Orthopalladated imidazolones and thiazolones: synthesis, photophysical properties and photochemical reactivity.

The reaction of Pd(OAc) with ()-5-arylidene-4-(4)-imidazolones (2a-e) and ()-4-arylidene-5(4)-thiazolones (3a-e) in trifluoroacetic acid results in the corresponding orthopalladated dinuclear complexes (4a-e, imidazolones; 11a-d, thiazolones) with trifluoroacetate bridges through regioselective C-H activation at the position of the 4-arylidene group. Compound 4e, which contains an imidazolone substituted at 2- and 4-positions of the arylidene ring with methoxide groups and exhibits strong push-pull charge transfer, is an excellent precursor for the synthesis of fluorescent complexes with green yellowish emission and remarkable quantum yields. Breaking the bridging system with pyridine yields the mononuclear complex 5e ( = 5%), while metathesis of trifluoroacetate ligands with chloride leads to the dinuclear complex 6e, also a precursor of fluorescent complexes by breaking the chloride bridging system with pyridine (7e, = 7%), or by substitution of chloride ligands with pyridine (8e, = 15%) or acetylacetonate (9e, = 2%).

Metal Complexes Containing Homoleptic Diorganoselenium(II) Ligands: Synthesis, Characterization and Investigation of Optical Properties.

[()-2'-{-CH-(4)-oxazol-5-one}CHCH]Se (, L) and [()-4'-{2-CH-(4)-oxazol-5-one}CHCH]Se (, L) were prepared, structurally characterized and used as ligands to obtain new metal complexes of types [MX(L)] [L: M = Ag, X = OTf (); M = Au, X = Cl (); L: M = Ag, X = OTf (); M = Au, X = Cl ()], [(MX)(L)] [M = Ag, X = OTf, L (); L ()], [ZnCl(L)] [L (); L ()] and [Ag(L)][PF] [L (); L ()]. The silver complexes and were ionic species (1:1 electrolytes) in a MeCN solution, while in the solid state, the triflate fragments were bonded to the silver cations. Similarly, the 2:1 complexes and were found to behave as 1:2 electrolytes in a MeCN solution, but single-crystal X-ray diffraction demonstrated that compound showed the formation of a dimer in the solid state: a tetranuclear [Ag(OTf)] built through bridging triflate ligands was coordinated by two bridging organoselenium ligands through the nitrogen from the oxazolone ring and the selenium atoms in a 1κN:2κSe fashion.

Planar Chiral -Terphenyl-Based Cyclophanes with Remarkable Enantiomer Stability: Synthesis, Theoretical Investigations, and Complexation Studies.

Design of conformationally stable compounds with planar chirality is a topic of great interest mainly because of their potential applications as enantioselective ligands or other functional materials. Herein, we present the design and synthesis of novel planar chiral cyclophanes, obtained by anchoring of the -terphenyl unit, with bridges of different lengths and rigidities, along with their nuclear magnetic resonance, mass spectrometry, and X-ray characterizations. We investigated the influence of the structural particularities of the bridges over the stability of the enantiomers, by means of nuclear magnetic resonance and chiral high-performance liquid chromatography as well as by density functional theory calculations.

BMP-induced non-canonical signaling is upregulated during autophagy-mediated regeneration in inflamed mesothelial cells.

Previously, we showed that after Freund's adjuvant-induced peritonitis, rat mesothelial cells regain their epithelial phenotype through mesenchymal-epithelial transition (MET) accompanied by autophagy. Since bone morphogenetic proteins (BMPs) are well-known MET-inducers, we were interested in the potential expression of BMPs and BMP-induced pathways. Although mesothelial cells expressed lower amounts of BMP7, its level in the peritoneal cavity and mesothelial synthesis of BMP4 were significantly increased during inflammation.

Synthesis of Bis(amino acids) Containing the Styryl-cyclobutane Core by Photosensitized [2+2]-Cross-cycloaddition of Allylidene-5(4)-oxazolones.

The irradiation of 2-aryl-4-(-3'-aryl-allylidene)-5(4)-oxazolones with blue light (456 nm) in the presence of [Ru(bpy)](BF) (bpy = 2,2'-bipyridine, 5% mol) gives the unstable cyclobutane-bis(oxazolones) by [2+2]-photocycloaddition of two oxazolones . Each oxazolone contributes to the formation of with a different C=C bond, one of them reacting through the exocyclic C=C bond, while the other does so through the styryl group. Treatment of unstable cyclobutanes with NaOMe/MeOH produces the oxazolone ring opening reaction, affording stable styryl-cyclobutane bis(amino acids) .

