RATIONALE Alkaloids with significant therapeutic effects are the main active constituents of Corydalis (C.) species. There are several kinds of alkaloids in C. species associated with diverse alkaloid metabolism in plants, but they are rarely identified. This study aimed to identify diverse alkaloids in C. species by liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI‐MS/MS). METHODS Several types of alkaloids were extracted from C. species using ultrasonication with 70% CH3OH, and the extract was partitioned at pH 2 and 12. Separation of alkaloids was achieved by C18 high‐performance liquid chromatography (HPLC), and MS/MS analysis was conducted by electrospray ionization triple‐quadrupole mass spectrometry. For further confirmation, LC/Fourier transform ion cyclotron resonance (FTICR)‐MS was used to obtain accurate mass data and gas chromatography (GC)/MS combined with trimethylsilyl derivatization was applied for identification of the minor alkaloids. RESULTS Thirty‐three alkaloids among three different C. species were successfully separated and identified by LC/ESI‐MS/MS and LC/FTICR‐MS. Structural assignment of individual alkaloids was performed according to MS/MS spectral patterns. For further confirmation, accurate mass data of alkaloids by LC/FTICR‐MS were obtained within 5 ppm and the GC/MS data for the trimethylsilyl alkaloids were also obtained. Among 33 alkaloids identified from this study, 13 alkaloids were reported for the first time in the investigated C. species. CONCLUSIONS The LC/ESI‐MS/MS technique was effective in obtaining structural information and yielded diagnostic ions for diverse alkaloids. Based on the identified 33 alkaloids, marker compounds were suggested for the three C. species with different geographic origins. This study may also be useful for elucidating unknown alkaloids in herbal medicines. Copyright © 2012 John Wiley & Sons, Ltd.
The phase transitions of Ge2Sb2Te5 (GST) films after bombardment with 40keV N2+ ions were investigated. Comparing the nitrogen incorporated GST films with a pure GST film, the suppression of a crystalline grain growth was more effective in the N2+ implanted GST film than in a nitrogen codeposited GST film, i.e., x-ray diffraction data showed that the intensities of the crystalline diffraction peaks were decreased and the full widths at half maximum were broader than that of a pure GST film. This suppression of crystallization owing to the incorporation of nitrogen drastically reduced the roughness of surface morphology and decreased the electrical conductivity of the crystalline film. A near edge x-ray absorption fine structure experiment and x-ray photoemission spectroscopy data demonstrated that the suppression of crystalline grain growth is due to the formation of Ge3N4 and interstitial N2 molecules. In N2+ implanted GST films, in particular, interstitial N2 molecules played a major role in the suppression of crystallization.
In this study, enzymatic hydrolysis and chemometric methods were utilized to discriminate glycosylated platycosides in the extract of Platycodi Radix by LC-MS. Laminarinase, whose enzymatic activity was evaluated using gentiobiose and laminaritriose, was a suitable enzyme to identify the glycosylated platycosides. The laminarinase produced deapi-platycodin D and platycodin D from the isolated deapi-platycoside E and platycoside E through the loss of two glucose units by enzymatic reaction, respectively. After hydrolyzing a crude extract by laminarinase, the reconstructed total ion chromatogram generated by a chemometric technique sorted peaks of deglycosylated platycosides easily. Structural information of the glycosylated isomers was revealed through fragment ions generated by the sodiated C0β ion corresponding to reduced disaccharides in the positive MS(4) spectra. Characteristic fragment ions of Glc-(1→6)-Glc moieties were observed through ring cleavages of (0,2)A0β, (0,3)A0β, and (0,4)A0β, whereas Glc-(1→3)-Glc moieties produced only (0,3)A0β ions. Lithium-adducted platycosides allowed more detailed structural analysis of glycosidic bond cleavage corresponding to Y1β and B1β in addition to ring cleavage.
The objective of this study was to examine the association between periodontitis and risk of incident Parkinson’s disease using large-scale cohort data on the entire population of South Korea. Health checkup data from 6,856,180 participants aged 40 and older were provided by the National Health Insurance Service of South Korea between January 1, 2009, and December 31, 2009, and the data were followed until December 31, 2017. The hazard ratio (HR) of Parkinson’s disease and 95% confidence interval (CI) were estimated using a Cox proportional hazards model adjusted for potential confounders. The incidence probability of Parkinson’s disease was positively correlated with the presence of periodontitis. The HR of Parkinson’s disease for the participants without the need of further dentist visits was 0.96 (95% CI 0.921–1.002); the HR of Parkinson’s disease increased to 1.142 (95% CI 1.094–1.193) for the individuals who needed further dentist visits. Compared to individuals without periodontitis and without metabolic syndrome, the HR of incident Parkinson’s disease gradually increased for individuals with periodontitis, with metabolic syndrome, and with both periodontitis and metabolic syndrome. People with periodontitis and metabolic syndrome had the highest HR of incident Parkinson’s disease, at 1.167 (95% CI 1.118–1.219). In conclusion, a weak association between periodontitis and Parkinson’s disease was suggested after adjusting for confounding factors from the population-based large-scale cohort of the entire South Korean population.
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