Affiliation: | a Chemical Bioactives Center, Central University of Las Villas, Santa Clara 54830, Villa Clara, Cuba b Department of Organic Chemistry, Faculty of Pharmacy, University of Santiago de Compostela, 15706 Santiago de Compostela, Spain c Universität Rostock, FB Chemie, Albert-Einstein-Str. 3a, D 18059 Rostock, Germany |