1. Leiden/Amsterdam Center of Drug Research (LACDR), Division of Medicinal Chemistry, Faculty of Sciences, Vrije Universiteit Amsterdam, The Netherlands, Department of Pharmaceutical Chemistry and Pharmacognosy, Faculty of Pharmaceutical Sciences, Naresuan University, Phitsanulok, Thailand, and UCB Pharma, Chemin du Foriest, B-1420 Braine-l'Alleud, Belgium