: The unpolarized absorption and circular dichroism spectra of the fundamental vibrational transitions of the chiral molecule, 4-methyl-2-oxetanone, are calculated ab initio. Harmonic force fields are obtained using Density Functional Theory (DFT), MP2, and SCF methodologies and a 5S4P2D/3S2P (TZ2P) basis set. DFT calculations use the Local Spin Density Approximation (LSDA), BLYP, and Becke3LYP (B3LYP) density functionals. Mid-IR spectra predicted using LSDA, BLYP, and B3LYP force fields are of significantly different quality, the B3LYP force field yielding spectra in clearly superior, and overall excellent, agreement with experiment. The MP2 force field yields spectra in slightly worse agreement with experiment than the B3LYP force field. The SCF force field yields spectra in poor agreement with experiment.The basis set dependence of B3LYP force fields is also explored: the 6-31G* and TZ2P basis sets give very similar results while the 3-21G basis set yields spectra in substantially worse agreements with experiment. jg

Ab initio calculation of vibrational absorption and circular dichroism spectra using density functional force fields

Copper is an essential cofactor for all organisms, and yet it becomes toxic if concentrations exceed a threshold maintained by evolutionarily conserved homeostatic mechanisms. How excess copper induces cell death, however, is unknown. Here, we show in human cells that copper-dependent, regulated cell death is distinct from known death mechanisms and is dependent on mitochondrial respiration. We show that copper-dependent death occurs by means of direct binding of copper to lipoylated components of the tricarboxylic acid (TCA) cycle. This results in lipoylated protein aggregation and subsequent iron-sulfur cluster protein loss, which leads to proteotoxic stress and ultimately cell death. These findings may explain the need for ancient copper homeostatic mechanisms. Description Copper induces cell death Cell death is an essential, finely tuned process that is critical for the removal of damaged and superfluous cells. Multiple forms of programmed and nonprogrammed cell death have been identified, including apoptosis, ferroptosis, and necroptosis. Tsvetkov et al. investigated whether abnormal copper ion elevations may sensitize cells toward a previously unidentified death pathway (see the Perspective by Kahlson and Dixon). By performing CRISPR/Cas9 screens, several genes were identified that could protect against copper-induced cell killing. Using genetically modified cells and a mouse model of a copper overload disorder, the researchers report that excess copper promotes the aggregation of lipoylated proteins and links mitochondrial metabolism to copper-dependent death. —PNK Lipoylation determines sensitivity to copper-induced cell death.

Copper induces cell death by targeting lipoylated TCA cycle proteins

There is great need for stand-alone luminescence-based chemosensors that exemplify selectivity, sensitivity, and applicability and that overcome the challenges that arise from complex, real-world media. Discussed herein are recent developments toward these goals in the field of supramolecular luminescent chemosensors, including macrocycles, polymers, and nanomaterials. Specific focus is placed on the development of new macrocycle hosts since 2010, coupled with considerations of the underlying principles of supramolecular chemistry as well as analytes of interest and common luminophores. State-of-the-art developments in the fields of polymer and nanomaterial sensors are also examined, and some remaining unsolved challenges in the area of chemosensors are discussed.

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Supramolecular Luminescent Sensors

Oxidative stress has become widely viewed as an underlying condition in a number of diseases, such as ischemia–reperfusion disorders, central nervous system disorders, cardiovascular conditions, cancer, and diabetes. Thus, natural and synthetic antioxidants have been actively sought. Superoxide dismutase is a first line of defense against oxidative stress under physiological and pathological conditions. Therefore, the development of therapeutics aimed at mimicking superoxide dismutase was a natural maneuver. Metalloporphyrins, as well as Mn cyclic polyamines, Mn salen derivatives and nitroxides were all originally developed as SOD mimics. The same thermodynamic and electrostatic properties that make them potent SOD mimics may allow them to reduce other reactive species such as peroxynitrite, peroxynitrite-derived CO3·−, peroxyl radical, and less efficiently H2O2. By doing so SOD mimics can decrease both primary and secondary oxidative events, the latter arising from the inhibition of cellular tra...

/pdf/superoxide-dismutase-mimics-chemistry-pharmacology-and-1ttn9834vf.pdf

Superoxide Dismutase Mimics: Chemistry, Pharmacology, and Therapeutic Potential

Neurodegenerative diseases pose a substantial socioeconomic burden on society. Unfortunately, the aging world population and lack of effective cures foreshadow a negative outlook. Although a large amount of research has been dedicated to elucidating the pathologies of neurodegenerative diseases, their principal causes remain elusive. Metal ion dyshomeostasis, proteopathy, oxidative stress, and neurotransmitter deficiencies are pathological features shared across multiple neurodegenerative disorders. In addition, these factors are proposed to be interrelated upon disease progression. Thus, the development of multifunctional compounds capable of simultaneously interacting with several pathological components has been suggested as a solution to undertake the complex pathologies of neurodegenerative diseases. In this review, we outline and discuss possible therapeutic targets in Alzheimer’s disease, Parkinson’s disease, and amyotrophic lateral sclerosis and molecules, previously designed or discovered as pote...

