An analyses of flavonoids present in the inflorescence of sunflower

Abstract

Flavonoids are low molecular weight secondary metabolites present ubiquitously in plants. They are known to have diverse metabolic functions, including regulation of growth and development, protection against biotic and abiotic stress, male fertility and pollen–stigma interaction. Present investigations deal with the importance of flavonoids in reproductive biology of sunflower (Helianthus annuus L. 1753), a member of family Asteraceae. A relationship among flavonoids, phenols and reactive oxygen species has been established in the reproductive component of sunflower. Flavonoids have been quantified, localized and compared using diphenylboric acid 2-aminoethyl ester fluorescent probe, high-performance liquid chromatography, thin-layer chromatography and spectrophotometry. Present investigations reveal that flavonoids and phenols are present in all the components of inflorescence—stigma, pollen, ray and disc florets. Quercetin is the main flavonoid identified in all the components of the inflorescence. Quercetin and kaempferol have been identified in pollen grains. These investigations further reveal that flavonoids act as antioxidants, have a developmental role in stigma, metabolic role in pollen and also play a signalling role in pollen–stigma interactions.