RESUMEN
Biodiesel has several drawbacks, such as being prone to oxidation, having reduced stability, and having limited storage time. Antioxidants compatible with biodiesel are being used to address its drawbacks. Utilizing antioxidants effectively improves the quality of biodiesel. Enhancing the quality of biodiesel for use as a clean energy source benefits both the global economy and ecology. Therefore, we believe that our work will contribute to the advancement of the biodiesel industry worldwide. This study used blends consisting of 20% biodiesel and 80% diesel fuel. Isatin-thiosemicarbazones were tested as additives in blends at a concentration of 3000 parts per million (ppm) using an oxifast device and were compared with the chemical antioxidant Trolox. FT-IR, DSC, and TGA were used to characterize these samples. DSC measured sample crystallization temperatures (Tc). Samples with antioxidants showed decreased values compared to the non-antioxidant diesel sample D100. Several DSC tests were conducted to determine the antioxidant strengths of various samples. The results show that the FT-IR spectrum's antioxidant effect regions grow clearer with antioxidants. The extra antioxidant is effective. Biodiesel's oxidative stability improves with isatin-thiosemicarbazones at varying concentrations. The kinetics of thermal decomposition of isatin-thiosemicarbazones under non-isothermal conditions were determined using the Kissinger, Ozawa, and Boswell techniques. The activation energies of compounds 1 and 2 were calculated as 137-147 kJ mol-1 and 173-183 kJ mol-1, respectively.
RESUMEN
Parietin was isolated from Xanthoria parietina (L.) Th. Fr.' (methanol:chloroform) extract, using a silica column. 13 C NMR and 1H NMR were used to confirm the structure of the isolated parietin. For the first time, parietin was investigated for its antioxidant, antibacterial and DNA protective activities. Molecular docking was carried out to determine the binding affinity and interactions between the enzymes and our molecule. Inhibition and kinetic mechanism studies for the action of the enzymes were performed too. Parietin exhibited high metal chelating activity. The MIC values of parietin were sufficient to inhibit different bacterial strains; E. coli, P. aeruginosa, K. pneumoniae and S. aureus. Molecular docking applications exhibited that acetylcholinesterase (AChE), butyrylcholinesterase (BChE), lipase, and tyrosinase have high potential for binding with the parietin. Especially, the parietin's highest binding affinity was recorded with AChE and tyrosinase. These results were confirmed by the inhibition and kinetics results, where, parietin observed a potent inhibition with an IC50 values between 0.013-0.003 µM. Moreover, parietin acts' as a non-competitive inhibitor against AChE, BChE, and lipase, and as a competitive inhibitor against tyrosinase with a high rate of inhibition stability. The promising biological properties of parietin revealed its effectiveness in terms of suitability in the food and pharmaceutical industries.Communicated by Ramaswamy H. Sarma.
Asunto(s)
Antioxidantes , Ascomicetos , Butirilcolinesterasa , Emodina/análogos & derivados , Butirilcolinesterasa/metabolismo , Antioxidantes/química , Acetilcolinesterasa/química , Simulación del Acoplamiento Molecular , Cinética , Monofenol Monooxigenasa/metabolismo , Staphylococcus aureus , Escherichia coli/metabolismo , Antibacterianos/farmacología , Antibacterianos/química , Lipasa , Inhibidores de la Colinesterasa/farmacología , Inhibidores de la Colinesterasa/químicaRESUMEN
The acid catalyzed hydrolysis of the N-(p-substitutedphenyl) phthalimides in three different acids was investigated at 50.0±0.1°C. Two different antioxidant activity tests as DPPH⢠and ABTSâ¢+ scavenging activities, and three various enzyme inhibition activity tests as urease, acetylcholinesterase (AChE), and butyrylcholinesterase (BChE) inhibition activities, were applied. Compound 3c (2.03 µg/mL ) has higher antioxidant activity than other compounds and standards according to DPPH test. In AChE assay, compounds 3a and 3b (13.13 and 9.59 µg/mL) has higher enzyme inhibition activity than the standard Galantamine (14.37 µg/mL). In BChE and urease tests, all compounds (6.84-13.60 and 10.49-17.73 µg/mL) have higher enzyme inhibition activity than the standard Galantamine (49.40 µg/mL) and thiourea (26.19 µg/mL), respectively. The molecule interaction for each of the three compounds with the active sites of AChE, BChE, and urease enzymes was examined via molecular docking simulations.