Congonha, congonha-de-bugre and bugre are popular names for several medicinal plant species, including Rudgea viburnoides (Cham.) Benth. (Rubiaceae), whose leaves are widely used in popular medicine as diuretic, hypotensive, antirheumatic, and blood depurative. This species has been commercialized as porangaba, and used for diet purposes in substitution of Cordia ecalyculata Vell. (Boraginaceae). This study determines botanical, physico-chemical and chemical characteristics of R. viburnoides with the objective of providing tools for its taxonomical identification and the quality control of derived products. A reference sample was collected and submitted to macroscopical, microscopical and organoleptical characterization, total ash and water content, phytochemical screening, and TLC profile determination. Samples of Rudgea viburnoides can be easily distinguished from those of Cordia ecalyculata by the pilose epidermis with paracytic stomata, outstanding cuticularized striation, the presence of cristalliferous idioblasts, and by the arc pattern of the midvein vascular tissues. Furthermore, C. ecalyculata presents cystoliths and medullary mucilaginous channels differing from R. viburnoides. TLC analysis demostrated the presence of flavonoids and saponins. Commercially acquired samples submitted to the same assays have therefore validated the proposed methods, and confirmed the wide commercialization of R. viburnoides in the state of Minas Gerais, Brazil.
Rudgea viburnoides; congonha; bugre; porangaba; botanical; physico-chemical; chemical characteristics