Synthesis and biological evaluation of some new 3 ,4-dihydropyrimidin-4-ones.

Condensation of 5-cyano-2-hydrazino-3-N-methyl-6-phenyl/p-chlorophenyl-3,4-dihydropyrimidin-4-one (3a and 3b) with 2,4-bisalkyl/arylamino-6-chloro-s-triazine (4) gave the corresponding 2,4-bisalkyl/arylamino-6-[5'-cyano-3'-N-methyl]-6'-phenyl/pchlorophenyl-3',4'-dihydropyrimidin-4'-one-2'-yl-hydrazino-s-triazines (5a-n and 6a-n). The compounds 4 have been prepared by the condensation of cyanuric chloride and different alkyl/aryl amines. The reaction between 5-cyano-3-N-methyl-2-methylthio-6-phenyl/p-chlorophenyl-3,4-dihydropyrimidin-4-one (2a and 2b) with hydrazine hydrate furnished 3a and 3b, respectively. The condensation of 6-phenyl/p-chlorophenyl/5-cyano-2-mercapto-3,4-dihydropyrimidin-4-one (1a and 1b) with methyl iodide yielded 2a and 2b, respectively. All the products have been evaluated in vitro for their antimicrobial activity against several microbes and antitubercular activity against Mycobacterium tuberculosis H37 Rv.     

Synthesis and calcium-antagonist activity of some phosphonates

The synthesis and pharmacological evaluation of a series of phosphonates related to Fostedil, diethyl 4-(benzothiazol-2-yl)benzylphosphonate 1 , a potent calcium antogonist are reported. Among the compounds studied, only diethyl 4-(benzooxazol-2-yl)benzylphosphonate 5 , which is closely related to Fostedil, shows a low calcium-antagonist activity.     

Synthesis and biological evaluation of some stilbene derivatives

Several trans and cis stilbenes with substitution on the olefinic bridge were synthesized and characterized by IR, NMR and mass spectroscopy in an effort to obtain substances that could be more readily formulated. All the synthesized compounds were screened against Molt4/C8, CEM and L1210 cell lines. None of these compounds were endowed with pronounced cytostatic activity. However, Schiff derivatives emerged as cytostatic agents (IC₅₀: 0.77–10 μg/ml) that deserve further investigation.     

Synthesis and biological evaluation of some stilbene-based analogues

The phytoalexin 3,5,4′-trihydroxy-trans-stilbene (resveratrol) has attracted considerable attention from biologists and chemists due to its diverse biological properties. Owing to the biological importance of this compound, we have synthesized new stilbene-based analogues by using substituted benzyl chlorides and substituted aldehydes in a two-step reaction and evaluated their in vitro antioxidant, antibacterial and antifungal potential. Most of the compounds displayed moderate to significant radical scavenging activity. (E)-1-(3,4-difluorophenyl)-2-(4-fluorophenyl)ethene (4c) showed nearer equipotent antibacterial activity against Staphylococcus aureus. (E)-1,2-bis(4-fluorophenyl)ethene (4a), (E)-1-(3-fluorophenyl)-2-(4-fluorophenyl)ethene (4b), (E)-1-(2,4-dichlorophenyl)-2-(3,4-dichlorophenyl)ethene (4f), (E)-1-(2,4-dichlorophenyl)-2-(3-chlorophenyl)ethene (4g), (E)-1-(2,4-dichlorophenyl)-2-(4-fluorophenyl)ethene (4j) (E)-1-(4-fluorophenyl)-2-(3-chlorophenyl)ethene (4l) and (E)-1-(4-chlorophenyl)-2-(4-fluorophenyl)ethene (4n) inhibited the growth of Penicillium chrysogenum.     

Synthesis and biological evaluation of new thiazolopyrimidines

In this study, a series of 4-amino-5-cyano-3-substituted-2,3-dihydrothiazol-2-thiones (1a-c), as well as their triazolo and triazinopyrimidine derivatives such as 8-substituted-3-benzyl-5-methylthiazolo[5,4-e][1,2,4] triazolo[1,5-c]pyrimidin-2-thiones (4-6, 10) and 3-benzyl-5-methyl thiazolo[5,4-e]pyrimidino[3,4-b][1,2,4]triazin-2-thiones (7a-b) were prepared as potential antimicrobial and antitumor agents. Some of the tested compounds showed promising antimicrobial activity and non of them showed any appreciable antitumor activity.     

Synthesis and biological evaluation of some pyrazolinylpyridines and pyrazolylpyridines

Various new 2-(1'-acetyl-5'-substituted-aryl-2'-pyrazolin-3'-yl)aminopyridines (3a-3e) and 2-(1'-phenyl 5'-substituted aryl-2'-pyrazol-3'-yl)aminopyridines (4a-4e) have been derived from 2-(substituted benzylidenylacetyl)aminopyridines (2a-2e). The structure of these compounds have been elucidated by elemental and spectral (IR, 1H-NMR, mass) analysis. Furthermore, above said compounds were evaluated for their insecticidal, antifungal, and antibacterial activities. Compound 4b 2-[1'-phenyl-5'-(o-chlorophenyl)-2'-pyrazol-3'-yl]aminopyridine, when compared for insecticidal and antifungal activities with parathion and fluconazole, respectively, was found to be the most potent one in this series. It also possessed remarkable antibacterial properties.     

Synthesis, structure characterization, and biological evaluation of some new 1,2,3-benzotriazole derivatives

Ten novel benzotriazole compounds were synthesized. Their chemical structures were confirmed by ¹H NMR, IR, and elemental analyses, coupled with three selected single-crystal structures (compounds A2, B3, and B5). Their antimycotic and antitumor activities were also investigated. The title compounds showed some antitumor activities, especially in the case of A3 and A4, which showed the most potent activity of propagation inhibition in liver and galactophore cancer cells.     

