Betulinic Acid from Zizyphus Joazeiro Bark Using Focused Microwave-Assisted Extraction and Response Surface Methodology Fernanda Carolina Sousa Fonseca, Letícia Caribé Batista Reis, Jener David Gonçalves dos Santos,

Background: The effect of the extraction time (min) and temperature (ºC) on the yield of betulinic acid (BA) from Zizyphus joazeiro barks using focused microwave-assisted extraction was investigated. Materials and Methods: The ethyl acetate was used as extractor solvent because it was shown to provide a betulinic acid-clean extract. A full two-level statistical factorial design was applied to determine the important effects and interactions of these independent variables upon the yield of BA. Results: The conditions that produced the highest yield of BA were at temperature of 70 ºC and an extraction time of 15 min (3.33 mg per gram of plant). Conclusion: The BA has drawn attention due to its use as a raw material in the synthesis of active compounds against the Human Immunodeficiency Virus (HIV).