1. Molecular Structure Analysis, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, D-69120 Heidelberg, Germany
2. Natural Substances Biochemistry Laboratory, LBSN, FSTE, BP 509, Boutalamine, Errachidia, Morocco
3. Division of Preventive Oncology, National Center for Tumor Diseases, Im Neuenheimer Feld 460=German Cancer Research Center (DKFZ), Im Neuenheimer Feld 581, D-69120 Heidelberg, Germany