Development of Multifunctional Molecules as Potential Therapeutic Candidates for Alzheimer’s Disease, Parkinson’s Disease, and Amyotrophic Lateral Sclerosis in the Last Decade

8-Hydroxyquinolines in medicinal chemistry: A structural perspective.

8-Hydroxyquinolines are systems of great interest in the field of inorganic and bioinorganic chemistry. They are metal-binding compounds and are known to exhibit a variety of biological activities, such as antibacterial and anticancer activities. Among these systems, clioquinol has been the focus of a renewed interest in recent years. In this scenario, we synthesized and characterized the new clioquinol glucoconjugate, 5-chloro-7-iodo-8-quinolinyl-β-D-glucopyranoside in order to compare this system to that of clioquinol. We also synthesized, 8-quinolinyl-β-D-glucopyranoside, an 8-hydroxyquinoline glucoconjugate. The reason for the development of glucoconjugates is the glucose avidity, and the over-expression of glucose transporters in cancer cells. Here we demonstrate that glycoconjugates are cleaved in vitro by β-glucosidase and these systems exhibit antiproliferative activity against different tumor cell lines in the presence of copper(II) ions.

Gluconjugates of 8-hydroxyquinolines as potential anti-cancer prodrugs

Magnetic Fe3O4 nanoparticles (MNPs) have been covalently modified with β-cyclodextrin (β-CD) cavities by adopting a two-step anchoring route based on particle prefunctionalization with a phosphonic monolayer, which acts as a covalent linker between the MNPs and β-CD. Particular attention has been devoted to the study of the functionalization process by adopting bifunctional phosphonic linkers to investigate the efficiency of the anchoring group (phosphonic acid or ester) and the role of a second functional group. The grafting process of the phosphonic linkers has been monitored by using X-ray photoelectron and FTIR spectroscopy. β-CD has then been successfully anchored on MNPs prefunctionalized with (3-aminopropyl)phosphonic acid. The ability of β-CD-functionalized nanoparticles to carry and slowly release some drugs has been tested by adopting the anti-inflammatory drug diclofenac sodium salt as a model.

Cyclodextrin Anchoring on Magnetic Fe3O4 Nanoparticles Modified with Phosphonic Linkers

Recent investigations have rekindled interest in 8-hydroxyquinolines as therapeutic agents for cancer, Alzheimer’s disease, and other neurodegenerative disorders. Three new β-cyclodextrin conjugates of 8-hydroxyquinolines and their copper(II) and zinc(II) complexes have been synthesized and characterized spectroscopically. In addition to improving aqueous solubility, due to the presence of the cyclodextrin moiety, the hybrid systems have interesting characteristics including antioxidant activity, and their copper(II) complexes are efficient superoxide dismutase (SOD) mimics. The ligands and their copper(II) complexes show low cytotoxicity, attributed to the presence of the cyclodextrin moiety. These compounds have potential as therapeutic agents in diseases related both to metal dyshomeostasis and oxidative stress.

New cyclodextrin-bearing 8-hydroxyquinoline ligands as multifunctional molecules

8-Hydroxyquinoline derivatives are metal-binding compounds that have recently attracted interest as therapeutic agents for cancer therapy. In this scenario, we designed and synthesized three new glucoconjugates, 5,7-dichloro-8-quinolinyl-β-D-glucopyranoside, 5-chloro-8-quinolinyl-β-D-glucopyranoside and 2-methyl-8-quinolinyl-β-D-glucopyranoside and investigated their biological properties in comparison to the parent 8-hydroxyquinoline derivatives in the presence of Cu(2+). In vitro data show that 2 out of 3 glycosylated compounds possess a pharmacologically-relevant antiproliferative activity against tumor cells, similar to that of their parent compounds; this activity is associated with a relevant triggering of apoptosis. The pharmacological profile of the glucoconjugates depends on the cellular enzymatic β-glucosidase activity, as demonstrated by the inhibition of antiproliferative activity in the presence of the 2,5-dideoxy-2,5-imino-D-mannitol.

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Valentina Oliveri

Papers

8-Hydroxyquinolines in medicinal chemistry: A structural perspective.

Gluconjugates of 8-hydroxyquinolines as potential anti-cancer prodrugs

Cyclodextrin Anchoring on Magnetic Fe3O4 Nanoparticles Modified with Phosphonic Linkers

New cyclodextrin-bearing 8-hydroxyquinoline ligands as multifunctional molecules

Glycosylated copper(II) ionophores as prodrugs for β-glucosidase activation in targeted cancer therapy