Lampteromyces japonicus (Japanese name, Tsukiyotake) is a poisonous and bioluminescent mushroom, which causes vomiting, stomachache and diarrhea.
This mushroom is often mistaken by amateur mushroom hunters for the edible mushrooms Pleurotos osteatus (Hiratake), Lentinus edodes (Shiitake), and Panellus serotinus (Mukitake), since these species are all very similar in shape and color. Some people in the Shounai area of Yamagata Prefecture have eaten the salted poisonous mushrooms.
We examined the gastrointestinal toxicity of the salted mushrooms and the nature of the toxic principles by using mice and frogs.
Oral administration of the methanolic extract of L. japonicus to mice and frogs caused toxic effects such as swelling of the stomach in mice and vomiting in frogs. However, no toxic effects were associated with the extract of the salted mushroom.
Isolation of the toxic principles from L. japonicus with guidance by biological assay was carried out by chromatographic separation, NMR and mass spectroscopic analysis revealed that illudin S was one of the toxic principles.

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A simple and rapid method for the simultaneous determination of carbadox (CDX) and quinoxaline-2-carboxylic acid (QCA), the most persistent metabolite, in swine tissues has been developed by HPLC with photodiode array detection. The drugs were extracted with 0.3% metaphosphoric acid-MeOH (7:3, v/v), and the extracts were cleaned up with a Bond Elut C₁₈ cartridge. The HPLC separation was performed on a Wakosil-II 5C18 RS column (150×4.6mm i. d.) with a gradient system of 0.01M phosphate buffer (pH 2.5)-MeCN as the mobile phase, at the flow-rate of 0.6ml/min. The calibration graphs were rectilinear from 0.5 to 50ng for CDX and QCA. The recoveries of CDX and QCA from swine muscle and liver fortified at the level of 0.1μg/g were 85.0-94.3%, with high precision. The limits of detection were 0.005-0.01μg/g for CDX and QCA. Further, a preliminary investigation was carried out in order to determine the toxic metabolite desoxy-carbadox.

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A method was developed for the simultaneous determination of caffeine (CF), theobromine (TB) and theophylline (TP) in various kinds of foods by HPLC.
Solid foods except chewing gum were dialyzed for 1 hour against hot water, then for 5 hours against water at room temperature. CF, TB and TP in chewing gum were extracted with a blender into hot water. Liquid samples were diluted with 1% phosphoric acid.
The test solutions described above were each passed through a BAKERBOND spe (SO₃H) cartridge. The cartridge was washed with water and CF, TB and TP were eluted with a mixture of 2% ammonium solution-15% aqueous sodium chloride solution-MeOH (1:1:2). The three compounds were separated on a Cosmosil 5C18-AR column with a mobile phase of MeCN-0.01M phosphate buffer (pH 3.5) (1:9).Detection was done at 275nm.
The recoveries of CF, TB and TP added to various kinds of foods were 90-98%, 98-104%, 90-103%, respectively. The determination limits of CF, TB and TP were 10μg/g.

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Twenty-four paprika colors, which are commercially available as food colorants in Japan, were analyzed by reversed-phase HPLC with the gradient solvent system described in the legend to Fig. 1. The analyzed paprika colors were classified into two groups on the basis of their HPLC profiles. One group consisted of colors originating from Spain (15 samples) and three other countries (3 samples). The highest peak in any chromatogram of this group was c1 or b5 (β-carotene) and the number of peaks which showed 40% height or more relative to the highest peak was about 5. The other group consisted of colors originating from China (5 samples). The major peaks of this group were c1, c3, c5 and b5 and the number of peaks which showed 40% height or more was about 10.
The compounds corresponding to the peaks b2, c0, c1 and c3 were isolated by preparative TLC and HPLC, and characterized by LC/MS and NMR. The spectroscopic data revealed that b2, c0, c1 and c3 were 3′-O-myristoylcapsanthin, dilauroylcapsanthin, lauroylmyristoylcapsanthin and dimyristoylcapsanthin, respectively.

