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This work deals with the study of the inhibition activity of three thiazolidinones (prepared from monoterpenic ketones) on the deterioration of S300 steel in hydrochloric acid solution. The potenti...

International audience; In this work, the compound 2 named ethyl (1,1-dichloro-1a,5,5,7-tetramethyl-8-oxo-1a,2,3,4,5,5a,8,9-octahydro-1H-benzo[a]cyclopropa[b][7]annulen-6-yl)glycinate (C20H29Cl2NO3) was synthesized from the α,β-unsaturated sesquiterpenicketone1 using the azido-Schmidt reaction catalyzed by titanium tetrachloride (TiCl4). The structure of the newly synthesized enaminone 2 was fully identified on the basis of its HRMS, FT-IR, UV-Visible, NMR (1 H & 13 C) spectral data, and X-ray crystallography. The compounds 1 and 2 were evaluated for their cytotoxic activity in four human cancer cell lines, fibrosarcoma (HT-1080), lung carcinoma (A-549), and breast (MCF-7 and MDA-MB-231). Data showed that compound 1 wasthe most activeagainst HT-1080 and A-549 cells with IC50 values between 13.28 and 16.41 µM.Thetheoretical Study Theory (DFT) was used to predict the molecular proprieties which lead to the highest potential of cytotoxic effect, in accordance to the experimental spectroscopic data.

COVID-19 is a global pandemic caused by infection with the SARS-CoV-2 virus. Remdesivir, a SARS-CoV-2 RNA polymerase inhibitor, is the only drug to have received widespread approval for treatment of COVID-19. The SARS-CoV-2 main protease enzyme (MPro), essential for viral replication and transcription, remains an active target in the search for new treatments. In this study, the ability of novel thiazolyl-indazole derivatives to inhibit MPro is evaluated. These compounds were synthesized via the heterocyclization of phenacyl bromide with (R)-carvone and (R)-pulegone thiosemicarbazones. The binding affinity and atomistic interactions of each compound were evaluated through Schrödinger Glide docking, AMBER molecular dynamics simulations, and MM-GBSA free energy estimation, and these results were compared with similar calculations of MPro binding various 5-mer substrates (VKLQA, VKLQS, VKLQG). From these simulations, we can see that binding is driven by residue specific interactions such as π-stacking with His41, and S/π interactions with Met49 and Met165. The compounds were also experimentally evaluated in a MPro biochemical assay and the most potent compound containing a phenylthiazole moiety inhibited protease activity with an IC50 of 92.9 µM. This suggests that the phenylthiazole scaffold is a promising candidate for the development of future MPro inhibitors.

In the current study, natural (R)-carvone was used as starting material for the efficient synthesis of several 1,2,3-triazole derivatives. The produced products were obtained in good yields and characterized by

The title compound, C17H18ClNO2, was prepared and isolated as a pure diastereoisomer, using column chromatography followed by a succession of fractional crystallizations. Its exact structure was fully identified via 1H NMR and confirmed by X-ray diffraction. It is built up from a central five-membered dihydroisoxazole ring to which a p-chlorophenyl group and a cyclohex-2-enone ring are attached in the 3 and 5 positions. The cyclohex-2-one and isoxazoline rings each exhibit an envelope conformation. The crystal packing features C—H...O, C—H...N and C—H...π interactions, which generate a three-dimensional network.

The present work focuses on the synthesis, structural characterization and electrochemical investigation of some heterocyclic compounds prepared from d -limonene. Firstly, 3-acetylisoxazoline was synthesized from d -limonene, this precursor is then converted to its thiosemicarbazone derivatives which were then cyclized to produce their corresponding thiazolidine-4-ones. The obtained compounds were characterized by FT-IR, 1H NMR, 13C NMR and mass spectrometric techniques. Further, DFT quantum chemical studies were also used to interpret the structural properties of the compounds using the B3LYP/6–311++G (d, p) basis set. The obtained results from experimental and theoretical studies were in good agreement showing that compounds bearing both isoxazoline and thiazolidine-4-one moieties act as good corrosion inhibitors for stainless steel in 1 M sulfuric acid.

A new series of diverse triazoles linked to the hydroxyl group of totarol were synthesized using click chemistry approach. The structures of these compounds were elucidated by HRMS, IR and NMR spectroscopy. The structure of compound 3 g was also confirmed by x-ray single crystal diffraction. The cytotoxicity of these compounds was evaluated by the MTT method against four cancer cell lines, including fibrosarcoma HT-1080, lung carcinoma A-549 and breast adenocarcinoma (MDA-MB-231 and MCF-7), and the results indicated that all compounds showed weak to moderate activities against all cancer cell lines with IC50 values ranging from 14.44 to 46.25 μM. On the basis of our research the structure–activity relationships (SAR) of these compounds were discussed. This work provides some important hints for further structural modification of totarol towards developing novel and highly effective anticancer drugs respectively. It is interesting to note that compound 3 g indicated a very significant cytotoxicity against HT-1080 and A-549 cell lines. The molecular docking showed that compound 3 g activated the caspase-3 and inhibited tubulin by forming stable protein–ligand complexes.

