Identification of flavonoid diglycosides in several genotypes of asparagus from the Huétor-Tájar population variety.

The qualitative and quantitative composition of flavonoids from the Huétor-Tájar population variety of asparagus (commonly known as " triguero") was investigated. Flavonoids were analyzed by reversed-phase high-performance liquid chromatography-diode array detection (HPLC-DAD). Liquid chromatography-mass spectrometry (LC-MS) under identical HPLC conditions was used to verify the identities of the flavonoid glycosides from triguero asparagus. The quantities of asparagus flavonoids were calculated according to concentration curves constructed with authentic standards. Total flavonoid contents, calculated as the sum of individual compounds, were determined and ranged from 400 to 700 mg/kg fresh weight. The most abundant was rutin, which represented 55-98% of the total flavonoid complement. Triguero asparagus were revealed to be an important source of not only quercetin derivatives but also kaempferol and isorhamnetin glycosides. Significant differences (p < 0.05) in the content and relative composition of flavonoids were found among the spears of the distinct asparagus genotypes from the Huétor-Tájar population variety.