53-73-6

Hypertensin,Ciba,W. Germany,1961

ChEBI: Angiotensinamide is an oligopeptide.

48 mg (0.042 mmol) of L-asparaginyl-L-arginyl-L-valyl-L-tyrosyl-L-valyl-Lhistidyl- L-prolyl-L-phenylalanine methyl ester trihydrochloride are suspended in 0.5 ml of methanol, and treated gradually in the course of one hour with 0.3 ml of N-caustic soda solution (about 7 equivalents) so that the pH value of the solution is maintained between 10.5 and 11.5. After a further 30 minutes the solution is freed from methanol under vacuum at room temperature, adjusted with 1 N acetic acid to pH 7.4 and lyophilized. The residual mixture of free peptide and inorganic salts (79 mg) is fractionated by countercurrent distribution in the system butanol/0.1 N ammonium hydroxide. The pure octapeptide is obtained as a colorless powder which is soluble in water and methanol, more sparingly soluble in ethanol, and insoluble in acetone.

Vasoconstrictor

Angiotensin amide (Hypertensin)is a synthetic polypeptide (1-L-aspariginyl-5-L-valine angiotensinoctapeptide) and has twice the pressor activity ofangiotensin II. It is pharmaceutically available as alyophilized powder for injection (0.5–2.5 mg diluted in500 mL of sodium chloride injection or 5% dextrose for injection)to be administered by continuous infusion. The pressoreffect of angiotensin is due to an increase in peripheralresistance; it constricts resistance vessels but has little or nostimulating action on the heart and little effect on the capacitancevessels. Angiotensin has been used as an adjunct invarious hypotensive states. It is mainly useful in controllingacute hypotension during administration of general anestheticsthat sensitize the heart to the effects of catecholamines.