Introduction of amino moiety enhances the inhibitory potency of 1-tetralone chalcone derivatives against LPS-stimulated reactive oxygen species production in RAW 264.7 macrophages

Flexibility in the bridge of chalcone derivatives is important for the inhibition of cellular growth

Chalcones and their derivatives are a privileged scaffold in medicinal chemistry, demonstrating numerous biological activities. These molecules have shown significant potential toward the development of novel cancer therapies. While much is known about modification to the chalcone aryl rings, little is known about conformations of the bridge between the aryl rings. Here we report the synthesis and biological evaluation of a series of molecules with flexible and rigid bridge conformations. Crystal structures of a select group of molecules were determined. Flexibility in the chalcone bridge containing the enone moiety was determined to be important for activity. Screening in three distinct cancer cell lines showed significant differences in the activity between the flexible and rigid conformations. Crystal structures suggest an increase in bond rotation and weakened π-bonding in the flexible chalcone bridge, which may contribute to the stronger anti-proliferative activity.

Crystal structure of (E)-7-methoxy-2-(4-morpholinobenzylidene)-3,4-dihydronaphthalen-1(2H)-one, C22H23NO3

C22H23NO3, triclinic, P 1 ‾ $P\overline{1}$ (no. 2), a = 9.6505(4) Å, b = 9.9712(5) Å, c = 10.0845(4) Å, α = 68.177(4)°, β = 88.106(3)°, γ = 79.234(4)°, V = 884.30(7) Å3, Z = 2, Rgt (F) = 0.0424, wRref (F 2) = 0.1150, T = 293 K.

Crystal structure of 9-(2-chloroethoxy)-4-(4-methoxy-3-(trifluoromethyl)phenyl)- 5,6-dihydrobenzo[h]quinazolin-2-amine, C22H19ClF3N3O2

C22H19ClF3N3O2, triclinic, P 1 ‾ $P\overline{1}$ (no. 2), a = 9.8138(7) Å, b = 10.9739(7) Å, c = 11.6878(9) Å, α = 62.633(7)°, β = 67.095(7)°, γ = 68.817(6)°, V = 1003.78(14) Å3, Z = 2, R gt (F) = 0.0454, wR ref (F 2) = 0.1158, T = 293 K.

Potent inhibitory activity of hydroxylated 2-benzylidene-3,4-dihydronaphthalen-1(2H)-ones on LPS-stimulated reactive oxygen species production in RAW 264.7 macrophages

This study attempted to discover tetralone-derived potent ROS inhibitors by synthesizing sixty-six hydroxylated and halogenated 2-benzylidene-3,4-dihydronaphthalen-1(2H)-ones via Claisen-Schmidt condensation reaction. The majority of the synthesized and investigated compounds significantly inhibited ROS in LPS-stimulated RAW 264.7 macrophages. When compared to malvidin (IC₅₀ = 9.00 µM), compound 28 (IC₅₀ = 0.18 µM) possessing 6‑hydroxyl and 2‑trifluoromethylphenyl moiety showed the most potent ROS inhibition. In addition, the compounds 20, 31, 39, 45, 47-48, 52, 55-56, 58-60, and 62 also displayed ten folds greater ROS inhibitory activity relative to the reference compound. Based on the structure-activity relationship study, incorporating hydroxyl groups at the 6- and 7-positions of tetralone scaffold along with different halogen functionalities in phenyl ring B is crucial for potent ROS suppression. This study contributes to a better understanding of the effect of halogen and phenolic groups in ROS suppression, and further investigations on 2-benzylidene-3,4-dihydronaphthalen-1(2H)-ones will potentially lead to the discovery of effective anti-inflammatory agents.

Topoisomerase IIα inhibitory and antiproliferative activity of dihydroxylated 2,6-diphenyl-4-fluorophenylpyridines: Design, synthesis, and structure-activity relationships

