Joint NAM S&T Centre - ICCBS Fellowship, 2009

Project Completion Report of Ms. Mudyawati Kamaruddin, Indonesia

Ms. Mudyawati Kamaruddin, Lecturer, Tahirah Al-Baeti Education Foundation, Makassar, Indonesia was affiliated with the International Centre for Chemical and Biological Sciences (ICCBS), HEJ Research Institute of Chemistry, Karachi, Pakistan from 6^th April to 5^th October 2009 as a Fellow under the Joint NAM S&T Centre-ICCBS Fellowship scheme. She worked on 'Structure Elucidation of Acetylcholinesterase Inhibitors from Marine-derived microorganisms use NMR' under the guidance of Prof. Muhammad Iqbal Choudhary, Director, ICCBS.

Acetycholinesterase Inhibitors (AChEIs) are still the best available therapeutic agents for Alzheimer's patients. The present sources of currently available AChE inhibitors are mostly plants. To date, only three AChE inhibitors; donepezil, rivastigmine and galantamine, have been approved by US FDA for the treatment of Alzheimer diseases. However, some of these drugs are known to have limitations such as a short half-life or side-effect i.e. hepatotoxicity. Marine microorganisms have potential as important new sources of enzyme inhibitors. The objectives of the research work of Ms. Mudyawati Kamaruddin to screening AChEIs of marine microorganisms as marine natural product in acetylcholinesterase inhibition and to identify structural elucidation of the AChEIs from marine-derived microorganism by spectroscopic (NMR) techniques. Marine microorganisms were isolated from marine specimens such as sponges, alga, biofilms, and animal and plant materials. All of the isolates were cultivated in four different cultivation media. After 7 days incubation, the cultivation media contained secondary metabolites of marine microorganisms and AChE inhibitory activity was measured using TLC assay method. Five of 15 isolates showed white spots on the yellow background on the TLC plate indicating AChE inhibition. The five crude extracts that contained AChE inhibitory activity were subjected to a size exclusion gel column chromatography on Sephadex LH-20 using methanol as an eluent yielding three fractions, MG01 MG05. The bioassay guided fractionation of MG01 (10.1 mg) was further separated and purified by a preparative High Performance Liquid Chromatography, HPLC (Luna 100, C-18, 25010 mm, 10 µm) using 30:70 methanol in water as a mobile phase with a flow rate of 4.5 ml/min; detection: UV detection at 210 nm yielding compounds M1 (3.37 mg), and M2 (4.8 mg), at retention times of 20, and 23 minutes, respectively. M1 and M2 compounds identified using NMR spectra.