title: Synthesis, Anti-inflammatory and Antibacterial Activities of Novel Pyrazolo[4,3-g]pteridines.
abstract: A novel series of 6-substituted pyrazolo[3,4-g]pteridines 2-9 and pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pteridin-2(3H)-one (thione) 10 and 11 was synthesized using the starting compound 3,7-dimethyl-1-phenylpyrazolo[4',3':5,6]pyrazino[2,3-d][1,3]oxazin-5(1H)-one 2. The structure of the newly synthesized compounds was elucidated by IR, (1)H-NMR, (13)C-NMR, mass spectroscopy and elemental analyses. The anti-inflammatory activity of all the newly synthesized compounds was evaluated using the carrageenan-induced paw oedema test in rats using indomethacin as the reference drug. Compound 11 and the two derivatives 7f and 8b were the most active compounds, showing an activity comparable to indomethacin. Also, the synthesized compounds were evaluated for their antibacterial activity against Gram-positive bacteria (Staphylococcus aureus and Bacillus cereus) and Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) using chloramphenicol as control. The pyrazolotriazolopteridin-2-thione 11, 6-hydroxyethyl- 6a, 6-(4-nitrophenyl)-7g, and 6-(phenylamino) 8b derivatives were found to be the most active compounds against the Gram-positive species. None of them showed any activity against Gram-negative species.
authors.affiliation: Department of Chemistry, Faculty of Science, Assiut University.
authors.forename: Shawkat Ahmed
authors.initials: SA
authors.lastname: Abdel-Mohsen
authors.forename: Talaat Ibrahim
authors.initials: TI
authors.lastname: El-Emary
authors.forename: Hussein Salama
authors.initials: HS
authors.lastname: El-Kashef
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004487:Edema / Q000188:drug therapy*; D006090:Gram-Negative Bacteria / Q000187:drug effects*; D006094:Gram-Positive Bacteria / Q000187:drug effects*; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D011621:Pteridines / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D011720:Pyrazoles / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D013329:Structure-Activity Relationship
chemical_list: D000900:Anti-Bacterial Agents; D000894:Anti-Inflammatory Agents, Non-Steroidal; D011621:Pteridines; D011720:Pyrazoles