Distinction of theC-glycosylflavone isomer pairs orientin/isoorientin and vitexin/isovitexin using HPLC-MS exact mass measurement and in-source CID

Abstract

HPLC-MS using collision induced dissociation (CID) has been utilised for the identification of the C-glycosylflavone isomer pairs orientin/isoorientin and vitexin/isovitexin. HPLC-CID/MS analyses produced pseudo-MS/MS spectra that allowed the identification of the flavone C-glycosides. The efficient differentiation of isomers was performed by comparing the CID-MS/MS spectra (including exact mass measurements) of particular fragments from the C-glycoside unit. In order to illustrate some possibilities of these MS techniques, they were applied to the comparative analyses of extracts of Passiflora alata, P. edulis, P. incarnata and P. caerulea (Passifloraceae) that are employed as phytomedicines in Brazil and South America.

Identification of phenolic constituents of Cytisus multiflorus

“…The presence of these two isomers in contiguous fractions were confirmed by HPLC-MS analysis (results not shown). Moreover, considering that in nature the C-glycosyl moieties appear almost exclusively at 6 and/or 8-positions of flavones (Cuyckens & Claeys, 2004) and that the 8-C-glycosyl-luteolin isomer elutes before the 6-C-glycosyl-luteolin under reversed phase conditions (Kazuno, Yanagida, Shindo, & Murayama, 2005;Pereira, Yariwake, & McCullagh, 2005;Piccinelli et al, 2008), the phenolic compounds in fractions 1 and 2 were respectively assigned to 2 00 -O-pentosyl-6-C-hexosyl-luteolin and 2 00 -O-pentosyl-8-C-hexosylluteolin. The structures of these two compounds are depicted in Fig.…”

“…3). Attending that 8-C-glucosyl-apigenin elutes before 6-C-glucosyl-apigenin under HPLC reverse phase conditions (Kazuno et al, 2005;Pereira et al, 2005;Piccinelli et al, 2008), compounds of MW 564 Da in fractions 4 and 5 were respectively assigned to 2 00 -O-pentosyl-vitexin and 2 00 -O-pentosyl-isovitexin. To our knowledge, these compounds were here detected for the first time in Fabaceae family.…”

Study of C- and O-glycosylflavones in sugarcane extracts using liquid chromatography: exact mass measurement mass spectrometry

“…We have recently demonstrated that the combination of mass measurement and in-source collision-induced dissociation (CID) is a valuable tool for the unequivocal identification of isomeric C-glycosylflavonoids in Passiflora extracts. 7 Sugarcane (Saccharum officinarum L.; Gramineae) is the main source of industrial sugar in tropical countries and is also one of the most important crop plants in Brazil. Various HPLC-UV-MS techniques (including APCI-MS/ MS and UV detection using post-column addition of shift reagents) have been employed previously in the investigation of sugarcane components, resulting in the identification of 15 flavone glycosides and aglycones.…”

Screening for potential co-products in a Miscanthus sinensis mapping family by liquid chromatography with mass spectrometry detection

“…In mono-C-hexosyl flavones, the presence of ions - -90] -was typical of the 6-C isomer (Ferreres et al, 2008(Ferreres et al, , 2007(Ferreres et al, , 2003 (Pereira et al, 2005;Ferreres et al, 2003;Sánches-Rabaneda et al, 2003).…”