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Chitosan Blending With Water-Soluble Polymers As Dissolving Microneedles For Controlled Drug Release, Fuad Abdullah Farhan Saleh

Chulalongkorn University Theses and Dissertations (Chula ETD)

Chitosan has gained significant interest due to its ability to film-forming, biodegradability, and biocompatibility, making it suitable for topical and transdermal drug delivery such as fabricating microneedles. In this study, chitosan microneedles were prepared by incorporating polyvinylpyrrolidone (PVP) and polyvinyl alcohol (PVA) in three different ratios (1:1, 2:1, and 3:1 chitosan: polymers) to control drug release. The microneedles were fabricated using a molding method, their mechanical properties were tested using the universal testing machine (UTM), and their skin penetration ability was tested using pig skin (ex vivo). The results indicated that the microneedles exhibited sufficient strength to penetrate the outer …

One-Pot Iodine-Mediated Synthesis Of Cannabinol And Derivatives, Mongkonkorn Thanakorncharoenwit

Chulalongkorn University Theses and Dissertations (Chula ETD)

Cannabinol (CBN) is a minor cannabinoid that exhibits a broad range of medicinal activities without psychoactive effects. CBN derivatives have been typically synthesized from a terpenoid and a resorcinol derivative, through a multistep reaction including the Friedel-Crafts alkylation, cyclization, and aromatization. In this study, we envisioned that iodine could act as a Lewis acid catalyst and an aromatization agent. Consequently, we developed a one-pot iodine-mediated reaction between (1S,4R)-p-menthadienol and 5-(1,1-dimethylheptyl)resorcinol for the synthesis of 3-(1,1-dimethylheptyl)cannabinol (DMH-CBN). Various reaction parameters were evaluated, and the reaction yields were analyzed by quantitative 1H NMR. The optimized reaction conditions were found to be 1.5 …

Development Of A Gel-Based Electrolyte For Determination Of Heavy Metals Using Smartphone, Nuntanuch Lersanantasit

Chulalongkorn University Theses and Dissertations (Chula ETD)

Herein, a portable electrochemical device using biopolymeric gel-based electrolyte for the on-field simultaneous determination of Cd(II) and Pb(II) is presented. Pectin, a natural polymer, was used as a chemical delivery medium due to its biodegradation and fast-dissolving properties. Differential pulse voltammetry (DPV) was used to detect electrochemical signal of Cd(II) and Pb(II) solution dropped on the pectin-based electrolyte platform. The modification of screen-printed graphene electrode with Sb-Bi bimetallic alloy using both in situ and pre-mixed method was able to enhance the sensitivity of the sensor. The experimental results demonstrated that the developed gel-based electrolyte was capable of generating sharp and …

Molecular Assembly Of Hyaluronic Acid Nanoparticles For Drug Delivery By Molecular Dynamics Simulation, Pisit Lerttanakij

Chulalongkorn University Theses and Dissertations (Chula ETD)

Nanoparticles (NPs) offer a promising approach in modern medicine for the treatment of various diseases. They serve as effective carriers for various drugs including antibiotics, antivirals and anticancer agents. Hyaluronic acid-based nanoparticles (HA-NPs) have been interested owing to their exceptional biocompatibility and biodegradability. Hyaluronic acid (HA) is a natural biopolymer with versatile applications. However, there have been limited numbers of studies on molecular simulations of nanoparticles, particularly HA-NPs. In this study, molecular dynamics simulations were employed to explore molecular models representing the assembly of HA-NPs. Two types of HA-NPs, acetylated hyaluronic acid nanoparticles (AcHA-NPs) and hyaluronic acid-ceramide nanoparticles (HACe-NPs), were …

Design, Synthesis, And Biological Evaluation Of Darunavir Analogs As Hiv-1 Protease Inhibitors, Muhammad Asad Ur Rehman

Chulalongkorn University Theses and Dissertations (Chula ETD)

Darunavir, a potent inhibitor for HIV protease (PR) for the treatment of HIV infection, encounters limitations due to the emergence of multi-drug resistance HIV strains, imposing the development of darunavir analogs as new HIV protease inhibitors (PI) with enhanced efficacy. In this study, a combinatorial in silico method was used to at first design a several HIV-1 PI analogs with variations at key sites, P1' and P2', to improve the interactions with HIV-1 PR. Fifteen analogs with encouraging binding score were selected for synthesis and assessed for the inhibition activity of HIV-1 PR. The study demonstrated the effectiveness of P2' …

