Influence Of Coumarin Research Articles

Electrospun Janus film: Innovative design of “macro + micro” to achieve thermochromic-anisotropic conductive-fluorescent tri-functionality

Multi-functionalized thermochromic materials will greatly expand their application scopes. In this work, two functions of electrical conductivity and fluorescence are innovatively integrated into a thermochromic material by designing specific “macro + micro” Janus structures. Tri-functional thermochromic-anisotropic conductive-fluorescent thermochromic microcapsules-45 °C (TCM-45)/polymethyl methacrylate (PMMA) microfibers non-array&{[polypyrrole (PPy)/PMMA]//[Coumarin/PMMA] Janus microfibers array} up-down Janus film (named as TCFJAJF) is constructed by two-step electrospinning techniques of “single axis + parallel axis”. The up layer of TCFJAJF is TCM-45/PMMA microfibers non-array film (defined as U-TCFJAJF, viz. thermochromic layer) and the down layer of TCFJAJF is [PPy/PMMA]//[Coumarin/PMMA] Janus microfibers array film (denoted as D-TCFJAJF, viz. anisotropic conductive-fluorescent layer). The macroscopic up-down Janus structure eliminates the mutual influences between D-TCFJAJF and U-TCFJAJF. U-TCFJAJF has excellent color conversion and fading/coloring performances, achieving a reversible and multiple colors conversion from blue to white upon heating from 25 to 45 °C. A new concept of “transient thermal printing” is proposed based on fast thermal coloring/fading conversion of thermally printed patterns on film. Meanwhile, the microscopic Janus microfiber structure of D-TCFJAJF largely alleviates absorption to the excitation light and emission light of Coumarin by PPy and influence of Coumarin on conduction of PPy, ensuring the intense fluorescence and high conductivity. Due to the ordered arrangement of Janus microfibers, D-TCFJAJF has excellent anisotropic conductivity. As a demo application, TCFJAJF as a conductor can light up LED bulbs in a microcircuit and emit bright blue fluorescence under UV light excitation, achieving the working state visualization of the conductive microcircuit in dark surroundings. The multi-functionalized thermochromic film will have huge application prospects in fields of temperature monitoring, transient information reading and displaying, flexible electronics, fluorescent labeling and thermal-fluorescent dual encryption anti-counterfeiting, etc.

A Biophysical Research on the Determination of Morphological and Structural Properties of Coumarin-Loaded Liposomes

The major goal of this research was to examine how coumarin affects lipid model membranes. For this reason, liposome membranes were formed using dimyristoyl phosphatidylcholine (DMPC) as zwitterionic lipid. The influence of coumarin on the morphology, packing order, fluidity, and hydration state of lipid membranes was specifically investigated by means of microscopic (field emission scanning electron microscopy (FE-SEM)) and spectroscopic (attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy) techniques. Taken into account the results obtained with FE-SEM images and analysis, liposomes without and with coumarin have uniform structures and spherical shapes in appearance. However, coumarin-loaded liposomes are observed with an increase in size when compared to a mean diameter of unloaded-liposomes. Considering ATR-FTIR analysis, the investigation of the vibrational bands which belong to the hydrophobic and hydrophilic parts of DMPC lipid reveals that coumarin alters the physical features of the DMPC liposomes by decreasing the order and increasing the fluidity of the system and making hydrogen bonding with the interfacial and headgroup regions of zwitterionic lipid DMPC. Finally, performing more biophysical studies on the interactions of biologically active compounds with model membranes plays an important role in determining the molecular action mechanisms of these compounds in drug discovery and formulations.

Novel Homo-and Co-polymers Based on 7-Methacryloyloxy-4-methylcoumarin: Synthesis, Antimicrobial Activity, Pour-Point Depressants and Their Effects on the Rheology of the Waxy Crude Oil

