Enantiomeric Separation and Thermodynamic Investigation of (R)-N-Tert-Butoxy Carbonyl-Piperidine-3-Carboxylic Acid Hydrazide, a Key Starting Material of Zidebactam

A new selective, accurate and precise chiral high-performance liquid chromatography method for the separation of (R)-N-tert-butoxy carbonyl-piperidine-3-carboxylic acid hydrazide (RE) and its enantiomer was developed. RE is a key starting material of novel β-lactam enhancer drug Zidebactam. Chiral resolution of more than 10 was achieved on Chiralpak IA column using mobile phase consisting of n-hexane, ethanol in the ratio of 70:30, v/v. The flow rate of the mobile phase was 1.0 mL min−1 and the column oven temperature was 30°C. Detection was carried out at 225 nm. The developed method was validated as per the International Conference on Harmonization guideline. Limit of detection and limit of quantification of the enantiomeric impurity (S)-N-tert-butoxy carbonyl-piperidine-3-carboxylic acid hydrazide (SE) was 2.5 and 7.5 μg mL−1, respectively. Mean recovery of the SE was 96.83 ± 1.4%. The effect of thermodynamic parameters on the chiral separation was evaluated.

The N’-Substituted Derivatives of 5-Chloro-3-Methylisothiazole-4-Carboxylic Acid Hydrazide with Antiproliferative Activity

Thanks to the progress in oncology, pharmacological treatment of cancer is gaining in importance and in the near future anti-cancer chemotherapeutics are expected to be the main method of treatment for cancer diseases. What is more, the search for new anti-cancer compounds with the desired application properties is constantly underway. As a result of designed syntheses, we obtained some new N’-substituted 5-chloro-3-methylisothiazole-4-carboxylic acid hydrazide derivatives with anticancer activity. The structure of new compounds was determined by mass spectrometry (MS), elemental analysis, proton nuclear magnetic resonance spectroscopy (1H-NMR), carbon nuclear magnetic resonance spectroscopy (13C-NMR), 1H-13C NMR correlations and infrared spectroscopy (IR). Moreover, the structures of the compounds were confirmed by crystallographic examination. The antiproliferative MTT tests for 11 prepared compounds was conducted towards human biphenotypic B cell myelomonocytic leukemia MV4-11. SRB test was used to examine their potential anticancer activity towards human colon adenocarcinoma cell lines sensitive LoVo, resistant to doxorubicin LoVo/DX, breast adenocarcinoma MCF-7 and normal non-tumorigenic epithelial cell line derived from mammary gland MCF-10A. The most active compound was 5-chloro-3-methyl-N′-[(1E,2E)-(3-phenyloprop-2-en-1-ylidene]isothiazole-4-carbohydrazide, which showed the highest antiproliferative activity against all tested cell lines.

New Hydrazide-hydrazone Derivatives of Quinoline 3-Carboxylic Acid Hydrazide: Synthesis, Theoretical Modeling and Antibacterial Evaluation

A series of biologically active 3-quinoline carboxylic acid hydrazide-hydrazones has been synthesized from 3-quinoline carboxylic acid hydrazide and a variety of aldehydes, with moderate to good yields. The chemical structures of the new products were confirmed by elemental analysis, IR, and 1H NMR, 13C NMR spectral data. The structural and frontier molecular orbital (FMO) properties and the density functional theory (DFT) calculations were conducted for the new compounds. The new hydrazide-hydrazones exhibited low to moderate antibacterial activity against Staphylococcus aureus and Esherichia coli in comparison with gentamycin. Among the tested compounds, compounds 9 and 13 were found to be the most active. Phthalimide derivative 2 of 3-quioline carboxylic acid hydrazide showed remarkable antibacterial activity.

Synthesis, In Vitro Screening and Docking Studies of New Thiosemicarbazide Derivatives as Antitubercular Agents

A series of thiosemicarbazide derivatives was designed and synthesized by reaction of carboxylic acid hydrazide with isothiocyanates. The molecular structures of the investigated thiosemicarbazides were confirmed and characterized by spectroscopic analysis. The conformational preference of carbonylthiosemicarbazide chain and intra- and intermolecular interactions in the crystalline state were characterized using X-ray analysis. The antituberculosis activity of the target compounds were tested in vitro against four Mycobacterium strains: M. H37Ra, M. phlei, M. smegmatis, M. timereck. The most active compounds were those with 2-pyridine ring. They exhibited lower minimal inhibitory concentration (MIC) values in the range 7.81–31.25 μg/mL in comparison to the other isomers. Compound 5 had activity against M. smegmatis at a concentration of 7.81 μg/mL whereas compound 2 had activity against all tested strains at a concentration of 15.625 μg/mL. The molecular docking studies were performed for investigated compounds using the Mycobacterium tuberculosis glutamine synthetase MtGS as their molecular target.

Computing Eccentricity Based Topological Indices of Octagonal Grid Omn

Graph theory is successfully applied in developing a relationship between chemical structure and biological activity. The relationship of two graph invariants, the eccentric connectivity index and the eccentric Zagreb index are investigated with regard to anti-inflammatory activity, for a dataset consisting of 76 pyrazole carboxylic acid hydrazide analogs. The eccentricity ε v of vertex v in a graph G is the distance between v and the vertex furthermost from v in a graph G. The distance between two vertices is the length of a shortest path between those vertices in a graph G. In this paper, we consider the Octagonal Grid O n m . We compute Connective Eccentric index C ξ ( G ) = ∑ v ∈ V ( G ) d v / ε v , Eccentric Connective Index ξ ( G ) = ∑ v ∈ V ( G ) d v ε v and eccentric Zagreb index of Octagonal Grid O n m , where d v represents the degree of the vertex v in G.