การผลิตและการประยุกต์คาร์บอนดอทจากยางก้อนถ้วยด้วยวิธีไฮโดรเทอร์มอล, ศุภิสรา จันสีไหม

Chulalongkorn University Theses and Dissertations (Chula ETD)

ในงานวิจัยนี้ศึกษาการสังเคราะห์คาร์บอนดอทจากยางก้อนถ้วยผ่านกระบวนการไฮโดรเทอร์มอลที่อุณหภูมิ 200 องศาเซลเซียส ศึกษาปัจจัยของเวลาในการเกิดปฏิกิริยา ปริมาณสารตั้งต้น ปริมาตรตัวทำละลาย และชนิดของสารเคมีสำหรับการสังเคราะห์คาร์บอนดอทเพื่อให้มีสมบัติเชิงแสงที่มีประสิทธิภาพสูงสุด ศึกษาหมู่ฟังก์ชันของคาร์บอนดอทจากเทคนิคฟูเรียร์ทรานส์ฟอร์มอินฟราเรดพลังงานยึดเหนี่ยวของคาร์บอนดอทวิเคราะห์ด้วยเทคนิคเอ็กซ์เรย์โฟโตอิเล็กตรอนสเปกโทรสโกปี ลักษณะทางสัณฐานวิทยาของคาร์บอนดอทศึกษาด้วยกล้องจุลทรรศน์อิเล็กตรอนแบบส่องผ่าน สมบัติเชิงแสงศึกษาด้วยเครื่องยูวีวิสิเบิลสเปกโตสโกปีและฟลูออเรสเซนต์สเปกโตรโฟโตมิเตอร์ ภาวะการเปียกถูกวิเคราะห์ด้วยเทคนิคคอนแทคแองเกิล ผลการทดลองพบว่าการใช้ระยะเวลาในการสังเคราะห์ 18 ชั่วโมง ปริมาณสารตั้งต้น 0.4 กรัม และปริมาตรน้ำปราศจากไอออน 20 มิลลิลิตร เป็นตัวแปรที่เหมาะสมสำหรับการสังเคราะห์คาร์บอนดอทมากที่สุด โดยพิจารณาจากลักษณะทางกายภาย ความเข้มข้นของสาร และสมบัติเชิงแสง นอกจากนี้การใช้แอมโมเนียมเปอร์ซัลเฟตเป็นสารเจือส่งผลให้มีหมู่ฟังก์ชัน -NH และ S=O บนพื้นผิว ทำให้คาร์บอนดอทมีความเป็นขั้วมากขึ้น ขนาดอนุภาคของคาร์บอนดอทประมาณ 6.31 นาโนเมตร ผลผลิตการเปล่งแสงฟลูออเรสเซนต์เพิ่มขึ้นจาก 4.3 ไปเป็น 12.0 เปอร์เซ็นต์ เมื่อเทียบกับการไม่ใช้สารเคมี อีกทั้งช่องว่างแถบพลังงานของคาร์บอนดอทลดลงอย่างมีนัยสำคัญจาก 6.24 เป็น 5.18 อิเล็กตรอนโวลต์ (การเติมแอมโมเนียมเพอร์ซัลเฟต) ดังนั้น คาร์บอนดอทที่ได้จากงานวิจัยมีสมบัติที่เหมาะสมสำหรับใช้การใช้งานเป็นหมึกเรืองแสงที่เป็นมิตรกับสิ่งแวดล้อมในงานป้องกันการปลอมแปลงได้

การผสมผสานแบบใหม่ของขั้ว Lifepo4 และอิเล็กโทรไลต์อินทรีย์สำหรับแบตเตอรี่สังกะสี-ไอออน, ศศิศิริ สินทอง

Chulalongkorn University Theses and Dissertations (Chula ETD)

