Application of mixture analysis to crude materials from natural resources (III): NMR spectral studies to analyze chalcones from Angelica keiskei.

This study presents the application of the NMR-based analyses, DOSY and ROSY, to the chalcones, xanthoangelol (1) and 4-hydroxyderricin (2) from Angelica keiskei. We investigated whether virtual separation and structural information from each compound can be obtained. DOSY displays spectra of (1) and (2) in one dimension and diffusion spectra in the other.

Application to classification of mulberry leaves using multivariate analysis of proton NMR metabolomic data.

Recently, NMR-based metabolomic analysis has been used to acquire information based on differentiation among biological samples. In the present study, we examined whether multivariate analysis was able to be applied to natural products and/or material field. Each extraction of 24 leaf samples, divided into six locations from the tip of the stem in each of four strains, was analyzed by pattern recognition methods, known as Principal Component Analysis (PCA) and Soft Independent Modeling of Class Analogy (SIMCA).

Characterization of the complex formation of 1,6-anhydro-β-maltose and potassium ions using NMR spectroscopy and single-crystal X-ray crystallography.

The formation of a complex between 1,6-anhydro-β-maltose and potassium ions was characterized using (1)H, (13)C and (39)K NMR spectroscopy and single-crystal X-ray crystallography. In the NMR study, the spin-lattice relaxation times (T(1)) of C1, C3, C5, C6, and C5' significantly decreased in the presence of potassium ions, and (39)K-T(1) also decreased in the presence of 1,6-anhydro-β-maltose, indicating complex formation. In a crystal, both 8- and 9-coordination structures, corresponding to the distorted capped pentagonal bipyramidal structure and the capped hexagonal bipyramidal structure, respectively, were identified.

Identification of Glycyrrhiza species by direct analysis in real time mass spectrometry.

DART (Direct Analysis in Real Time)-MS is a novel mass spectrometric ion source, and allows the analysis of most compounds at ambient pressure and ground potential by producing [M+H]+ molecular ion species. Using this method, we examined the compounds characteristic of several kinds of licorices. For the analysis of Glycyrrhiza inflata Batalin, the peak at m/z 339 originates mainly from [M+H]+ of licochalcone A (LA), a species-specific compound.

Characterization of the complex formation of 1,6-anhydro-beta-maltotriose with potassium using 1H and 39K NMR spectroscopy.

The (1)H and (39)K longitudinal relaxation times (T(1)) and (1)H diffusion coefficients were measured to investigate the complex formation of 1,6-anhydro-beta-maltotriose and potassium ions. Although the (1)H-T(1) values of H3', H5', H1'' and H4'' decreased in the presence of potassium ions, (1)H chemical shifts and (1)H diffusion coefficients did not show significant changes. The long-range coupling constants of (3)J(C-H) around the glycosyl bonds did not show significant changes either.