Crystal structure of methyl (Z)-2-[(Z)-3-methyl-2-({(E)-1-[(R*)-4-methyl-cyclo-hex-3-en-1-yl]ethyl-idene}hydrazinyl-idene)-4-oxo-thia-zolidin-5-yl-idene]acetate

Novel hydrazono-2-iminothiazolidin-4-ones based on a monoterpenic skelton as potential antitumor agents: Synthesis, DFT studies, in vitro cytotoxicity, apoptosis inducing properties and molecular docking

A new series of analogs-2-imino-4-thiazolidinone hybrid derivatives were synthesized by treatment of limonaketone-thiosemicarbazone derivatives with ethyl bromoacetate and dimethyl acetylene dicarboxylate (DMAD) as the cyclizing reagents. The new derivatives were characterized by HRMS, 1 H NMR and 13 C NMR spectroscopy techniques and one of them is characterized by single crystal X-ray diffraction. The newly synthesized products were biologically evaluated in vitro for their cytotoxic activity against three cancer cell lines including fibrosarcoma (HT-1080), lung carcinoma (A549), and breast carcinoma (MCF-7). Data showed that compounds 9 and 10 were the most active against HT-1080 cancer cell lines with the IC 50 values of 15.85±1.75 and16.13±1.55µM, respectively. The possible mechanism of apoptosis induction by the derivatives was investigated using Annexin V staining, caspase-3/7 activity and cell cycle analysis. Compound 10 was highly induced apoptosis through caspase-3/7 activation and S-phase arrest in HT-1080, while compound 9 showed a moderate induction of apoptosis through G0/G1-phase arrest in the same cell line. The molecular docking showed that compounds 9 and 10 activated the caspase-3 by forming a stable protein-ligand complex. Besides, the presence of phenyl moiety in ligand 10 is responsible for the enhancement of the caspase-3 activation by the apparition of two additional hydrogen bonds with Cys163 and Gln161amino acids.

New polysubstituted monoterpenic thiazolidinones: synthesis, spectroscopic and crystal structure studies

The synthesis of three new polysubstituted monoterpenic thiazolidin-4-ones, namely (Z)-3-methyl-2-{(E)-[(1R,4R)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-ylidene]hydrazinylidene}thiazolidin-4-one, C14H21N3OS (2), (2Z,5Z)-5-[(dimethylamino)methylidene]-2-{(E)-[(1R,4R)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-ylidene]hydrazinylidene}thiazolidin-4-one, C16H24N4OS (3), and (2Z,5Z)-5-[(dimethylamino)methylidene]-3-methyl-2-{(E)-[(1R,4R)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-ylidene]hydrazinylidene}thiazolidin-4-one, C17H26N4OS (4), is reported, starting from the corresponding thiosemicarbazones obtained from naturally occurring (R)-camphor. All the newly obtained thiazolidin-4-ones have been fully characterized by HRMS and 1H and 13C (1D and 2D) NMR spectroscopy. Two of them, i.e. 2 and 3, were identified by single-crystal X-ray crystallography, confirming the synthetic pathway and the spectroscopic analyses. In 3, there are two roughly identical molecules within the asymmetric unit with the same absolute configuration. These two molecules are linked through N—H...O hydrogen bonds, building an R 2 2(8) graph-set motif.