งานวิจัยนี้มุ่งเน้นศึกษากลไกการเกิดปฏิกิริยาเคมีไฟฟ้าของแบตเตอรี่สังกะสี-ไอออนที่ใช้ลิเทียมไอรอนฟอสเฟตเป็นขั้วบวกและต้องการศึกษาผลของสารละลายอิเล็กโทรไลต์อินทรีย์ที่มีต่อสมรรถนะและประสิทธิภาพทางเคมีไฟฟ้าของแบตเตอรี่สังกะสี-ไอออน โดยใช้อิเล็กโทรไลต์ฐานอินทรีย์ที่มีเกลือซิงค์ไตรเฟลตและเกลือลิเทียมคลอไรด์ละลายปนอยู่ในตัวทำละลายอินทรีย์ ซึ่งตัวทำละลายอินทรีย์ที่เลือกใช้ ได้แก่ ไดเมทิลฟอร์มาไมด์ (DMF) เตตระไฮโดรฟูแรน (THF) และเตตระเอทิลีนไกลคอลไดเมทิลอีเทอร์ (TEGDME) การวิเคราะห์สมรรถนะและประสิทธิภาพทางเคมีไฟฟ้าใช้เทคนิคการอัด-จ่ายประจุแบบวนรอบด้วยกระแสคงที่ ผลการวิเคราะห์พบว่าระบบอิเล็กโทรไลต์ที่ใช้ TEGDME เป็นตัวทำละลายอินทรีย์แสดงสมรรถนะและประสิทธิภาพทางเคมีไฟฟ้าดีที่สุดในด้านความเสถียรซึ่งให้ค่าความจุจำเพาะเริ่มต้น 118.3 มิลลิแอมแปร์-ชั่วโมงต่อกรัม และประสิทธิภาพความจุลดลงเหลือ 91.4% เมื่อทดสอบวนรอบระยะยาว 100 รอบที่ความหนาแน่นกระแสเท่ากับ 10 มิลลิแอมแปร์ต่อกรัม สำหรับกลไกการเกิดปฏิกิริยาของแบตเตอรี่ขณะเกิดการอัด-จ่ายประจุวิเคราะห์ด้วยเทคนิค XAS และ XRD พบว่ามีการหลุดออก/แทรกตัวของไอออนของลิเทียมในโครงสร้างผลึก LiFePO4 ขณะเกิดการอัดและจ่ายประจุ และโครงสร้างผลึกมีการเปลี่ยนแปลงจาก LiFePO4 เป็น FePO4 เมื่ออัดประจุ และกลับมาเป็น LiFePO4 อีกครั้งเมื่อจ่ายประจุ เมื่อพิจารณาขั้วสังกะสีด้วยเทคนิค XRD และ SEM พบว่าในระบบ DMF และTHF ยังคงเกิดซิงค์ออกไซด์ (ZnO) ซึ่งเป็นสารประกอบที่เป็นฉนวน ส่งผลให้ประสิทธิภาพของแบตเตอรี่ลดลง สำหรับขั้วสังกะสีในระบบ TEGDME ไม่มีสารประกอบอื่นเกิดขึ้น ตัวทำละลาย TEGDME จึงเหมาะสมสำหรับใช้เป็นตัวทำละลายในอิเล็กโทรไลต์ของแบตเตอรี่ ซึ่งให้ผลที่ดีทั้งในด้านเสถียรภาพของส่วนประกอบในเซลล์แบตเตอรี่สังกะสี-ไอออน

Synthesis Of Thymol Derivatives And Their Inhibitory Effects On Alpha-Glucosidase And Tyrosinase, Ahmad Ullah Safi

Chulalongkorn University Theses and Dissertations (Chula ETD)

Diabetes is a chronic disease all over the world. More than 90% of patients have diabetes of type II and require effective methods to control their blood glucose. A promising treatment for diabetes mellitus is to reduce postprandial hyperglycemia by using α-glucosidase inhibitors to prevent carbohydrate digestion. Thymol is a naturally occurring monoterpene. Thymol motifs have a wide range of biological activities, including anti-cancer, antibacterial, antimalarial, antifungal and antioxidant. In this study, thymol-esters AS01-AS04, piperazine-containing thymols AS15-AS17 and thymol acetohydrazones AS21-AS49 were synthesized and subjected to α-glucosidase inhibitory activities. AS21-AS49 were obtained as a mixture of geometrical isomers (E/Z). All …

Phytochemical Of Dioscorea Bulbifera For Cosmeceuticals, Shabnam Pari

Chulalongkorn University Theses and Dissertations (Chula ETD)

