Pusat Pengajian Sains Kimia - Tesis

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Binary And Ternary Complexes Of Β-Cyclodextrin With Isoniazid And Ethambutol: Characterization And Molecular Modeling Studies
(2023-09)
Goh, Soen Qeng
Long term intake of antituberculosis drugs will lead to severe adverse reactions that will ultimately deteriorate a patient’s health and well-being. Presently, it is known that supramolecular macrocycles such as cyclodextrins (CDs) are useful to enhance drug solubility and targeting mechanism while reducing drug dosage by providing many therapeutic benefits. With that, the possibility of formation of drug-CDs ternary inclusion complex was explored, whereby β-cyclodextrin (β-CD) was chosen as the supramolecular host carrier to accommodate two kinds of first-line antituberculosis guest drug molecules simultaneously, namely isoniazid (INH) and ethambutol (ETB). The inclusion complex of β-CD/INH/ETB was prepared using solvent evaporation method. Fourier transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance spectroscopy (1H-NMR), and 2-dimensional nuclear Overhauser effect spectroscopy (2D-NOESY) NMR were used to investigate the functional groups and structure of the complex. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were employed to study the surface morphology and crystallinity changes during complex formation. Thermogravimetric analysis (TGA) was performed to investigate the thermal properties of the complex. FT-IR and both types of NMR results had revealed the successful penetration of both the drug molecules into the β- CD cavity. SEM images and XRD spectra had shown a drastic change in surface structure and reduction in crystallinity during complex formation, which had indicated successful formation of a new compound.
Bio-Based Graphene From The Oil Palm Empty Fruit Bunches As A Fluid Loss Additive In The Water-Based Drilling Mud
(2024-04)
Safian, Muhammad Taqi-Uddeen
One of the most serious issues encountered during drilling operations is the loss of drilling fluid through the well formation, which is referred to as fluid loss, resulting in dry drilling fluid and increasing the likelihood of the drill being stuck. To prevent this scenario, a fluid loss additive was added to the drilling mud. The effectiveness of bio-based graphene (BG) prepared from oil palm (Elaeis guineensis) empty fruit bunches biomass as a fluid loss additive for water-based drilling mud (WBM) was investigated. To accomplish this, BG was exfoliated from lignin extracted through a soda pulping process. The BG exfoliation process consisted of a combination of thermal treatment via pyrolysis at 300, 600, 800, and 1000 °C with a reaction time of 60 minutes under an argon atmosphere, followed by a mechanical exfoliation using a homogenizer with a shear rate of 12400 rpm for 1 hour. Ultraviolet-visible spectroscopy (UV-Vis), thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM), atomic force microscopy (AFM), and x-ray photoelectron spectroscopy (XPS) were used to characterize each prepared sample. The Raman analysis confirmed the graphene formation based on the I2D/IG value similar to the commercial graphene, i.e., 0.91. The FTIR analysis revealed that the BG structure has a less functional group than GO, which has been confirmed using XPS as the C/O ratio of BG is less than GO.
Bioassay-Guided Isolation, Characterisation And Molecular Docking Study Of Acetylcholinesterase And Butyrylcholinesterase Inhibitors From Horsfieldia Polyspherula And Horsfieldia Tomentosa
(2025-01)
Mohammed, Idriss
Alzheimer’s disease (ad) is a neurodegenerative disorder associated with ageing. It is characterised by beta-amyloid deposition, aggregation of neurofibrillary tangles, oxidative stress and decreased acetylcholine levels. Horsfieldia species, known for their medicinal properties, have yielded secondary metabolites with various health benefits. This research highlighted the emergence of various secondary metabolites coupled with a considerable amount of phenolic and flavonoid constituents in the extracts of h. Polyspherula and h. Tomentosa. A total of seventeen unique compounds were isolated, ten of which were from the ethyl acetate (etoac) extract of the bark of h. Polyspherula, while another seven from the etoac extract of h. Tomentosa fruit. Hence, the isolated compounds from h. Polyspherula are; 3,4-dihydroxybenzoic acid (85), 16-phenylhexadecanoic acid (86), undecylbenzene (87), lauric acid (88), myristic acid (89), pentadecanoic acid (90), 1-tridecene (91), trimyristin (92), δ-tocotrienol (93) and stigmasterol (94). Meanwhile, for h. Tomentosa, the isolated compounds include trimyristin (92), (-)-sesamin (95), 1-(2,4,6-trihydroxyphenyl)decan-1-one (96), 1-(2,4,6-trihydroxyphenyl)-12-phenyl-dodecan-one (97), 1-(2,6-dihydroxy-4-(octylo-xy)phenyl)-11-undecan-1-one (98), 9-octyl-sesamin (99) and methyl myristate (100), three of which 97-99 are new.