A novel series of 1,2,3-triazole-thiazolidinone-carvone hybrid compounds has been designed and synthesized using the copper-catalyzed Huisgen azide-alkyne 1,3-dipolar cycloaddition (CuAAC) process based on (R)-Carvone-O-propargylated 5-hydroxybenzylidene-thiazolidin-4-one derivative as starting material. All compounds were characterized and identified based on their NMR and HRMS spectroscopic data. HMBC correlations confirm that under the CuAAC reaction conditions, only the 1,4-disubstituted triazole regioisomers were formed. The targeted 1,2,3-triazole-thiazolidinone-carvone hybrids and their precursors were evaluated for their cytotoxic activity against four human cancer cell lines, including fibrosarcoma (HT-1080), lung carcinoma (A-549), and breast carcinoma (MCF-7 and MDA-MB-231). The obtained data showed that most of these compounds have moderate anti-proliferative activity with IC50 values between 15.04 ± 0.71 and 42.22 ± 1.20 µM. The mechanism of action of the most active compounds 14e and 14f suggested that they induce apoptosis through caspase-3/7 activation, and the compound 14e elicited S-phase arrest, while compound 14f evoked G2/M phase blockade. The molecular docking confirmed that compounds 14e and 14f were nicely bonded with caspace-3 leading up to stable protein-ligand complexes.

International audience; New series of chiral isoxazoles and pyrazoles with monoterpenic skeleton, have been efficiently synthesized from naturally occurring (R)-Carvone, using 1,3-dipolar cycloaddition reaction with arylonitrile oxides and diarylnitrilimines. The reaction showed high peri-, and regioselectivity. In the case of diarylnitrilimines, the reaction revealed to be highly diastereoselective. The structure of the newly synthesized adducts were fully established via spectroscopic analysis and X-ray crystallography. A succinct theoretical study was used to explain the diastereoselectivity experimentally observed. All the newly synthesized monoterpenic isoxazole and pyrazole derivatives were evaluated for their cytotoxic activity against human HT1080, MCF-7 and A-549 cancer cells.

This article describes firstly the synthesis of a new series of isoxazole 5a-e from p-methoxythymol, extracted from Tetraclinis Articulata, as starting material involving 1,3-dipolar cycloaddition reaction and secondly a detailed study of the molecular packing and intermolecular interactions in crystals of five related 5-((2-isopropyl-4-‑methoxy‑5-methylphenoxy)methyl)-3-phenylisoxazole derivatives. All compounds were synthesized and subjected to solid state characterization by single-crystal X-ray diffraction analysis, and to studies with the use of NMR and Hirshfeld surface analysis. All structures display intermolecular C—H···O hydrogen bonding and C—H···π interactions, forming layers in the crystal lattice. The crystal structures of compounds 5a; 5c and 5d are consolidated by π—π interactions. Hirshfeld surface analysis, the dnorm surfaces, electrostatic potential and two-dimensional fingerprint plots were examined to verify the contributions of the different intermolecular contacts within the supramolecular structure. The most important contributions for the crystal packing are from H···H, H···C/C···H and O···H/H···O interactions. Additionally, DFT calculations have been used to analyze the electronic and geometric frontier molecular orbital and Molecular Electrostatic Potential map analyses of the compounds were produced using the optimized structures.

Treatment of thiosemicarbazones prepared from sesquiterpenes with ethyl 2-bromoacetate in the presence of sodium acetate afforded the corresponding thiazolidin-4-ones. The structures of all the newly synthesized compounds were established by considering spectral and single-crystal X-ray diffraction data. The title compound, ethyl 2-((Z)-2-{(Z)-[(1aR,5aR,9aS)-1,1-dichloro-1a,5,5,7-tetramethyl-1a,2,3,4,5,5a,8,9-octahydro-1H-benzo[a]cyclopropa[b][7]annulen-8-ylidene]hydrazono}-4-oxothiazolidin-3-yl)acetate, C23H31Cl2N3O3S, 5, crystallizes in the orthorhombic noncentrosymmetric space group P212121 with Z = 4. Within the molecule in the crystal structure, the cyclohexene ring has an envelope conformation and the cycloheptane ring, to which it is fused, has a boat conformation. In the crystal, molecules are linked by C—H...Cl hydrogen bonds forming chains propagating along the b-axis direction. The absolute configuration of the molecule in the crystal could be fully confirmed from anomalous dispersion effects [Flack parameter = −0.04 (2)]. Thiosemicarbazones 1 and 2 are efficient inhibitors for steel corrosion in 1 M H2SO4 solution, with a maximum efficiency of 92.28% at 10−3 M. Furthermore, thiosemicarbazone compounds were found to be more efficient than thiazolidin-4-one derivatives. In addition, cyclic voltammetry was used to characterize the tested molecules, as well to estimate the experimental value of the energy band gap.

