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Full-Text Articles in Physical Sciences and Mathematics
Aerobic C-C And C-O Bond Formation Reactions Mediated By High-Valent Nickel Species., Sofia Smith, Oriol Planas, Laura Gómez, Nigam Rath, Xavi Ribas, Liviu Mirica, Liviu Mirica
Aerobic C-C And C-O Bond Formation Reactions Mediated By High-Valent Nickel Species., Sofia Smith, Oriol Planas, Laura Gómez, Nigam Rath, Xavi Ribas, Liviu Mirica, Liviu Mirica
Chemistry & Biochemistry Faculty Works
Nickel complexes have been widely employed as catalysts in C–C and C–heteroatom bond formation reactions. While Ni(0), Ni(I), and Ni(II) intermediates are most relevant in these transformations, recently Ni(III) and Ni(IV) species have also been proposed to play a role in catalysis. Reported herein is the synthesis, detailed characterization, and reactivity of a series of Ni(II) and Ni(III) metallacycle complexes stabilized by tetradentate pyridinophane ligands with various N-substituents. Interestingly, while the oxidation of the Ni(II) complexes with various other oxidants led to exclusive C–C bond formation in very good yields, the use of O2 or H2O2 as oxidants led to …
The Chemistry And Biology Of Cyclophostin, The Cyclipostins And Related Compounds, Christopher Spilling
The Chemistry And Biology Of Cyclophostin, The Cyclipostins And Related Compounds, Christopher Spilling
Chemistry & Biochemistry Faculty Works
Cyclophostin, the cyclipostins and the salinipostins are structurally related cyclic enolphosphate natural products. This mini review describes their isolation, synthesis and biological activities. In addition, the synthesis and biological activities of monocyclic enolphosphate and mono and bicyclic enolphosphonate analogs are presented.
G-Quadruplex Dynamics Contribute To Regulation Of Mitochondrial Gene Expression, M. Falabella, J. E. Kolesar, C. Wallace, D. De Jesus, L. Sun, Y. V. Taguichi, C. Wang, T. Wang, Irene M. Xiang , '18, J. K. Alder, R. Maheshan, W. Horne, Joshua R. Turek-Herman , '16, P. J. Pagano, C. M. St. Croix, N. Sondheimer, Liliya A. Yatsunyk, F. B. Johnson, B. A. Kaufman
G-Quadruplex Dynamics Contribute To Regulation Of Mitochondrial Gene Expression, M. Falabella, J. E. Kolesar, C. Wallace, D. De Jesus, L. Sun, Y. V. Taguichi, C. Wang, T. Wang, Irene M. Xiang , '18, J. K. Alder, R. Maheshan, W. Horne, Joshua R. Turek-Herman , '16, P. J. Pagano, C. M. St. Croix, N. Sondheimer, Liliya A. Yatsunyk, F. B. Johnson, B. A. Kaufman
Chemistry & Biochemistry Faculty Works
Single-stranded DNA or RNA sequences rich in guanine (G) can adopt non-canonical structures known as G-quadruplexes (G4). Mitochondrial DNA (mtDNA) sequences that are predicted to form G4 are enriched on the heavy-strand and have been associated with formation of deletion breakpoints. Increasing evidence supports the ability of mtDNA to form G4 in cancer cells; however, the functional roles of G4 structures in regulating mitochondrial nucleic acid homeostasis in non-cancerous cells remain unclear. Here, we demonstrate by live cell imaging that the G4-ligand RHPS4 localizes primarily to mitochondria at low doses. We find that low doses of RHPS4 do not induce …
Biosensor Applications Of Electrodeposited Nanostructures, Keith Stine
Biosensor Applications Of Electrodeposited Nanostructures, Keith Stine
Chemistry & Biochemistry Faculty Works
The development of biosensors for a range of analytes from small molecules to proteins to oligonucleotides is an intensely active field. Detection methods based on electrochemistry or on localized surface plasmon responses have advanced through using nanostructured electrodes prepared by electrodeposition, which is capable of preparing a wide range of different structures. Supported nanoparticles can be prepared by electrodeposition through applying fixed potentials, cycling potentials, and fixed current methods. Nanoparticle sizes, shapes, and surface densities can be controlled, and regular structures can be prepared by electrodeposition through templates. The incorporation of multiple nanomaterials into composite films can take advantage of …
