Linden (Tilia spp.), a profusely flowering temperate tree that provides bees with vital pollen and nectar, has been associated with bumble bee (Bombus spp.) mortality in Europe and North America. Bee deaths have been attributed, with inadequate evidence, to toxicity from mannose in nectar or starvation due to low nectar...
Metal-oxo clusters can be described as soluble pieces of metal-oxide frameworks. Currently, metal-oxo clusters are being considered as solution-based precursors for extreme ultraviolet (EUV, 13.5 nm) photoresist materials, which are a crucial component in the fabrication of microelectronic devices. Two different photoresist precursor systems have been investigated – alkyltin clusters...
Atmospheric fine particulate matter (PM2.5) has been linked to the death of 7 million people per year around the planet. The organic portion of PM2.5 is responsible for increases in oxidative stress, inflammation, mutation and carcinogenesis. Anthropogenic activity releases more organic material into the atmosphere, and has increased the amount...
Exploring bioactive natural products has contributed largely to clinically approved drugs we have been using over the last 100 years. Especially among the anti-infective drugs, around 70% of currently used antibiotics were discovered or derived from microbial secondary metabolites, among them compounds like vancomycin, chloramphenicol, and erythromycin. Facing the unavoidable...
Metal-oxo clusters are discrete molecular metal-oxides. Most metals form numerous cluster compounds that can be ligated, unligated, charged or neutral, controlling their solubility in water and/or organic solvents. They are important species to study reaction pathways from the monomeric building units to the bulk metal oxides, and have many application...
Dental plaque is one of the well-characterized biofilms in the human body. Oral bacterial species play vital roles in maintaining healthy bacterial homeostasis as well as causing oral infections. Many of the oral diseases are caused by opportunistic pathogens, and therefore, the bacterial metabolic activities become important in dictating their...
Part I of this dissertation includes the chronological synthetic background of mandelalide A as well as the synthesis of the C1-C14 glycosylated southern subunit of mandelalide. A key aspect of the synthesis includes a novel silver-catalyzed cyclization (AgCC) of a propargylic benzoate to construct the substituted cis-pyran ring system present...
Small molecule drugs have been instrumental in our fight against diseases, beginning when some of the earliest ancient cultures used plant remedies to treat illnesses. More recently, the skill of isolating and characterizing the active ingredients within bioactive plants and microbial extracts has led to the isolation and design of...
Fungi have long been used for discovery of new chemical scaffolds. In the clinical setting, the fungal natural products penicillin, statins, and cyclosporine have revolutionized medicine to treat diseases and infections. In the environment, fungal natural products have been used as herbicides, fungicides, and insecticides to protect crops, livestock, and...
Dearomatization reactions exist broadly in biosynthesis and chemical synthesis. The highly functionalized atoms of arenes can be masked by it aromaticity, and upon dearomatization, those reactive atoms can be readily applied to bond formation and further manipulation. The total synthesis of (–)-cephalotaxine and (–)- homoharringtonine is described via an oxidative...
Mandelalide A has attracted considerable interest from the synthetic community due to its intriguing structure and important cytotoxic activity. Madeirolide A, a structurally related macrolide, shows promising antifungal activity but no appreciable anticancer activity. This dissertation describes synthetic studies toward mandelalide A, madeirolide A and their hybrid structures.
Part I...
Nanostars have many potential applications, particularly in biomedicine, such as drug delivery, detection assays, and even cancer treatment. Seeing how their plasmon changes in response to changes to the environment of the nanostars can give us an insight to the stability of the nanostars. Our current studies involve the effect...
Tethering fluorophores on metal nanoparticles for metal enhanced fluorescence (MEF) has attracted a lot of attention from scientists interested in fluorescence based approaches. MEF has many benefits in fluorescence related techniques, because the analytical signal increases and enables potentially lower detection limits or better sensitivity. Many types of nanoparticles have...
Analytical techniques are utilized in a wide variety of applications. Traditionally, analytical measurements are achieved by trained personnel in a laboratory setting using expensive scientific instruments, which limits their applicability in resource-limited areas and point-of-care applications. Therefore, the concept of enabling these laboratory-based qualitative and quantitative assays in microfluidic device...
My work has focused on streamlining the study of organic compound structure, properties, and reactions by 1) understanding and using available computational software, 2) developing software packages to facilitate data manipulation as well as augment public programs, and 3) applying public and in-house developed software to further the understanding of...
In this dissertation, the process of computational modeling of amorphous oxide materials is studied. Amorphous oxides have random atomic arrangements with no long-range structural order which makes it difficult to study structure-property relationships. Despite the difficulties, amorphous oxides have great uses as semiconductors and dielectrics in thin-film transistors. The ability...
In this dissertation, I describe the experimental investigation of large superfluid helium droplets. The goal and direction of this thesis is to facilitate the use of these droplets as part of our project ss-EDI. The overall scheme of ss-EDI is to dope proteins inside helium droplets and collect a diffraction...
Aqueous film forming foams (AFFFs) are proprietary mixtures containing hydrocarbon surfactants and per-and polyfluoroalkyl substances (PFASs) that are used to extinguish hydrocarbon-based fuel fires. There is limited information on hydrocarbon surfactants in AFFFs and AFFF-contaminated groundwater even though they are more abundant (5-10% w/w) than PFASs (0.9-1.5% w /w) in...
Mensacarcin is a stereogenic complex polyketide with potent anti-tumor activity produced by a soil-dwelling Streptomyces bottropensis. The US National Cancer Institute (NCI) 60 human tumor cell line anticancer drug screen (NCI-60) reveals mensacarcin’s cytostatic properties in almost all tested cell lines and distinct cytotoxic properties specifically in eight melanoma cell...