This study aimed to synthesize new polymeric additives including homo- and co-polymers based on 4-methyl-2-oxo-2H-chromen-7-yl methacrylate monomer and evaluating their activity as potential antimicrobials and as pour-point depressants for modification of waxy crude oil rheology. The resultant compounds were characterized by their IR, 1H NMR and 13C NMR spectral data. The formation of the new polymers, namely, poly(7-methacryloyloxy-4-methylcoumarin) [poly(MAOMC)] homo-polymer, poly(7-methacryloyloxy-4-methylcoumarin-co-vinylacetate) [poly(MAOMC)-co-(VA)] and poly(7-methacryloyloxy-4-methylcoumarin-co- octadecyl 4-(methacryloyloxy)benzoate) [poly(MAOMC)-co-(OMAOB)] co-polymers was based on free radical polymerization. The polymerization reaction was carried at 70±2°C using 2,2’-azobisisobutyronitrile (AIBN) as an initiator and dimethylformamide (DMF)/toluene as a solvent in the case of homo-polymer [poly(MAOMC)] and co-polymer [poly(MAOMC)-co-(VA)], while polymerization proceeds at the same temperature by using benzoyl peroxide as an initiator and toluene as a solvent in the case of co-polymer [poly(MAOMC)-co-(OMAOB)] The activities of the resultant compounds as potential antibacterial agents were evaluated against the two Gram-positive (Bacillus cereus and Staphylococcus aureus), the four Gram-negative (Escherichia coli, Neisseria gonorrhoeae, Pseudomonas aeruginosa, and Salmonella typhimrium) bacterial strains, and as antifungal agents against two fungal species (Aspergillus flavus and Candids albicans). The results showed that MAOMC monomer and poly(MAOMC)-co-(OMAOB) copolymer indicated moderate potent activity towards the bacterial and fungal strains used. At the other extreme, the influence of coumarin and octadecyl benzoate based compounds on the pour-point depression and on the rheological properties of crude oil with low asphaltene content was studied. The results indicated that all three polymers exhibited very good efficiency as additives to improve the flow-ability of the tested crude oil. Moreover, the poly(MAOMC)-co-(OMAOB) co-polymer was found to exhibit the highest performance to reduce and depress the pour-point of the tested crude oil and decrease the viscosity to a large extent due to the presence of two aromatic units with the long aliphatic carbon chain in its structure.

Influence of coumarin and some coumarin derivatives on serum lipid profiles in carbontetrachloride-exposed rats.

In the present study, coumarin and some coumarin derivatives (esculetin, scoparone, and 4-methylumbelliferone) were investigated for their lipid-lowering effect in rats. Male Sprague-Dawley rats (150-200 g) were divided into six groups and each group comprised of five rats. Hepatic injury-dependent hyperlipidemia was induced by carbon tetrachloride (CCl4, 1.25 ml/kg). Coumarin and coumarin derivatives esculetin (35 mg/kg), scoparone (35 mg/kg), 4-methylumbelliferone (35 mg/kg), or coumarin (30 mg/kg) were administered to experimental groups at 12-h intervals. Animals received the derivatives esculetin, scoparone or 4-methylumbelliferone prior to the administration of a single toxic dose of CCl4. Serum total cholesterol (TC), triglyceride (TG), very low-density lipoprotein cholesterol (VLDL-C), and low-density lipoprotein cholesterol (LDL-C) levels significantly increased in CCl4-treated group ( p < 0.05, p < 0.01, p < 0.01, and p < 0.05, respectively), while levels of serum high-density lipoprotein cholesterol (HDL-C) decreased ( p < 0.01). 4-Methylumbelliferone had no recovery effects on serum TC levels, however, significantly prevented CCl4-induced hyperlipidemia by reducing TG and VLDL-C levels ( p < 0.05 and p < 0.05, respectively). In addition, coumarin had no recovery effect on any of the serum lipid parameters against CCl4-induced hyperlipidemia. Among the coumarin derivatives only esculetin and scoparone significantly prevented serum HDL-C in CCl4-induced dyslipidemia. The results from this study indicate that the chemical structure of coumarins plays an important role on the regulation of serum lipid profiles.

Influence of coumarin as an additive on CuO nanostructures prepared by successive ionic layer adsorption and reaction (SILAR) method

The effect of coumarin doping during the growth of CuO nanostructures by SILAR method has been studied. It was found that coumarin considerably influences the growth process, manipulates the bandgap and modifies the crystallite size of the films. XRD experiments evidenced that with higher coumarin concentrations in the growth solution, the microstrain and dislocation density increased, while the crystallite size of the films decreased. SEM images revealed that the thicknesses of the plate-like nanostructures decreased with increasing coumarin concentration. By UV/vis spectrophotometer analysis it is found that the coumarin concentration affects both the optical band gap and the transmission rate: both the band gap and spectral transmittance values of the films decreased for higher coumarin content.

Electrodeposition and characterization of zinc–cobalt alloy from chloride bath; influence of coumarin as additive

Zinc–cobalt alloys were electrodeposited from chloride bath under continuous current and in the presence and absence of coumarin. The deposit morphology was analyzed using Scanning Electron Microscopy (SEM) and X-ray diffraction (XRD) was used to determine the preferred crystallographic orientations of the deposits. Zinc–cobalt alloys was without texture in the absence of coumarin whereas, the preferred crystallographic orientations was (103) at 65% in the presence of coumarin. The presence of coumarin yields deposits with a finer grain size. The alloy composition was examined using the Energy Dispersive X-ray Fluorescence Spectroscopy (EDXRF). The percentage of cobalt in the alloy decreases from 1.04 wt.% to 0.69 wt.% in the presence of coumarin. Voltammetric studies show that coumarin affects the reduction of zinc but it was without effect on cobalt reduction. That explains the decrease of cobalt percentage in the alloy in the presence of coumarin.

