An investigation of steric influence on the reactivity of Fe(O)(OH) tautomers in stereospecific C-H hydroxylation.

Two new tetradentate N4 ligands (LN4), LN4 = Me2,Me2PyzTACN (1-(2-(3,5-dimethyl-1-pyrazol-1-yl)ethyl)-4,7-dimethyl-1,4,7-triazacyclononane) and Me2,MeImTACN (1-((1-methyl-1-imidazol-1-yl)methyl)-4,7-dimethyl-1,4,7-triazacyclononane) have been synthesized and their corresponding Fe(II) complexes [Fe(Me2,Me2PyzTACN)(CFSO)], 1Pz, and [Fe(Me2,MeImTACN)(CFSO)], 1Im, have been prepared and characterized. Complexes 1Pz and 1Im catalyse the hydroxylation of C-H bonds of alkanes with excellent efficiencies, using hydrogen peroxide as oxidant. The high H/D kinetic isotope effect values for C-H hydroxylation, large normalized tertiary/secondary C-H (C3/C2) bond selectivities in adamantane oxidation, and high degrees of stereoretention in the oxidation of -1,2-dimethylcyclohexane are indicative of metal-based oxidation processes.

MUC4 and MMP7 in saliva and gingival crevicular fluid (GCF) in adolescents at West Bengal, India.

Mucin 4 (MUC4) and matrix metalloproteinase 7 (MMP7) have been reported to be associated with chronic periodontitis as seen in gingival tissue biopsies. Therefore, it is of interest to estimate the levels of MUC4 and MMP7 in saliva and gingival crevicular fluid (GCF) samples of periodontitis in adolescents patients at West Bengal, India. MUC4 levels were significantly lower in saliva and GCF from periodontitis patients compared to healthy controls.

Catechol oxidation promoted by bridging phenoxo moieties in a bis(μ-phenoxo)-bridged dicopper(ii) complex.

A dinuclear copper(ii) complex [Cu(papy)(CHOH)] has been synthesized by reaction of one equiv. of Cu(OAc)·2HO with one equiv. of the tetradentate tripodal ligand Hpapy [-(2-hydroxybenzyl)--(2-picolyl)glycine] and has been characterized by various spectroscopic techniques and its solid state structure has been confirmed by X-ray crystal structure analysis.

Highly enantioselective epoxidation of olefins by HO catalyzed by a non-heme Fe(ii) catalyst of a chiral tetradentate ligand.

The chiral tetradentate N4-donor ligand, 1-methyl-2-({(S)-2-[(S)-1-(1-methylbenzimidazol-2-yl methyl)pyrrolidin-2-yl]pyrrolidin-1-yl}methyl) benzimidazole (S,S-PDBzL), based on a chiral dipyrrolidine backbone, has been synthesized and its corresponding Fe(ii) complex has been prepared and characterized. The X-ray structure of the complex reveals that the Fe(ii) ion is in a distorted octahedral coordination environment with two cis-oriented coordination sites occupied by (labile) triflate anions. The ability of the iron complex to catalyze asymmetric epoxidation reactions of olefins with H2O2 was investigated, using 2-cyclohexen-1-one, 2-cyclopenten-1-one, cis-β-methylstyrene, isophorone, chalcones and tetralones as substrates.

Nonheme Fe(IV) Oxo Complexes of Two New Pentadentate Ligands and Their Hydrogen-Atom and Oxygen-Atom Transfer Reactions.

Two new pentadentate {N5} donor ligands based on the N4Py (N4Py = N,N-bis(2-pyridylmethyl)-N-bis(2-pyridyl)methylamine) framework have been synthesized, viz. [N-(1-methyl-2-benzimidazolyl)methyl-N-(2-pyridyl)methyl-N-(bis-2-pyridyl methyl)amine] (L(1)) and [N-bis(1-methyl-2-benzimidazolyl)methyl-N-(bis-2-pyridylmethyl)amine] (L(2)), where one or two pyridyl arms of N4Py have been replaced by corresponding (N-methyl)benzimidazolyl-containing arms. The complexes [Fe(II)(CH3CN)(L)](2+) (L = L(1) (1); L(2) (2)) were synthesized, and reaction of these ferrous complexes with iodosylbenzene led to the formation of the ferryl complexes [Fe(IV)(O)(L)](2+) (L = L(1) (3); L(2) (4)), which were characterized by UV-vis spectroscopy, high resolution mass spectrometry, and Mössbauer spectroscopy.

Evidence that steric factors modulate reactivity of tautomeric iron-oxo species in stereospecific alkane C-H hydroxylation.

A new iron complex mediates stereospecific hydroxylation of alkyl C-H bonds with hydrogen peroxide, exhibiting excellent efficiency. Isotope labelling studies provide evidence that the relative reactivity of tautomerically related oxo-iron species responsible for the C-H hydroxylation reaction is dominated by steric factors.

Development and validation of a pressure-type automated quantitative sensory testing system for point-of-care pain assessment.

Quantitative sensory testing (QST) can provide useful information about the underlying mechanisms involved in chronic pain. However, currently available devices typically employed suffer from operator-dependent effects, or are too cumbersome for routine clinical care. This paper presents the design and initial validation of a novel automated pressure-pain type QST platform, termed the multi-modal automated sensory testing (MAST) system.