title: Biological effects of a new set 1,2,4-triazolo[1,5-a]quinazolines on heart rate and blood pressure.
abstract: BACKGROUND
  Several quinazoline and triazole derivatives are reported to possess a wide-range of interesting pharmacological effects. Although various triazoloquinazoline subclasses having been synthesized and studied, the preparation of 1,2,4-triazolo[1,5-a]quinazolines as antihypertensive agent is still relatively unexplored. In continuation of our earlier research, we aimed at the synthesis and development of various potent antihypertensive 1,2,4-triazoloquinazoline derivatives.
  
  
  RESULTS
  A new series of 1,2,4-triazolo[1,5-a]quinazoline derivatives have been synthesized. Their structures were mainly established by spectroscopic methods of analysis (IR, MS, 1H and 13C NMR). Their in vivo antihypertensive activity was evaluated by tail cuff method using Muromachi Blood Pressure Monitor (Model MK 2000) for rats and mice. Some of the tested compounds were found to exhibit valuable effects in terms of heart rate and blood pressure. According to the biological results, some of tested derivatives have abolished completely the tachycardia of the parent compounds and may be studied and modified as potential adrenoblockers and cardiac stimulant.
  
  
  CONCLUSIONS
  New series of fifteen 1,2,4-triazolo[1,5-a]quinazolines were synthesized by convenient methodology from four key molecules, whereby their structures were established by advanced spectroscopic analyses. Some lead compounds have abolished completely the tachycardia of the parent compounds, that may be examined as potent adrenoblockers and some other compounds seem to be a cardiac stimulant or may be modified to enhance their hypotensive activity.
authors.forename: Rashad
authors.initials: R
authors.lastname: Al-Salahi
authors.forename: Kamal-Eldin
authors.initials: KE
authors.lastname: El-Tahir
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Alswaidan
authors.forename: Nabih
authors.initials: N
authors.lastname: Lolak
authors.forename: Mohammed
authors.initials: M
authors.lastname: Hamidaddin
authors.affiliation: Department of Pharmacetical Chemistry, College of Pharmacy, King Saud University, P, O, Box 2457, Riyadh 11451, Saudi Arabia. msmarzouk@yahoo.co.uk.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Marzouk