1. a Department of Pharmacognosy , Faculty of Pharmacy, Hacettepe University , 06100 Ankara, Turkey
2. c National Center for Natural Products Research , Research Institute of Pharmaceutical Sciences , MS 38677, USA
3. b Department of Biology , Faculty of Science, Hacettepe University , 06532 Ankara, Turkey
4. d Department of Pharmacognosy , University of Mississippi, University , MS 38677, USA