Papers by Keyword: Coumarin

Abstract: Coumarin dye laser compounds are often used as components in coloring agents and sprays., as well as in the odorization of foods. Therefore, the important of these compounds in many felids leading to growth of several ways aiming to advance the control of pharmaceutical and superficial producing. Solvents play an important role in changing the character of coumarin. The investigated spectral properties, as well as the effect of changing the solvent on this property, have been published. results referred that the molar electronic transition energy increased with decreasing the maximum absorption wavelength, and the highest intensity of the absorption spectrum was in the case of acetone solvent. In addition, many bands appear in Raman shift attributed to the ''C=O'' band, ''O=C–O, C–C'', and ''C–O'' deformation. The characteristic vibrations involving the ''O-H'' group is the stretching and bending modes of the ''O-H'' and ''C-O'' parts.

Abstract: The effect of thermal treatment on optical constants of pure PMMA and with addition (15 and 35) ml of coumarin at different temperatures (100, 110 and 120) C⁰ for 1 hour were investigated. Cast method used to prepares films of pure PMMA and PMMA with (15 and 35) of coumarin. UV/VIS spectrometer technique used to measure the absorption spectra for these films. The optical constant (absorption spectra and absorption coefficient) don’t changes after applied temperatures in pure PMMA film but the optical constant (absorption spectra and absorption coefficient) in PMMA with (15 and 35) ml of coumarin increased with applied temperatures. The optical energy gap of pure PMMA and PMMA with (15 and 35) ml of coumarin slightly decreased after applied temperature up to 120⁰ C.

Abstract: Study on anti breast cancer activity of 3-substituted 4-anilino coumarin derivatives by using quantitative structure-activity relationship (QSAR) has been performed. The structures and the activity data were literatured from Guoshun et al. experiment. The molecular and electronic molecule properties were obtained from DFT/BPV86 6-31G method calculation after was through methods validation. The QSAR analysis were shown by Multi Linear Regression method (MLR). The best model of obtained for 3-substituted 4-anilino coumarin derivatives is: Log IC50 = 5.905 + (0.936 x qC1) + (-8.225 x qC8) + (-0.582 x qC13) + (11.273 x qC15) + (0.869 x ∆E) ; n = 26; r² = 0.704; Fcal/Ftab = 2.462; SEE = 0.184.

Abstract: In this work, we designed and synthesized two photoresponsive materials with 3-indoleacetic acid (IAA) plant hormone which can be monitored from the photoreposive properties of coumarin. The varied position of the long alkoxy side chain (-OC₁₆H₃₃) was purposely introduced to adhesive on the plant leaves. Two coumarin-caged nanomaterials showed average particle diameter about 400 nm and gave the maximum emission wavelength at 425 and 450 nm. The formulated nanoemulsion showed good wettability (θ=48^o) with Cassia fistula leave surface. Interestingly, CM2 gave the short photoresponse of photolysis within one day.

Abstract: A new coumarin-1,2,3-triazole diad was designed and synthesized by Pechmann-Duisberg reaction and click chemistry. The three-step synthetic route to the target compound afforded an overall yield of 56%. The structures of the synthesized compounds were characterized by ¹H NMR, ¹³C NMR, IR and mass spectrum. The click chemistry provided an ideal approach for synthesis under mild conditions of coumarin-1,2,3-triazole diads which may exhibit excellent biological activities such as antitubercular activity.

Abstract: A new coumarin derivative L was synthesized and characterized by ¹H NMR, ¹³C NMR, IR and mass spectrum. UV-Vis and fluorescence emission spectra of L without or with different anions (NO₂, F, Cl, HSO₃, HSO₄, AcO or NO₃) or metal ions were measured, which showed while addition of anions or metal ions Mg²⁺, Zn²⁺, Ca²⁺, Cu²⁺, Ni²⁺, Co²⁺, Fe³⁺ or Al³⁺ led to decrease in intensity of the maximum emission peak at about 480 nm, addition of Hg²⁺ ions caused increase in intensity of the maximum emission peak, suggesting that L may act as a fluorescent probe for detection of Hg²⁺ ions.

Abstract: Flow chemistry, as a rapidly emerging technology, is exploited to provide a safe and scalable route for the pharmaceutically interesting coumarin. Here, a continuous flow approach for the generation of coumarin is reported, which relies on the two connected coil reactors design. The synthesis of coumarin has been performed successfully in high conversion on small scale and can be scaled up substantially.

Abstract: Aflatoxin B₁ (AFB1), as a kind of mycotoxin produced by Aspergillus spp., is a highly toxic substance and widely distributed in food matrix. Cumarin was used first as the only carbon and energy source to screen the strains which were separated from different kinds of food. The strains selected were then added into nutrient agar and broth media to assess the ability to deplete AFB1. Results showed that a strain isolated from mustiness foodstuff was able to degrade AFB1 in nutrient broth, with a degradation rate of 26.3% after 48h fermentation. The microorganism was identified as a strain of Aspergillus niger, with analysis of phylogenetic tree based on 18S rDNA. This provides a potential solution for biological degradation of AFB1.

Abstract: A novel coumarin-based fluorescent sensor CFe1 containing imine and thiourea groups was designed and synthesized. It showed good sensitivity and selectivity for Fe3+ ion over other commonly coexistent metal ions with fluorescent enhancement and blue-shift.

Abstract: A new type of able liquid crystalline polymer with a coumarin-containing mesogenic side group that could be photo-crosslinked was synthesized in this paper. The structure of the intermediates, monomers and polymers were characterized with FTIR and ¹HNMR measurement. DSC, TG, and hot stage polarized optical microscopy were employed to study the phase transition temperature, mesophase texture, and thermal stability of the liquid crystalline polymers. The results indicated that both the monomer and polymer exhibited liquid-crystalline features over a wide temperature range.