1. Biotechnology Department and Pharmaceutical Research and Development, Pharmacia S.p.A., Via Giovanni XXIII 23, 20014 Nerviano, Milano, Italy
2. Department of Pharmaceutical Sciences, University of Bologna, Via Belmeloro 6, 40126 Bologna, Italy
3. Department of Pharmaceutical Sciences, University of Firenze, Via G. Capponi 6, 50121 Firenze, Italy
4. Department of Organic Chemistry, University of Milano, Via G. Venezian 23, 20133 Milano, Italy