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Full-Text Articles in Physical Sciences and Mathematics

Stereocontrolled Access To Δ-Lactone-Fused-Γ-Lactams Bearing Angular Benzylic Quaternary Stereocenters, Timothy K. Beng, Morgan J. Rodriguez, Claire Borg Jun 2022

Stereocontrolled Access To Δ-Lactone-Fused-Γ-Lactams Bearing Angular Benzylic Quaternary Stereocenters, Timothy K. Beng, Morgan J. Rodriguez, Claire Borg

All Faculty Scholarship for the College of the Sciences

C-fused γ-lactam-lactones are resident in several bioactive molecules, including anticancer agents such as omuralide. In this embodiment, we report mild conditions for the catalytic halolactonization of lactam-tethered 5-aryl-4(E)-pentenoic acids. The use of dichloromethane as the solvent and Ph3PS as the catalyst led to predominant 6-endo-trig cyclization and furnished the trans-fused-γ-lactam-δ-lactones. The transformation is modular, regioselective, chemoselective, and diastereoselective. The γ-lactam-δ-lactones bear angular quaternary benzylic stereocenters, which is noteworthy since the presence of a quaternary carbon in bioactive small molecules often promotes an element of conformational restriction that imparts potency, selectivity, and metabolic stability. The …


Fast Photochemical Oxidation And Footprinting Of Proteins Via Trifluoromethyl Radical Chemistry, Elaine Morrow Apr 2022

Fast Photochemical Oxidation And Footprinting Of Proteins Via Trifluoromethyl Radical Chemistry, Elaine Morrow

Honors Theses

Fast photochemical oxidation of proteins (FPOP) is a useful tool in proteomics because of the ability for modifications to occur on the scale of microseconds which reduces the modifications to tertiary and quaternary structure allowing for more accurate labeling of the protein. Labels for FPOP are generated from various radicals in our experiments which include hydroxyl radicals and trifluoromethyl radicals. Hydroxyl radicals are easily generated by using an excimer laser (KrF laser, 248 nm) or a UV flash lamp (as a part of the Fox™ System) by the photolysis of hydrogen peroxide. Trifluoromethyl radicals, however, need hydroxyl radicals to be …


The Vagabond Flourine Atom Revisited: Dissociative Photoionization Of Tri- And Pentafluoropropene, Jessica K. De La Cruz Jan 2022

The Vagabond Flourine Atom Revisited: Dissociative Photoionization Of Tri- And Pentafluoropropene, Jessica K. De La Cruz

University of the Pacific Theses and Dissertations

Photoelectron Photoion Coincidence (PEPICO) Spectroscopy studies on two unsaturated hydrofluorocarbons (HFCs), also known as hydrofluoroolefines (HFOs), are presented here. Previously, the Sztáray group has studied the dissociation of trans-1,3,3,3-tetrafluoroprop-1-ene (ElixClean), which is a fourth-generation refrigerant and propellant and has lower global warming potential than its precursors. My study is an extension of the ElixClean study as it aims to explore how the different number of fluorine atoms impact the dissociation reactions of these molecules. Both 3,3,3-trifluoropropene (TFP) and cis-1,2,3,3,3- pentafluoropropene (PFP) are also utilized as propellants and refrigerants.Measurements were carried out with remote access to the CRF-PEPICO (combustion reactions followed …


Gc/Ms And Lc/Ms Approaches To Chemical Communication In Plants And Marine Cyanobacteria, Carolyn Keim Jan 2022

Gc/Ms And Lc/Ms Approaches To Chemical Communication In Plants And Marine Cyanobacteria, Carolyn Keim

University of the Pacific Theses and Dissertations

Natural products are small organic compounds synthesized by living organisms including plants, animals, and microbes. These fall into one of two categories, primary metabolites are required for survival, but secondary metabolites usually play a more accessory role. Extracts from organisms have proven to be useful to humans throughout history. Prior to evidence-based western medicine practices, natural products were the only source of medicine and remain as a treatment source for underdeveloped nations. Today, natural products have either been approved by or have served as the template for many FDA approved drugs. Based on a survey of all FDA approved drugs …


Peripherally Restricted Opioid Conjugates And Its Use As Pharmacological Probes And Potential Therapeutics, Md Tariqul Haque Tuhin Jan 2022

Peripherally Restricted Opioid Conjugates And Its Use As Pharmacological Probes And Potential Therapeutics, Md Tariqul Haque Tuhin

University of the Pacific Theses and Dissertations

Opioid-induced constipation (OIC) is one of the major adverse effects of opioid analgesics used by millions of patients each year. While progress has been made, there remains a significant unmet medical need in the treatment of OIC. Major gaps remain in our understanding of the role of the gastrointestinal tract and central nervous system (CNS) in precipitating OIC. For the last four decades, numerous investigations to study the sites of action of opioid analgesics have utilized peripherally acting mu-opioid receptor antagonists (PAMORAs), which have been incorrectly believed to have limited penetration across the blood-brain barrier (BBB). Several preclinical and clinical …