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