1. Department of Pharmaceutical and Medicinal Chemistry, Eberhard-Karls-University Tübingen, Auf der Morgenstelle 8, 72076 Tübingen, Germany; Merckle GmbH, Graf-Arco-Str. 3, 89079 Ulm, Germany, and Department of Pharmacy, Benemérita Universidad Autónoma de Puebla, 14 Sur con Avienda San Claudio, C.P. 72570 Puebla, México