Organics

Hidden chemistry of substituted aniline radical cations in water: a mechanistic study
Absolute rate constants for hydroxyl radical, azide radical, and hydrated electron reactions with a sulfa drug 4,4'-diamino diphenyl sulfone (dapsone) in water have been evaluated using electron pulse radiolysis technique. Absolute rate constants for hydroxyl radical and azide radical were determined as (8.4 ± 0.3) × 109 and (5.6 ± 0.5) × 109 M−1 s−1, respectively. T...


Brevisulcatic Acids, Marine Ladder-Frame Polyethers from the Red Tide Dinoflagellate Karenia brevisulcata in New Zealand
The isolation and structural determination of new marine ladder-frame polyethers, brevisulcatic acids-1 (1) and -4 are reported. Brevisulcatic acids were isolated from the dinoflagellate Karenia brevisulcata, which was identified as the causative species of a major red tide event in New Zealand in 1998. The ether ring composition and a β-hydroxy, γ-methylene valeric acid side chain of 1 and 2...
Bowman-Birk Protease Inhibitor from Vigna unguiculata Seeds Enhances the Action of Bradykinin-Related Peptides
The hydrolysis of bradykinin (Bk) by different classes of proteases in plasma and tissues leads to a decrease in its half-life. Here, Bk actions on smooth muscle and in vivo cardiovascular assays in association with a protease inhibitor, Black eyed-pea trypsin and chymotrypsin inhibitor (BTCI) and also under the effect of trypsin and chymotrypsin were evaluated. Two synthetic Bk-related peptide...


Poly(Ethylene Glycol)-Based Backbones with High Peptide Loading Capacities
Polymer-peptide conjugates are a promising class of compounds, where polymers can be used to overcome some of the limitations associated with peptides intended for therapeutic and/or diagnostic applications. Linear polymers such as poly(ethylene glycol) can be conjugated through terminal moieties and have therefore limited loading capacities. In this research, functionalised linear poly(ethylen...
ESI(+)-MS and GC-MS Study of the Hydrolysis of N-Azobenzyl Derivatives of Chitosan
New N-p-chloro-, N-p-bromo-, and N-p-nitrophenylazobenzylchitosan derivatives, as well as the corresponding azophenyl and azophenyl-p-sulfonic acids, were synthesized by coupling N-benzylvchitosan with aryl diazonium salts. The synthesized molecules were analyzed by UV-Vis, FT-IR, 1H-NMR and 15N-NMR spectroscopy. The capacity of copper chelation by these materials was studied by AAS. Chitosan a...


The Sustained Delivery of Resveratrol or a Defined Grape Powder Inhibits New Blood Vessel Formation in a Mouse Model of Choroidal Neovascularization
The objective of this study was to determine whether resveratrol or a defined, reconstituted grape powder can attenuate the formation of new blood vessels in a mouse model of choroidal neovascularization (CNV). To accomplish this objective, C57BL/6J mice were randomized into control or treatment groups which received either resveratrol or grape powder by daily oral gavage, resveratrol or grape ...
Β-Sitosterol Protects against Carbon Tetrachloride Hepatotoxicity but not Gentamicin Nephrotoxicity in Rats via the Induction of Mitochondrial Glutathione Redox Cycling
Previous findings have demonstrated that β-sitosterol (BSS), an active component of Cistanches Herba, protected against oxidant injury in H9c2 cardiomyocytes and in rat hearts by enhancing mitochondrial glutathione redox cycling, possibly through the intermediacy of mitochondrial reactive oxygen species production. We therefore hypothesized that BSS pretreatment can also confer tissue protecti...

Syntheses of Chiral Ferrocenophanes and Their Application to Asymmetric Catalysis
N-Substituted 2-aza-[3]-ferrocenophanes were easily synthesized from 1,1′-ferrocenedicarbaldehyde and aliphatic amines in high yields. One of the ferrocenophanes served as a ligand for the copper-catalyzed oxidative coupling of 2-naphthol derivatives to give the products in good yields with up to 92 % ee, and it also efficiently catalyzed the asymmetric Michael addition reaction as an organ...
Rhodium(III)-Catalyzed One-Pot Access to Isoquinolines and Heterocycle-Fused Pyridines in Aqueous Medium through C–H Cleavage
An efficient RhIII-catalyzed ortho-C–H bond activation for the synthesis of substituted isoquinolines and heterocycle-fused pyridines in aqueous medium has been developed. This method involves the in situ generation of ketimines from ketones and ammonium acetate and subsequent oxidative C–H bond activation/annulation of ketimines with alkynes to form the C–C/C–N bonds spontaneously. Var...

Construction and Multiple Exterior Surface Functionalization of Giant Molecular Cages
By a one-pot reaction strategy and a stepwise fragment-coupling approach, three types of giant cage molecules with a triangular prism shape and an approximate cavity volume of 930 Å3 were synthesized. Through efficient aromatic nucleophilic substitution reactions of chlorotriazine with functionalized amines or aliphatic substitution reactions of the linking imino moieties with allyl bromide, t...
Iron(III)-Catalyzed C–H Functionalization: ortho-Benzoyloxylation of N,N-Dialkylanilines and Its Application to 1,4-Benzoxazepines
A c–o bond-formation reaction that proceeds through C–H functionalization of N,N-dialkylanilines at the ortho-position is presented. The iron-catalyzed selective ortho-benzoyloxylation follows a polar Friedel–Crafts-like mechanism and is sensitive to the nucleophilicity of the anilines. The benzoyloxylation of a variety of N,N-disubstituted anilines and N-phenyl heterocycles is carried ou...

Specific dephosphorylation of janus kinase 2 by protein tyrosine phosphatases
Many protein kinases are activated through phosphorylation of an activation loop thereby turning on downstream signaling pathways. Activation of JAK2, a non-receptor tyrosine kinase with an important role in growth factor and cytokine signaling, requires phosphorylation of the 1007 and 1008 tyrosyl residues. Dephosphorylation of these two sites by phosphatases presumably inactivates the enzyme,...
High-throughput parallel proteogenomics: A bacterial case study
In recent years a new paradigm for genome annotation has emerged that leverages peptide mass spectrometry to annotate a genome, termed ‘proteogenomics’. This is achieved by mapping peptides to a 6-frame translation of a genome, including available splice databases, which may suggest refinements to gene models. Using this approach it is possible to refine gene regions such as exon boundaries...
Iodine-Mediated Thiolation of Substituted Naphthols/Naphthylamines and Arylsulfonyl Hydrazides via C(sp2)–H Bond Functionalization
A direct method has been developed for iodine-mediated thiolation of naphthols/naphthylamines and arylsulfonyl hydrazides through the formation of C–S bond and cleavage of S–N/S–O bonds. In this transformation, a range of valuable thioethers are easily achieved in moderate to good yields.
Copper-Mediated Direct Alkoxylation of Arenes Using an N,O-Bidentate Directing System
Highly effective CuCl-mediated C—H alkoxylation of arenes and heteroarenes has been developed by using a 2-aminopyridine 1-oxide moiety as an N,O-bidentate directing group. The reaction proceeds smoothly using a broad range of substrates to afford o-alkoxylated benzoic and heteroaromatic amide products. Moreover, the reaction system shows remarkable compatibility when hexafluoroisopropanol is...