Flavonoids from Fridericia speciosa Mart. (Bignoniaceae)

Bignoniaceae is a pantropical family with diversity center in Brazil, comprising 33 from 82 genera1. Several species are well known in folk medicine and recognized by production of bioactive compounds2,3. For example, Fridericia chica (Bonpl.) L.G. Lohmann is used for treatment of anemia, inflammation, intestinal crump, hepatitis and skin infections4. Studies have shown the heal proprieties of genus due to the production of phenolic compounds, as flavonoids and antocianidins4,5. Fridericia comprises 69 species with neotropical distribution6. In literature, the chemical composition of five species have been described and bioactive compounds with antioxidant, antifungal, trypanocidal and anti-inflammatory activities were described7-11. The aim of this work was to characterize the chemical composition of Fridericia speciosa Mart.. Leaves of F. speciosa were collected at Instituto de Botânica (São Paulo – SP), air-dried, grinded and extracted until exhaustion with hexane and, subsequently, with methanol. After removal of solvent, MeOH extract was re-suspended in MeOH:H2O (7:3) and partitioned successively with hexane, CH2Cl2, EtOAc and n-BuOH. DCM phase was fractionated using Sephadex LH-20 column eluted with chloroform: methanol (1:1) affording 8 groups. From these groups, four compounds were purified by semipreparative HPLC (1,7-9). Structures were elucidated through 1H and 13C NMR data. Isolated compounds were identified as seven flavones: acacetin (1), apigenin (2), crisoeriol (3), eupafolin (4), hispidulin (5), luteolin (6) and cosmosin (7) and two flavanones: demethoxyblumeatin (8) and hesperetin (9). This is the first report of flavanones in Fridericia genus, which has mainly been characterized by glycosylated and methoxylated flavones and flavonols9-11.