1. School of Chemistry; University of Manchester; Oxford Road, M13 9PL Manchester UK
2. Dr. B. C. Guha Centre for Genetic Engineering and Biotechnology and Department of Biotechnology; Calcutta University; Ballygunge Circular Road Kolkata 700019 India
3. Department of Chemistry; Bose Institute; 93/1 A. P. C. Road Kolkata 700 009 India