Bis-, Tris-, And Tetrakisbenzimidazolium Salts And Their Silver(I) Complexes: Synthesis, Characterization And Biological Applications
(2024-09)
Abdurrahman, Nuraddeen
This research describes the synthesis, characterization, crystal structure and cytotoxicity activity of several new bis-, tris- and tetrakis-benzimidazolium salts, (1- 24) and their respective silver(I)-benzimidazol-2-ylidene complexes, (Ag1-Ag24). All the compounds synthesized were new based on literature reviewed, it was achieved by changing the either the alkyl or aryl substituents on the benzimidazolium systems and or the bridging ligands related to the previously reported compounds. The salts were synthesized by nucleophilic substitution reaction and were categorized into five series. The salts were 1-5, 6-9, 10-14, 15-19, 20-24 as first, second, third, fourth and fifth series respectively. The synthesized salts were utilized for the synthesis of their respective silver(I)-benzimidazol-2-ylidene complexes, by in-situ deprotonation method in the presence of silver(I)oxide. The cytotoxicity potential of the synthesized compounds was carried out by MTT assay method, in which the breast and cervical cancer cell lines were used. Salt 1-5, 6-9, 15-19, and their silver(I)-benzimidazol-2-ylidene complexes, (Ag1-Ag5, Ag6 -Ag9, Ag15-Ag19) were tested against breast cancer cell lines, while salts, 10-14, 20-24, and their silver(I)-benzimidazol-2-ylidene complexes, (Ag10-Ag14, Ag20-Ag24) were tested against cervical cancer cell lines. The positive control used for the breast cancer cell was tamoxifen and etoposide for the cervical cancer cell. All the salts and their respective silver(I)-benzimidazol-2-ylidene complexes synthesized were characterized using various characterization techniques including FTIR, 1H, 13C NMR, elemental analysis, and single crystal X-ray diffraction method. Physical properties were accessed by melting point analysis, and solubility tests in various organic solvents. From structural elucidation, it was confirmed that Ag2 was dinuclear silver(I)-benzimidazol-2-ylidene complex, with two PF6 anions as counterions balancing the charges of the entire molecule. Complex Ag13 confirmed to be a cylinder-like trinuclear silver(I)-benzimidazol-2-ylidene complex containing three silver(I) ions bridged by two disc-like ligands.
Characterization, Kinetics And Equilibrium Studies Of Paracetamol Adsorption On The Oil Palm Fronds (Opf) Cellulose Nanocrystals
(2022-02)
Idris, Nor Najhan
Pollution of water via pharmaceutical drugs such as paracetamol have been a highly concerning issue; and effective measures must be taken to treat these aquatic contaminants. Hence, the present study explored use of cellulose nanocrystals (CNC) isolated from oil palm fronds (OPF) through pre-treatments and acid hydrolysis as an environmental friendly adsorbent. The complementary analyses showed that the OPF CNC possesses a crystallinity index of 43.60 %, surface area (10.51 m2 g-1), and an aspect ratio of 19.98. Besides, the OPF CNC and OPF CNC-AC hydrogel beads have been successfully produced, optimised, and applied for paracetamol removal. The modification of OPF CNC-AC hydrogel beads with the commercial activated carbon (AC) has improved the BET surface area up to 85.19 m2 g-1. The adsorption studies of paracetamol onto OPF CNC and OPF CNC-AC hydrogel beads can be achieved at 60 g and 0.6 g of adsorbent dosage, respectively, at a pH 3 with a contact time of 170 min under room temperature. It was observed that the produced data fitted best with the pseudo-second order kinetic model and Freundlich isotherm model for characterising the adsorption of paracetamol onto OPF CNC hydrogel beads with a maximum adsorption capacity, qmax of 0.03 mg g-1. Meanwhile, for OPF CNC-AC hydrogel beads, the pseudo-second order kinetic model and Langmuir isotherm model showed the best correlation for the adsorption of paracetamol with a qmax value of 21.31 mg g-1. Therefore, the output from this study may suggest that OPF CNC and OPF CNC- xxiv AC hydrogel beads can be used as natural adsorbents for the removal of paracetamol waste.
