Leichtlösliche, lichtechte Perylen-Fluoreszenzfarbstoffe

Die Synthese von Perylenfarbstoffen 2 mit terminalen Alkylgruppen wird beschrieben. Langkettige n-Alkylgruppen führen nicht zu einer Erhöhung der Löslichkeit, sondern zu einer Erniedrigung. Cycloalkyl-Reste bewirken ein Minimum an Löslichkeit im Bereich der mittleren Ringe und ein Maximum beim Cyclotetradecyl-Rest (2p). Starke Löslichkeitserhöhungen bewirken sekundäre Alkylreste mit zwei langen Ketten. Von diesen ist der Farbstoff 2v mit zwei 1-Hexylheptyl-Resten mit einer Löslichkeit von über 100 g/l in den meisten Lösungsmitteln, einer Fluoreszenzquantenausbeute von ca. 100% und einer ausgesprochen hohen Lichtechtheit auch für Spezialanwendungen geeignet

Expression of the chemokine decoy receptor D6 mediates dendritic cell function and promotes corneal allograft rejection

Purpose To identify the role of chemokine receptor 6 (D6) expression by dendritic cells (DCs) and its role in corneal transplant immunity. Methods: Flow cytometry analysis was used to assess the expression level of the D6 chemokine receptor in different leukocyte populations and DC maturation following lipopolysaccharides (LPS) stimulation of bone marrow–derived DCs isolated from wild-type (WT) or D6−/− mice (C57BL/6 background). Mixed-lymphocyte reactions and delayed-type hypersensitivity assays were performed with bone marrow–derived DCs from WT or D6−/− mice to evaluate T-cell alloreactivity. Adoptive transfer experiments with T cells from WT or D6−/− hosts with BALB/c corneal allografts were performed. Graft opacity was assessed over an 8-week period, and graft survival was plotted using Kaplan–Meier survival curves. Results: Expression of the D6 chemokine receptor was significantly higher in DCs compared to other leukocyte subpopulations, including neutrophils, lymphocytes, and monocytes/macrophages. LPS challenge of D6−/− bone marrow–derived DCs elicited significantly lower levels of major histocompatibility complex II and costimulatory molecules (CD40, CD80, and CD86) compared to WT bone marrow–derived DCs, indicating the role of the D6 chemokine receptor in DC maturation. Further, DCs isolated from D6−/− mice induced less T-cell proliferation (p≤0.001) and interferon-gamma production in T cells of draining lymph nodes compared to WT mice following corneal transplantation (p≤0.001). Moreover, adoptively transferred T cells from D6−/− corneal transplanted mice to WT mice led to impaired graft rejection, compared to the hosts that received T cells from the WT transplanted mice. Conclusions: We demonstrated D6 chemokine receptor expression by DCs and identified its critical function in multiple aspects of DC biology, including maturation and consequent elicitation of alloreactive T-cell responses that are responsible for corneal allograft rejection

The Relation between Packing Effects and Solid State Fluorescence of Dyes

The solid state fluorescence of diketopyrrolopyrrole dyes and perylene-3,4:9,10- tetracarboxylic bisimides with alkyl substituents are investigated and compared with noncovalent interactions. The latter are estimated by crystal structure analysis, heats and entropies of fusion and solubilities in organic solvents. Applications of the dyes are discussed

An exploration of triarylmethane leucohydroxides

To explore the possibilities of the potential use of photochromism of triarylmethane leucohydroxides and leucobisulfites , five leucohydroxides (see Table [5]) and five leucobisulfites were synthesized and two leucohydroxides and one leucobisulfite were investigated in a variety of solvents with different Brownstein Coefficients. Malachite green leucohydroxide and crystal violet leucohydroxide showed opposite behavior in the same basic solutions, while both of them were dramati cally affected by the change in solutions basicity. Photodegradation induced by repeated exposure (fatigue) manifested itself in the form of lower photo -induced optical density, with a constant halflife in malachite green leucohydroxide and in the form of longer halflife and constant optical density in crystal violet leucohydroxide. The three tested compounds were very sensitive to ambient oxygen and carbon dioxide

Photophysics, Molecular Reorientation in Solution and X-Ray Structure of a New Fluorescent Probe 1,7-Diazaperylene

