1. EMBRAPA/CENARGEN/ACB, Cx. Postal 02372, 70849–970, Brasília,
2. EMBRAPA/CNPH, BR 060 Km 09. 70359–970, Brasília, DF, Brazil,
3. Department of Chemistry, Science University of Tokyo, Kagurazaka I‐3, Shinjuku‐Ku, Tokyo 162, Japan,,
4. UFSCar/Dep. Química/Lab. Sintese Produtos Naturais, 13565–905, São Carlos, SP, Brazil