1. Department of Organic Chemistry; Indian Association for the Cultivation of Science; Jadavpur University; 2A ∞ B Raja S. C. Mullick Road Jadavpur Kolkata 700032 India
2. CSIR-Institute of Genomics and Integrative Biology; Mathura Road Delhi 110 025 India
3. Institute of Organic Chemistry and Chemical Biology; Goethe University Frankfurt; and Center for Biomolecular Magnetic Resonance; Max-von-Laue Strasse 7 60438 Frankfurt am Main Germany