1. Jodrell Laboratory, Royal Botanic Gardens, Kew, Richmond, Surrey TW9 3DS, United Kingdom, Institute of Chemistry and Environmental Protection, Szczecin University of Technology, Al. Piastów 42, 71-065 Szczecin, Poland, and Institute of Organic Chemistry, Leibniz University Hannover, Schneiderberg 1B, D-30167 Hannover, Germany