A Review of the Biological Activity of Amidrazone Derivatives.

Amidrazones are widely used in chemical synthesis, industry and agriculture. We compiled some of the most important findings on the biological activities of amidrazones described in the years 2010-2022. The data were obtained using the ScienceDirect, Reaxys and Google Scholar search engines with keywords (amidrazone, carbohydrazonamide, carboximidohydrazide, aminoguanidine) and structure strategies. Compounds with significant biological activities were included in the review. The described structures derived from amidrazones include: amidrazone derivatives; aminoguanidine derivatives; complexes obtained using amidrazones as ligands; and some cyclic compounds obtained from amidrazones and/or containing an amidrazone moiety in their structures. This review includes chapters based on compound activities, including: tuberculostatic, antibacterial, antifungal, antiparasitic, antiviral, anti-inflammatory, cytoprotective, and antitumor compounds, as well as furin and acetylocholinesterase inhibitors. Detailed information on the compounds tested in vivo, along the mechanisms of action and toxicity of the selected amidrazone derivatives, are described. We describe examples of compounds that have a chance of becoming drugs due to promising preclinical or clinical research, as well as old drugs with new therapeutic targets (repositioning) which have the potential to be used in the treatment of other diseases. The described examples prove that amidrazone derivatives are a potential source of new therapeutic substances and deserve further research.

Synthesis of the N-methyl Derivatives of 2-Aminothiazol-4(5H)-one and Their Interactions with 11ßHSD1-Molecular Modeling and in Vitro Studies.

11ß-Hydroxysteroid dehydrogenase type 1 (11ß-HSD1) is an enzyme that affects the body's cortisol levels. The inhibition of its activity can be used in the treatment of Cushing's syndrome, metabolic syndrome and type 2 diabetes. In this study, we synthesized new derivatives of 2-(methylamino)thiazol-4(5H)-one and tested their activity towards inhibition of 11ß-HSD1 and its isoform - 11ß-HSD2. The results were compared with the previously tested allyl derivatives. We found out that methyl derivatives are weaker inhibitors of 11ß-HSD1 in comparison to their allyl analogs. Due to significant differences in the activity of the compounds, molecular modeling was performed, which was aimed at comparing the interactions between 11ß-HSD1 and ligands differing by substituent at the amine group (allyl vs. methyl). Modeling showed that the absence of the allyl group can lead to the rotation of whole ligand molecule which affects its interaction with the enzyme.

Thiazolo[3,2-a]pyrimidin-5-one derivatives as a novel class of 11ß-hydroxysteroid dehydrogenase inhibitors.

11ß-hydroxysteroid type 1 dehydrogenase (11ß-HSD1) is an enzyme that increases tissue concentrations of cortisol. Selective inhibitors of this enzyme regulate the level of cortisol and thus play a key role in the treatment of Cushing's syndrome, metabolic syndrome and type 2 diabetes. In this study the inhibitory activity of 29 thiazolo[3,2-a]pyrimidin-5-one derivatives on 11ß-HSD1 were investigated. Studies were carried out with pooled human liver microsomes. A lot of analyzed compounds show activity for inhibiting 11ß-HSD1 (up to 59.15% at concentration 10 µmol/l). Molecular docking simulation show that the molecule of the most active compound: 7-(cyclohexylmethyl)-2-iodomethyl-2,3-dihydrothiazolo[3,2-a]pyrimidin-5-one forms hydrogen bonds with Ala172, Leu171, Leu215 or Tyr177. In addition, the cycloalkane moiety can create the hydrophobic contacts with NADP+. For this compound also the most favourable Docking Score value was obtained. The most active compound only in the slight degree inhibits 11ß-HSD2 activity and is a selective inhibitor of 11ß-hydroxysteroid dehydrogenase type 1. Consequently it can have a real effect on the regulation of the cortisol level in the body.

Synthesis and evaluation of new amidrazone-derived hydrazides as a potential anti-inflammatory agents.

