The genus Fridericia belongs to the family Bignoniaceae and comprises 60 species that occur in humid to dry forests, cerrado, and caatinga vegetation. It may be found from Mexico to Argentina and southern Brazil. This article reviews studies conducted on this genus, primarily focusing on its chemical composition and biological activities. Of the 60 known Fridericia species, only 14 have been the object of chemical and biological studies, accounting for 23% of the researched species. Eighty-four compounds, mainly flavonoids, terpenes, xanthones, and phenylethanoids, have been isolated from these species. The biological properties described in this review include antimicrobial, antioxidant, anti-inflammatory, hepatoprotective, antiviral, healing, antiproliferative, trypanocidal, and antileishmania activities. Notably, the species F. chica has been the most studied, as it is listed in the National List of Medicinal Plants of Interest to the Brazilian Unified Health System (RENISUS).

Fridericia speciosa (Bignoniaceae) is a liana that occurs in humid to dry vegetation in eastern and southeastern Brazil. Species belonging to the genus Fridericia are employed as medicinal plants. This study evaluates the antipromastigote and cytotoxic activities of the crude extract, fractions, and compounds isolated from F. speciosa, and an HPLC (High-Performance Liquid Chromatography) analytical method was used to quantify the bioactive flavonoids. The flavonoids alpinetin (1), luteolin (2), diosmetin (3), and apigenin (4) were isolated from the active EtOAc-soluble fraction (EAF) of the crude ethanol extract (LCE) obtained from F. speciosa leaves. Both LCE and EAF were active against the normal human lung fibroblast cell line GM07492A (IC50 of 460.7 µg mL-1 and 381.4 µg mL-1, respectively). Only EAF showed activity against Leishmania amazonensis (80.4% at 50 µg mL-1). Compounds 1 and 2 were quantified by HPLC-DAD in both LCE (1: 6.21%; 2: 1.11%) and EAF (1: 45.32%; 2: 2.00%). At 100 µM, compounds1-4 inhibited L. amazonensis flagellar motility by 40.2%, 26.8%, 1.0%, and 24.8%, respectively, while their toxicities (IC50) to the normal cell were > 1000, 353.0, 766.2, and >1000 µg mL-1, respectively. Therefore, F. speciosa leaves are a prolific source of bioactive flavonoids.

Lipoxygenase (LOX) plays an important role in inflammatory processes and Arrabidaea brachypoda (DC.) Bureau (Bignoniaceae) has been described as presenting anti-inflammatory activity. Therefore, the objective of this study was to develop a high-performance liquid chromatography (HPLC) procedure to directly recognize LOX inhibitor compounds in A. brachypoda crude extract, facilitating the isolation, characterization of bioactive compounds, evaluation of natural compounds using an in vitro 15-LOX assay and prediction of the most probable binding modes of their main constituent through molecular docking simulations. The chemical analysis was performed by ethanol crude extract microfractionation using HPLC-DAD (diode array detector) associated to a fraction collector. The bioactive chromatogram displayed a peak with 50.9% LOX inhibition at 13.6 min retention time. The extract was purified and conandroside was isolated, presenting a LOX inhibitory activity with an inhibitory concentration (IC50) of 7.8 ± 1.1 µM, close to standard quercetin (IC50 7.6 ± 0.3 µM). Additionally, conandroside was not cytotoxic to normal cells (GM07492A). The LOX-conandroside complex displayed a slightly higher docking score (92.7) than quercetin (71.5). These results together suggest that conandroside could be explored as lipoxygenase inhibitor.