Comparative Analysis Of The Bioethanol Yield And Components Of Sugar Extracted From Oil Palm Frond Under Different Prehydrolysis Treatments
(2021-11)
Dissanayake Mudiyanselage Rushan Lakshitha Bonuwan Diyanilla
this study was designed to produce a high bioethanol yield from OPF adopting eco-friendly and viable pretreatment methods, which are acid, autohydrolysis, alkaline, alkaline peroxide, and alkaline peroxide pretreatment coupled with acidified sodium chlorite (ASC) pretreatment
Computational Design And Investigation Of New Benzophenones And Benzophenone Imines Inhibitors For Breast Cancer
(2018-10)
Shtaiwi, Amneh Mohammad
The computational methods of protein-ligand interactions are core components in drug design and modem drug discovery. This study attempted to design and investigate the interactions of new human estrogen receptor (hERa) inhibitors to treat breast cancer cells using molecular modeling approach. The proposed inhibitors were designed by replacing the triarylethylene estrogenic scaffold found in the synthetic inhibitor 4-hydroxytamoxifen (4-0HT) with triarylimine Schiff bases.
Crystallization Study Of Silicoaluminophosphate Zeolites Templated Using Pyridinium Cations And Their Catalytic Behaviors In Esterification Reactions
(2025-06)
Mohammad, Al Issa Jehad Mohdfathi
This thesis presents three interconnected studies on the crystallization of SAPO zeolites. The first study investigates the crystallization of SAPO-11 under ionothermal conditions using 1-propylpyridinium bromide ([PPy]Br) as template. The effects of synthesis parameters are studied, and SAPO-11 with an acidic nature and high surface area is successfully synthesized after 133 h of heating at 150 °C. The second study explores the crystallization of SAPO-5 under hydrothermal conditions using 5-ethyl-2-methyl-1-propylpyridinium hydroxide ([empy]OH) new template, where H3PO4 and H4P2O7 are used as comparative P sources. Both crystallization processes are followed, and the effects of these P sources on the crystallization and structural properties of SAPO-5 are examined. The findings reveal that H3PO4 yields highly crystalline hierarchical SAPO-5 with high acidity, whereas H4P2O7 promotes nucleation, forming SAPO-5 nanoplates with textural mesoporosity. The third component focuses on the catalytic performance of synthesized SAPO zeolites.
