1. Department of Biochemistry, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038
2. Department of Organic and Inorganic Chemistry, Federal University of Ceara, Center for Sciences, CEP 60455-760 Fortaleza-Ceara, Brazil
3. Department of Microbiology, University of Hawaii, 2538 The Mall, Snyder Hall 207, Honolulu, Hawaii 96822
4. Centre for Chemical Biology, Persiaran Bukit Jambul, 11900 Bayan Lepas, Penang, Malaysia