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A simple and rapid determination method was developed for oligosaccharides in foods: lactosylfructoside (=lactosucrose), soy-oligosaccharides, fructooligosaccharides, palatinose, maltitol and xylotriose.
Milk was deproteinized with 1.8% trichloroacetic acid and then defatted with diethylether. Youkan or gum was cut into small pieces, then warm water was added and the mixture was ultrasonicated. Oligosaccharides were extracted with 50% ethanol and the solution was filtered. The oligosaccharides were analyzed by normal-phase HPLC [column, TSKgel Amide-80 (4.6mm i. d.×250mm); mobile phase, MeCN-water (70:30); detection, differential refractometer].
Contents of oligosaccharides in six commercial oligosaccharides for foodstuffs and seven commercial foods, mainly Foods for Specified Health Use (functional foods) were determined by the proposed method. The content of oligosaccharide was consistent with the indicated content in all cases.
Recoveries of the oligosaccharides from foods were in the range of 95.0-118%. The detection limit of the oligosaccharides was 0.2mg/ml for juice, 0.5mg/g for milk, and 1mg/g for Youkan and gum.

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The freshness of breast meat from male broiler chicks (Arbor Acres) fed diet containing 3% tea leaf powder was studied. Feeding the diet with green tea or used tea for 35 days had no effect on dietary intake or body weight change, but resulted in better maintenance of freshness and a lower lipid peroxide level in the meat. Levels of lipid-soluble antioxidants such as α-tocopherol and retinol were significantly increased in the meat of broilers fed the tea leaf powder. The freshness-improving potency seemed to be closely associated with the increases of antioxidants in chicken. The used tea leaves are produced in the manufacturing process of green tea canned beverage and they contain large amounts of lipid-soluble antioxidants and some caffeine. The addition of used tea leaf powder to chicken feed may be valuable not only for long-term breeding, but also for solving the problem of disposal of the used tea.

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A rapid and efficient clean-up method was developed for determining 16 organochlorine pesticides, 8 pyrethroid pesticides and 24 organophosphorus pesticides in foodstuffs such as onion and garlic, which contain high levels of matrix compounds. First, the sample was treated in a microwave oven to inactivate enzymes which caused interfering peaks. Pesticides were extracted with acetone, re-extracted with dichloromethane and determined by ECD-GC and FPD-GC. Major interfering peaks were not found on ECD-GC and FPD-GC chromatograms. Recoveries of the pesticides were 49.8-132.5%.

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A simultaneous analytical method was developed for 9 nitrophenol pesticides and 2 aromatic nitro pesticides in drinking water by HPLC. The analytical HPLC was run on a Wakosil II 3C18AR column (4.6mm i. d. ×15cm) with a gradient formed from A: 0.1M monochloroacetic acid (pH 2.5)-MeCN-0.01M sodium butanesulfonic acid (10:30:60) and B: 0.1M monochloroacetic acid (pH 2.5)-MeCN (10:90), UV detection at 280nm and amperometric detection (AMD) with a glassy-carbon electrode (+1.2V). A drinking water sample was adjusted to pH 4 with 0.1M hydrochloric acid and purified on a Sep-pak Plus PS-2 cartridge. The cartridge was washed with water, and retained substances were eluted with MeCN. The eluate was concentrated under an N₂ stream and was analyzed by HPLC. Recoveries for pesticides spiked into drinking water were 58.0-98.6% at the level of 20μg/L. The detection limits of these pesticides in water are 1μg/l.

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The analytical method for determination of fumonisin B₁ and fumonisin B₂ in unpolished rice, polished rice and corn soup has been improved. Fumonisins (fumonisin B₁ and fumonisin B₂), which are the major metabolites produced by Fusarium moniliforme and Fusarium proliferatum, have been implicated in human esophageal cancer, induced pulmonary edema in pigs and leukoencephalacia in horses. In the determination of fumonisins from unpolished rice and polished rice, α-amylase digestion was conducted before the extraction and clean-up used in the case of corn, to increase the recovery of fumonisins. The recoveries of spiked fumonisin B₁ and fumonisin B₂ from polished rice averaged 91% and 94%, respectively, at the level of 0.5μg/g. In the determination of fumonisins from corn soup containing guar gum, α-amylase digestion and β-mannosidase digestion were employed before the usual extraction and clean-up. The recoveries of fumonisin B₁ and fumonisin B₂ spiked in corn soup averaged 90% and 92%, respectively, at the level of 0.5μg/g.

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[in Japanese]

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