Pusat Pengajian Sains Kimia - Tesis

Browse

Now showing 1 - 20 of 67

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.
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
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 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.
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.
Enhanced Photocatalytic Degradation Of Bisphenol A Under Visible Light Irradiation Using Nano Disc Rice Husk Ash Silica Templated Oxygen Doped Mesoporous Carbon Nitride And Carbon Dots Modified Graphitic Carbon Nitride
(2022-12)
Bukola, Shittu Fatimah
A series of oxygen doped mesoporous carbon nitride (O-MCN) was synthesized via thermal polymerization method. Another series of carbon dots modified graphitic carbon nitride (CDs/g-C3N4) was also synthesized via microwave assisted thermal polymerization method. Both were used for the photodegradation of bisphenol A (BPA) under visible light irradiation. The O-MCN were labelled as xO-MCN ( x = 0.1, 0.2, 0.3, 0.4 and 0.5 g glucose) whereas the CDs/g-C3N4 were labelled as yCDs/g-C3N4 (y = 0.5, 1.0 and 1.5 ml CDs). The Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen adsorption-desorption (NAD), UV–vis diffuse reflectance spectroscopy (UV-vis DRS), photoluminescence (PL) spectroscopy, and X-ray photoelectron (XPS) spectroscopy were used to characterize the nanocomposites.
Evaluation Of The Insecticidal Activity Of Cashew (Anacardium Occidentale L.) Nut Shell Liquid Against Adult Bactrocera Dorsalis (Hendel) (Diptera: Tephritidae)
(2023-10)
Keita, Sainey
The Oriental fruit fly, Bactrocera dorsalis (Hendel), is one of the most notorious pests of agricultural fruits. It has been found to attack over 250 host plants, including commercial fruits and a wide variety of crops. The insecticidal activity of Cashew (Anacardium occidentale L.) nut shell liquid (CNSL) against adult B. dorsalis (Hendel) was investigated under laboratory and field conditions. Two extracting solvents, dichloromethane and hexane were used to extract the CNSL from the cashew nut shell. Contact toxicity, topical application and repellency tests were carried out in the laboratory. For both the contact and topical experiments, concentrations of 0.625, 1.25, 2.5, 5.0, 10.0 and 20.0 x 104 ppm were prepared, whereas 0.07, 0.14, 0.21, 0.28 and 0.35 μL/cm2 concentrations were prepared for the repellency tests. The LC50 values recorded after 24 hours of exposure for the contact toxicity tests of the dichloromethane extract was 4.66 x 104 ppm, whereas 6.58 x 104 ppm was recorded for the hexane extract, which showed the dichloromethane extract to be significantly higher with 1.32 times more lethal than the hexane extract against B. dorsalis (t-test, P<0.05).
Fabrication Of Bismuth Ferrite/Poly(O-Phenylenediamine) Based Carboxymethyl Cellulose Hydrogel And Its Photocatalytic Performance Towards Methyl Orange Under Direct Sunlight
(2022-10)
Nor Atilia Athira Binti Zaahari
CMC/BFO/PoPD (CBP) hydrogel film is successfully prepared by impregnating of the optimized BFO/PoPD into carboxymethyl cellulose (CMC) hydrogel with condition of molar ratio of BFO:oPD was 1:0.4 in 0.1 M HCl and the molar ratio of ammonium persulphate (APS) to oPD was 1.5:1 for degradation of methyl orange (MO) under direct sunlight
Fabrication Of Three Dimensional (3d)-Printed Electrodes-Based Thermoplastic Carbon Nanomaterials For Electrochemical Breast Cancer Dna Biosensor
(2023-08)
Omar, Muhamad Huzaifah
Three-dimensional (3D) printing or additive manufacturing is a promising technology to revolutionise traditional manufacturing methods. Nowadays, numerous studies have utilised 3D printing technology to replace conventional electrodes in the fabrication of electrochemical sensors and biosensors due to its low cost, rapid prototyping, and flexibility in design. The main aim of this study is to explore the 3D-printed electrode’s potential as an electrochemical biosensor for breast cancer gene (BRCA1) detection. The first section focuses on the electrochemical performances of 3D-printed polylactic acid/carbon fiber (PLA/CF) electrodes. A novel electrochemical treatment using the differential pulse voltammetry (DPV) technique in hexaammineruthenium (III) chloride (RuHex) solution is proposed. Electrochemical characterisations revealed that the DPV-RuHex electrochemical treatment significantly improved the electrochemical performance of the 3D PLA/CF electrode. Furthermore, field emission scanning electron microscopy (FESEM) micrographs demonstrated that more PLA layers degraded after the treatment, which increased the electrode’s electroactive surface area. The second part investigates the effect of DPV treatment in RuHex and sodium hydroxide (NaOH) solutions on the 3D-printed PLA/graphene (PLA/G) electrode. The electrochemical analyses revealed no significant difference between the two treatments.
Functional Cellulose Nanocrystal-Alginate Hydrogel Beads Prepared From Oil Palm Fronds For The Adsorption Of 4-Chlorophenol In Aqueous Solution
(2023-01)
Tuan Sherwyn Hamidon
The present study aimed to develop efficient cellulose nanocrystal-based hydrogel beads in treating simulated wastewater contaminated with 4-chlorophenol. Initially, cellulose nanocrystals (CNCs) were extracted from oil palm fronds (OPF) employing the sulphuric acid hydrolysis method along with various pretreatments.

Browse

Browsing Pusat Pengajian Sains Kimia - Tesis by Title

Results Per Page

Sort Options