A method for the treatment of symptoms of Parkinson's disease in animal subjects, including man, wherein there is administered a therapeutically effective amount of at least one ester of dl- or L-m-tyrosine of the formula ##SPC1## Wherein R denotes a lower, straight or branched alkyl having one to three carbon atoms in the form of a base or a pharmaceutically acceptable acid. Said ester is administered by itself with at least one of the compounds s,4-dihydroxyphenyl-.alpha.-methyl-.alpha.-hydrazino-propionic acid (II) or N.sup.1 -seryl-N.sup.2 -(2,3,4-trihydroxybenzyl)-hydrazine (III) in an amount sufficient to potentiate the effectiveness of said ester. Compounds II and III may be used either concurrently with or prior to treatment with compound I.
This is a continuation-in-part of applications Ser. Nos. 387,370, pending, and 190,682 now abandoned, filed Aug. 10, 1973 and Oct. 19, 1971 respectively.
A compound of the formula ##STR1## possesses antihypertensive activity. Also provided are methods for the preparation of the compounds as well as pharmaceutical formulations and methods for their use as antihypertensive agents.
