1. Department of Phytochemistry, Medicinal Plants and Drugs Research Institute, Shahid Beheshti University, G. C., Evin, Tehran, Iran, Chemistry and Chemical Engineering Research Center of Iran, Tehran, Iran, Division of Pharmaceutical Biology, University of Basel, Klingelbergstrasse 50, 4056 Basel, Switzerland, Department of Chemistry, Shahid Beheshti University, G. C., Evin, Tehran, Iran, and Swiss Tropical and Public Health Institute, Socinstrasse 57, CH-4002 Basel, Switzerland