Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry of heteropolyflavan-3-ols and glucosylated heteropolyflavans in sorghum [Sorghum bicolor (L.) Moench].
Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) was used to characterize the structural diversity of polyflavans in Ruby Red sorghum [Sorghum bicolor (L.) Moench]. Deionization of the polyflavan fractions with Dowex 50 x 8-400 cation-exchange resin and subsequent addition of cesium trifluoroacetate ((133)Cs) allowed the detection of exclusively [M + Cs](+) ions. MALDI-TOF MS of the polyflavans that eluate from Sephadex LH-20 columns with methanol and acetone detected a series of masses corresponding to heteropolyflavan-3-ols differing in degree of hydroxylation and nature of the interflavan bond (A-type and B-type). MALDI-TOF MS of the Sephadex-ethanol/methanol (v/v) eluate revealed a series of masses corresponding to heteropolyflavan-5-O-beta-glucosides that vary in the extent of hydroxylation and contain a flavanone (eriodictyol or eriodictyol-5-O-beta-glucoside) as the terminal unit. The combination of liquid chromatographic separation and MALDI-TOF MS to characterize sorghum polyflavans indicates that the structural heterogeneity is much greater than previously described.
Krueger
Christian G
CG
Department of Animal Sciences, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
Vestling
Martha M
MM
Reed
Jess D
JD
D005419:Flavonoids / Q000032:analysis*; D006031:Glycosylation; D006571:Heterocyclic Compounds / Q000032:analysis*; D006109:Poaceae / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D005419:Flavonoids; D006571:Heterocyclic Compounds