Endopleura uchi (Huber) Cuatrec. (Humiriaceae), popularly known as “uxi amarelo”,it is a specimen widely spread in the Amazon biomes [1]. This plant has been known by its use in popular medicine in treating hypercholesterolemia, diabetes, arthritis, and as anti-inflammatory. Furthermore, the main popular use is against uterine fibroids and disorders of woman’s urinary tract. The bergenin, found in the fruits and barks of E. uchi trees, is possibly the main compound responsible for these effects [2]. Given its relevancy, studies on the methods for its successful extraction with high yields become important. This work compares the results of bergenin extraction obtained by maceration, ultrasonic and microwave methods. Moreover, the molecular properties of bergenin associated with intermolecular interaction of extractive solvents were analyzed. Also the samples of E. uchi barks were submitted to dynamic maceration, ultrasonic and microwave assisted extraction using hydroethanolic solutions as solvents. The ethanol strengths utilized were 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 96%, and 100% (m/m). The bergenin contents in the extracts were determined by High Performance Liquid Chromatography (HPLC). The logP and TPSA of bergenin were calculated with the Molinspiration server, while the electrostatic potential map (EPM) and the molecular interaction field (MIF) were calculated by the softwares DS ViewerPro 6.0 and Torch v.10.4. Analysis of the extracts obtained by dynamic maceration in several conditions, the ethanol strength that better extracted the bergenin was 40%, while for ultrasonic and microwave the best extractions occurred for ethanol 60% and 30% (m/m), respectively. Finally, comparing these tree methods, the ultrasonic assisted extraction gave the larger amounts of extracted bergenin. The calculated bergenin logP is - 0,90, indicating that this molecule does not have a lipophilic character, but a polar character which is associated to its total polar surface area TPSA of 145.91. The EPM shows that the hydroxyl group in the bergenin molecule provides a field favorable to interaction with water molecules, but having also capacity to interact with the apolar region of ethanol, since it has a field for hydrophobic interaction. Therefore best extraction with low ethanol strengths were observed for the three methods. Based on the physicochemical properties studied, it was observed that the logP analysis is meaningful to justify the polarity difference of the compound. On the other hand, the complementary analysis ran by TPSA, EPM and MIF was able to predict more accurately the choice of hydroethanolic concentrations for each extraction method.

[1] Tacon, LA, Freitas, LAP: Box-Behnken design to study the berginin content and antioxidant activity of Endopleura uchi bark extracts obtained by dynamic maceration: Brazilian Journal of Pharmacognosy. 23(1): 65-71, Jan/feb.2013. [2] Nunomura RCS, Oliveira VG, Da Silva SL, Nunomura SM; Characterization of Bergenin in Endopleura uchi Bark and its Anti-Inflammatory Activity. J Brazil Chem Soc 2009, 20: 1060-1064. [3] Molinspiration cheminformatics. Novaulica, SK-9 Slovensky grob, Slovak Republic: available at: http/www.molinspiration.com. [4] DsviewerPro6.0, 2005. Accelrys Software Inc.