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PubMed1989

[Studies on pyrazine derivatives. XXVI. Synthesis and tuberculostatic activity of N-pyrazinylthiourea].

2-Amino-3-chloropyrazine and 2-amino-6-chloropyrazine were reacted with appropriate sodium alkoxides to give 2-aminopyrazine derivatives with the methoxy, benzyloxy, chlorobenzyloxy, dichlorobenzyloxy, bromobenzyloxy or dibromobenzyloxy group at positions 3 and 6 (I-XIV). The obtained compounds were converted into N-pyrazinyl-N'-benzoylthioureas (XV-XXXI) by reacting with benzoyl isothiocyanate. Their hydrolysis yielded N-pyrazinylthioureas XXXII-XLVII. Analogical reactions of alkoxyaminopyrazines with p-chlorophenyl isothiocyanate or 2,6-dichlorophenyl isothiocyanate afforded corresponding N-pyrazinyl-N'-(p-chlorophenyl)thioureas and N-pyrazinyl-N'- (2,6-dichlorophenyl)thioureas (XLVIII-LVIII). The obtained compounds were found to display tuberculostatic in vitro activity with MIC values from 8 meg/cm3 to 1000 mu meg/cm3.

Antitubercular Agents↗
PubMed1987

Comparison of 1,2-dihydropyrido[3,4-b]pyrazines (1-deaza-7,8-dihydropteridines) with several other inhibitors of mitosis.

Several properties of four 1-deaza-7,8-dihydropteridines were compared with those of each other and with those of colchicine, nocodazole, podophyllotoxin, and vincristine. Compound NSC 370147 was more active than the other compounds of this type with respect to inhibition of proliferation of cultured L1210 cells and to increase of the mitotic index. On an equimolar basis it was more active than two of the 1-deaza-7,8-dihydropteridines, colchicine, and nocodazole and was comparable to podophyllotoxin and vincristine in inhibiting the polymerization of partially purified pig brain tubulin. All four of the 1-deaza-7,8-dihydropteridines caused decreases in the extent of binding of [3H]colchicine to partially purified tubulin and enhanced the binding of [3H]vincristine to the tubulin. Emphasis in further testing was placed upon NSC 370147, because it is easier to synthesize and is more stable than some of the other compounds of this type and because its greater solubility in water facilitates its formulation for therapeutic administration. Compound NSC 370147 inhibited competitively the binding of [3H]colchicine to purified tubulin and enhanced slightly the binding of [3H]vincristine to tubulin. It was also synergistic with vincristine in killing cultured L1210 cells and in increasing the life-spans of mice bearing P388 leukemia. It is suggested that it would be worthwhile to evaluate combinations of NSC 370147 and vincristine in tests with other experimental neoplasms.

Animals↗