1. Department of Medicine, Laboratory of Biochemistry, Univeristy of Udine, P.le Kolbe 4, 33100 Udine, Italy
2. Department of Life Science, University of Trieste, P.le Europa 1, 34127 Trieste, Italy
3. Department of Molecular Medicine, University of Padova, via A. Gabelli 63, 35121 Padova, Italy
4. Gause Institute of New Antibiotics, B. Pirogovskaya 11, 119021 Moscow, Russia