An attempt to synthesize a terthienyl-based analog of indacenedithiophene (IDT): unexpected synthesis of a naphtho[2,3-]thiophene derivative.

We report herein our attempt to synthesize an analog of indacenedithiophene (IDT) based on a tetraphenylhexyl substituted, covalently bridged -terthienyl unit. Instead of the expected compound the adopted synthetic route led to the formation of an unexpected, new naphtho[2,3-]thiophene derivative. The structure of this compound was fully characterized by NMR and HRMS as well as single crystal X-ray diffraction and its electronic properties have been analyzed by UV-vis absorption spectroscopy and cyclic voltammetry.

Stereoselective, Ruthenium-Photocatalyzed Synthesis of 1,2-Diaminotruxinic Bis-amino Acids from 4-Arylidene-5(4)-oxazolones.

The irradiation of ()-2-phenyl-4-aryliden-5(4)-oxazolones in deoxygenated CHCl at 25 °C with blue light (465 nm) in the presence of [Ru(bpy)](BF) (5% mole ratio) as a triplet photocatalyst promotes the [2+2] photocycloaddition of the C═C bonds of the 4-arylidene moiety, thus allowing the completely regio- and stereoselective formation of cyclobutane-bis(oxazolone)s as single stereoisomers. Cyclobutanes have been unambiguously characterized as the μ-isomers and contain two -oxazolones coupled in an -head-to-head form. The use of continuous-flow techniques in microreactors allows the synthesis of cyclobutanes in only 60 min, compared with the 24-48 h required in batch mode.

Reactivity of ()-4-Aryliden-5(4)-thiazolones: [2 + 2]-Photocycloaddition, Ring-Opening Reactions, and Influence of the Lewis Acid BF.

The irradiation of ()-2-phenyl-4-aryliden-5(4)-thiazolones with blue light (465 nm) in CHCl solution promotes [2 + 2]-photocycloaddition of the exocyclic C═C bonds and the formation of the dispirocyclobutanes . This reaction takes place with high stereoselectivity, given that the ε-isomer (1,3 head-to-tail syn coupling) is formed in more than 90% yield in most of the cases. However, irradiation of 5(4)-thiazolones with blue light (456 nm) in dry MeOH in the presence of BF·OEt leads to the monospirocyclobutanes with full stereoselectivity, also affording the ε-isomer.

Pd-Oxazolone complexes conjugated to an engineered enzyme: improving fluorescence and catalytic properties.

Different Pd-complexes containing orthometallated push-pull oxazolones were inserted by supramolecular Pd-amino acid coordination on two genetically engineered modified variants of the thermoalkalophilic Geobacillus thermocatenolatus lipase (GTL). Pd-lipase conjugation was performed on the solid phase in the previously immobilized form of GTL under mild conditions, and soluble conjugated Pd-GTL complexes were obtained by simply desorbing by washing with an acetonitrile aqueous solution. Three different Pd complexes were incorporated into two different genetically modified enzyme variants, one containing all the natural cysteine residues changed to serine residues, and another variant including an additional Cys mutation directly in the catalytic serine (Ser114Cys).

Fluorescent Orthopalladated Complexes of 4-Aryliden-5(4)-oxazolones from the Kaede Protein: Synthesis and Characterization.

The goal of the work reported here was to amplify the fluorescent properties of 4-aryliden-5(4)-oxazolones by suppression of the hula-twist non-radiative deactivation pathway. This aim was achieved by simultaneous bonding of a Pd center to the N atom of the heterocycle and the carbon of the arylidene ring. Two different 4-(()-arylidene)-2-(()-styryl)-5(4)-oxazolones, the structures of which are closely related to the chromophore of the Kaede protein and substituted at the 2- and 4-positions of the arylidene ring ( OMe; F), were used as starting materials.

Ultrasound-assisted Strecker synthesis of novel 2-(hetero)aryl-2-(arylamino)acetonitrile derivatives.

This work describes an efficient, simple, and ecofriendly sonochemical procedure for the preparation of new α-(arylamino)acetonitrile derivatives C-substituted with phenothiazine or ferrocene units. The synthetic protocol is based on the Strecker reaction of a (hetero)aryl aldimine substrate with trimethylsilyl cyanide (TMSCN) in poly(ethylene glycol) (PEG) solution. The advantages of the sonochemical versus the conventional α-(arylamino)acetonitrile synthesis are the significantly shorter reaction time (30 min instead of 72 hours), the higher purity and the easier separation of the product that precipitated from the reaction mixture in crystalline form as depicted by scanning electron microscopy (SEM) analysis.

