The Synthesis and Anticonvulsant Activity of 1-Substituted-7-Methoxy-1,2,4-Triazolo [4,~3-a]Quinoline

Authors: LI-PING GUAN, XIAN-YU SUN, GUAN-RONG TIAN, KYU-YUN CHAI, ZHE-SHAN QUAN

Abstract: A new series of 1-substituted-7-methoxy-5-phenyl-1,2,4-triazolo [4,3-a]quinolines were synthesized using ethyl-3-oxo-3-phenylpropanoate and 4-methoxybenzenamine as the starting material. Their anticonvulsant activity was evaluated by the maximal electroshock (MES) test and 7-methoxy-5-phenyl-1,2,4-triazolo[4,3-a]quinoline (4a) was identified as the most potent compound, with an ED_{50} value of 9.2 mg kg^{-1}, which is comparable to the reference drug phenytoin (ED_{50} = 9.9 mg kg^{-1}). To explore the possible mechanism of its anticonvulsant activity, compound 4a was tested with the rotarod neurotoxicity test, pentylenetetrazole (sc-PTZ) test, and isoniazid test. Compound 4a had a higher protective index (PI = TD_{50}/ED_{50}) value (16.6) than phenytoin (PI = 7.0), and it antagonized pentylenetetrazole- and isoniazid-induced seizures with an ED_{50} of 21.1 mg kg^{-1} and 83.3 mg kg^{-1}, respectively.

Keywords: 1,2,4-triazolo[4,3-a] quinoline, Anticonvulsant, MES, sc-PTZ, Isoniazid

Full Text: PDF