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|Title: ||Bioassay-guided isolation of acetyl cholinesterase inhibitors from Mesua Elegans (King) Kosterm|
|Authors: ||Gomathi, Chan|
|Issue Date: ||Jul-2009 |
|Publisher: ||University Malaya|
|Abstract: ||A bioassay-guided study of the bark from Mesua elegans (King) Kosterm was performed.
The hexane extract showed potent acetyl cholinesterase (AChE) inhibitory activity with 90 % of inhibition at 10 μg/mL concentration. Thus, this extract had been carried forward for the further fractionation steps. The hexane : ethyl acetate _ 95 : 5 fraction of hexane extract
gave 100 % of inhibition at 10 μg/mL concentration. Further purification and structural elucidation of compounds were performed on this fraction.
Chromatographic separation of compounds from this fraction had afforded nine 4-phenylcoumarins, namely 5-hydroxy-2-methyl-6-(3-methylbutanoyl)-2-(4-methylpent-3-
enyl)-10-phenyl-2H-pyrano[2,3-f]chromen-8-one 156, 5-hydroxy-2-methyl-6-(2-
isomammeigin 158, 5,7-dihydroxy-8-(2-methylbutanoyl)-6-[(E)-3,7-dimethylocta-2,6-
dienyl]-4-phenyl-2H-chromen-2-one 159, 5,7-dihydroxy-8-(3-methylbutanoyl)-6-[(E)-3,7-
dimethylocta-2,6-dienyl]-4-phenyl-2H-chromen-2-one 160, 4-hydroxy-2-(2-hydroxy-6-
chromen-2-one 162, mammea A/BA 163 and mammea A/BA cyclo F 164, in which
compounds 156, 161 and 162 are new.
The isolated compounds had been tested for the AChE inhibitory activity, and it was
discovered that compounds 156, 157, 159 and 161 are the ones responsible as AChE
inhibitors, especially compound 157 which is the most potent with an activity of 80 % of
inhibition at 10 μg/mL concentration.|
|Description: ||Dissertation -- Faculty of Science, University of Malaya, 2009.|
|Appears in Collections:||Masters Dissertations : Science|