People across various cultures have utilized plant-based substances to enhance their appearance, and cosmetics with active agents to lighten skin tone has been used. Skin whitening practices typically involve chemical constituents designed to reduce melanin and oxidative stress. People worldwide prefer using natural products to enhance their appearance due to its safety and less side effects. The intake of plant-derived bioactive agents has become increasingly popular due to their health benefits. Different forms of plants contain varying quantity of bioactive compounds. For example, drying, a common method of food preparation, significantly impacts the quantity of these compounds. Fresh and dried …

Characterization Of Aroma-Active Compounds In Fried Chicken, Nattapon Deesom

Chulalongkorn University Theses and Dissertations (Chula ETD)

Fried chicken is a product with high consumption demand both in Thailand and abroad. Thailand ranks as the world's 4th largest in terms of export volume, accounting for 105 million baths. In addition, there is a growing preference for white meat among consumers today, leading to increased consumption rates of fried chicken. Therefore, quality control is essential, especially regarding aroma, which is the first sensory perception people experience with food. In this work, olfactory profile of fried chicken was first constructed to evaluate extracts obtained from different organic solvents. The dichloromethane extracts obtained from solvent assisted flavor evaporation (SAFE) showed …

Volatile Compound Profiles In Human Sweat Before And After Covid-19 Vaccination, Sorachar Phusrisom

Chulalongkorn University Theses and Dissertations (Chula ETD)

Vaccines have been reported to be effective at preventing people from getting the coronavirus (COVID-19) as well as reducing the harmful levels. This led to incorporation of the vaccinations into the protection protocol worldwide. The vaccinations could influence metabolisms, microbiome and metabolite distribution throughout human bodies including skin. This thesis applied gas chromatography ion mobility spectrometry (GC-IMS) and gas chromatography mass spectrometry (GC-MS) to differentiate the population with COVID-19 vaccination based on their different sweat volatile compound profiles. This involves tentative identification of 160 axillary swab samples obtained from 20 healthy volunteers before or after the COVID-19 vaccination at different …

Α-Glucosidase Inhibitors From Leaves Of Cannabis Sativa And Cannabinoid Derivatives, Areeba Nayab

Chulalongkorn University Theses and Dissertations (Chula ETD)

Cannabinoids are naturally occurring secondary metabolites with antidiabetic, anti-inflammatory, and anticancer activity because of their enormous interaction efficiency with the human endocannabinoid system. α-glucosidase inhibitory activity guided isolation of Cannabis sativa L. yielded 6 compounds including Δ9-THC, cannabinol (CBN), and cannabichromene (CBC) as major compounds. This study also focused on the study of the structure-activity relationship of Δ9-THC that yielded 4 including 3 new compounds. The structures of isolated and synthesized compounds were elucidated by multiple spectroscopic techniques and with the comparison of previous reports. The isolated and derivatized compounds were evaluated for α-glucosidase inhibition. Among the isolated compounds cannabinol …

Microalgal-Plant Growth Promoting Bacterial Living Biofilters As Soil Amendment For Vegetable Cultivation, Augustine Odibo

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study explored the use of microalgal-plant growth-promoting bacterial co-cultures as living biofilters (Chlorella vulgaris (CV) and Bacillus subtilis (BS) in different ratios) for soil amendment in vegetable cultivation. It aimed to investigate the soil amendment potential of these biofilters on three selected plants (i.e. morning glory, sunflower, and cucumber) over a 20-days plantation in a controlled environment. The highest biomass yields of morning glory, cucumber, and sunflower were 1.3 ± 0.1 g, 2.0 ± 0.3 g, and 1.5 ± 0.2 g when using CV/BS 1:1, CV/BS 3:1, and CV/BS 3:1 respectively. For sunflower, the biomass yield with CV/BS 1:1, …

Identification Of Volatile Markers In Sweat For Screening Of Covid-19 Infection By Gas Chromatography-Mass Spectrometry, Suriwipa Chuachaina

Chulalongkorn University Theses and Dissertations (Chula ETD)

