Synthesis and analgesic activity of new pyridine-based heterocyclic derivatives

A series of new heterocyclic derivatives having a pyridine nucleus were synthesized. 4-(5-(2-Chlorophenyl)-4H-1,2,4-triazol-3-yl)pyridine (7c) and 4-(5-(2-Nitrophenyl)-4H-1,2,4-triazol-3-yl)pyridine (7d) presented the best analgesic profie of this series in hot-plate, tail-flick, and formalin-induced licking tests, which was partially prevented by pretreatment with mecamylamine, a nicotinic receptor antagonist.     

Synthesis and antitumor activity of epoxy heterocyclic compounds

Translated from Khimiko-farmatsevticheskii Zhurnal, Vol. 27, No. 1, pp. 51–54, January, 1993.     

Synthesis, pharmacological activity evaluation and molecular modeling of new polynuclear heterocyclic compounds containing benzimidazole derivatives

Novel heterocyclic compounds containing benzimidazole derivatives were synthesized from 2-(1Hbenzimidazol-2-yl) acetonitrile (1) and arylhydrazononitrile derivative 2 was obtained via coupling of 1 with 4-methyl phenyldiazonium salt, which was then reacted with hydroxylamine hydrochloride to give amidooxime derivative 3. This product was cyclized into the corresponding oxadiazole derivative 4 upon reflux in acetic anhydride. Compound 4 was refluxed in DMF in the presence of triethylamine to give the corresponding 5-(1H-benzimidazol-2-yl)-2-p-tolyl-2H-1,2,3-triazol-4-amine 6. Treatment of compound 6 with ethyl chloroformate afforded 2,6-dihydro-2-(4-methylphenyl)-1,2,3-triazolo[4″,5″-4′,5′]pyrimido[1,6-a]benzimidazole-5(4H)-one (8). 1,2-bis(2-cyanomethyl-1H-benzimidazol-1-yl)ethane-1,2-dione (10) was synthesized via the condensation reaction of 2-(1H-benzimidazol-2-yl) acetonitrile (1) and diethyloxalate. The reactivity of compound 10 towards some diamine reagents was studied. The in vitro antimicrobial activity of the synthesized compounds was investigated against several pathogenic bacterial strains such as Escherichia coli O157, Salmonella typhimurium, E. coli O119, S. paratyphi, Pseudomonas aeruginosa, Staphylococcus aureus, Listeria monocytogenes and Bacillus cereus. The results of MIC revealed that compounds 12a–c showed the most effective antimicrobial activity against tested strains. On the other hand, compounds 12a, b exhibited high activity against rotavirus Wa strain while compounds 12b, c exhibited high activity against adenovirus type 7. In silico target prediction, docking and validation of the compounds 12a–c were performed. The dialkylglycine decarboxylase bacterial enzyme was predicted as a potential bacterial target receptor using pharmacophorebased correspondence with previous leads; giving the highest normalized scores and a high correlation docking score with mean inhibition concentrations. A novel binding mechanism was predicted after docking using the MOE software and its validation.     

Synthesis and enzyme inhibitory activities of some new pyrazole-based heterocyclic compounds

Three tridentate N,N-bis(3,5-dimethylpyrazol-1-ylmethyl)-1-hydroxy-2-aminoethane (2), N,N-bis(3,5-dimethylpyrazol-1-ylmethyl)-cyclohexylamine (3) and 2-[bis(1,5-dimethyl-1H-pyrazol-3-ylmethyl)amino]ethan-1-ol (4) are synthesized and spectroscopically characterized together with 1-hydroxymethyl-3,5-dimethylpyrazole (1). These have been tested in inhibitory activities against various hyperactive enzymes like urease, β-glucuronidase, phosphodiesterase, α-chymotrypsin, acetylcholinesterase and butyrylcholinesterase. Compounds 1, 2 and 3 were found to be selective inhibitors of urease. Compound 4 was found to be selective inhibitor of butyrylcholinesterase. The nature of the junction between pyrazoles cycles determined the activities of these tripods. While the tripods are inactive towards urease or glucuronidase, they turn to be selective towards butyrylcholinesterase.     

Synthesis,antiinflammatory and analgesic activity of new hexahydropyrimidine derivatives

A number of potentially active hexahydropyrimidine derivatives of pharmaceutical interest have been synthesized. Various diSchiff's bases prepared by reacting different aromatic aldehydes with 1,3-diaminopropane were suitably reduced to give their tetrahydro derivatives which were then condensed with appropriate aldehydes to give a series of hitherto unreported hexahydropyrimidines. The resulting products were evaluated by oral route for their antiinflammatory activity. The activity of compounds 11, 23 and 4 was excellent and comparable to indomethacin. In addition to oral route of administration, the antiinflammatory activity of hexahydropyrimidine derivatives was also studied topically through transdermal gels. Compounds 11, 23, 4 and 22 produced significant inhibition in edema and showed good antiinflammatory activity comparable to diclofenac sodium gel (Relaxyl gel). All these compounds were also tested for their analgesic activity and their LD50 determined. Compounds 11, 20 and 23 showed a comparable activity with aspirin. The MTD for all the compounds was found to be > 1800 mg/kg.     

Synthesis and pharmacological evaluation of new N-methyl-arylpyrrolidinols with analgesic activity

In the present paper, we report on the synthesis and antinociceptive activity of a new series of N-methyl-arylpyrrolidinols that we designed for a rational structure-activity relationship (SAR) study. The antinociceptive properties were investigated in vivo by the hot plate and formalin tests in mice and control on the locomotory activity was also monitored by the rota rod test. With this aim, the evaluation of the lipophilicity of all compounds was performed by the Daylight computational method in order to better understand the SAR. Interesting properties were proven for the compounds of the entire series.     

