Synthesis, characterization and crystal structure of new tetrahydro-β-carboline as acetylcholinesterase inhibitor 由 Mohamad Arshad, Ahmad Saifuddin, Chear, Nelson Jeng Yeou, Ezzat, Mohammed Oday, Hanapi, Nur Aziah, Meesala, Ramu, Arshad, Suhana, Mansor, Sharif Mahsufi, Mordi, Mohd Nizam