Due to an outbreak of coronavirus spreading in recent years, there is an urgent need for effective, rapid, and non-invasive diagnostics to detect and differentiate among patients who are infected and uninfected with SARS-CoV-2 for controlling the virus propagation. This study developed an alternative method for COVID-19 screening from volatile analysis of metabolites mainly studied in sweat samples obtained from the populations in Bangkok, Thailand, during December 2020 to April 2022. A total of 140 collected samples tested by RT-PCR; 70 positives and 70 negatives confirmed COVID-19 cases were applied to be separated, detected, and identified as volatile organic compounds …

Ultrasonic-Assisted Extraction Of Andrographolide And Bioactive Diterpene Lactones From Andrographis Paniculata, Ayomide Gbadebo

Chulalongkorn University Theses and Dissertations (Chula ETD)

Andrographis paniculata is an herbaceous plant known for its medicinally active diterpene lactones, including andrographolide (AG), neoandrographolide (NAG), 14-deoxy-11,12-didehydroandrographolide (DDHAG), and 14-deoxyandrographolide (DAG). These compounds are typically extracted using polar solvents like methanol and ethanol, yielding ≤4% w/w. This research focused on combining a fairly polar solvent with a highly polar solvent in an ultrasonic-assisted extraction (UAE) process, which is both time and energy efficient. The optimized conditions for the extraction were 40°C, 3 hours, 50% duty cycle, 1:10 solute-solvent ratio using a 6:4 ratio of ethyl acetate to ethanol, and 180W power. Quantitative nuclear magnetic resonance (qNMR) analysis successfully …

Volatile Compound Profiles In Human Sweat For Stress Screening, Teerada Somphot

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research aimed to develop an alternative stress assessment method by analyzing sweat volatile compounds, given the limited access to psychiatric evaluations. Sweat samples were collected from the armpits of 44 male firefighters using cotton rods and analyzed for volatile organic compounds (VOCs). The extraction of VOCs utilized headspace solid-phase microextraction (HS-SPME) followed by gas chromatography-mass spectrometry (GC-MS), with identification based on comparing experimental retention indices and mass spectra against the NIST Library database. The results were correlated with perceived stress scores (PSS) from the same 44 firefighters. Significant peaks, chosen for their accuracy and statistical significance, identified potential stress …

Development Of Electrochemical Methods For Determination Of Cannabinoids In Cannabis, Tavechai Pholsiri

Chulalongkorn University Theses and Dissertations (Chula ETD)

This thesis focuses on the development of electrochemical devices for the determination of major cannabinoids in various samples obtained from cannabis such as cannabis oil, cannabis flower, and body fluids such as saliva. The developed electrochemical device comprises three distinct platforms, each platform a crucial role in solving the cannabis-related challenges in Thailand. These devices are instrumental in controlling the quality of cannabis products, ensuring the quality of cannabis flowers intended for medical use, and screening individuals who smoke cannabis within legally regulated areas. This thesis can be segmented into three parts, each focusing on addressing specific aspects of the …

Determination Of Methanol Using Polymers And Mn-Doped Zns Quantum Dots, Sophanat Khenthaphak

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study aimed to develop a method for methanol detection using digital-image colorimetry (DIC). We synthesized and characterized nanomaterials, including gold nanoparticles (AuNPs) and Mn-doped ZnS quantum dots (Mn/ZnS-QDs), to determine their minimum detectable concentration using DIC. We investigated NMPPy-modified Mn/ZnS-QDs, focusing on optimal temperature for the synthesis, and the effects of NMPPy volume, pH, and buffer solution concentration on methanol detection. However, direct methanol detection was not achieved, this research highlights the potential of NMPPy-modified Mn/ZnS-QDs for methanol detection using DIC. Further development is needed to enhance direct methanol detection.

What Moves The Needle On Dfw Rates And Student Success In General Chemistry? A Quarter-Century Perspective, Vijay Vyas, Scott A. Reid

Chemistry Faculty Research and Publications

Second-term general chemistry is a key gateway course at our institution for a variety of STEM (Science, Technology, Engineering, and Mathematics) majors. Herein, we examine data on DFW% (i.e., % of D and F grades and withdrawals) in our general chemistry courses over roughly a quarter-century period, focusing on sections taught by the authors. The data are discussed in light of changes in curriculum, pedagogy, and assessments, which included introduction of recitation sections, classroom response systems (clickers), and online homework, restructuring of course content into a modular format, followed by a redesign of the course modules along an anchoring concepts …

