1. Laboratory of Chemical Transformation of Antibiotics, Gause Institute of New Antibiotics, 11 B. Pirogovskaya Street, Moscow 119021, Russia
2. Department of Chemistry, University of Sheffield, Sheffield S3 7HF, United Kingdom
3. Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan, Republic of China
4. School of Pharmacy, University College London, 29-39 Brunswick Square, London WC1N 1AX, United Kingdom