Resultant compound from sublimation test for Gentianae Radix in Japanese Pharmacopoeia was 5-(hydroxymethyl)furfural.

Gentianae Radix, an herbal medicine, has been used as a gastrointestinal drug in Japan. In the Japanese Pharmacopoeia 18th Revision, the sublimation test is specified as an identification test for Gentianae Radix. The compound obtained in this sublimation test was believed to be gentisin, a xanthone family compound. However, the compound we identified using liquid chromatography-high-resolution mass spectrometry (LC-HRMS) and 1H- and 13C-NMR was 5-(hydroxymethyl)furfural (5-HMF). The same compound was found to be a sublimate of Gentianae Scabrae Radix and Gentianae Macrophyllae Radix, belonging to the same genus as Gentianae Radix. These results indicate the necessity to revise the identification test for Gentianae Radix to a more unique method.

Genetic and Chemical Diversity of Commercial Japanese Valerian.

In order to investigate the relationship between the chemical composition of essential oils and haplotypes of the psbA-trnH intergenic spacer region of chloroplast DNA (psbA-trnH) in Valerianae Fauriei Radix (Japanese Valerian; JV), we analyzed the DNA sequence and GC-MS metabolome of JV from Japanese markets and of herbal specimens from related species. DNA analysis revealed that JV products from Japan consisted of three haplotypes, namely AH-1, -2 and -5 reported in our previous study. The GC-MS metabolome revealed five chemotypes (J1, J2, C, K and O), of which J1, J2 and C were detected in the JV products from Japan. Chemotypes J1 and J2, with kessyl glycol diacetate (KGD) as the main volatile component, were found in the products of Japanese origin whereas chemotype C, with 1-O-acetyl-2,10-bisaboladiene-1,6-diol (ABD), was found in the products of Chinese and Korean origin. The haplotypes were correlated with the chemotypes: haplotype AH-1 for chemotype J1, AH-2 for chemotype J2 and AH-5 for chemotype C, suggesting that the chemical diversity of JV is not attributed to the environmental factors rather to the genetic factors. Since KGD and ABD were reported to have sedative effects and nerve growth factor (NGF)-potentiating effects, respectively, understanding the chemotypes and selecting an appropriate one would be important for the application of JV. The psbA-trnH haplotypes could be useful DNA markers for the quality control and standardization of JV.

Theoretical and Experimental Studies on the Near-Infrared Photoreaction Mechanism of a Silicon Phthalocyanine Photoimmunotherapy Dye: Photoinduced Hydrolysis by Radical Anion Generation.

Invited for this month's cover are the collaborating groups of Dr. Masato Kobayashi and Prof. Mikako Ogawa, both from Hokkaido University, Sapporo, Japan. The cover picture shows the photochemical reaction process of the near-infrared (NIR) photoimmunotherapy dye IR700, and subsequent cancer cell death. A computational study predicted that ligand dissociation, which is known to initiate cancer cell death, proceeds by the hydrolysis of the IR700 radical anion, rather than as a direct result of NIR irradiation. This mechanism has also been supported by experimental work. Read the full text of the Communication at 10.1002/cplu.202000338.

Theoretical and Experimental Studies on the Near-Infrared Photoreaction Mechanism of a Silicon Phthalocyanine Photoimmunotherapy Dye: Photoinduced Hydrolysis by Radical Anion Generation.

Ligand release from IR700, a silicon phthalocyanine dye used in near-infrared (NIR) photoimmunotherapy, initiates cancer cell death after NIR absorption, although its photochemical mechanism has remained unclear. This theoretical study reveals that the direct Si-ligand dissociation by NIR light is difficult to activate because of the high dissociation energy even in excited states, i. e., >1.30 eV. Instead, irradiation generates the IR700 radical anion, leading to acid-base reactions with nearby water molecules (i. e., calculated pKb for the radical anion is 7.7) to produce hydrophobic ligand-released dyes. This suggests two possibilities: (1) water molecules participate in ligand release and (2) light is not required for Si-ligand dissociation as formation of the IR700 radical anion is sufficient. Experimental evidence confirmed possibility (1) by using 18 O-labeled water as the solvent, while (2) is supported by the pH dependence of ligand exchange, providing a complete description of the Si-ligand bond dissociation mechanism.

Construction of Prediction Models for the Transient Receptor Potential Vanilloid Subtype 1 (TRPV1)-Stimulating Activity of Ginger and Processed Ginger Based on LC-HRMS Data and PLS Regression Analyses.

To construct a model formula to evaluate the thermogenetic effect of ginger (Zingiber officinale Roscoe) from the ingredient information, we established transient receptor potential vanilloid subtype 1 (TRPV1)-stimulating activity prediction models by using a partial least-squares projections to latent structures (PLS) regression analysis in which the ingredient data from liquid chromatography-high-resolution mass spectrometry (LC-HRMS) and the stimulating activity values for TRPV1 receptor were used as explanatory and objective variables, respectively. By optimizing the peak extraction condition of the LC-HRMS data and the data preprocessing parameters of the PLS regression analysis, we succeeded in the construction of a TRPV1-stimulating activity prediction model with high precision ability. We then searched for the components responsible for the TRPV1-stimulating activity by analyzing the loading plot and s-plot of the model, and we identified [6]-gingerol (1) and hexahydrocurcumin (3) as TRPV1-stimulating activity components.