diurnal variation with a maximum during daytime, whereas diurnal variation of nonfossil SOC was relatively small. This behavior was reproduced by a chemical transport model (CTM). However, the CTM underestimated the concentration of anthropogenic secondary organic aerosol (ASOA) by a factor of 4-7, suggesting that ASOA enhancement during daytime is not explained by production from volatile organic compounds that are traditionally considered major ASOA precursors. This result suggests that unidentified semivolatile organic compounds or multiphase chemistry may contribute largely to ASOA production. As our knowledge of production pathways of secondary organic aerosol (SOA) is still limited, diurnal variations of fossil and nonfossil SOC in our estimate give an important experimental constraint for future development of SOA models.     

Bioaccumulation, temporal trend, and geographical distribution of synthetic musks in the marine environment

Bioaccumulation of synthetic musks in a marine food chain was investigated by analyzing marine organisms at various trophic levels, including lugworm, clam, crustacean, fish, marine mammal, and bird samples collected from tidal flat and shallow water areas of the Ariake Sea, Japan. Two of the polycyclic musks, HHCB and AHTN, were the dominant compounds found in most of the samples analyzed, whereas nitro musks were not detected in any of the organisms, suggesting greater usage of polycyclic musks relative to the nitro musks in Japan. The highest concentrations of HHCB were detected in clams (258-2730 ng/g lipid wt.), whereas HHCB concentrations in mallard and black-headed gull were low, and comparable with concentrations in fish and crab. These results are in contrast to the bioaccumulation pattern of polychlorinated biphenyls; for which a positive correlation between the concentration and the trophic status of organisms was found. Such a difference in the bioaccumulation is probably due to the metabolism and elimination of HHCB in higher trophic organisms. Temporal trends in concentrations of synthetic musks were examined by analyzing tissues of marine mammals from Japanese coastal waters collected during 1977-2005. HHCB concentrations in marine mammals have shown significant increase since the early 1990s, suggesting a continuous input of this compound into the marine environment. Comparison of the time trend for HHCB with those for PCBs and PBDEs suggested that the rates of increase in HHCB concentrations were higher than the other classes of pollutants. To examine the geographical distribution of HHCB, we have analyzed tissues of fish, marine mammals, and birds collected from several locations. Synthetic musks were not detected in a sperm whale (pelagic species) from Japanese coastal water and in eggs of south polar skua from Antarctica. While the number of samples analyzed is limited, these results imply a lack of long-range transportation potential of synthetic musks in the environment.     

α-Sulfonated fatty acid esters: I. Structural effects of sodium α-sulfonated fatty acid higher alcohol esters on surface-active properties and emulsification ability

The surface-active properties and emulsification ability of sodium α-sulfonated fatty acid esters, C_mH_2m+1CH-(SO₃Na)COOC_nH_2n+1, were studied as a function of the hydrophobic alkyl chainlength in the fatty acid (m=8−16) and the alcohol (n=8−18). As a result, it was discovered that sodium α-sulfonated fatty acid esters have a structural effect on the Krafft point different from that of amphiphiles with short alkyl chains. Moreover, some of the α-sulfonated fatty acid esters have quite low interfacial tensions, as well as non-foaming properties, which depend upon the total (m+n) number of carbon atoms in the alkyl chains.     

Simple,Mild, and Practical Esterification,Thioesterification, and Amide Formation Utilizing p‐Toluenesulfonyl Chloride and N‐Methylimidazole

We have developed an efficient method for the esterification or thioesterification of equimolar amounts of carboxylic acids and alcohols or thiols using a novel reagent, p‐toluenesulfonyl chloride (TsCl) together with N‐methylimidazole. The present method is simple, mild, and reactive, uses readily available and economical reagents. The choice of amine is critical for the present method. The amine, N‐methylimidazole, has two roles: (i) as an HCl scavenger for the initial smooth generation of mixed anhydrides between carboxylic acids and TsCl and (ii) successive formation of highly reactive ammonium intermediates from mixed anhydrides. This method could be applied to various types of carboxylic acids, alcohols, and thiols: a) several functionalities were tolerated; b) two N‐Cbz amino acids were smoothly esterified without racemization; and c) the labile 1β‐methylcarbapenem key intermediate and a pyrethroid insecticide, prallethrin, were successfully prepared. The related amide formation between carboxylic acids and primary or secondary amines was also performed. The proposed reaction mechanism involves a novel method for producing the reactive acylammonium intermediates. The production of these intermediates was rationally supported by a careful ¹H NMR monitoring study.     