Cytotoxic Activity Of Isolated Alkaloids From The Bark Of Kopsia Terengganensis (Apocynaceae) And Corrosion Inhibition Studies Of Its Extract
(2023-09)
Hanafi, Wan Nur Huda Wan
The use of natural products in developing chemotherapy agents has shown a positive impact in the oncology field. Besides, they also showed a significant result as a corrosion inhibitor. Hence, this study aims to evaluate the cytotoxic activity and corrosion inhibition potential of the crude extract and isolated alkaloids from Kopsia terengganensis (K. terengganensis). The experimental involved extraction and isolation of alkaloids using different chromatographic methods, structural elucidation using various chromatographic techniques and evaluation of cytotoxic activity on HT-29 colorectal adenocarcinoma. Meanwhile, corrosion inhibition studies included weight loss studies, electrochemical studies, and surface analysis. The extraction and isolation process resulted in seven alkaloid compounds: eburnamine (90), isoeburnamine (58), eburnaminol (99), larutensine (100), eburnamenine (114), eburnamonine (56) and quebrachamine (148). In the cytotoxic activity, only compound 99 was able to suppress the growth of HT-29 with moderate activity (IC50 =75.8± 3.06 μM). For the corrosion inhibition potential, the alkaloid crude showed significant results (80-90% inhibition efficiency) in both weight loss and electrochemical studies. The inhibitor followed the Langmuir adsorption isotherm and the formation of an inhibitive film on the mild steel surface was proved in the surface analysis. In conclusion, the alkaloids from K. terengganensis were noteworthy to be investigated in both cancer and corrosion inhibition studies as it gives a positive result in the toxicity towards cancer cells and also mitigated the mild steel corrosion.
Design, Synthesis, Biological Evaluation, And Molecular Docking Studies Of Ortho-Carboxamido Stilbenes As Anti-Diabetic And Anti-Proliferative Agents
(2022-09)
Norhadi Bin Mohamad
A total of eleven ortho-carboxamido stilbenes (50a-50k) in 63-83 % yield have been synthesized using our modified Heck coupling method, and characterized using FT-IR, NMR, and HRMS. The research started with the Wittig reaction of 3,5-dimethoxybenzaldehyde (45) and methyltriphenylphosphonium iodide to form 3,5-dimethoxystyrene (46) followed by the Heck reaction with amide derivatives (49) under basic conditions to provide the corresponding (E)-stilbene derivatives (50a-50k). Five ortho-carboxamido stilbenes (50a-50e) were subjected to anti-diabetic studies on α-amylase and α-glucosidase enzymes.
Design, Synthesis, Molecular Docking And Cytotoxic Activity Of New Ortho-Hydroxy Chalcone And Pyrazoline Derivatives
(2019-06)
Luhaibi, Maadh Jumaah Owaid
This study focused on the design and synthesis of new compounds with anticancer activity. The compounds were constructed using the structure-based drug design, focusing on their binding capabilities to the Colchicine (PDB code: IS AO) active site in a bidentate manner, with the most energetically preferable binding modes using Autodock Vina 1.1.2 and Discovery studio 4.1. In the molecular docking analysis, the binding energy and interactions between protein receptors and ligands provide a better understanding of the biological functions to determine the amino acid residues which are crucial to docking interactions. The modification and replacement of the pyrazoline structure and chaicone led to the development of the structureactivity relationship and identified potent and selective inhibitors of drug design.
Development Of An Electrochemical Sensor Based On Molecularly Imprinted Go/Zno/Ppy Composites On Pencil Graphite Electrode For Determination Of Andrographolide
(2021-12)
Rabia Tasaduq Hussain
This research highlights the development of an electrochemical sensor based on graphene derivatives with a molecularly imprinted polypyyrole (PPy) layer on a pencil graphite electrode (PGE) to detect andrographolide, which is a bioactive component of an ancient plant known as Andrographis paniculata. Conventionally, andrographolide detection based on tedious and heavy instrumentation.
Development Of Extraction And Separation Techniques For The Determination Of Polycyclic Aromatic Hydrocarbons And Biogenic Amines In Food
(2024-01)
Hor, Jia Yi
Polycyclic aromatic hydrocarbons (PAHs) and biogenic amines (BAs) are potential contaminants in various food products. Quantitative analysis of these contaminants in food is challenging due to their high physicochemical variability and complexity. This thesis describes the method developments for quantitative analysis of PAHs and BAs in selected food products.
