Noorsaadah Abd. Rahman
University of Malaya, Malaysia, Chemistry, Faculty Member
Muscarinic acetylcholine receptor-active compounds have potential for the treatment of Alzheimer's disease. In this study, a series of natural and synthetic flavones and flavonols was assayed in vitro for their ability to inhibit... more
Muscarinic acetylcholine receptor-active compounds have potential for the treatment of Alzheimer's disease. In this study, a series of natural and synthetic flavones and flavonols was assayed in vitro for their ability to inhibit radioligand binding at human cloned M1 muscarinic receptors. Several compounds were found to possess competitive binding affinity (Ki=40-110 µM), comparable to that of acetylcholine (Ki=59 µM). Despite the fact that these compounds lack a positively-charged ammonium group under physiological conditions, molecular modelling studies suggested that they bind to the orthosteric site of the receptor, mainly through non-polar interactions.
Research Interests:
Research Interests:
Research Interests:
ABSTRACT Our strategy is to use the computational method through the transition state study and molecular design the appropriate substrate in control the enantioselectivity. The mechanistic study employing quantum mechanical calculations... more
ABSTRACT Our strategy is to use the computational method through the transition state study and molecular design the appropriate substrate in control the enantioselectivity. The mechanistic study employing quantum mechanical calculations has been studied for the peptide catalyzed flavanone synthesis. The pathways using synchronous transit method with local density approximations with PWC functional for the fragment in the cyclization step were obtained. The reactions between substrate and peptide in both axial and equatorial attacks of hydroxyl which leads to different enantiomers were investigated. The calculated energies for both systems were comparable with the barrier difference of 1.42 kcal/mol.
Research Interests:
Research Interests:
This work discusses the application of an Artificial Intelligence (AI) technique called Qualitative Reasoning (QR) coupled with the Qualitative Process Theory (QPT) ontology to model, simulate and explain chemical behaviours of reaction... more
This work discusses the application of an Artificial Intelligence (AI) technique called Qualitative Reasoning (QR) coupled with the Qualitative Process Theory (QPT) ontology to model, simulate and explain chemical behaviours of reaction mechanisms. We have tested the new approach on two types of organic mechanisms under nucleophilic substitution reaction. This paper describes one specific type of the mechanisms called SN1 to demonstrate how the qualitative models can be constructed for chemical processes such ...
This work discusses the explanation facility of a tool called QRIOM for providing support to teaching and learning in the area of organic reactions. The approach is to use Qualitative Reasoning (QR), in particular, Qualitative Process... more
This work discusses the explanation facility of a tool called QRIOM for providing support to teaching and learning in the area of organic reactions. The approach is to use Qualitative Reasoning (QR), in particular, Qualitative Process Theory (QPT). This paper will focus on the reasoning engine and the explanation modules that served as embedded intelligence in the software tool. Explanation
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Compatibility of the phenyl(dimethyl)silyl group as a masked hydroxyl group in the presence of cyclopropane rings and the enone functionality was studied. The result showed that conditions for the silyl-to-hydroxyl group conversion is not... more
Compatibility of the phenyl(dimethyl)silyl group as a masked hydroxyl group in the presence of cyclopropane rings and the enone functionality was studied. The result showed that conditions for the silyl-to-hydroxyl group conversion is not compatible with cyclopropane rings. However, under a modified two-step transformation procedure, the silyl group is converted to a hydroxyl group in the presence of an enone
Research Interests:
Research Interests:
Research Interests:
Multiple sequence alignment was performed against eight proteases from the Flaviviridae family using ClustalW to illustrate conserved domains. Two sets of prediction approaches were applied and the results compared. Firstly, secondary... more
Multiple sequence alignment was performed against eight proteases from the Flaviviridae family using ClustalW to illustrate conserved domains. Two sets of prediction approaches were applied and the results compared. Firstly, secondary structure prediction was performed using available structure prediction servers. The second approach made use of the information on the secondary structures extracted from structure prediction servers, threading techniques and DSSP database of some of the templates used in the threading techniques. Consensus on the one-dimensional secondary structure of Den2 protease was obtained from each approach and evaluated against data from the recently crystallised Den2 NS2B/NS3 obtained from the Protein Data Bank (PDB). Results indicated the second approach to show higher accuracy compared to the use of prediction servers only. Thus, it is plausible that this approach is applicable to the initial stage of structural studies of proteins with low amino acid sequence homology against other available proteins in the PDB.
Research Interests: Bioinformatics, Prediction, Structural Analysis, Macromolecular X-Ray Crystallography, Dengue Virus, and 10 moreComputer Simulation, Virus, Silico Biology, Amino Acids, Protein Sequence Analysis, Secondary Structure, Protein Secondary Structure Prediction, Amino Acid Sequence, Crystalline Structure, and Molecular Sequence Data
1694 © 1994 The Chemical Society of Japan Bull. Chem. Soc. Jpn.,67,16941700(1994) [Vol.67, No.6 Generation of 2-Lithio-2-(trimethylsilyl)silacyclopentane and 2-Lithio-2-(phenylthio )silacyclopentane and Their Use for the Synthesis of... more
1694 © 1994 The Chemical Society of Japan Bull. Chem. Soc. Jpn.,67,16941700(1994) [Vol.67, No.6 Generation of 2-Lithio-2-(trimethylsilyl)silacyclopentane and 2-Lithio-2-(phenylthio )silacyclopentane and Their Use for the Synthesis of 1,4-Butanediols and 7-Hydroxy ...
Research Interests:
Research Interests:
Research Interests:
Research Interests:
AbstractSeveral flaviviruses are important human pathogens, including dengue virus, a disease against which neither a vaccine nor specific antiviral therapies currently exist. QSAR study was carried out with the purpose of searching new... more
AbstractSeveral flaviviruses are important human pathogens, including dengue virus, a disease against which neither a vaccine nor specific antiviral therapies currently exist. QSAR study was carried out with the purpose of searching new competitive dengue inhibitors with similar ...
Research Interests:
Research Interests:
Contamination of wastewater by organic pollutants is a major worldwide issue. For instance plastic additives such as phthalates are found in wastewater. Efficient techniques are thus needed to clean wastewaters. The Fenton reaction... more
Contamination of wastewater by organic pollutants is a major worldwide issue. For instance plastic additives such as phthalates are found in wastewater. Efficient techniques are thus needed to clean wastewaters. The Fenton reaction involving H2O2 and Fe(II) salts can be used to treat polluted water. During the Fenton reaction pollutants are decomposed directly by hydroxyl radicals. In some cases toxic