Studies on quinoxaline derivatives. Synthesis of quinoxalylamino-1,3-diazacycloalkanes with potential hypotensive activity.

A series of quinoxalylamino-1,3-diazacycloalkanes was obtained by the reaction of the corresponding substituted aminoquinoxalines with alcohols and amines. The effect of selected compounds on the blood pressure of anaesthesized normotensive rats was studied.

Studies on pyrazine derivatives. XXX. Synthesis of pyrazinylamino-1,3-diazacycloalkanes of potential circulatory activity.

A series of pyrazinylamino-1,3-diazacycloalkanes was obtained by reaction of the corresponding substituted aminopyrazines with aliphatic amines. Selected compounds were studied with respect to their potential circulatory activity. The effect on the blood pressure, isolated rat tail artery and heart atria, and an influence on the human blood platelet aggregation were investigated.

Synthesis, structure and biological activity of 1,2,4-triazolo-1,3-thiazine derivatives.

A group of condensed triazole-thiazine derivatives (2a-i, 3b, 3j) was obtained in reaction of the corresponding 5-substituted 1,2,4-triazole-3-thiones (1a-j) with epichlorohydrin in alkaline medium. The structure of the compounds synthesized was confirmed by spectral and roentgenographic methods. Tuberculostatic and circulatory activities of the compounds were also studied.

New antagonists of the vasopressin receptor mediated contraction in rat tail artery.

A perfused isolated rat tail artery preparation was employed to study antagonistic properties of four newly synthesized arginine-vasopressin (AVP) analogues against the V1 receptor. The activity of the agents SCATyr(Me)AVP, OCATyr(Me)AVP, OCAAVP and SCAAVP was related to that of a recognized antagonist d(CH2)5Tyr(Me)AVP. SCATyr(Me)AVP elicited outstanding antagonistic properties by blocking at concentration of 10(-7) M nearly completely the constrictory activity of AVP.