Development Of Fatty Acid-Based Deep Eutectic Solvents In Liquid Phase Microextraction With Back Extraction For Determination Of Selected Organic Pollutants
(2024-04)
Sazali, Nur Hidayah
Environmental pollution has become a significant global issue in recent times. The primary sources of this pollution are human activities such as industrial processes, marine dumping, agricultural practices, and wastewater discharges. Some of the most concerning environmental pollutants are pesticides, herbicides, and polycyclic aromatic hydrocarbons (PAHs) due to their high toxicity and their persistence in the environment. These pollutants have harmful effects on human health and the ecosystem. Due to their high toxicity and trace amount in environment, developing an effective extraction method is essential. Deep eutectic solvent (DES) is a possible green alternative to the conventional solvent utilised in most extraction procedures in light of the increased demand for developing green extraction techniques. Microextraction-based DES fits favourably with the Green Analytical Chemistry (GAC) concept because of its rapid sample preparation time, low organic solvent usage, and straightforward procedure. In this study, an eco-friendly microextraction utilising hydrophobic deep eutectic solvents from fatty acids derived from the combination of lauric acid, which acted as a hydrogen bond acceptor (HBA), and pelargonic acid, which acted as a hydrogen bond donor (HBD), was prepared to determine herbicide mixtures using emulsification liquid-liquid microextraction with back extraction (ELLME-BE) method. In addition, a ferrofluid was developed by incorporating DES, a combination of lauric acid (HBA) and caprylic acid (HBD) with magnetic nanoparticles (MNP) to determine polycyclic aromatic hydrocarbons xxviii (PAHs) using liquid phase microextraction with back extraction (LPME-BE) method. Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA),
Development of polymeric nanocomposite hydrogel using poly (vinyl alcohol) reinforced with organically modified layered double hydroxides for drug delivery systems
(2022-12)
Nor Jannah binti Mohd Sebri
A new advanced polymeric material with a potential for drug delivery systems was developed using the versatile poly (vinyl alcohol), PVA, enhanced with layered double hydroxides (LDH) organically modified with sodium dodecyl sulfate (SDS) and sodium isethionate (Ise) via co-precipitation method.
Diversity And Distribution Of Benthic Foraminifera In Mangrove Forests Of Penang Island
(2023-02)
Malek, Muhamad Naim Abd
Foraminifera is one of the diverse groups of organisms inhabiting mangrove environment, but local studies regarding benthic foraminifera are limited. Therefore, this study was conducted to examine the diversity and distribution patterns of the foraminifera species in mangrove forests around Penang Island, which were Teluk Tempoyak, Pulau Betong, and Kuala Sungai Pinang. A total of 648 surface sediment samples (N=18 points × 3 mangrove forests × 12 months) of 1 cm thick were randomly collected using scoops during the lowest spring tide. The sampling was conducted monthly from March 2017 to February 2018. The results showed low to moderate species diversity (H’ index: 0-1.4), typical of a mangrove environment. Overall, 29 benthic foraminifera species were identified, predominantly agglutinated with some combination of hyaline and porcelaneous tests. Benthic foraminifera in Pulau Betong mangrove recorded the highest species diversity (29 species), followed by Teluk Tempoyak (25 species) and Kuala Sungai Pinang (19 species). The species idetified are commonly found in mangrove swamps and in the coastal environment. Species distribution demonstrated significant variation among the different locations, zones, and seasonal factors in the three mangrove forests (p < 0.05).
Docking And Molecular Dynamics Simulation Studies Of Insulin-P- Cyclodextrin Interactions
(2016-02)
Muhammad, Erma Fatiha
Protein-ligand interactions play an essential role in the design of new pharmaceutical products. This study attempts to understand the theoretical basis on the structure and dynamics of insulin-cyclodextrin complex for new oral insulin formulation. Docking and molecular dynamics simulations explore the interactions between insulin monomer and insulin dimer with 0- cyclodextrins (0-CDs). A multiple molecular docking study was performed using the Autodock v4.2 program to determine the number of 0-CD that can adhere to the binding sites of insulin as well as to determine the most stable conformations of insulin to p-CDs. A 100 random structure docking using 1:1 insulin monomer-P-CD and insulin dimer-p-CD ratio were conducted and from the final docked structure, additional 0-CDs were added and the process were repeated until the energy increase. Molecular docking results revealed that a maximum of four 0-CDs can bind to an insulin structure with the 1:3 insulin-P-CD ratios having the lowest binding free energy. A 100 ns molecular dynamics simulation was then conducted to verify the results obtained by molecular docking.
