Antituberculosis activity of hydrazones derived from 4-fluorobenzoic acid hydrazide

Synthesis of hydrazides of heterocyclic amines and their antimicrobial and spasmolytic activity

Un unsolvable issue of a significant number increase of drug multi resistant strains of microorganisms including Mycobacterium tuberculosis force researchers for continuous design novel pharmaceuticals.

The purpose of the study is the establishment of the correlation between the structure of novel heterocyclic hydrazide derivatives and their biological activity. Several hydrazide derivatives of N-piperidinyl and N-morpholinyl and propionic acids and N-piperidinyl acetic and their derivatives were synthesized via condensation of corresponding esters with hydrazine hydrate.The structure of synthesized compounds were confirmed by the use of FTIR, H1NMR, Mass-spectroscopy and element analysis. Investigation of synthesized substances using PASS software was carried out to predict probability of pharmacological activity in silico. The antibacterial, antifungal and spasmolytic activity as well as acute toxicity of obtained compounds were evaluated in vivo. 2-(N-piperidinyl)acetic acid hydrazide and 2-methyl-3-N-piperidinyl)propanacid hydrazide revealed antibacterial and spasmolytic activities comparable to the model drugs (drotaverin) in vitro study. Synthesized compounds in in vivo experiment showed significantly low acute toxicity (LD50 520–5750 mg/kg) compared to commercially available drugs (streptomicine, ciprofloxacinum and drotaverin LD50 100–215 mg/kg). The structure- activity relationship was established that the increasing of the length of the linker between heterocyclic amine and hydrazide group results in a decrease of antimicrobial activity against studied strains (Escherichia coli, Salmonella typhymurium, Salmonella choleraesuis, Staphylococcus aureus).

Synthesis and in vitro antimicrobial activity of new steroidal hydrazone derivatives

Background

For many years, various drugs have been used for the treatment of infectious diseases but some bacterial microorganisms have induced resistance to several drugs. In a search of new antimicrobial agents, a series of new steroidal hydrazones were designed and synthesized.

Result

The structures of the compounds were established based on the spectral data. The in vitro antimicrobial activity of some newly synthesized compounds against bacteria and fungi was studied.

Conclusion

New compounds showed better or similar antimicrobial activity. Designing more efficient steroidal hydrazones from ketosteroid based on the current study may successfully lead to the development of antimicrobial agent.

Graphical abstract

Application of Topological Descriptors in QSAR Modeling: Substituted Hydrazones Used As a Model System

Background:

QSAR study of p-substituted aromatic hydrazones was performed to estimate the quantitative effects of selected topological descriptors on their antimicrobial activity. None of the hydrazones inhibited the growth of the Aspergillus spp., while the data obtained with regard to the antifungal activity of the compounds against Candida utilis were insufficient to develop reliable statistical QSAR models. Therefore, the investigation was focused on developing QSAR models for predicting the antibacterial activity of the compounds against Bacillus subtilis.

Methods:

A set of substituted hydrazones were tested for their in vitro growth inhibitory activity against Candida utilis, Bacillus subtilis and Aspergillus niger and the diameter of the inhibition zone (mm) was measured. The inhibitory activity data, determined in μg/mL, were transformed to the negative logarithms of molar MICs (log1/CMIC). Using Marvinsketch software package, 28 topological descriptors were calculated. Statistical parameters, such as R2, Sd, F-test, R2 adj, Q, SPRESS, PSE and Q2, were used to test the quality of the developed two-, three-, four-parametric and higher QSAR models.

Results and Conclusion:

Statistical evaluation of the data used to test the quality of the obtained QSAR models indicated that the two-parametric model involving the descriptors Atom Count (AC) and Maximal Projection Area (MAPA) was statistically significant when all the statistical parameters were summarized. The two parameters, AC and MAPA, had opposite input in modeling the antimicrobial activity of the selected hydrazones against Bacillus subtilis.

Synthesis and Anticancer Activity of New Hydrazide-hydrazones and Their Pd(II) Complexes

Background:

Hydrazones, one of the important classes of organic molecules, are pharmaceutical agents comprising –CO-NH-N=CH- group in the structure therefore and exhibiting significant biological activity.

Methods:

5-Chloro-N’-[(substituted)methylidene] pyrazine-2-carbohydrazide (3a-g) and their Pd(II) complexes (4a-h) were synthesized and investigated in vitro anticancer activity on A549, Caco2 cancer and normal 3T3 fibroblast cell lines, using the MTT assay.

Results:

Anticancer activity screening results revealed that some compounds showed remarkable cytotoxic effect. Among them, 5-chloro-N'-[(4-hydroxyphenyl)methylidene] pyrazine-2-carbohydrazide (3c) displayed higher cytotoxic activity against A549 cancer cell line than the reference drug cisplatin.

Conclusion:

Compound 3c showed high cytotoxic activity against A549 cancer cell line but it showed low cytotoxic effect against normal 3T3 fibroblast cell line. Antiproliferative and antimetastatic effects of 3c were determined by the real-time monitoring of cell proliferative system (RTCA DP). The cell proliferation, metastatic and invasive activities of A549 cells were decreased due to increased concentration of 3c.

