Novel (E)-1-(pyrrole-2-yl)-3-(aryl)-2-(propen-1-one) derivatives as efficient singlet oxygen quenchers: kinetics and quantum chemical calculations

Abstract

†Electronic Supplementary InformaƟon (ESI) available: Cartesian coordinates (and geometries) of the ground and first triplet states computed by quantum chemical calculations as well as the IR and NMR experimental spectra are presented. See Chalcones constitute an important group of natural and synthetic products that have been screened due to their wide range of pharmacological applications. Herein, we studied the antioxidant activity of five newly synthetized (E)-1-(pyrrole-2-yl)-3-(aryl)-2-(propen-1-one) (PAPs) derivatives against singlet oxygen ( 1 O2). The differences among the compounds are related to the aryl substitution in the p-position where: 3a = C6H5, 3b = 4-H3COC6H4, 3c = 4-FC6H4, 3d = 4-ClC6H4, 3e = 4-BrC6H4. The PAPs were synthesized by Claisen-Schmidt condensation reaction between 2-acetylpyrrole and aromatic aldehydes under ultrasonic irradiation (yields between 79-86%) and were characterized by IR, mass spectrometry, NMR and quantum chemical calculations. The total singlet oxygen quenching rate constants (kQ) by the PAPs were measured spectrophotometrically in ethanol at 25 °C and determined by using the Stern-Volmer model. As the character of the EWGs is increased from 3a to 3e, the kQ diminishes smoothly. The best quencher is found to be the 3a compound (where the aryl group is unsubstituted) with a kQ = 5.71 (±0.21) x10 7 M -1 s -1 , which is similar to those for other antioxidants e.g. flavonoids. These results suggest these compounds as efficient quenchers of singlet oxygen and their potential aplicability in biological systems.

An Efficient K2CO3-Promoted Synthesis of 1-Bromo-2-aryloxyethane Derivatives and Evaluation of Larval Mortality against Aedes aegypti

“…In this context, the synthesis of organic compounds including aromatic rings in their structure has been widely reported in the literature. The compounds with aromatic substructure have been reported to show a broad spectrum of pharmaceutical, agricultural, and chemical engineering applications and are scaffolding reagents for synthetic organic chemistry [1][2][3][4][5][6]. They are also ubiquitous structural units in biologically important molecules such as cyclooxygenase and -galactosidase inhibitors and anticancer porphyrins [7].…”

Preliminary Insight of Pyrrolylated-Chalcones as New Anti-Methicillin-Resistant Staphylococcus aureus (Anti-MRSA) Agents

“…It is important to highlight that though many analogues of pyrrolylated-chalcones have been previously synthesized for various bioactivities [ 9 , 11 , 12 , 13 , 14 ], we would like to explore further the therapeutic uses of the synthesized chalcones particularly as anti-MRSA agents in this present study. Little has been reported on the in-depth anti-MRSA potential of pyrrolylated-chalcones thus far.…”

“…All the synthesized compounds were purified by gravitational column chromatography and recrystallization techniques, followed by structural elucidation via spectroscopic analyses, including 1 H-, 13 C-, and 19 F-NMR, Fourier transform infra-red (FT-IR), and direct infusion-mass spectrometry (DI-MS), as well as high-resolution mass spectrometry (HRMS) for new molecules. The spectroscopic data of the newly synthesized analogues (5 and 11-15), general physical properties (Table S1), as well as the predicted physicochemical and drug-likeness properties (Table S2) of the synthesized molecules (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15) were appended in Supplementary Materials.…”

“…mass spectrometry (DI-MS), as well as high-resolution mass spectrometry (HRMS) for new molecules. The spectroscopic data of the newly synthesized analogues (5 and 11-15), general physical properties (Table S1), as well as the predicted physicochemical and druglikeness properties (Table S2) of the synthesized molecules (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15) were appended in Supplementary Materials.…”

Study of the Molecular Properties of Mono- and Binuclear Metal s-Indacenyl Complexes with Ir, Rh, and Re: A Theoretical Approach

“…In order to clarify the dependency of the reactivity with the molecular structure, we also analyzed the condensed Fukui functions [25,30,31]. In Figure 3, we included the wavefunctions for nucleophilic ( + ) and electrophilic ( − ) attacks.…”