[1] Division of Organic Chemistry, National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411 008, India
[2] Center for Materials Characterization, National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411 008, India
[3] Central NMR Facility, National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411 008, India
[4] Chemistry Department, Durham University, Durham, DH1 3 L, United Kingdom
[5] Universität Leipzig, Fakultät für Biowissenschaften, Pharmazie and Psychologie, Institut für Biochemie, Brüderstraße 34, D-04103 Leipzig, Germany