Hydroxyl‐ and Halogen‐containing Chalcones for the Inhibition of LPS‐stimulated ROS Production in RAW 264.7 Macrophages: Design, Synthesis and Structure–Activity Relationship Study

Chemical Constituents from the Fruit of Melia azedarach and Their Anti-Inflammatory Activity

Phytochemical investigations of Melia azedarach fruits have led to the isolation of a novel tirucallane triterpenoid (1), four new limonoids (2-5), and four known limonoids (6-9). Their structures were clarified by comprehensive spectroscopic and spectrometric analyses. The anti-inflammatory activities of isolated compounds were assessed in vitro. Compound 2 exhibited the most potent anti-inflammatory effect, with an IC50 value of 22.04 μM. Additionally, compound 2 attenuated LPS-induced reactive oxygen species (ROS) production and reduced the levels of inflammatory mediators IL-6 and TNF-α. A mechanistic study revealed that limonoid 2 suppresses the expression of iNOS and JAK2 and is implicated in the modulation of the NF-κB signaling cascade, which reveals its anti-inflammatory actions.

Synthesis, Antimicrobial Activities, and Molecular Modeling Studies of Agents for the Sortase A Enzyme

Sortase A (SrtA) is an attractive target for developing new anti-infective drugs that aim to interfere with essential virulence mechanisms, such as adhesion to host cells and biofilm formation. Herein, twenty hydroxy, nitro, bromo, fluoro, and methoxy substituted chalcone compounds were synthesized, antimicrobial activities and molecular modeling strategies against the SrtA enzyme were investigated. The most active compounds were found to be T2, T4, and T19 against Streptococcus mutans (S. mutans) with MIC values of 1.93, 3.8, 3.94 μg/mL, and docking scores of -6.46, -6.63, -6.73 kcal/mol, respectively. Also, these three active compounds showed better activity than the chlorohexidine (CHX) (MIC value: 4.88 μg/mL, docking score: -6.29 kcal/mol) in both in vitro and in silico. Structural stability and binding free energy analysis of S.mutans SrtA with active compounds were measured by molecular dynamic (MD) simulations throughout 100 nanoseconds (ns) time. It was observed that the stability of the critical interactions between these compounds and the target enzyme was preserved. To prove further, in vivo biological evaluation studies could be conducted for the most promising precursor compounds T2, T4, and T19, and it might open new avenues to the discovery of more potent SrtA inhibitors.

Stabilized Arylzinc Iodides in Negishi Acylative Cross-Coupling: A Modular Synthesis of Chalcones

Stabilized arylzinc iodides, synthesized by direct insertion of zinc into the corresponding halides, were used as nucleophiles into an acylative Negishi coupling reaction to synthesize chalcones. The reaction conditions were optimized to afford optimal results on a model reaction and then applied to synthesize nine compounds. Esters, chlorides, electron-rich, electron-poor and sterically hindered substrates are well tolerated and even heteroaryl derivatives can be synthesized.

A new isostructural halogenated chalcone with optical properties

Chalcones are organic compounds that present a number of properties. This study presents a comprehensive structural description of a new derivative of a chlorine-substituted chalcone in comparison with a bromine chalcone. Also, supermolecule and sum-over-state approach were used to describe the optical properties of these structures regarding the substitution of the bromine by the chlorine atom. In addition, the electrical properties, dipole moment, linear polarizability, and second IDRI hyperpolarizability were calculated. The linear refractive index and the third-order nonlinear macroscopic susceptibility were evaluated as a function of the applied electric field frequency. Furthermore, the quantum mechanics calculations that were implemented at the M06-2X/6-311++G(d,p) level of the theory for these isostructural chalcones indicate that the change in halogen atoms does not cause meaningful changes in their conformation. Finally, we can postulate that side-to-side and the antiparallel interactions are the interaction forces that drive the crystal growth for new isostructural chalcones. The NLO properties showed title compounds that are good candidates for use as NLO materials.