Effect Of Multi-Elemental Doping On The Catalytic Activity Of Carbocatalysts For Antibiotics Degradation Via Peroxymonosulfate Activation
(2024-04)
Gasim, Mohamed Faisal Malik
Presently, the utilization of heteroatoms- and/or metal-doped carbocatalysts for the degradation of organic pollutants via catalytic peroxymonosulfate (PMS) activation has drawn significant attention. Yet, there exists a necessity for an in-depth exploration in: (i) understanding the influence of carbonaceous properties on N, S-co-doping, (ii) assessing the effectiveness of heteroatoms tri-doping and apprehending the intra-actions among multiple heteroatoms, and (iii) identifying new transition metals that are suitable for co-doping with N to improve the catalytic activity of carbocatalysts. In view of these research gaps, the main objective of this study is to prepare multi-doped carbocatalysts for PMS activation and unveil the roles of the doped elements in the catalytic activity. Firstly, five N, S-co-doped carbocatalysts were prepared from different carbonaceous precursors, namely sawdust (SD), biochar (BC), carbon-nanotubes (CNTs), graphite (GP), and graphene oxide (GO) and compared. Generally, as the graphitization degree increased, the extent of N and S doping decreased, graphitic N configuration is preferred, and S configuration is unaltered. NS-CNTs illustrated the highest catalytic removal of ciprofloxacin (CIP) under PMS activation (0.037 min−1) due to its remarkable conductivity (3.38 S m−1) and defective sites (ID/IG = 1.28). The PMS activation pathway was dominated by singlet oxygen generation and electron-transfer regime. Secondly, N, S, B-tri-doped biochar was fabricated via a one-pot calcination technique.
Effect Of Various Pre-Treatments Onto Oil Palm Frond Leaves For Bioethanol Production As Renewable Bioenergy Source In Fuel Cell Application
(2025-03)
Azani, Nur Fatin Silmi Mohd
Oil palm frond leaves (opfls) are one of the biomass by-products originating from oil palm plantations. Currently, opfls are under-valued since they can be classified as a high recalcitrance feedstock due to the high lignin and hemicellulose content. This current study proposed an alternative of using opfls as a bioenergy source. This study highlighted the impact of different pre-treatments on the physicochemical properties, enzymatic digestibility, and fermentation efficiency of pretreated opfls. Each of the pre-treatments revealed the distinctive traits that influence the efficiency of the conversion of cellulose into bioethanol. From physicochemical pretreatments, steam explosion much more effective in disrupting the compact cell wall structure of opfls in contrast to autohydrolysis pre-treatment, by a vast dissolution of hemicellulose and depolymerization of lignin. The pre-impregnation with h2so4 prior to steam explosion was beneficial to enhance the hemicellulose removal up to 89.94 %. The cellulose content of the autohydrolysis pre-treated and steam-exploded opfls pulp were enhanced up to 31.03 wt.% and 39.18 wt.%, respectively. Meanwhile, the dilute naoh pre-treatment enhanced the delignification by 87.14 %, led to the enrichment of cellulosic fraction up to 51.21 wt.%. The removal of hemicellulose and lignin fraction was confirmed by the reduction of xylan c=o peak at 1730 cm-1 and lignin structural units c=o peak at 1600 cm-1, observed in attenuated total reflection (atr) spectra
Electrochemical Degradation Of Reactive Red 4 Using Graphite/Chitosan-Poly(Vinyl Chloride) Composite Electrodes
(2021-12)
Nadhra Hidayah Binti Mohd Halim
In this study, graphite/chitosan-poly(vinyl chloride) (C/Chi-PVC) composite electrode was used as anode to investigate the degradation of Reactive Red 4 (RR4) in the presence of graphite rod and sodium chloride (NaCl) respectively as cathode and supporting electrolytes.

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