1. Department of Pharmacognosy, Albert Szent-Györgyi Medical University, P.O. Box 121, H-6701 Szeged, Department of Pharmaceutical Analysis, Albert Szent-Györgyi Medical University, 4 Somogyi u., H-6720 Szeged, Hungary, and Spectroscopic Department, Institute for Drug Research Ltd., P.O. Box 82, H-1325 Budapest, Hungary