Effect of microstructures on dielectric breakdown strength of sintered reaction-bonded silicon nitride ceramics

Silicon nitride (Si₃N₄) was prepared from silicon by a sintered reaction-bonded silicon nitride method using yttria and magnesia as sintering additives. Post-sintering (PS) of nitrided compacts was carried out at 1850°C under a nitrogen pressure of 1 MPa. Effect of PS time on microstructure and dielectric breakdown strength (DBS) of the prepared Si₃N₄ ceramics was evaluated. The DBS was measured using specimens with four different thicknesses (0.30, 0.20, 0.10, and 0.05 mm) in order to examine the thickness dependence. The porosity of the sintered Si₃N₄ decreased by prolonging the PS time, and the full density could be achieved at the PS time of over 6 h. After full densification, rod-like β-Si₃N₄ grains grew up, and their maximum grain size increased from 45.1 to 154.7 μm by prolonging the PS time from 6 to 48 h. The DBS of the thick Si₃N₄ substrates (0.30 mm) showed little variation from 35.4 to 47.0 kV/mm, regardless of the PS time. On the other hand, that of the thin ones (0.05 mm) dramatically decreased from 99.5 to 9.8 kV/mm with increased the PS time from 6 to 48 h. Because the DBS sharply decreased at the thin substrate sintered for longer time in which some large-elongated grains might span the substrate thickness-wise throughout, it was inferred that the interface between β-Si₃N₄ grains and grain boundary phase/intergranular glassy films might be a path of the dielectric breakdown.     

Synthesis of Red-Light-Responsive Pheophorbide-a Tryptamine Conjugated Photosensitizers for Photodynamic Therapy

Six methyl pheophorbide-a derivatives were prepared by linking a tryptamine side chain at the C-13 ¹ , C-15 ² and C-17 ³ positions of pheophorbide-a. P repared conjugates were characterized and evaluated for their photocytotoxicity against A549 cells. The conjugate 6 a with strong absorption at 413 nm (Soret band), 663–671 nm (Q bands) and comparable fluorescence quantum yield (0.26) was found to exhibit significant cytotoxicity (659 nM). Molecular integration of pheophorbide-a and tryptamines showed synergistic effects as the most potent conjugate 6 a was identified with enhanced photocytotoxicity when compared to methyl pheophorbide-a. T he conjugate 6 a was smoothly taken up by A549 cells and exhibited intracellular localization predominantly to lysosome in the cytoplasm. Upon photoirradiation 6 a generated singlet oxygen to show potent cytotoxicity toward A549 cells.     

Catalytic Rearrangement of Epoxide Compounds

Products formed by rearrangement of epoxide compounds provide useful intermediates in organic syntheses and some of them are valuable as raw materials in the chemical industry. Many studies on the catalytic rearrangement of the epoxides have been made. The reactions which have been used most frequently are homogeneous with acid or base catalysts such as BF3, MgBr2, t-BuOK, or lithium dialkylamides; the acid catalysts form mainly carbonyl compounds (ketone and aldehyde) and the base catalysts in most cases yield allylic alcohols. Recently the heterogeneous reaction over solid catalysts was also investigated, but the catalysts used were just alumina and silica gel, solid acid and base catalysts, and it is very recent that various kinds of the solid acids and bases have been used as catalysts for epoxide isomerization, especially by the authors (Section VI-A). Studies with molten salts are few, and investigations with metal complex and organometal catalysts have just begun.