Ring Expansion Of Alkylidenecarbenes Derived From Lactams, Lactones, And Thiolactones Into Strained Heterocyclic Alkynes: A Theoretical Study, N. N. Thu Le, J. Just, J. M. Pankauski, Paul R. Rablen, D. M. Thamattoor
Ring Expansion Of Alkylidenecarbenes Derived From Lactams, Lactones, And Thiolactones Into Strained Heterocyclic Alkynes: A Theoretical Study, N. N. Thu Le, J. Just, J. M. Pankauski, Paul R. Rablen, D. M. Thamattoor
Chemistry & Biochemistry Faculty Works
Strained cycloalkynes are of considerable interest to theoreticians and experimentalists, and possess much synthetic value as well. Herein, a series of cyclic alkylidenecarbenes—formally obtained by replacing the carbonyl oxygen of four-, five-, and six-membered lactams, lactones, and thiolactones with a divalent carbon—were modeled at the CCSD(T)/cc-pVTZ//B3LYP/6-311+G** and CCSD(T)/cc-pVTZ//CCSD/6-311+G** levels of theory. The singlet carbenes were found to be more stable than the triplets. The strained heterocyclic alkynes formed by ring expansion of these singlet carbenes were also modeled. Interestingly, the C≡C bonds in the five-membered heterocycles, obtained from the rearrangement of β-lactam- and β-lactone-derived alkylidenecarbenes, displayed lengths intermediate between formal …
Synthetic Ionophores As Non-Resistant Antibiotic Adjuvants, George Gokel, Mohit Patel, Evan Garrad, Joseph Meisel, Saeedeh Negin, Michael Gokel
Synthetic Ionophores As Non-Resistant Antibiotic Adjuvants, George Gokel, Mohit Patel, Evan Garrad, Joseph Meisel, Saeedeh Negin, Michael Gokel
Chemistry & Biochemistry Faculty Works
Antimicrobial resistance is a world-wide health care crisis. New antimicrobials must both exhibit potency and thwart the ability of bacteria to develop resistance to them. We report the use of synthetic ionophores as a new approach to developing non-resistant antimicrobials and adjuvants. Most studies involving amphiphilic antimicrobials have focused on either developing synthetic amphiphiles that show ion transport, or developing non-cytotoxic analogs of such peptidic amphiphiles as colistin. We have rationally designed, prepared, and evaluated crown ether-based synthetic ionophores (‘hydraphiles’) that show selective ion transport through bilayer membranes and are toxic to bacteria. We report here that hydraphiles exhibit a …
N-Methyl Mesoporphyrin Ix As A Highly Selective Light-Up Probe For G-Quadruplex Dna, Ariana Yett , '21, Linda Yingqi Lin , '20, Dana Beseiso , '21, Joanne Miao , '22, Liliya A. Yatsunyk
N-Methyl Mesoporphyrin Ix As A Highly Selective Light-Up Probe For G-Quadruplex Dna, Ariana Yett , '21, Linda Yingqi Lin , '20, Dana Beseiso , '21, Joanne Miao , '22, Liliya A. Yatsunyk
Chemistry & Biochemistry Faculty Works
N-methyl mesoporphyrin IX (NMM) is a water-soluble, non-symmetric porphyrin with excellent optical properties and unparalleled selectivity for G-quadruplex (GQ) DNA. G-quadruplexes are non-canonical DNA structures formed by guanine-rich sequences. They are implicated in genomic stability, longevity, and cancer. The ability of NMM to selectively recognize GQ structures makes it a valuable scaffold for designing novel GQ binders. In this review, we survey the literature describing the GQ-binding properties of NMM as well as its wide utility in chemistry and biology. We start with the discovery of the GQ-binding properties of NMM and the development of NMM-binding aptamers. We then discuss …