Cytotoxicity Profiling And Apoptotic Potential Of Carboxylic Acids-Based Deep Eutectic Solvents On Mammalian Cell Lines, Mavis Korankye

Electronic Theses and Dissertations

In the past few years, there has been a notable surge in demand for high-purity medicines due to the prevalence of chronic diseases such as cancer, hypertension, diabetes, cardiovascular diseases, and neurological disorders. Considerable efforts have been dedicated to discovering new solvents that are environmentally friendly and cost-effective that are well-suited for industrial applications. Deep eutectic solvents have gained recognition as a highly promising alternative to organic solvents and ionic liquids due to their easily sourced raw materials, simple and cheap preparation methods, high tunability, low volatility, low toxicity, and biodegradability. The industrial utilization of deep eutectic solvents (DESs) is …

Food Waste Storage Gaseous Emissions Detection And Quantification Using Infrared Spectroscopy, Ryley A. Burton-Tauzer

Cal Poly Humboldt theses and projects

A growing interest in sustainable waste management and the implementation of new policies have prompted a shift towards alternative resource recovery methods for organic waste, including food waste. To effectively assess alternative food waste treatment scenarios, it is important to evaluate the life cycle impacts associated with each scenario. The storage phase of food waste, encompassing its accumulation in kitchens, and storage in bins for collection and transportation, has been overlooked as a source of greenhouse gases in previous studies. This investigation aimed to identify the greenhouse gases emitted during the initial five-day period of low-oxygen storage. An open dynamic …

Neutral And Charged Bis(Triarylamines) For Use In Grid Scale Battery Technologies, Taylor Matthews

Online Theses and Dissertations

Energy storage systems allow flexibility in control and maintenance of the electric grid while integrating renewable energy resources to mitigate carbon emissions. Redox flow batteries (RFBs) are stationary energy storage systems that convert chemical energy to electrical energy by charge-transfer reactions. Designing molecules that are capable of stable multi-electron redox reactions per active-species molecule can increase the efficiency of future systems. Spectroelectrochemistry, the combination of spectroscopy and electrochemistry, allows for quantitative and qualitative analyses of electron-transfer processes. The focus of this research is to use optical and electrochemical properties obtained from spectroelectrochemistry to determine the stability of neutral and charge …

Color-Changing Reflection Hologram For Quality Assurance Of Therapeutic Ultrasound Systems, Tatsiana Mikulchyk, John Walsh, Jacinta Browne, Izabela Naydenova, Dervil Cody

Articles

The acoustic output of clinical therapeutic ultrasound equipment requires regular quality assurance (QA) testing to ensure the safety and efficacy of the treatment and that any potentially harmful deviations from the expected output power density are detected as soon as possible. A hologram, consisting of a reflection grating fabricated in an acrylate photopolymer film, has been developed to produce an immediate, visible, and permanent change in the color of the reconstructed hologram from red to green in response to incident ultrasound energy. The influence of the therapeutic ultrasound insonation parameters (exposure time, ultrasound power density, and proximity to the point …

Effects Of Flexibility In Coarse-Grained Models For Bovine Serum Albumin And Immunoglobulin G, Frank Hirschmann, Hender Lopez, Felix Roosen-Runge, Tilo Seydel, Frank Schreiber, Martin Oettel

Articles

We construct a coarse-grained, structure-based, low-resolution, 6-bead flexible model of bovine serum albumin (BSA, PDB: 4F5S), which is a popular example of a globular protein in biophysical research. The model is obtained via direct Boltzmann inversion using all-atom simulations of a single molecule, and its particular form is selected from a large pool of 6-bead coarse-grained models using two suitable metrics that quantify the agreement in the distribution of collective coordinates between all-atom and coarse-grained Brownian dynamics simulations of solutions in the dilute limit. For immunoglobulin G (IgG), a similar structure-based 12-bead model has been introduced in the literature [Chaudhri …

Identification And Quantification Of Novel Antimicrobials, Hazera Khatun Koly

Electronic Theses and Dissertations

No abstract provided.