Synthesis and anticonvulsant evaluation of some new 2-benzylsuccinimides.

A series of 2-benzylsuccinimides (4a-f) were prepared for evaluation as potential anticonvulsants. Primary (Phase I) screening of these compounds indicated that succinimides 4d and 4e, containing lipophilic (+ pi), electron-withdrawing (+ sigma) phenyl substituents, were the most effective in controlling seizures induced by maximal electroshock (MES) and subcutaneous pentylenetetrazol (scMet). Compounds 4a, 4c, and 4d showed activity against scMet-induced seizures equal to that of their 2-phenylsuccinimide analogues and were somewhat more effective in the MES test. In quantitative (Phase II) testing, when administered ip in mice, 4d and 4e both demonstrated anticonvulsant potency superior to that of the prototype drug (ethosuximide) by the MES and scMet assays. However, they also exhibited greater neurotoxicity than ethosuximide in the rotorod test.     

Synthesis and biological activity of some new flavone derivatives

In this study, a new series of 2-(4-[substituted benzylamino-methyl)-phenyl]-4H-benzopyrane-4-one (IVa-e) and N-substituted benzyl-N-[4-(4-oxo-4H-benzopyrane-2-yl)benzyl]-3-phenyl-acrylamide (Va-e) derivatives was synthesized and the results of their biological activity are reported. The synthesized compounds were tested for their in vitro antifungal and antibacterial activities. Compound IVa showed the best antifungal activity compared with miconazole (CAS 22916-47-8). Compound IVe indicated the same antibacterial activity compared with the control drug ampicillin (CAS 69-53-4).     

Synthesis and biological evaluation of new niphathesine analogues

Niphathesine C and related pyridine alkaloids are well known natural products with interesting antimicrobial activities, characterized by a pyridine ring and a lipophilic side chain with a terminal nitrogen-containing functional group. This paper describes the synthesis of analogues of these alkylpyridine alkaloids with variation of the heterocyclic ring and the terminal functional group. Key steps of the syntheses are a Sonogashira reaction of appropriate aryl iodides with undec-10-ynol or undec-10-ynoic acid derivatives. The resulting compounds were tested in an agar diffusion assay against several bacteria and fungi.     

Synthesis and biological evaluation of some differently substituted 9,10-anthracenediones

9,10-Anthracenedione derivatives are known to exhibit a quite potent anticancer activity. It has also been reported that these compounds can be effectively employed in both antibacterial and antitrypanosomal therapy. Anthraquinones also exhibit some undesirable side effects, like cardiotoxicity. So many interactions seem to demonstrate that 9,10-anthracenediones strongly interact with a number of biological sites. In this paper we wish to report on the synthesis and the pharmaceutical activity of some newly synthesised derivatives containing the anthraquinone pharmacophore.     

Synthesis and biological evaluation of some cyclic phosphoramidate nucleoside derivatives

(E)-5-(2-Bromovinyl)-2'-deoxy-5'-O-(3-methyl-2-oxo-5-formyl-1,3,2- oxazaphosphacyclopentan-2-yl)uridine has been synthesized and, under physiological conditions and without the necessity for enzyme activity, has been shown to yield the 5'-nucleotide in vitro. Unfortunately this compound is not sufficiently stable in solution for it to be tested in vivo. The biological properties of this and some related derivatives of (E)-5-(2-bromovinyl)-2'-deoxyuridine and acyclovir have been evaluated in in vitro and in vivo systems designed to show the effects of any intracellular liberation of the nucleotide. Although some of the derivatives are probably acting as prodrugs of the active nucleosides, there is no evidence for the liberation of meaningful concentrations of the 5'-nucleotide by any of the compounds.     

Synthesis and biological evaluation of some novel 3,4-disubstituted isocoumarins

In this paper we report the synthesis of a new family of 4-alkyl isocoumarin derivatives having bromo carbonyl and amino carbonyl group at 3(rd) position of the heterocyclic ring. Synthesis, spectral analysis and bioactivity of new isocoumarin derivatives are discussed in this paper. Some of the synthesized compounds displayed comparable antibacterial activity and some of the new compounds showed an interesting inhibitory effect on the growth of four pathogen fungi involved in plant diseases. A fair number of compounds were found to have good analgesic property on comparing with standard drug analgin.     

Synthesis,characterization and biological evaluation of some novel fluoroquinolones

Different derivatives of fluoroquinolones were synthesized by combining it with different thiadiazoles. The synthesized compounds were characterized by infrared spectroscopy, proton nuclear magnetic resonance and mass spectral data. The compounds were screened for their antibacterial and antifungal activity. Ciprofloxacin derivatives with thiadiazoles 7c showed good antibacterial as well as antifungal activities, whereas 13c and 13e showed antibacterial and antifungal activity respectively. Sparfloxacin derivative 8c showed both antibacterial and antifungal activity. Sparfloxacin derivatives 14b and 14e showed antibacterial and antifungal activity respectively.     

Cardenolide analogues. 7. Synthesis and biological activity of some new steroidal guanylhydrazones.

The synthesis, proof of structure, and biological activity of some new steroidal 17beta-formyl guanylhydrazones are described. The guanylhydrazones of nondigitalis-like steroids inhibited myocardial Na+,K+-ATPase but had only a depressant effect on myocardial contractility. By comparison, the corresponding guanylhydrazone of a digitalis-like steroid gave a positive inotropic effect in concentrations that also inhibited Na+,K+-ATPase. The nondigitalis-like guanylhydrazones also inhibited membrane Mg2+-ATPase and this may infer that the compounds act nonspecifically by membrane stabilization rather than by interaction with stereoselective receptors. Biological activity was determined in the guinea pig.