title: TLC determination of flavonoids from different cultivars of Allium cepa and Allium ascalonicum.
abstract: This study comprises the optimization and validation of a new TLC method for determination of flavonols in the bulbs of seven cultivars of onions and shallots. Separation was performed on RP-18 plates with the solvent mixture tetrahydrofuran/water/formic acid (40+60+6, V/V/V) as a mobile phase. The method was evaluated for precision, linearity, LOD, LOQ, accuracy and robustness. Chromatographic analysis of the extracts revealed the presence of three main flavonols, quercetin, quercetin-4'-O-glucoside and quercetin-3,4'-O-diglucoside in the majority of analyzed cultivars. The content of flavonols in the analyzed extracts of onion bulbs varied from 123 ('Exihibition') to 1079 mg kg-1 fresh mass (fm) ('Hybing') in edible parts, and from 1727 ('Hyline') to 28949 mg kg-1 fm ('Red Baron') in outer scales. The bulbs of two shallot cultivars contained 209 ('Ambition') and 523 mg kg-1 fm ('Matador') of flavonols in edible parts and 5426 and 8916 mg kg-1 fm in outer scales, respectively.
authors.forename: Loretta
authors.initials: L
authors.lastname: Pobłocka-Olech
authors.forename: Daniel
authors.initials: D
authors.lastname: Głód
authors.forename: Maria E
authors.initials: ME
authors.lastname: Żebrowska
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Sznitowska
authors.forename: Miroslawa
authors.initials: M
authors.lastname: Krauze-Baranowska
mesh_terms: D000975:Antioxidants / Q000032:analysis* / Q000302:isolation & purification; D002138:Calibration; D002626:Chemistry, Pharmaceutical / Q000379:methods*; D056148:Chromatography, Reverse-Phase; D002855:Chromatography, Thin Layer; D018556:Crops, Agricultural / Q000737:chemistry*; D003720:Densitometry; D005419:Flavonoids / Q000032:analysis* / Q000302:isolation & purification; D005960:Glucosides / Q000032:analysis / Q000302:isolation & purification; D057230:Limit of Detection; D019697:Onions / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification; D018517:Plant Roots / Q000737:chemistry*; D011044:Poland; D011786:Quality Control; D011794:Quercetin / Q000031:analogs & derivatives / Q000032:analysis / Q000302:isolation & purification; D015203:Reproducibility of Results; D027781:Shallots / Q000737:chemistry*; D013045:Species Specificity; D013056:Spectrophotometry, Ultraviolet
chemical_list: D000975:Antioxidants; D005419:Flavonoids; D005960:Glucosides; D010936:Plant Extracts; C000613585:quercetin-3,4'-O-diglucoside; D011794:Quercetin; C080613:spiraeoside