A new series of fifty-four 2-phenol-4-aryl-6-hydroxyphenylpyridines containing fluorophenyl, trifluoromethylphenyl, and trifluoromethoxy phenyl groups were synthesized and tested for topoisomerase IIα inhibitory and antiproliferative activity against different cancer cell lines in an attempt to look into topoisomerase IIα-targeted prospective anticancer agents to counter the limitations of available treatment options. When compared to positive controls, several compounds 11-12, 37, 50, and 51 showed high antiproliferative activity, while several 4-fluorophenyl substituted compounds 13-14 and 18 showed strong topoisomerase IIα inhibition. Surprisingly, most of the compounds had a significant antiproliferative effect on the HCT15 colorectal adenocarcinoma and T47D breast cancer cell lines. Moreover, compound 12 with para-fluorophenyl at the 4-position and meta-phenolic groups at the 2- and 6-positions inhibited proliferating HeLa cervix adenocarcinoma cells with an IC₅₀ value of 1.28 μM. Based on biological results, the structure-activity relationships of the synthesized derivatives emphasized the significance of 4-trifluoromethoxyphenyl groups for strong antiproliferative activity and 4-fluorophenyl groups for strong topo IIα inhibition. Furthermore, meta- and para-phenolic groups at the 2- and 4-positions are favorable for strong topo IIα inhibitory and antiproliferative activity. The research findings provide insight into the effect of different fluorine functionalities in the discovery of novel topoisomerase IIα-targeted anticancer agents.

(2E)-2-(4-ethoxybenzylidene)-3,4-dihydro-2H-naphthalen-1-one single crystal: Synthesis, growth, crystal structure, spectral characterization, biological evaluation and binding interactions with SARS-CoV-2 main protease

A new α-Tetralone based chalcone compound, (2E)-2-(4-ethoxybenzylidene)-3,4-dihydro-2H-naphthalen-1-one (EBDN) has been synthesized by Claisen–Schmidt condensation reaction of α-Tetralone (1) with 4-Ethoxybenzaldehyde (2) in basic medium. Then it was allowed to grow through slow evaporation solution growth technique. The molecular structure of grown EBDN has been systematically characterized by SCXRD, FT-IR, ¹H NMR and ¹³C NMR spectroscopic studies. The micro-hardness, thermal (TGA & DTA) and photoluminence studies of the synthesized EBDN were also examined. The EBDN was screened for its anti-inflammatory, antidiabetic and anti-oxidant activity. It has shown admirable anti-inflammatory and antidiabetic activity. Protein-Ligand interactions of EBDN with SARS-CoV-2 main protease (PDB code: 6yb7) also performed.

Research progress in pharmacological activities and structure-activity relationships of tetralone scaffolds as pharmacophore and fluorescent skeleton

The tetralone and tetralone derivatives, as crucial structural scaffolds of potential novel drugs targeted at multiple biological end-points, are normally found in several natural compounds and also, it can be used as parental scaffold and/or intermediate for the synthesis of a series of pharmacologically active compounds with a broad-spectrum of bioactivities including antibacterial, antitumor, CNS effect and so on. Meanwhile, SAR information of its analogues has drawn attentions among medicinal chemists, which could contribute to the further research related to tetralone derivatives aimed at multiple targets. This review encompasses pharmacological activities, SAR analysis and docking study of tetralone and its derivatives, expecting to provide a general retrospect and prospect on tetralone derivatives.

Crystal structure of (E)-2-((3-fluoropyridin-4-yl)methylene)-7-methoxy-3,4-dihydronaphthalen-1(2H)-one, C17H14FNO2

C17H14FNO2, monoclinic, P21/n (no. 14), a = 8.0937(8) Å, b = 7.1326(6) Å, c = 22.367(2) Å, β = 90.863(9)°, V = 1291.1(2) Å3, Z = 4, R gt (F) = 0.0404, wR ref (F 2) = 0.0974, T = 99.97(16) K.

Crystal structure of (E)-7-methoxy-2-((6-methoxypyridin-3-yl)methylene)-3,4-dihydronaphthalen-1(2H)-one, C18H17NO3

C18H17NO3, monoclinic, P21/n (no. 14), a = 14.702(3) Å, b = 7.0421(11) Å, c = 15.303(3) Å, β = 113.32(2)°, V = 1454.9(5) Å3, Z = 4, R gt (F) = 0.0522, wR ref (F 2) = 0.1274, T = 100.03(18) K.

Crystal structure of (E)-7-methoxy-2-((6-methoxypyridin-2-yl)methylene)-tetralone, C18H17NO3

C18H17NO3, triclinic, P 1 ‾ $P‾{1}$ (no. 2), a = 4.0929(4) Å, b = 12.9527(11) Å, c = 14.4228(12) Å, α = 70.171(8)°, β = 87.229(8)°, γ = 87.567(8)°, V = 718.16(12) Å3, Z = 2, R gt (F) = 0.0549, wR ref (F 2) = 0.1526, T = 99.9(3) K.