A new fluorescent molecule 1,7-diazaperylene (DP) has been investigated by means of time-resolved and steady-state polarized fluorescence spectroscopy, as well as X-ray spectroscopy. Absorption and fluorescence spectra of DP in solution are similar to those of perylene. However, absorption and fluorescence spectra of 2,8-dimethoxy DP and 2,8-dipentyloxy DP in solution are red-shifted by ca. 55 nm relative to perylene. The fluorescence decay of DP is exponential with a lifetime of 5.1 ns in ethanol, 4.9 ns in glycerol and 4.3 ns in paraffin oil. The radiative lifetime in ethanol was calculated to be 6.3 ns for DP, 8.0 ns for 2,8-dimethoxy DP and 7.6 ns for 2,8-dipentyloxy DP. The calculated fluorescence quantum yields of 0.8 for DP and its alkoxy derivatives in ethanol, are in good agreement with those obtained from measurements. The calculated Förster radius is 37.2 ± 1 Å for DP and 41.9 ± 1 Å for its alkoxy derivatives in ethanol. Examining the S0 S1 transition, we obtain a limiting fluorescence anisotropy of r0 0.38 for DP and its alkoxy derivatives. The rotational rates of DP in paraffin oil and glycerol were compared to that of perylene. In paraffin oil both molecules show an almost identical biexponential decay of the fluorescence anisotropy, which is compatible with a rotational motion like an oblate ellipsoid. The fluorescence anisotropy is monoexponential for DP in glycerol, and DP appears to rotate like a spherical particle while perylene in glycerol appears to rotate like an oblate ellipsoid. Moreover, the rotational diffusion constant, corresponding to rotation about an axis in the aromatic plane (D), is the same for both DP and perylene in glycerol

Laser performance of perylenebis (dicarboximide) dyes with long secondary alkyl chains

The laser performance and related photophysical properties of two very soluble perylene dyes with long chain secondary alkyl groups were investigated in cyclohexane solution. With a dye laser as pump source a tuning range of 555–580 nm was obtained at an optimum concentration of 3×10–4 M. The quantum efficiencies (=0.29 and 0.21) were better than 1/2 that of rhodamine 6G. No photodegradation was observed over an excitation period of several hours

Investigating Different Types of Cinnamon in Iran with Attention to Its Toxicity and Contamination

Introduction: The present research is a resource-based retrospective study with reference to conducted studies and the results of the cinnamon study by referring to various foods and attaries (groceries) factories such as Golha, Bartar, Yekoyek, and Hati Kara companies in Iran has been answered to the questions related to probable toxicity of cinnamon. Methods and results: In this study, which is both a research and library study for this research topic, referring to sites, articles, journals, and various search engines including Science Direct and Google Scholar and SCOPUS, provide necessary information in regard to cinnamon types, cinnamon history, Cinnamon advantages and disadvantages, types of cinnamon ingredients, were found to be the cause of the toxicity of the probable types of cinnamon, and the results obtained that were related to the subject. According to the obtained data, it was found that cinnamomum zeylanicum bloom (Cinnamomum verum J. Presl) is less common (0-486 mg/kg) and (190 mg/kg)  also it is known as a good cinnamon for cinnamon cassia (Chinese) (Cinnamomum aromaticum Nees or Cinnamomum cassia (L) J. Presl) (coumarin is between 40 and 12180 mg / kg in the sample) and 700 mg/kg, and in Iran, abundance, import and use of cinnamon zeylanicum (Ceylon) is more than the other. Conclusions: According to obtain results, it was not proved camarin hepatic toxicity among the whole population and highest sensitivity was observed among people with previous hepatic disease, its daily use (permissible use on a daily basis is 1.5 mg/kg). With regard to this fact that in Iran, cinnamon as is used a flavoring of food and medicine, and the frequency of more Indian cinnamon (Ceylon , zeylanicum) than other cats in market due to higher quality. It can be concluded that with the max daily usage is (for a person body weight 60 kg) 1.5 mg of comarin per day, humans may be exposed to its complications, and that in Iran cinnamon species, which is most commonly used for cinnamomum zeylanicum cinnamon food, medicine (diabetes, etc.) and in various industries, and that it is not possible to enter this amount of comarin per day through the use of cinnamon to the body, it can be said that Iran is not exposed to the (probable) toxicside effects