Determinação de taninos e metilxantinas no guaraná em pó (Paullinia cupana Kunth, Sapindaceae) por cromatografia líquida de alta eficiência

Abstract

The seeds of Paullinia cupana Kunth, Sapindaceae, are used as a stimulant and the main chemical constituents are the methylxanthines and tannins, as catechin and epicatechin. This study aimed to investigate a method by high performance liquid chromatography (HPLC) to quantify both caffeine, theophylline, theobromine, catechin and epicatechin in powdered of P. cupana. The values obtained were compared with the results of the spectrophotometric method of the Brazilian Pharmacopoeia IV ed. For the chromatographic method, the levels of methylxanthines and total tannins were 4.04% and 1.48%, respectively. The levels of methylxanthines and total tannins o btained by the spectrophotometric method, were 4.88% and 4.05%, respectively. It is believed that, under our experimental conditions, the spectrophotometric method was not specific and quantified others phenolic substances present in the P. cupana. Therefore we suggest the use of this chromatographic method in quality control of P. cupana powder, to be accurate, sensitive, specific and fast.