ABSTRACT: The series of new hydrazide derivatives were synthesized in reactions of N3-substituted amidrazones with cyclic anhydrides as potential anti-inflammatory and antibacterial agents. The compounds were characterized by 1H-13C two-dimensional NMR techniques, which revealed the presence of two tautomeric forms in DMSO-d6 solutions, while the molecular structure of one species was confirmed by single-crystal X-ray diffraction. The anti-inflammatory effects of hydrazides on peripheral blood mononuclear cells were experimentally evaluated. Three compounds showed antiproliferative activity comparable to ibuprofen. One derivative demonstrated strong reduction of lymphocyte proliferation stimulated by anti-CD3 antibody (by 90%) and PHA, as well as low cell toxicity. The obtained compounds exhibited relatively weak antibacterial activity; they were more effective against Gram-positive bacterial strains.

Study of the Room-Temperature Synthesis of Oxime Ethers by using a Super Base.

In this study, we present a convenient method for the synthesis of oxime ethers by reacting oximes with various chlorides (alkyl, functionalized alkyl, and benzyl) and with the subsequent use of a super base-pulverized potassium hydroxide in DMSO. The reactions take place at room temperature and the products are obtained in high yields. The final products were received within 2 min to 3 h. In addition, the compounds do not require chromatographic separation. The structure elucidation of the titled compounds was performed by using 1H NMR and 13C NMR spectroscopy as well as mass spectrometry. The presented method of synthesis for oxime ethers is environmentally friendly, because neither water cooling or heating of the reaction mixture/solvents (necessary for chromatographic purification) is required. The synthesis can be carried out very easily on a large scale.

ANTIBACTERIAL AND CENTRAL NERVOUS SYSTEM ACTIVITY OF (4,5-DIARYL-4H-1,2,4-TRIAZOL-3-YL)METHACRYLIC ACID DERIVATIVES.

The series of 1,2,4-triazole derivatives containing methacrylic acid moiety were synthesized in reaction of N3-substituted amidrazones with itaconic anhydride. Preliminary calculated bioavailability parameters of obtained compounds suggested good penetration via cell membranes and their good absorption after oral intake. Antimicrobial evaluation in vitio showed diverse activity of obtained triazoles mainly on Gram-positive bacterial strains. One derivative was also examined to determine the effect on the central nervous system of mice.

2-Allylaminothiazole and 2-allylaminodihydrothiazole derivatives: synthesis, characterization, and evaluation of bioactivity.

ABSTRACT: Some reactions of selected chlorooxoesters and haloesters with a 1-allylthiourea under various conditions have been performed. The reactions have been performed in methanol in alkaline and neutral environment. Condensation of 1-allylthiourea with chlorooxoesters has been further led via acetal as intermediate compound. As a result, the compounds containing thiazole and a 4,5-dihydrothiazole ring with a good yield have been obtained. The structures of the compounds were verified by 1H NMR, 13C NMR as well as X-ray diffraction analysis. Due to the potential biological activity of the synthesized compounds, the parameters of their bioavailability have been determined, and the probability of pharmacological action has been defined. All of the obtained compounds fulfilled the rule of five, which indicate their good absorption after oral intake. The probability of pharmacological action and potential targets calculated for the obtained compounds show that they can be potential drugs.

Synthesis and anti-inflammatory activity of new 1,2,4-triazole derivatives.

The series of new 1,2,4-triazole derivatives with methacrylic acid moiety were synthesized and characterized by NMR and IR spectroscopy as well as X-ray crystallography. The influence of newly synthesized compounds on the inflammation on the level of cytokine production and the proliferation of human peripheral blood mononuclear cells (PBMC) were experimentally evaluated. Obtained triazoles showed antiproliferative activity and diverse effects on cytokine production. Two compounds demonstrated potentially anti-inflammatory activity and comparable effects with ibuprofen.

2-{[5-(Pyridin-4-yl)-4-p-tolyl-4H-1,2,4-triazol-3-yl]meth-yl}acrylic acid hemi-hydrate.

The asymmetric unit of the title compound, 2C18H16N4O2·H2O, consists of two organic molecules and one solvent molecule. The symmetry-independent organic mol-ecules have slightly different conformations: the 1,2,4-triazole ring forms dihedral angles of 84.61 (4), 89.68 (5) and 22.38 (6)°, respectively, with the 2-propenecarbocylic, p-tolyl and 4-pyridyl groups in one independent molecule, and 71.35 (4), 82.13 (5) and 24.82 (6)°, respectively, in the second. In the crystal, mol-ecules ralated by the 21 screw axes are assembled via O-H⋯N and O-H⋯O hydrogen bonds into infinite chains and these are linked by further O-H⋯N hydrogen bonds into undulating sheets parallel to the bc plane. Adjacent sheets are connected by weak C-H⋯O inter-actions, forming a three-dimensional structure.

