Analgesic compounds ofCroton urucurana Baillon. Pharmaco-chemical criteria used in their isolation

Croton urucurana, known in Brazil as Sangre de Grado or Sangra d'Água is a species employed in folk medicine because of its analgesic and antiinflammatory effects. This paper describes the isolation through exhaustive extraction with methanol of the air-dried, pulverized bark and chromatographic separation of this plant's active compounds. This procedure revealed several compounds presenting analgesic activity, namely campesterol, β-sitosterol, stigmasterol, acetyl aleuritolic acid, catechin, gallocatechin and β-sitosterol glucoside. A comparison between the analgesic potency of the identified extracts and that of the pure compounds suggests the existence of other, more potent analgesic compounds that are probably present in a very small proportions and that were not determined or it also suggests the existence of a synergistic effect.