Length Of Course-Based Undergraduate Research Experiences (Cure) Impacts Student Learning And Attitudinal Outcomes: A Study Of The Malate Dehydrogenase Cures Community (Mcc), Sue Ellen Dechenne-Peters, John F. Rakus, Amy D. Parente, Tamara L. Mans, Rebecca Eddy, Nicole Galport, Courtney Joletar, Joeseph J. Provost, J. Ellis Bell, Jessica K. Bell

Chemistry and Biochemistry: Faculty Scholarship

Course-based undergraduate research experiences (CUREs) are laboratory courses that integrate broadly relevant problems, discovery, use of the scientific process, collaboration, and iteration to provide more students with research experiences than is possible in individually mentored faculty laboratories. Members of the national Malate dehydrogenase CUREs Community (MCC) investigated the differences in student impacts between traditional laboratory courses (control), a short module CURE within traditional laboratory courses (mCURE), and CUREs lasting the entire course (cCURE). The sample included approximately 1,500 students taught by 22 faculty at 19 institutions. We investigated course structures for elements of a CURE and student outcomes including student …

Enabling Technologies For Chemical Synthesis: I. Selective Microwave Heating; Ii. Synthesis And Regioselective Cyclotrimerizations Of Tethered 1,6-Diynes, Amir Tavakoli

Graduate Theses, Dissertations, and Problem Reports (ETD)

Reaction discoveries, method developments, and technology advancements lie at the heart of synthetic organic chemistry. These innovations are essential for creating and manipulating complex molecules, which are the building blocks of many important chemical compounds, including pharmaceuticals, materials, and agrochemicals. Here, we first describe new methods to prepare neopentylene-tethered (NPT) 1,6-diynes which are valuable substrates for reaction discovery and target-oriented synthesis, especially in benzannulation strategies toward illudalane natural products. NPT 1,6-diynes have been employed as coupling partners in cyclotrimerization reactions for the synthesis of highly substituted benzene rings which present a persistent challenge in chemical synthesis and are underrepresented scaffolds …

Enantioselective Dearomatization Facilitated By Non-Covalent Interactions Of N-Heterocyclic Carbene Catalysts And Pyridinium Salts, Jack A. Patterson

Graduate Theses, Dissertations, and Problem Reports (ETD)

Dihydropyridines are a practical organic scaffold commonly used for their pharmaceutical properties. Nucleophilic dearomatization of pyridines has proven to be a useful method in obtaining dihydropyridines. By using N-heterocyclic carbene (NHC) organocatalysts, dihydropyridines can be synthesized with high regioselectivity of the 1,4 regioisomer over the 1,2- regioisomer but often with low enantioselectivity. By incorporating non-covalent interaction contact points, we hypothesize that enantioselectivity can be enhanced. By synthesizing numerous NHCs, each proposed to exhibit a different type of non-covalent interaction (i.e., hydrogen bonding or ion pairing), an understanding of the secondary interactions within this reaction system can be studied and …

Synthesis And Pharmacology Of Illudalic Acid And Analogous Chemical Structures, Robert Gaston Jr

Graduate Theses, Dissertations, and Problem Reports (ETD)

Natural products are the foundation of modern medicine and an inspiration for chemical innovation. Developing new synthetic strategies to complex natural products drives synthetic innovation and promotes pharmacological exploration. As bioactive secondary metabolites of fungi, illudalic acid and associated analogs have unrealized medicinal potential due to synthetic limitations. Illudalic acid is notably the first selective covalent inhibitor of the LAR-PTPs, a class of enzymes linked to many human illnesses, including stimulant addiction. The chemistry herein focuses on optimizing synthetic routes to illudalic acid and associated analogs toward exploring their pharmaceutical potential. We report a second-generation synthesis of illudinine (55% overall …

Ambient Ammonia Synthesis Via Microwave-Catalytic Materials And Plasma Chemistry, Siobhan Brown

Graduate Theses, Dissertations, and Problem Reports (ETD)

Ammonia is critical to supporting human life on earth because of its use as fertilizer. The Haber-Bosch process to produce ammonia has been practiced for over 100 years. This process operates at high pressure and temperature to overcome the thermodynamic and kinetic limitations of the ammonia synthesis reaction thus researchers have tried to overcome it for decades. At present this process represents 1% of global energy usage and 2.5% of global CO₂ emissions. The proposed chemical looping ammonia synthesis approach seeks to reduce the environmental impact of this critical process and to elucidate microwave-catalytic principles.

This research aims to …