Textile materials are one of the primary sources of microplastic pollution. The washing procedure is by far the most significant way that textile products release microplastic fibers (MPFs). Therefore, in this study, the effects of various textile raw materials (A acrylic, PA polyamide, PET polyester, RPET recycled polyester and PP polypropylene), fabric construction properties (woven, knitted), thickness and basis weight values on MPFs release at different washing stages (pre-washing, soaping/rinsing) were examined separately. To mimic the most popular home washing procedures, a 10-min pre-wash and a 35-min soaping/rinsing phase at 40 °C were selected for the washing procedure. Utilizing the Image J program on macroscopic images captured by a high-resolution SL. R camera, the microfibers collected by filtering the water have been visually counted. According to the results, knitted fabrics released fewer MPFs than woven fabrics, with the woven acrylic sample (A3-w) exhibiting the highest release (2405 MPFs). The number of MPFs increased along with the thickness and weight of the fabric. Recycled polyester was found to release more MPFs than virgin polyester under the same conditions (1193 MPFs vs. 908 MPFs). This study demonstrates how recycled polyester, although initially an environmentally beneficial solution, can eventually become detrimental to the environment. Furthermore, it is known that the pre-washing procedure-which is optional-releases a lot more MPFs than the soaping and rinsing procedures, and that stopping this procedure will drastically lower the amount of MPFs incorporated into the water.
1 December 2017 in Science of The Total Environment
In this study, the synthesis of novel 7-hydroxy-3-ethyl-6-hexyl-4-methylcoumarin (1), four respective phthalonitriles; 4-(7-oxy-3-ethyl-6-hexyl-4-methylcoumarin)phthalonitrile (2), 3-(7-oxy-3-ethyl-6-hexyl-4-methylcoumarin)phthalonitrile (3), 4-chloro-5-(7-oxy-3-ethyl-6-hexyl-4-methylcoumarin)phthalonitrile (4), and 4,5-bis(7-oxy-3-ethyl-6-hexyl-4-methylcoumarin)phthalonitrile (5) and their corresponding alpha tetra, beta tetra and beta octa 7-oxy-3-ethyl-6-hexyl-4-methylcoumarin and beta octa 4-chloro-5-(7-oxy-3-ethyl-6-hexyl-4-methylcoumarin) substituted Zn(II) (6a–9a) and In(III) Cl (6b–9b) phthalocyanines has been performed. The novel purified compounds were characterized by standard characterization techniques such as elemental analysis, thermal analysis, FT-IR, UV-vis, 1H-NMR and MALDI-TOF mass spectrometry. All of the obtained phthalocyanines showed lipophilic behaviour with excellent solubility in organic solvents such as acetone, dichloromethane, chloroform, pyridine and ethyl acetate. The fluorescence quenching behaviour was investigated using 1,4-benzoquinone and potassium iodide as quenchers. The photophysical (fluorescence quantum yields and lifetimes) and photochemical (singlet oxygen and photodegradation quantum yields) properties of these novel phthalocyanines (6a–9a and 6b–9b) were studied in DMF. They produced high singlet oxygen (for example ΦΔ = 0.99 for 7b) and showed appropriate photodegradation (in the order of 10−5) which is very important for photodynamic therapy (PDT), and thus these phthalocyanines can be used as Type II photosensitizers in PDT applications.
27 December 2020 in Journal of Biomolecular Structure and Dynamics
The novel coronavirus (SARS-CoV-2) causes severe acute respiratory syndrome and can be fatal. In particular, antiviral drugs that are currently available to treat infection in the respiratory tract have been experienced, but there is a need for new antiviral drugs that are targeted and inhibit coronavirus. The antiviral properties of organic compounds found in nature, especially coumarins, are known and widely studied. Coumarins, which are also metabolites in many medicinal drugs, should be investigated as inhibitors against coronavirus due to their pharmacophore properties (low toxicity and high pharmacokinetic properties). The easy addition of substituents to the chemical structures of coumarins makes these structures unique for the drug design. This study focuses on factors that increase the molecular binding and antiviral properties of coumarins. Molecular docking studies have been carried out to five different proteins (Spike S1-subunit, NSP5, NSP12, NSP15, and NSP16) of the SARS-CoV-2 and two proteins (ACE2 and VKORC1) of human. The best binding scores for 17 coumarins were determined for NSP12 (NonStructural Protein-12). The highest score (–10.01 kcal/mol) in the coumarin group is 2-morpholinoethan-1-amine substituted coumarin. Molecular mechanics Poisson-Boltzmann surface area (MM-PBSA) analyses of selected ligand-protein complexes were performed. The binding energies in each 5 ns were calculated and it was found that the interaction between ligand and target protein were stable. Communicated by Ramaswamy H. Sarma
1 December 2020 in Journal of Photochemistry and Photobiology A: Chemistry