Study on Catalpol Content in Rehmannia glutinosa Root, an Important Ingredient in Kampo Prescriptions.

Rehmannia glutinosa is an important medicinal plant in Asia, and its roots are used as an ingredient in herbal medicine. However, the roots exhibit different medicinal effects depending on the processing conditions. Since the catalpol content differs greatly during the process, the catalpol content is an essential index for quality evaluation.

Study on morphological and genetic diversity of Rehmannia glutinosa cultivated in Japan.

It is said that Rehmannia glutinosa is grouped into two types, Akaya and Kaikei, in Japan. However, previous reports of genetic analysis of R. glutinosa in commercial products suggest the existence of varieties other than these two, and therefore, it is inappropriate to simply classify them into these two varieties.

Aggregate Formation of Oligonucleotides that Assist Molecular Imaging for Tracking of the Oxygen Status in Tumor Tissue.

The use of DNA aggregates could be a promising strategy for the molecular imaging of biological functions. Herein, phosphorescent oligodeoxynucleotides were designed with the aim of visualizing oxygen fluctuation in tumor cells. DNA-ruthenium conjugates (DRCs) that consisted of oligodeoxynucleotides, a phosphorescent ruthenium complex, a pyrene unit for high oxygen responsiveness, and a nitroimidazole unit as a tumor-targeting unit were prepared.

Ruthenium complexes with hydrophobic ligands that are key factors for the optical imaging of physiological hypoxia.

The phosphorescence emission of ruthenium complexes was applied to the optical imaging of physiological hypoxia. We prepared three complexes with hydrophobic substituents on the phenanthroline ligand and characterized their emission, which was quenched by molecular oxygen. Among the complexes synthesized in this study, a pyrene chromophore-linked ruthenium complex, Ru-Py, exhibited optimal properties for the imaging of hypoxia; the prolonged lifetime of the triplet excited state of the ruthenium chromophore, which was induced by efficient energy distribution and transfer from the pyrene unit, provided the highest sensitivity towards molecular oxygen.