Synthesis and antifungal activity of monoterpenoids of the carane series

The antifungal activity of terpenoids of the carane series was studied; an interaction was found between the structures of these compounds and their antifungal properties. The actions of several terpenoids on the adhesive activity and enzyme systems of the fungus Candida albicans were studied.     

Synthesis and analgesic activity of new 1,3,4-oxadiazoles and 1,2,4-triazoles

A series of new 1,3,4-oxadiazoles and 1,2,4-triazoles were synthesized in order to obtain new compounds with potential analgesic activity. Compounds were evaluated for their analgesic activities by formalin-induced nociception test. Mefenamic acid (as the reference drug) did not show any activity in the early phase of the formalin test, while compounds 7b, 7c, 8c, and 9a significantly reduced the nociception in this phase. However in the late phase of formalin test all of the target compounds and mefenamic acid showed analgesic activity in comparison to control.     

A new thiophene and two new monoterpenoids from Xanthium sibiricum

Three new compounds (1–3), together with six known compounds (4–9), were isolated from the fruits of Xanthium sibiricum. The structures and the absolute configurations of sibiricumthionol (1), (+)-(5Z)-6-methyl-2-ethenyl-5-hepten-1,2,7-triol [(+)-2], ( ? )-(5Z)-6-methyl-2-ethenyl-5-hepten-1,2,7-triol [( ? )-2], (2E,4E,1′S, 2′R, 4′S, 6′R)-dihydrophaseic acid (3), (+)-xanthienopyran [(+)-4] and ( ? )-xanthienopyran [( ? )-4] were established by extensive spectroscopic analyses, X-ray crystallographic analysis, ECCD analysis and ECD calculations. Caffeic acid (7) and caffeic acid ethyl ester (8) weekly inhibited α-glucosidase enzymatic activity by 44.5% and 40.2%, respectively, at 40 μM. Protocatechuic acid (9) selectively exhibited cytotoxicity against HepG2 cell lines, with an IC₅₀ value of 2.92 μM.     

Synthesis and biological properties of S-adamantylated heterocyclic compounds

A series of new S-adamantylated compounds were prepared by adamanlyl cation attack on the thiol group. The biological activity of new compounds as the inducers of TNF-alpha in genetically modified mouse melanoma cells is presented.     

Synthesis and antihepatotoxic activity of some heterocyclic compounds containing the 1,4-dioxane ring system

Silymarin isolated from Silybum marianum is a mixture of three isomers, silybin (1), silydianin (2) and silychristin (3). Silybin is the most active antihepatotoxic agent, and contains a 1,4-dioxane ring in addition to a flavonoid moiety. Based on the skeleton of silybin, we prepared some flavones and coumarins containing the 1,4-dioxane ring system and evaluated them for antihepatotoxic activity against carbon tetrachloride induced hepatotoxicity in albino rats. The degree of protection was determined by measuring biochemical parameters such as serum glutamic oxaloacetic transaminase (SGOT), serum glutamic pyruvate transaminase (SGPT), alkaline phosphatase (ALKP), total protein (TP) and total albumin (TA). The compounds namely 3',4'(1",4"-dioxino) flavone (4f), and 3',4'(2-hydroxy methyl, 1",4"-dioxino) flavone (4g) were found to exhibit a significant activity comparable to standard drug silymarin (silybon-70). Other compounds also exhibited good activity. The structure activity relationship (SAR) was also studied, and where the flavonoid analogues containing a hydroxy methyl group at position-2" in the dioxane ring exhibited superior antihepatotoxic activity in comparison to coumarin derivatives.     

Synthesis and anticholinesterase activity of new bispyridinium compounds.

Synthesis of new bis(1-methylpyridinium) compounds containing a 1,4-diacetylbenzene linkage between the pyridinium moieties from commercially available 2-, 3-, and 4-picoline precursors was accomplished via metallation, reaction of the picolyllithium with 1,4-dicyanobenzene, and subsequent quaternization of the resulting bispyridyl compounds. Acetylcholinesterase inhibitory activity was determined colorimetrically with purified electric eel enzyme. Examination of structure-activity relationships indicated that the 3-substituted pyridinium compound is the most potent isomer, followed by the 2-substituted isomer, and that the 4-substituted analogue is the least active.     

Synthesis of new compounds derived from metronidazole and amino acids and their esters as antiparasitic agents

A number of new compounds derived from metronidazole and amino acids and their esters have been synthesized through a reaction between 2-(2-methyl-5-nitro-1H-imidazol-1-yl)acetic acid and a number of amino acid esters in the presence of N,N′carbonyldiimidazole (CDI). Hydrolysis of the esters derivatives with sodium hydroxide (4%) followed by acidification with hydrochloric acid (3?M) afforded the corresponding acids. The newly synthesized compounds were characterized by elemental analysis and by spectroscopic techniques such as ¹H-NMR, ¹³C-NMR, and mass spectrometry. Some of the prepared compounds exhibited lethal activity against pathogenic protozoan parasites.     

Synthesis and psychotropic activity of new long-acting lithium compounds

Translated from Khimiko-farmatsevticheskii Zhurnal, Vol. 27, No. 3, pp. 19–22, March, 1993.