In order to seek for a good matrix material for neutral oligosaccharides instead of DEA in molecular SIMS, we examined seven amide compounds which possess intermediate proton affinity between glycerol and DEA. Among them, HEF, PR and PP were available for our purposes. The amide matrices-assisted mass spectra give surely both molecular adduct ions ([M + × + H]+, × = HEF, PR and PP) and some sequence ions. Additionally, the metastable ion spectra of [M + × + H]+ under linked scanning (B/E) conditions gave structurally reliable information.
The anthocyanin in the purplish-red flowers of carnation (Dianthus caryophyllus) has been considered for many years as cyanidin 3-glucoside (Cy 3-G). However, from chromatographic studies on the flower color in carnation, we previously found that the major anthocyanin was not Cy 3-G but an acylated one attached to an unknown organic acid.In the present studies, we have isolated and crystallized this anthocyanin from purplish-red flowers of carnation and analyzed it by chemical and spectroscopic means. This pigment was identified as cyanidin 3-malylglucoside (Cy 3-MG). Furthermore, by means of direct chromatographic comparison with this pigment, it was also found that Cy 3-MG was widely present in the purplish-red flower cultivars and in the same color hybrids which were obtained from intervarietal crossing of carnations.In addition, we have recently identified another anthocyanin, peralgonidin 3-malylglucoside (Pg3-MG) from a red flower carnation cultivar. Therefore, these results strongly suggest that malylation of anthocyanin is characteristic in the flowers of carnation.
It is known that several kinds of pyrrolidine alkaloids with a bis-amide structure are isolated from extracts from leaves and roots of Meliaceae family plants. A fragment ion m/z 85 was found in common in mass spectra of all these compounds. The structure and fragmentation mechanism of the ion were elucidated through high-resolution mass spectra and B/E as well as B2/E linked scan spectra. The fragment ion was also found useful as an index for searching compounds having similar structures.
We established a highly sensitive method to determine triazolam and its major metabolites, alpha-hydroxytriazolam and 4-hydroxytriazolam, in human plasma and urine with a liquid chromatography-mass spectrometry system which incorporates an atmospheric chemical ionization interface. A plasma sample and a urine sample after solvent extraction were injected into an ODS column of reversed phase with a mobile phase in a linear solvent gradient of initially 50 mM ammonium acetate (pH 4.0) 50%:methanol 50% and 15 min later methanol 100%; quantification limits of as low as 20 pg/mL at an SNR of 3 were obtained for each compound. With diazepam as an internal standard, recovery yields of 84, 81, and 77% were obtained for triazolam, alpha-hydroxytriazolam and 4-hydroxytriazolam, respectively.
Secondary ionization mass spectrometry (SIMS)-linked scanning analysis was used as a method for identifying a specific Aloe arborescens MILLER (Kidachi-aroe) component, aloenin, in health foods containing Kidachi-aroe. The compound was extracted with methanol and identified in positive mode and constant B/E using SIMS-linked scanning analysis without any further purification such as a chromatography. Kidachi-aroe was detected in the sample using aloenin as an indicator. In the SIMS-linked scanning spectra of health foods containing Kidachi-aroe, peaks were observed of a quasi-molecular ion (m/z 411[M+H]+) and its daughter ion at m/z 249, indicating the structure of aloenin. Kidachi-aroe was thus detected when present in health foods. The proposed method is easy, rapid and accurate for both characterization and estimation of aloe materials in health foods containing Kidachi-aroe.
Secondary ion mass spectra of underivatized neutral sphingoglycolipids are presented. In the spectra of mono- and di-glycosylceramide, ions (M + H)+ and (M + H-H2O)+ were observed as relatively intense quasimolecular ions, whereas in the spectra of higher glycolipids, the quasimolecular ion species were predominantly (M + Na)+. Ions due to the ceramide moiety were observed as intense peaks comparable to quasimolecular ions. Ions derived from the fragments cleaved at the glycosidic linkages were hardly detected due to their low intensities. In general, secondary ion mass spectrometry provides good stable spectra for a long time during analysis.
