The invention concerns novel renin-inhibitory peptides which contain novel amino acids having an .alpha.-heteroatom attached to the backbone of the amino acid. ##STR1## These novel amino acids are positioned at the P.sub.2 position of the peptide. These are useful for treating renin-associated hypertension, hyperaldosteronism, and congestive heart failure. Processes for preparing the peptides, compositions containing them and methods of using them are included. Novel intermediates are also disclosed. Also included is a diagnostic method which uses the compounds to determine the presence of renin-associated hypertension or hyperaldosteronism.
This is a divisional application of U.S. Ser. No. 07/200,444 filed Jun. 6, 1988, now U.S. Pat. No. 5,036,054 which is a continuation-in-part application of U.S. Ser. No. 07/154,727 filed Feb. 11, 1988, now abandoned.
A number of architectures of switch compensation networks are described for the provision of a compensation current which ensures the maintaining of a desired switching ratio in an acoustic printhead. The described architectures include those which provide column compensation, row compensation, and row and column compensation to a transducer switching matrix. Control of the switching ratio by the compensation networks, is used in consideration of the dissipation of heat energy through expulsion of a heated drop, to provide a precisely controlled balance.
Compounds of formula (1) are described wherein R represents a --CONHOH, carboxyl, carboxyl ester, or --P(O)(X.sup.1 R.sup.8)X.sup.2 R.sup.9, where X.sup.1 and X.sup.2 are the same or different and each is oxygen or sulphur, R.sup.8 and R.sup.9 are the same or different and each represents hydrogen or an optionally substituted alkyl, aryl or aralkylthioalkyl group; R.sup.2 represents an optionally substituted alkyl, alkenyl, cycloalkyl, cycloalkylalkyl, aryl, aralkyl, aralkoxy, or aralkylthio group, or an amino, substituted amino, carboxyl, or carboxyl ester group; R.sup.3 represents hydrogen or alkyl; R.sup.4 represents hydrogen or alkyl; R.sup.5 represents an optionally substituted alkyl or alkenyl group optionally interrupted by one or more --O-- or --S-- atoms or --N(R.sup.7)-- groups, where R.sup.7 is a hydrogen atom or a C.sub.1-6 alkyl group, or --(Alk).sub.n R.sup.6 where Alk is an alkyl or alkenyl group optionally interrupted by one or more --O-- or --S-- atoms or --N(R.sup.7)-- groups, n is zero or 1, and R.sup.6 is an optionally substituted cycloalkyl or cycloalkenyl group; X represents --NR.sup.10 R.sup.11 where R.sup.10 is hydrogen or an optionally substituted alkyl, alkanoyl, aryl, aroyl, aralkyl or aralkanoyl group, and R.sup.11 is a straight or branched alkylaminosulphonylamino group wherein the alkyl portion is optionally interrupted by one or more --O-- or --S-- atoms of --N(R.sup.7)-- or aminocarbonyloxy groups; or the salts, solvates and hydrates thereof. The compounds are metalloproteinase inhibitors and in particular have a selective inhibitory action against gelatinase and are useful in the treatment of cancer to control tumor metastasis.