1. São Paulo State University (UNESP), P.O. Box 355, 14801-970, Araraquara, SP, Brazil, and Organic Chemistry Department, Institute of Chemistry, Nuclei for Bioassays, Biosynthesis and Ecophysiology of Natural Products (NuBBE), and Section of Plant Biochemistry and Physiology, Institute of Botany (IBt), P.O. Box 4009, 01061-970, São Paulo, SP, Brazil