Synthesis, crystal structure and biological activities of a novel amidrazone derivative and its copper(II) complex--a potential antitumor drug.

A new linear amidrazone derivative, 6-acetyl-cyclohex-3-enecarboxylic acid [1-pyridin-2-yl-1-(pyridyn-2-yloamin)meth-(Z)-ylidene] hydrazide, H(2)L (2) and its Cu(II) complex, [Cu(2)L(2)]·4H(2)O (3) were synthesized and characterized by elemental analysis, IR and (1)H NMR spectroscopy and cyclic voltammetry. Compound 2 was synthesized in the equimolar reaction of N(3)-substituted amidrazone with cis-1,2,3,6-tetrahydrophthalic anhydride. The Cu complex of 2 was obtained in the reaction with copper(II) acetate. The molecular structures of 2 and 3 were determined by X-ray crystallography. The parent ligand exists in its amide-hydrazone form in the solid state. The central amidrazone moiety has a Z configuration with respect to the double C=N bond. Coordination to the metal center promotes Z/E isomerization of the hydrazone group of the ligand. Compound 3 is a dinuclear four-coordinated Cu(II) complex with the amidrazone ligand behaving as a tetradentate double deprotonated chelating one. Several biological activities of 2 and 3 were examined in vitro; they were: antimicrobial properties against selected bacterial and fungal strains, suppression of phytohemagglutinin A (PHA)-induced proliferation of human peripheral blood mononuclear cells (PBMC) and their effects on tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6) production. The cytotoxic activity of Cu(II) complex was determined with respect to the four carcinoma cell lines (SW 984, CX-1, L-1210, A-431). The studied complex exhibited significant cytotoxic effects (particularly against CX-1 colon carcinoma), comparable to those reported for cisplatin. Both compounds have shown a relatively low antibacterial activity and were devoid of antifungal properties.

Reactions of N(3) -substituted amidrazones with cis-1,2-cyclohexanedicarboxylic anhydride and biological activities of the products.

A series of novel compounds were synthesized in reactions of N(3) -substituted amidrazones with cis-1,2-cyclohexanedicarboxylic anhydride: linear, isoindole, and triazole derivatives. All new structures were confirmed by H(1) NMR and IR spectrometry as well as elemental analysis. Potential biological effects of new compounds were predicted with the Prediction of Activity Spectra for Substances (PASS) program. Antiviral, antibacterial, analgesic, and anti-inflammatory activities were experimentally verified.

2-[4-Phenyl-5-(2-pyridyl)-4H-1,2,4-triazol-3-yl]nicotinic acid: a case of solvent-dependent polymorphism.

The title compound, C(19)H(13)N(5)O(2), crystallizes in two monoclinic forms depending on the solvent used. From methanol or acetone, a yellow form [(Ia), m.p. 533 K] in the space group P2(1) is obtained, while with ethanol as the solvent, an orange form [(Ib), m.p. 541 K] in the space group Cc results. The conformers observed in the two polymorphs differ primarily in the relative orientation of pyridine/phenyl and triazole rings. Molecules of both polymorphs form chains through carboxyl O-H...N hydrogen bonding; however, in each crystal structure, a different group acts as acceptor, viz. a triazole and a pyridyl N atom for (Ia) and (Ib), respectively. This is the first case of polymorphism observed for crystals of a 3,4,5-trisubstituted 1,2,4-triazole derivative.

Synthesis and biological activity of new derivatives of 3-(3,4-diaryl-1,2,4-triazole-5-yl)propenoic acid.

New 3-(3,4-diaryl-1,2,4-triazole-5-yl)propenoic acid derivatives (8-14) were synthesized by condensation of N(3)-substituted amidrazones (1-7) with maleic anhydride. Molecular structure of obtained compounds was confirmed by an elemental analysis, IR and (1)H NMR spectra, and the X-ray crystallography for compound 11. The influence of the compound 9 on the central nervous system (CNS) of mice in some behavioural test was examined. The investigated compound showed anticonvulsive activity and potent antinociceptive action.