Antimicrobial, Antiproliferative and Proapoptotic Activities of Extract, Fractions and Isolated Compounds from the Stem of Erythroxylum caatingae Plowman oleh Silene C. Nascimento, Teresinha Gonçalves da Silva, Marcelo S. Silva, Josean F. Tavares, Steno L. Oliveira, Kêsia X. F. R. Sena, André M. Batista, Maria M. P. Guerra, Maria do Desterro Rodrigues, Rosilma O. Araújo, Jaciana S. Aguiar