The Rigid Tube as an Alternative in Controlling the Problematic Airway.

The unexpected problematic airway represents a large proportion of anesthesia-related morbidity and mortality. The retromolar or paraglossal approach is an alternative to the majority of the rigid instruments used for tracheal intubation, which follow the midline to access the glottis. This single-center, prospective case-series study offers an option to conventional laryngoscopy in case of a poor glottic view, introducing an instrument (the rigid tube for laryngoscopy) that uses the retromolar approach to accomplish tracheal intubation.

Synthesis of esters of diaminotruxillic bis-amino acids by Pd-mediated photocycloaddition of analogs of the Kaede protein chromophore.

The stereoselective synthesis of truxillic bis-amino esters from polyfunctional oxazolones is reported. The reaction of 4-(()-arylidene)-2-()-styryl-5(4)-oxazolones with Pd(OAc) resulted in -palladation and the formation of a dinuclear open-book complexes with carboxylate bridges, where the Pd atom is C^N bonded to the oxazolone. In the two exocyclic C=C bonds of the oxazolone are in a face-to-face arrangement, which is optimal for their [2 + 2] photocycloaddition.

High-frequency ultrasonography of psoriatic skin: A non-invasive technique in the evaluation of the entire skin of patients with psoriasis: A pilot study.

Psoriasis is a chronic, systemic, inflammatory disorder which accelerates the life process of skin cells, based on a genetically induced deviant immune response. High-frequency ultrasonography (HF-USG) is a painless, non-invasive imaging technique that can be performed and repeated whenever the need arises. We evaluated lesional and non-lesional skin of psoriatic patients with the use of HF-USG, focusing on the immune-induced inflammation and skin thickness.

Pemphigoid nodularis - rare presentation of bullous pemphigoid: A case report and literature review.

Pemphigoid nodularis (PN) is a rare clinical variant of bullous pemphigoid characterized by the presence of nodular prurigo-like lesions and pemphigoid blisters. The diagnosis is confirmed by direct immunofluorescence (DIF)/ indirect immunofluorescence (IIF) and immunoserology tests. For some patients, with long mean duration of symptoms, the correct diagnosis of PN is delayed because the disease is not recognized.

Bismuthπ arene versus bismuthhalide coordination in heterocyclic diorganobismuth(iii) compounds with transannular N→Bi interaction.

New diorganobismuth(iii) bromides of type [RN(CHCH)]BiBr [R = CHCH (1), CHCHCH (2), and CHOCHCH (3)], based on the heterocyclic butterfly-like tetrahydro-dibenzo[c,f][1,5]azabismocine framework, were prepared starting from the corresponding RN(CHCHBr-2) in a succession of reactions including ortho-lithiation and treatment of the dilithio derivative with BiBr in a 1 : 1 molar ratio. Further exchange reactions between bromides and appropriate metal halides or ammonium fluoride resulted in the formation of [RN(CHCH)]BiX [X = Cl and I for R = CHCH (4 and 5) and CHCHCH (6 and 7) and X = F (8), Cl (9), and I (10) for R = CHOCHCH]. All ten compounds were structurally characterized in solution by NMR and in the solid state by single-crystal X-ray diffraction.

Cadmium complexes bearing N^E^O (E = S, Se) organochalcogenoalkoxides and their zinc and mercury analogues.

Heteroleptic zinc and cadmium complexes of the type [{N^E^O}M-Nu] (M = Zn, Cd; E = S, Se; R = CH, CF; Nu = N(SiMe), I, Cl; n = 1-2) were prepared by reacting the alcohol proteo-ligands {N^E^O}H with [M(N(SiMe))] (M = Zn, Cd) or [XMN(SiMe)] (M = Zn, X = Cl; M = Cd, X = I) in an equimolar ratio. These group 12 metal complexes were characterised in solution by multinuclear NMR spectroscopy and their solid-state structures were determined by X-ray diffractometry. The ligands {N^E^O} bearing CH groups in α position to the alkoxide behave as κ-O,E-bidentate moieties (E = S, Se) and form centro-symmetric dinuclear O-bridged heteroleptic alkoxo-amido complexes both with zinc and cadmium, with four-coordinate metal centres resting in tetrahedral environments.

On the coordination chemistry of organochalcogenolates R(NMe2)^E(-) and R(NMe2)^E^O(-) (E = S, Se) onto lead(II) and lighter divalent tetrel elements.

