Flavonoid Aglycones in Species of Solanum

Solanum L. is the largest genus of the Solanaceae family, with approximately 1400 species, which are distributed throughout the world. The genus has economic importance, including several species consumed by humans, as well as toxic species and/or those that produce metabolites of pharmacological interest. In addition to alkaloids, flavonoids form a major group of compounds have been described for the Solanum species. This work provides a compilation of the flavone and flavonol aglycones reported for the genus Solanum. Additional aspects related to chemotaxonomy, extraction and isolation, spectroscopic assignments, analysis by ultra-performance liquid chromatography coupled with diode array detector and quadrupole time-of-flight mass spectrometry, and biological activities are discussed. The flavonoid aglycones are derived from flavone (apigenin and luteolin) and flavonol (kaempferol, quercetin, myricetin, and herbacetin) skeletons. The example presented with the species S. paludosum shows the extraction, isolation, and structural identification of bioactive methoxylated flavonoids, using both traditional and modern techniques.