1. Department of Applied Chemistry, National Yang Ming Chiao Tung University, 1001 Ta-Hseuh Road, Hsinchu 300-10, Taiwan, ROC
2. Department of Chemistry, MES Abasaheb Garware College, Pune 411004, India
3. Department of Medicinal and Applied Chemistry, Kaohsiung Medical University, 100, Shih-Chuan 1st Road, Kaohsiung 807-08, Taiwan, ROC