Alkaloids from Cryptocarya densiflora Blume (Lauraceae) and their cholinesterase inhibitory activity by Wan Othman, Wan Nurul Nazneem, Sivasothy, Yasodha, Liew, Sook Yee, Mohamad, Jamaludin, Nafiah, Mohd Azlan, Ahmad, Kartini, Litaudon, Marc, Awang, Khalijah