Phytochemicals and bioactivities of Cryptocarya Nigra (Lauraceae) / Ayu Afiqah Nasrullah

• Main Author: Ayu Afiqah, Nasrullah
• Format: Thesis
• Published: 2014
• Subjects: Q Science (General)
• Online Access: http://studentsrepo.um.edu.my/4802/4/ayu.pdf; http://studentsrepo.um.edu.my/4802/
• Institution: Universiti Malaya

Phytochemical study and biological activity were conducted on Cryptocarya nigra (Lauraceae). C. nigra plant sample were collected from the Ulu Sat Reserved Forest, Machang, Kelantan. Isolation of the secondary metabolites involved extraction, fractionation, and purification, using various chromatographic techniques. The structural elucidations were carried out via spectroscopic methods; notably 1D and 2D NMR (COSY, HMQC, HMBC, NOE-DIFF), MS, IR, UV and comparison with published data. In this study, a total of 8 known compounds were isolated from the samples of this plant species. Three phenanthrene alkaloids, namely atherosperminine 11, 2-hydroxyatherosperminine 20, noratherosperminine 47, and a benzylisoquinoline alkaloid, (+)-N-methylisocolaurine 46 were isolated from the bark dichloromethane extract of C. nigra. The leaf alkaloid extract of C. nigra afforded two aporphines (isocorydine 48 and norisocorydine 49), a phenanthrene alkaloid, argentinine 50 and a non-alkaloidal compound, benzamide 51. This plant was being studied for the first time on their alkaloidal content. A dichloromethane extract of the stem bark of C. nigra showed moderate in vitro inhibition of Plasmodium falciparum growth, with an IC50 value of 2.82 μg/mL. (+)-N-Methylisococlaurine 46, atherosperminine 11 and 2-hydroxy-atherosperminine 20 showed mild antiplasmodial activity (IC50: 5.40, 5.80 and 0.75 μM, respectively). In addition, compound 46 and 11 showed mild antioxidant activity in DPPH assay (IC50: 29.56 ug/mL and 54.53 ug/mL), FRAP assay (78.54 % and 70.66 %) and in the metal chelating assay (IC50: 50.08 ug/mL and 42.87 ug/mL) respectively. No study has been reported on the antiplasmodial and antioxidant activities from Cryptocrya nigra.