1. Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
2. Institute of Microbiology, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
3. Nucleo de Pos-Graduacao, Pesquisa e Eztenzao, Universidade Bandeirante de Sao Paulo, Rua Maria Candida, 1813, Villa Guilerme, SP, cep 02071-013, Brazil