Influence of coumarin on the net nitrate uptake in durum wheat

Summary The effects are reported here of coumarin, an allelopathic compound, on root anatomy and growth, nitrate uptake and translocation to the shoot, as well as respiration in Triticum durum (cv. Simeto) seedlings. Wheat seedlings were grown in nitrogen‐free hydroponic culture; after 6 d, coumarin (at concentrations of 0, 25 µM, 0.1, 1, 2.5 and 5 mM) and/or nitrate (50 µM) were added to the nutrient solution. Coumarin, in the range 25 µM–1 mM, decreased the relative growth rate of roots and increased the area of the root vessels. Within this concentration range, coumarin alone did not significantly affect net nitrate uptake. In seedlings exposed simultaneously to 100 µM coumarin and to 50 µM nitrate, the net nitrate uptake was significantly stimulated. In the presence of nitrate, even the lowest coumarin concentration tested significantly stimulated nitrate translocation from the root to the shoot. The effects of low coumarin concentrations on root vessel size could explain this observation, though specific interactions between coumarin and systems regulating nitrate uptake and transport within the root cell cannot be excluded.

DNA topoisomerases from Streptomyces noursei: Influence of coumarins and quinolones on the enzymatic activity

DNA topoisomerases have been purified from Streptomyces noursei. DNA gyrase and topoisomerase I show a differential sensitivity against quinolones and coumarins compared to the E. coli enzymes. Streptomyces gyrase is resistant to much higher levels of various drugs than is the E. coli enzyme. The observed differences between the gyrases from streptomycetes and E. coli are discussed in the light of present literature data.

Influence of coumarins on the biosynthesis of melanin by the fungusVerticillium dahliae

Influence of coumarins on the biosynthesis of melanin by the fungusVerticillium dahliae

Trials of Commercial Reagents in Anion-exchange Coagulation Procedures: Ortho Diagnostics

The suitability of Ortho Diagnostics one-stage prothrombin time (PT) reagent (Ortho Brain Thromboplastin) and activated partial thromboplastin (aPTT) reagent (Activated Thrombofax) has been evaluated for use in conjunction with the anion-exchange heparin removal maneuver. The PT/HR and aPTT/HR are tests used to follow the anticoagulant influence of coumarins when heparin also is being administered. After establishing a coumarin therapeutic range for Activated Thrombofax, a parallel trial was conducted with Ortho Brain Thromboplastin on coumarin-treated patient plasmas. Determinations also were made after heparin (0.2 mu/mL) was added and then removed by ECTEOLA microchromatography columns. Ortho Brain Thromboplastin was found to induce a shortening bias associated with a spurious improvement in the precision of tests run on anion-exchange treated plasmas that potentially could result in coumarin overdosage. The systematic error did not appear to result either from protracted incubation or the activation of prekallikrein, high molecular weight kininogen, Factor XI or XII. This reagent was found to perform appropriately with plasma not exposed to ECTEOLA. Activated Thrombofax gave reliable and reproducible results before and after heparin removal. This aPTT reagent could be used in the aPTT/HR anticoagulant surveillance scheme.

The influence of coumarin on blood levels of radio labelled protein and radio labelled poly-vinyl-pyrrolidone in thermally injured rats.

The evidence presented in this paper suggests that coumarin is a RES stimulator. An enhanced removal of both RPP and radio RPVP was observed beginning at or before 30 minutes and lasting up to 6 hours. Over this time, RPP removal was enhanced by an average of 40%, while RPVP removal was enhanced by 60%. Since RPVP is non-metbabolizable, its levels may be a more accurate estimate of the stimulatory effect of coumarin. This evidence fits in well previous results which have suggested that coumarin may increase the number of phagocytic cells. Other results have shown enhancement of protein lysis by 74% over similar periods, while enhanced protease activity levels of 50% have been observed to accompany this.

Electron microscopy of the effects of histamine and thermal injury on the blood and lymphatic endothelium, and the mesothelium of the mouse's diaphragm, together with the influence of coumarin and rutin.

Hitze und Histamin vermogen eine Kontraktion der Endothelzellen feiner Venen zu erzeugen. Hitze und Histaminschadigung des Mausezwerchfells (Endothelfensterung) fuhrt zu Kontraktionen von Endothelzellen und Mesothelialzellen. Venalot, ein Produkt aus Cumarin und Trihydroxyethyl-Rutin, vermag das Oedem zu beseitigen.

The influence of coumarin on the incorporation of32P into the leaf-discs of datura stramonium L.

The influence of coumarin on the incorporation of32P into the leaf-discs of datura stramonium L.