The title compound, an hemisynthetic product, was obtained by the tosyl­ation reaction of the naturally occurring meroterpene p-meth­oxy­thymol 1., The title compound, C18H22O4S, an hemisynthetic product, was obtained by the tosyl­ation reaction of the naturally occurring meroterpene p-meth­oxy­thymol. The mol­ecule comprises a tetra­substitued phenyl ring linked to a toluene­sulfonate through one of its O atoms. In the crystal, C—H⋯O and C—H⋯π inter­actions link the mol­ecules, forming a three-dimensional network.

We have studied the inhibitory effect of some Monoterpenic Thiosemicarbazones on steel corrosion in 1 M HCl solution. The potentiodynamic polarization and electrochemical impedance spectroscopy were used. The Monoterpenic Thiosemicarbazones have inhibited significantly the dissolution of steel. The inhibition efficiency increased with increasing inhibitor concentration and also with the increase in temperature (293–323 K). Furthermore, the results obtained revealed that the adsorption of inhibitor on steel surface obeys Langmuir adsorption model and the thermodynamic parameters such as enthalpy and activation energy were determined. The scanning electron microscopy combined with dispersive X-ray spectroscopy examinations were used to see the shape of the surface morphology and to determine the elemental composition. Scanning electron microscope (SEM) images show that the surface damage decreases when the inhibitor is added. The quantum chemical calculations using density functional theory (DFT) were performed in order to provide some insights into the electronic density distribution as well as the nature of inhibitor-steel interaction.

There are two independent molecules (AandB) in the asymmetric unit of the title compound, C11H19N3S. In moleculeB, two C atoms and the associated H atoms of the cyclohexene ring are disordered over two sets of sites with a site occupancy ratio of 0.649 (7):0.351 (7). The N—N—C—N fragments of the hydrazinecarbothioamide segments of both molecules are not planar, with a torsion angle of −5.8 (3)° forAand 11.6 (3)° forB. The stability of the conformations of both molecules is aided by the formation of intramolecular N—H...N hydrogen bonds. In the crystal, N—H...S hydrogen bonds link like molecules intoR22(8)A+Bdimers. These dimers are interconnected by additional N—H...S contacts, forming chains along thec-axis direction. The structure was refined as a two-component inversion twin.

The crystal structure of the title compound, dimethyl 2-((2Z,5Z)-5-(2-meth­oxy-2-oxo­ethyl­idene)-2-{(E)-[2-methyl-5-(prop-1-en-2-yl)cyclo­hex-2-enyl­idene]hydrazinyl­idene}-4-oxo­thia­zolidin-3-yl)fumarate displays a conformational disorder which inverts the configuration of the chiral C atom within the cyclo­hexyl­idene ring., The crystal structure and the conformation of the title compound, C22H27N3O7S, were determined from the synthetic pathway and by X-ray analysis. This compound is a new 4-thia­zolidinone derivative prepared and isolated as pure product from thio­semicarbazone carvone. The mol­ecule is built up from an oxo­thia­zolidine ring tetra­substituted by a meth­oxy–oxo­ethyl­idene, a maleate, an oxygen and a cyclo­hexyl­idene–hydrazone. The cyclo­hexyl­idene ring is statistically disordered over two positions, resulting in an inversion of configuration for the substituted carbon.

The title compound, C16H22Br4, was synthesized in two steps from β-himachalene, which was isolated from essential oil of the Atlas cedar (cedrus atlantica). It is built up from three fused rings, a seven-membered heptane ring, a six-membered cyclohexyl ring bearing both a bromine and a bromomethyl substituent, and a three-membered propane ring bearing two Br atoms. In the crystal, molecules are linked by C—H...Br hydrogen bonds, forming chains propagating along [001]. The absolute configuration was deduced from the chemical pathway and confirmed by resonant scattering [Flack parameter = 0.012 (10)].

The absolute structure of the title compound was determined from the synthetic pathway and by resonant scattering. The compound is a new thia­zolidin-4-one derivative, prepared from (R)-thio­semicarbazone pulegone, and was isolated on crystallization from ethanol as the pure (3aS,6R)-diastereisomer., The title compound, C13H19N3OS, is a new thia­zolidin-4-one derivative prepared and isolated as the pure (3aS,6R)-diastereisomer from (R)-thio­semicarbazone pulegone. It crystallized with two independent mol­ecules (A and B) in the asymmetric unit. The compound is composed of a hexhydro­indazole ring system (viz. a five-membered di­hydro­pyrazole ring fused to a cyclo­hexyl ring) with a thia­zole-4-one ring system attached to one of the pyrazole N atoms (at position 2). The overall geometry of the two mol­ecules differs slightly, with the mean planes of the pyrazole and thia­zole rings being inclined to one another by 10.4 (1)° in mol­ecule A and 0.9 (1)° in mol­ecule B. In the crystal, the A and B mol­ecules are linked via C—H⋯O hydrogen bonds, forming slabs parallel to the ab plane. There are C—H⋯π inter­actions present within the layers, and between the layers, so forming a three-dimensional structure.

