[Quantification of Clitidine in Paralepistopsis acromelalga Using Quantitative NMR Method].

Because one toxic component of Paralepistopsis acromelalga, clitidine, is not commercially available as a reagent and because standards are difficult to obtain, a quantitative NMR method that requires no standard was investigated for this study. To compare the quantitative values obtained using the two methods, the absolute purity of the standard used for the LC-MS/MS method was calculated using quantitative NMR. The result was calculated as 89.8±1.5%: more than 10% lower than the result obtained using conventional HPLC purity. This finding is presumably attributable to the presence of water in the crystals. Calculating the absolute purity of the product before use is crucially important. The values of the Paralepistopsis acromelalga fruit extract were quantified and compared using conventional LC-MS/MS and quantitative NMR. The quantitative values did not differ significantly, suggesting that, in most cases, they were within a 5% margin of error. Furthermore, quantitative NMR provides several benefits not obtained using conventional methods, including its rapid measurement capability and its obviation of the need for a reference material for the measured substance. By virtue of these benefits, quantitative NMR is an extremely useful tool for natural toxin analysis where sudden outbreaks occur and for which rapid calculation of results is necessary.

[Development of a Simple Identification Method for Omphalotus guepiniformis by Color Reaction].

A simple method of identification using a color reaction was developed for Omphalotus guepiniformis. Only Omphalotus guepiniformis turned turquoise green. Other edible mushrooms resembling the mushroom did not change color when the beam reagent (5 w/v% potassium hydroxide ethanolic solution) was dripped onto the mushroom pileus. Furthermore, ethanol extract and mock cooking products of this mushroom exhibited the same color reaction. These results demonstrate this method as useful for identifying Omphalotus guepiniformis during mushroom hunting or during investigations of food poisoning.

[Simultaneous Analysis of Paralepistopsis acromelalga Applied to Cooked and Processed Foods].

The applicability of a method for simultaneous analysis of Acromelic acids A, B, and Clitidine, which are venomous constituents of Paralepistopsis acromelalga, was assessed for three simulations: tempura, chikuzenni, and soy sauce soup. All components were detectable for all cooking methods. No interfering peak affecting the analysis was observed. The findings indicate that samples of leftover cooked products can be used to ascertain causes of food poisoning by Paralepistopsis acromelalga. Additionally, results showed that most of the toxic components were eluted into the soup broth. This property is useful for rapid screening for Paralepistopsis acromelalga in edible mushrooms.

[Color Reaction Identification of Omphalotus guepiniformis Causing Food Poisoning].

Simple identification using a color reaction was applied to investigate poisoning, putatively caused by Omphalotus guepiniformis. Some leftover uncooked mushrooms had turned turquoise green when a beam reagent (5 w/v% potassium hydroxide ethanolic solution) was dripped onto the mushroom pileus. Furthermore, ethanol extract of the mushrooms exhibited the same color reaction. Then, illudin S, a toxic compound contained in O. guepiniformis, was detected in uncooked leftover mushrooms using LC-MS/MS analysis. Therefore, this case was inferred as caused by O. guepiniformis. These results indicate the identification method described above as useful for screening tests for investigating food poisoning caused by O. guepiniformis.

[Isolating Venomous Constituents of Paralepistopsis acromelalgaand Simultaneous Analysis of Its Compounds].

An isolation method for Acromelic acids A, B and Clitidine, which are venomous constituents of Paralepistopsis acromelalga was developed. Highly purified products were obtained from the mushroom extract using silica gel, ODS, ion-exchange column chromatography and preparative TLC. Using those results, we optimized the LC-MS/MS conditions. Finally we developed a method for simultaneous analysis. In recovery tests, the average recovery was 80.8-112.4%, repeatability was 1.4-3.8RSD%. The limits of quantification of the respective compounds were estimated as 0.25 µg/g. Based on the results, this method can reveal causes of food poisoning by Paralepistopsis acromelalga.