1. Institute of Chemistry, Technology and Metallurgy, Belgrade, Yugoslavia, Centro Internazionale di Servizi di Spettrometria di Massa del CNR di Napoli, Naples, Italy, National Cancer Research Institute, Belgrade, Yugoslavia, Laboratoire de Chimie Physique et de Cristallographie, Université Catholique de Louvain, Louvain-la-Neuve, Belgium, Division of Experimental Therapeutics, Walter Reed Army Institute of Research, Washington, D.C. 20307-5100, and Faculty of Chemistry, University of Belgrade, 11001...