Isomeric flavonoid O-diglycosides were analyzed by positive and negative nano-electrospray ionization (ESI) ion trap mass spectrometry (ITMS) in order to evaluate whether the two most common interglycosidic linkage types, i.e. 1 --> 2 and 1 --> 6, found for glycosides containing a rhamnosylglucose glycan part can be differentiated. In the positive ion mode the degree of internal glucose residue loss was found to be strongly dependent on the aglycone type and was very pronounced for aglycones of the flavanone type. The relative abundance of the Y-type ions formed by fragmentation at glycosidic bonds only allows one to infer the interglycosidic linkage types in the case of flavone O-diglycosides. In contrast, the negative ion mode makes a clear differentiation between a rutinoside (1 --> 6) and a neohesperidoside (1 --> 2) glycan residue possible for all aglycone types. The neohesperidose-containing compounds could be characterized by additional product ions. When the compounds were dissolved in pure methanol a molecular radical ion was found to be the base peak in nano-ESI.
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http://dx.doi.org/10.1002/jms.224 | DOI Listing |
J Pharm Biomed Anal
February 2019
College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083, PR China; Hunan Provincial Key Laboratory of Efficient and Clean Utilization of Manganese Resources, Central South University, Changsha, 410083, PR China.
Rapid differentiation, characterization and quantification of isomers from complex mixtures by direct mass spectrometry (MS) remained an analytical challenge due to their similar or identical MS/MS spectra and matrix interferences. Here, we reported a novel online extraction-quadrupole time-of-flight tandem mass spectrometry (OLE-QTOF-MS/MS) system to rapid, efficient and sensitive analysis of interglycosidic linkage isomers (hesperidin and neohesperidin) in Citrus paradisi cv. Changshanhuyou (Changshanhuyou).
View Article and Find Full Text PDFBioorg Chem
October 2018
State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China. Electronic address:
Two new 3-hydroxy-3-methylglutaryl (HMG) flavanone 7-O-diglycosides, cigranosides A and B (1 and 2), the known naringenin 7-(2''-α-rhamnosyl-6''-(3''''-hydroxy-3''''-methylglutaryl)-glucoside (melitidin, 3), their common biosynthetic precursor flavanone 7-O-diglycoside (naringin, 4), and one known flavone 7-O-diglycoside (rhoifolin, 5) were isolated from the pericarp of Citrus grandis (L.) Osbeck. The structures of these compounds were elucidated by spectroscopic and chemical techniques.
View Article and Find Full Text PDFPlanta
April 2018
RIKEN Center for Sustainable Resource Science, 1-7-22, Suehiro-cho, Tsurumi-ku, Yokohama, 230-0045, Japan.
UGT79B31 encodes flavonol 3- O -glycoside: 2″- O -glucosyltransferase, an enzyme responsible for the terminal modification of pollen-specific flavonols in Petunia hybrida. Flavonoids are known to be involved in pollen fertility in petunia (P. hybrida) and maize (Zea mays).
View Article and Find Full Text PDFFitoterapia
January 2018
State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China. Electronic address:
Three new 3-hydroxy-3-methylglutaryl (HMG) flavone 7-O-diglycosides, argutosides A-C (1-3); two new flavone 7-O-triglycosides, argutosides D-E (4-5); and one known apigenin 7-O-triglycoside (6), were isolated from the leaves of Turpinia arguta. The structures of these compounds were elucidated by spectroscopic and chemical techniques. The NO inhibitory activities of compounds 1-6 were evaluated using lipopolysaccharide-induced RAW264.
View Article and Find Full Text PDFJ Nat Prod
October 2017
College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul 08826, Republic of Korea.
Three compounds in a new class of 2-acetoxy-ω-phenylpentaene fatty acid triglycosides, berchemiosides A-C (1-3), and a biosynthetically related phenolic glycoside (4) were isolated from the unripe fruits of Berchemia berchemiifolia, along with three flavonoid 5-O-diglycosides (5-7) and three known flavonoids (8-10). Their chemical structures including absolute configurations were determined by spectroscopic analysis in combination with chemical derivatization. The pentaene group of 1 was found to have (6E,8E,10Z,12Z,14E)-geometry, whereas those of 2 and 3 exhibited all-E geometries.
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