Vassya Bankova3 *, Jordanka Koeva-Todorovskab, Tatyana Stam bolijskab, Maria-Desislava Ignatova-Grocevab, Daniela Todorova3 and Simeon Popov3 a Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, Sofia 1113, Bulgaria. Fax: 003592-700-225 . E-mail: [email protected] b Faculty of Biology. Sofia University, Sofia 1000, Bulgaria * Author for corresponden...