1. Center of Excellence for Innovation in Drug Design and Discovery; Faculty of Pharmacy; Mahidol University; 447 Sri-Ayudya Road Bangkok 10400 Thailand
2. Department of Pharmaceutical Chemistry; Faculty of Pharmaceutical Science; KhonKaen University; KhonKaen 4000 Thailand
3. Department of Pharmacology; Skaggs School of Pharmacy and Pharmaceutical Sciences; University of California; San Diego 9500 Gilman Drive La Jolla CA 92093-0657 USA