New 1,3,4-thiadiazoles derivatives: synthesis, antiproliferative activity, molecular docking and molecular dynamics.

Aim: A series of 1,3,4-thiadiazole himachalene hybrids were prepared from the treatment of a himachalen-4-one thiosemicarbazone derivative with N-aryl-C-ethoxycarbonyl-nitrilimines and diarylnitrilimines via a 1,3-dipolar cycloaddition reaction. Materials & methods: The structures were confirmed by NMR, IR and high-resolution mass spectroscopy (HRMS). Results & conclusion: The newly synthesized hybrid compounds were tested for their in vitro antitumor activities against a panel of cancer cell lines including fibrosarcoma (HT-1080), lung carcinoma (A-549) and breast carcinoma (MCF-7 and MDA-MB-231). Among the tested products, 4a showed excellent activity against the HT-1080 and MCF-7 cell lines with IC50 values of 11.18 ± 0.69 and 12.38 ± 0.63 µm, comparable to that of the reference drug. Docking results confirmed that the active inhibitors were well accumulated in the mushroom tyrosinase active site. Flow cytometry analysis indicated that hybrid 4a induced apoptosis and cell cycle arrest in the G0/G1 phase. Molecular modeling studies affirmed the intercalative binding of compound 4a in the active site.

Design, synthesis, evaluation of new 3-acetylisoxazolines and their hybrid analogous as anticancer agents: In vitro and in silico analysis.

3-Acetylisoxazolines were synthesized by the reaction of natural (R)-limonene and (R)-carvone with acetone in the presence of iron (III) nitrate. The reaction showed to be highly peri- and regioselective. Next, using a 1,3-dipolar cycloaddition reaction, the mono-3-acylisoxazolines derived from these monoterpenes were evaluated for their reactivity with nitrilimines. Only the enone of carvone-isoxazoline was regioselectively reactive, providing a new fused isoxazoline-carvone-pyrazolines. The structure of all the newly synthesized mono-cycloadducts (3 & 5) and bis-cycloadducts (4 & 7a-c) were fully identified based on their HRMS and NMR spectral data. They have also been screened for their cytotoxic activity against four human cancer cell lines: fibrosarcoma (HT-1080), lung carcinoma (A-549), and breast (MCF-7 and MDA-MB-231) cell lines. The obtained results showed that compound 4 was a potent cytotoxic agent against all selected cells. The possible mechanism of apoptosis induction by compound 4 was investigated using Annexin-V binding assay, caspase-3/7 activity and analysis cell cycle progression. The compound 4 induced the early apoptosis of both MCF-7 and MDA-MB-231 through caspase-3/7 activation, and the compound 4 have elicited S and G2/M phase arrest in MCF-7and MDA-MB-231 cancer cells, respectively. For further target investigations, a molecular docking study was employed and it showed that compound 4 has an inhibitory activity against Pim-1 protein kinase. Molecular dynamics study showed that compound 4/Pim-1 complex was stable during the simulation run at different time intervals. In-Silico ADMET predicted that compound 4 has good pharmacokinetic properties with high estimated oral bioavailability.

Novel (+)-Neoisopulegol-Based O-Benzyl Derivatives as Antimicrobial Agents.

Discovery of novel antibacterial agents with new structures, which combat pathogens is an urgent task. In this study, a new library of (+)-neoisopulegol-based O-benzyl derivatives of aminodiols and aminotriols was designed and synthesized, and their antimicrobial activity against different bacterial and fungal strains were evaluated. The results showed that this new series of synthetic O-benzyl compounds exhibit potent antimicrobial activity. Di-O-benzyl derivatives showed high activity against Gram-positive bacteria and fungi, but moderate activity against Gram-negative bacteria. Therefore, these compounds may serve a good basis for antibacterial and antifungal drug discovery. Structure-activity relationships were also studied from the aspects of stereochemistry of the O-benzyl group on cyclohexane ring and the substituent effects on the ring system.

Synthesis and Application of 1,2-Aminoalcohols with Neoisopulegol-Based Octahydrobenzofuran Core.

A library of 1,2-aminoalcohol derivatives with a neoisopulegol-based octahydrobenzofuran core was developed and applied as chiral catalysts in the addition of diethylzinc to benzaldehyde. The allylic chlorination of (+)-neoisopulegol, derived from natural (-)-isopulegol followed by cyclization, gave the key methyleneoctahydrobenzofuran intermediate. The stereoselective epoxidation of the key intermediate and subsequent oxirane ring opening with primary amines afforded the required 1,2-aminoalcohols. The ring closure of the secondary amine analogues with formaldehyde provided spiro-oxazolidine ring systems. The dihydroxylation of the methylenetetrahydrofuran moiety with OsO4/NMO (4-methylmorpholine N-oxide) resulted in the formation of a neoisopulegol-based diol in a highly stereoselective reaction. The antimicrobial activity of both the aminoalcohol derivatives and the diol was also explored.