Novel triazolo[4,3-a]quinazolinone and bis-triazolo[4,3-a:4,3′-c]quinazolines: synthesis and antitoxoplasmosis effect

El-Tombary, Alaa A.; Ismail, Khadiga Ahmed; Aboulwafa, Omaima M.; Omar, A.-Mohsen M.E.; El‐Azzouni, Mervat Z.; el-Mansoury, S T

doi:10.1016/s0014-827x(99)00038-5

Cited by 31 publications

(25 citation statements)

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“…SEM allows the study of the surface of T. gondii at high magnification with three-dimensional perspectives (El-Tombary et al, 1999). The present work examined the details of the tachyzoites before and after therapy with the tested compounds.…”

Section: Discussionmentioning

confidence: 99%

“…Animals: Swiss strain albino mice were used to carry out this study. They were divided into two main groups: the infected control group 1, and the infected treated group 2, given orally the tested compounds 48 hour post infection (PI) at a dose of 0.25 mg/mouse (El-Tombary et al, 1999). Group 2 was further subdivided into 12 equal subgroups (six mice each) corresponding to the number of compounds to be evaluated.…”

Section: Methodsmentioning

confidence: 99%

“…Group 2 was further subdivided into 12 equal subgroups (six mice each) corresponding to the number of compounds to be evaluated. All groups were infected with a dose of 3.5 9 10 3 tachyzoites/mouse, and were sacrificed at the fifth day PI (El-Tombary et al, 1999).…”

Section: Methodsmentioning

confidence: 99%

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Synthesis and evaluation of some pyrimidine analogs against toxoplasmosis

et al. 2008

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Toxoplasmosis is a worldwide infection caused by the obligate intracellular protozoan parasite Toxoplasma gondii. Some pyrimidine analogs were synthesized to be evaluated for their antitoxoplasma effects in animal experiments. Results were assessed by studying parasite density, estimation of serum Toxoplasma antigen, studying the ultrastructural changes of the parasite, and the histopathological changes of the affected organs and inhibitory activity for dihydrofolate reductase (DHFR) isolated from Cryptosporidium parvum. The result showed that 4 out of 12 synthesized compounds have promising antitoxoplasma potentials. The animals that received these four compounds showed statistically significant decrease in the mean number of the parasite count in the liver and the spleen when compared to the corresponding control group. Moreover, Toxoplasma antigen was very low or even absent in the serum of animals receiving these compounds. Light microscopic examination of the peritoneal exudates of animals receiving these compounds showed stoppage of movement and deformity in shape of the tachyzoites, whereas scanning electron microscopy revealed that the organisms had lost their crescent shape, with dimples and deep ridges on their surfaces. Very mild histopathological changes were noticed in liver, spleen, and lungs of the groups of animals receiving these compounds in comparison to the other groups. Thus, these compounds proved their effectiveness in eradication of the experimental Toxoplasma infection and inhibition of DHFR from C. parvum.

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Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

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Synthesis and evaluation of some pyrimidine analogs against toxoplasmosis

et al. 2008

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“…This approach was not applied previously to the synthesis of fused imidazo-, pyrazolo[a]-and triazolo[a]-quinazolinones. There are published data only on the preparation of triazolo[a]quinazolinone derivatives via transformations of quinazolinones having a sulfanyl, hydrazino, thiosemicarbazido, or S-methylisothiosemicarbazido group in the 2-position [2,5,[12][13][14][15].In continuation of our studies on the synthesis of fused fluorine-containing nitrogen heterocycles, we have developed a general procedure for the preparation of fluorinated triazolo-, pyrazolo-, and imidazo[a]-quinazolinones by reaction of tetrafluorobenzoyl chloride with difunctional N,N'-dinucleophiles. By acylation of N,N'-diphenylguanidine (II) with tetrafluorobenzoyl chloride (I) in boiling toluene we obtained N, N'-diphenyl-N-(2,3,4,5-tetrafluorobenzoyl)-guanidine (III) (Scheme 1).…”

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confidence: 99%

“…Antibacterial, antitoxoplasmatic, antihypertensive, and antihistaminic agents, phosphodiesterase inhibitors, and compounds possessing other kinds of biological activity have been revealed among quinazolin-4-one derivatives [2][3][4][5][6][7][8]. A known procedure for building up such heterocyclic systems is based on cyclization of 2-halo-substituted benzoyl chlorides with difunctional nitrogen-centered nucleophiles [4,[9][10][11].…”

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confidence: 99%

Fluorine-Containing Heterocycles: XII. Fluorine-Containing Quinazolin-4-ones and Azolo[a]quinazolinone Derivatives

Lipunova¹,

Носова²,

Laeva³

et al. 2005

Russ J Org Chem

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Methods for the synthesis of fluorine-containing derivatives of 2-imino-1,3-diphenylquinazolin-4-one, imidazo[1,2-a]quinazolin-5-one, pyrazolo[1,5-a]quinazolin-5-one, and [1,2,4]triazolo[1,5-a]quinazolin-5-one were developed on the basis of the reaction of tetrafluorobenzoyl chloride with N,N'-diphenylguanidine and aminoazoles. * For communication XI, see [1].Fused quinazolin-4-one derivatives attract strong interest from the viewpoint of their potential biological activity. Antibacterial, antitoxoplasmatic, antihypertensive, and antihistaminic agents, phosphodiesterase inhibitors, and compounds possessing other kinds of biological activity have been revealed among quinazolin-4-one derivatives [2][3][4][5][6][7][8]. A known procedure for building up such heterocyclic systems is based on cyclization of 2-halo-substituted benzoyl chlorides with difunctional nitrogen-centered nucleophiles [4,[9][10][11]. This approach was not applied previously to the synthesis of fused imidazo-, pyrazolo[a]-and triazolo[a]-quinazolinones. There are published data only on the preparation of triazolo[a]quinazolinone derivatives via transformations of quinazolinones having a sulfanyl, hydrazino, thiosemicarbazido, or S-methylisothiosemicarbazido group in the 2-position [2,5,[12][13][14][15].In continuation of our studies on the synthesis of fused fluorine-containing nitrogen heterocycles, we have developed a general procedure for the preparation of fluorinated triazolo-, pyrazolo-, and imidazo[a]-quinazolinones by reaction of tetrafluorobenzoyl chloride with difunctional N,N'-dinucleophiles. By acylation of N,N'-diphenylguanidine (II) with tetrafluorobenzoyl chloride (I) in boiling toluene we obtained N, N'-diphenyl-N-(2,3,4,5-tetrafluorobenzoyl)-guanidine (III) (Scheme 1). The 1 H NMR spectrum of III confirmed the presence in its molecule of two

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