New Hydrazides and Hydrazide-Hydrazones of 2,3-Dihalogen Substituted Propionic Acids: Synthesis and in vitro Antimicrobial Activity Evaluation

The main aim of this research was the synthesis, spectral identification and in vitro antimicrobial evaluation of new hydrazides and hydrazide-hydrazones of 2,3-dihalogen substituted propionic acids. New hydrazides were obtained by the substitution reaction of appropriate ethyl esters of 2,3-dihalogen substituted propionic acids with hydrazine hydrate. Then obtained hydrazides were subjected to condensation reaction with various aldehydes which yielded with new hydrazide-hydrazone derivatives. All obtained compounds were identified on the basis of spectral methods (¹ H-NMR, ¹³ C-NMR) and in vitro screened against a panel of bacterial and fungal strains according to EUCAST and CLSI guidelines.

Synthesis and investigation of antimicrobial activities of nitrofurazone analogues containing hydrazide-hydrazone moiety

In this research we synthesized and tested for in vitro antimicrobial activity 21 nitrofurazone analogues. The compounds we obtained were identified on the basis of ¹H NMR and ¹³C NMR spectroscopy. The in vitro screening of antimicrobial properties of synthesized compounds revealed a wide spectrum of antimicrobial activity. Compounds 28, 29, 32–43, and 45–48 showed very high bactericidal effect towards Staphylococcus spp. ATTC and Bacillus spp. ATTC (MIC = 0.002–7.81 µg/ml and MBC = 0.002–31.25 µg/ml). The levels of activity of several compounds were far better than those of nitrofurantoin, ciprofloxacin or cefuroxime.

Design, synthesis, and in vitro antimicrobial activity of hydrazide-hydrazones of 2-substituted acetic acid

In this study, 30 hydrazide-hydrazones of phenylacetic (3-10) and hydroxyacetic acid (11-32) were synthesized by the condensation reaction of appropriate 2-substituted acetic acid hydrazide with different aromatic aldehydes. The obtained compounds were characterized by spectral data and evaluated in vitro for their potential antimicrobial activities against a panel of reference strains of micro-organisms, including Gram-positive bacteria, Gram-negative bacteria, and fungi belonging to the Candida spp. The results from our antimicrobial assays indicated that among synthesized compounds 3-32, especially compounds 6, 14, and 26 showed high bactericidal activity (MIC = 0.488-7.81 μg/ml) against reference Gram-positive bacteria, and in some cases, their activity was even better than that of commonly used antibiotics, such as cefuroxime or ampicillin.

New piperidine-hydrazone derivatives: Synthesis, biological evaluations and molecular docking studies as AChE and BChE inhibitors

Hydrazones and the piperidine ring containing compounds were considered as beneficial substrates in drug design. Therefore, this study was aimed at the synthesis of new benzoyl hydrazones derived from ethyl 4-oxopiperidine-1-carboxylate and 2,6-diphenylpiperidin-4-one. The synthesized compounds (1-19) were screened for their antioxidant, anticholinesterase and anticancer activities. The antioxidant capacity of the compounds was evaluated by using four complementary tests. The results showed that compound 7 and 17 have the higher lipid peroxidation inhibitory activity than the other compounds. In DPPH˙ scavenging assay, compounds 5, 6, 10, 14, 17 demonstrated better activity than that of standard BHT, while in ABTS⁺˙ scavenging assay compound 6 and 17 exhibited better activity among the other compounds. The CUPRAC assay disclosed that compound 2 displayed better activity than α-tocopherol. The anticholinesterase activity was performed against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes. Compound 11 (IC₅₀: 35.30 ± 1.11 μM) inhibited BChE better than galantamine (IC₅₀: 46.03 ± 0.14 μM). We conclude that the compound 11 can be considered as a candidate for BChE inhibitor. Moreover docking method was applied to elucidate the AChE and BChE inhibitory mechanism of the compound 11. Molecular docking analysis revealed that compound 11 bound to BChE enzyme more efficiently when compared to the AChE due to its orientations and different types of interactions. In addition, the non-cytotoxic properties of the compounds brought them into prominence, although they did not show significant anticancer properties.

Antibacterial, antifungal and antimycobacterial activities of some pyrazoline, hydrazone and chalcone derivatives

Twenty-seven previously reported chalcones and their pyrazoline and hydrazone derivatives as well as two further chalcones have been screened for their antimicrobial, antifungal and antimycobacterial activities against standard microbial strains and drug resistant isolates. The minimum inhibitory concentration (MIC) value of each compound was determined by a two-fold serial microdilution technique. The compounds were found to possess a broad spectrum of antimicrobial activities with MIC values of 8–128 μg/mL. One compound [(E)-1-(4-hydroxyphenyl)-3-p-tolylprop-2-en-1-one] had equal activity with gentamycin (8 μg/mL) against Enterococcus faecalis. Chalcones were found to be more active than their hydrazone and 2-pyrazoline derivatives against Staphylococcus aureus ATCC 29213 and E. faecalis ATCC 29212.

4-Hydroxy-3-methoxy-benzaldehyde series aroyl hydrazones: synthesis, thermostability and antimicrobial activities

Both number and position of hydroxyl groups contained in a series of aromatic hydrazides and aroyl hydrazones displayed remarkable difference in antimicrobial activity.

N'-[(5-Methyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)(thio-phen-2-yl)methyl-idene]benzohydrazide

In the title compound, C(22)H(18)N(4)O(2)S, the seven-membered ring generated by an intra-molecular N-H⋯O hydrogen bond adopts an envelope conformation in both of the two independent mol-ecules in the asymmetric unit. In the crystal, mol-ecules are linked into C(9) chains along [100] by N-H⋯O hydrogen bonds. The mol-ecules are also weakly linked by C-H⋯O and C-H⋯N inter-actions, forming dimers with edge-connected R(2) (2)(9) rings. The dimers are inter-linked by further weak C-H⋯N hydrogen bonds into chains along [010].