The antibacterial activity of different extracts of Quercus ilex bark (Fagaceae) was studied in vitro against seven reference strains of bacteria by using a disc-diffusion method and agar-dilution method. The ethyl acetate extract (QE), n-butanol extract (QB) and final aqueous layer (QA) were effective against all bacterial strains tested at MICs ranging from 128 to 512 microg/ml. The n-hexane extract (QH) and dichloromethane extract (QD) showed no activity.

The title compound, C16H24Cl2O, is built up from two fused six- and seven-membered rings which bear a dichlorocyclopropane group and an epoxy group, respectively. In the molecule, the six-membered ring adopts an envelope configuration with the C atom linking the epoxy ring at the flap, while the seven-membered ring adopts a boat–sofa conformation.

The allylic oxidation of (1S,3R,8R)‐2,2‐dichloro‐3,7,7,10‐tetramethyltricyclo[6,4,0,01,3]dodec‐9‐ene into the corresponding enone with N‐bromosuccinimide (NBS), CrO3 and t‐BuOOH has been studied. A good yield and high selectivity were obtained in the presence of t‐BuOOH and a copper catalyst.

Treatment of β-enaminone 4 with 2-hydrazinopyridine gives a regiospecific formation N-substituted pyrazole 6. Enaminone 4 was prepared for the first time by reacting enone 3 with sodium azide in acidic medium. The structural assignment of 2, 3, 4, 5 and 6 is based upon 1H, 13C NMR spectroscopy, mass spectrometry and X-ray structural analyses.

The title compound, C27H34O2, was hemisynthesized through direct benzoylation of the naturally occurring meroterpene totarol. The central fused six-membered ring has a half-chair conformation, whereas the terminal six-membered ring displays a chair conformation. The dihedral angle between the fused benzene ring and the benzoyl benzene ring is 73.05 (14)°. TheS,Schirality of the molecule is consistent with the synthetic pathway, and confirmed by the refinement of the Flack parameter.

The stereochemistries of the title compounds, both C16H24Cl2O, have been established by X-ray diffraction. In both structures, the seven-membered ring adopts the same conformation, whereas the six-membered ring shows an envelope conformation in the epoxy­do­decane structure and a boat conformation in the dodecan-9-one structure.

The stereochemistry of the title compound, C15H26O3, has been established. The compound crystallizes with three molecules in the asymmetric unit and significant variations in the bond distances and angles are reported. Intermolecular hydrogen bonds are observed between the hydroxyl groups.

In the search for cancer chemopreventive agents, we have studied the Diels-Alder reaction of trans-communic acid with tetra-cyano-ethyl-ene in the presence of SiO(2) as catalyst. The title cycloadduct, C(26)H(30)N(4)O(2), was obtained in 75% yield. The mol-ecules are arranged in pairs through O-H⋯O hydrogen bonds, forming an R(2) (2)(8) ring motif. Both the fused cyclohexyl rings adopt a chair conformation, whereas the nonfused ring adopts a half-chair conformation.

The absolute configuration of the title compound, C16H24O, has been deduced from the chemical pathway. The six-membered ring has a roughly half-chair conformation with the quaternary C atom as the flap. The seven-membered ring displays a chair conformation. In the crystal, there is a weak C—H...O hydrogen bond between the methylene group of the cyclopropane ring and the carbonyl group of a screw-axis-related molecule, which builds up a zigzag-like chain along the b-axis direction.

To a solution of 11 (1g, 1.68mmol) in 20ml of acetone, was added (0.50g, 0.85mmol) of chromic anhydride2.[...]

The stereochemistry of the title compound, C15H26O2, has been established. Intermolecular hydrogen bonds are observed between the hydroxyl groups.

The title compound, C(20)H(28)O(2), commonly named Sugiol, is a natural oxygenated diterpene that we have isolated for the first time from a hexane extract of the fruits of Juniperus Oxycedrus L. Its X-ray crystal structure determination confirms an abietane skeleton which was predicted by spectroscopic analysis, mainly by (1)H and (13)C NMR. The cyclo-hexane ring adopts a flattened chair conformation, while the cyclo-hexene ring adopts an envelope conformation. The mol-ecules are linked through O-H⋯O hydrogen bonds to form a zigzag chain extending parallel to the c axis.