Several families of heteroleptic tetrelenes of general formulae M(E^R(NMe2))[N(SiMe3)2] and M(O^E^R(NMe2))[N(SiMe3)2] (where E = S, Se; M = Ge, Sn, Pb; R(NMe2) = 2-(Me2NCH2)C6H4] supported by organochalcogenolato ligands have been prepared and fully characterised. The coordination chemistry of these ligands containing both hard (N, O) and soft (S, Se) atoms onto metals of varying size, polarisability, electropositivity and electrostatic surface potential has been explored. In the molecular solid-state, the complexes M(E^R(NMe2))[N(SiMe3)2] are monomeric, although an occurrence of weak PbSe intermolecular interactions yielding a bimolecular species has been identified in the case of the plumbylene Pb[SeC6H4(CH2NMe2)-2][N(SiMe3)2].

Organoselenium(II) halides containing the pincer 2,6-(Me2NCH2)2C6H3 ligand--an experimental and theoretical investigation.

New organoselenium(II) halides of the type [RSe](+)X(-) [R = 2,6-(Me2NCH2)2C6H3; X = Cl (2), Br (3), I (4)] were prepared by cleavage of the Se-Se bond in R2Se2 (1) with SO2Cl2 followed by halogen exchange when organoselenium chloride was treated with NaBr or KI. The reaction between 2 and R'2MCln resulted in new ionic [RSe](+)[R'2MCl(n+1)](-) [R' = 2-(Me2NCH2)C6H4, n = 1, M = Sb (5), Bi (6); R' = Ph, M = Sb, n = 1 (7) or n = 3 (8)] species. All new compounds were investigated in solution by multinuclear NMR spectroscopy ((1)H, (13)C, (77)Se, 2D experiments) and mass spectrometry.

Variability of skin autofluorescence measurement over 6 and 12 weeks and the influence of benfotiamine treatment.

Background: Measurements of skin autofluorescence (SAF) allow for a simple and noninvasive quantification of tissue advanced glycation end-products (AGEs), a marker linked to the risk of diabetes complications. The aim of this study was to test the repeatability of SAF over 6 and 12 weeks and to test whether benfotiamine, a thiamine prodrug suggested to reduce AGEs formation under hyperglycemic conditions, is able to attenuate SAF when administered over 6 weeks.

Patients And Methods: In a double-blind, placebo-controlled, randomized, crossover study, 22 patients with type 2 diabetes mellitus (T2DM) received 900 mg/day benfotiamine or placebo for 6 weeks (washout period of 6 weeks between).

New group 11 complexes with metal-selenium bonds of methyldiphenylphosphane selenide: a solid state, solution and theoretical investigation.

Reactions between methyldiphenylphosphane selenide, SePPh(2)Me, and different group 11 metal starting materials {CuCl, [CuNO(3)(PPh(3))(2)], AgOTf, [AgOTf(PPh(3))] (OTf = OSO(2)CF(3)), [AuCl(tht)], [Au(C(6)F(5))(tht)] and [Au(C(6)F(5))(3)(tht)] (tht = tetrahydrothiophene)} were performed in order to obtain several new species with metal-selenium bonds. The new complexes [CuCl(SePPh(2)Me)] (1), [AgOTf(SePPh(2)Me)] (2), [AuCl(SePPh(2)Me)] (5), [Au(C(6)F(5))(SePPh(2)Me)] (6) and [Au(C(6)F(5))(3)(SePPh(2)Me)] (7) were isolated and structurally characterized in solution by multinuclear NMR spectroscopy ((1)H, (31)P, (77)Se and (19)F where appropriate). Solid products were isolated also from the reactions between SePPh(2)Me and [CuNO(3)(PPh(3))(2)] or [AgOTf(PPh(3))], respectively.

Functional changes in microcirculation during hyperbaric and normobaric oxygen therapy.

Objectives: Treatment of cutaneous wounds is one of the many applications of hyperbaric oxygen therapy (HBO). However, the complex regulation of skin microcirculation during different phases of HBO is not completely understood. We therefore investigated skin microcirculation and oxygenation during HBO and normobaric oxygen (NBO) exposure.

Effects of n-3 fatty acids on macro- and microvascular function in subjects with type 2 diabetes mellitus.

Background: Recent evidence supports the protective effects of n-3 (omega-3) fatty acids (n-3 FAs), such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), on vascular function.

Objective: We investigated the effects of EPA and DHA on postprandial vascular function in subjects with type 2 diabetes mellitus.

Design: In a double-blind, placebo-controlled, randomized, crossover manner, 34 subjects with type 2 diabetes mellitus received daily either 2 g purified EPA/DHA (termed n-3 FAs) or olive oil (placebo) for 6 wk.