Abstract: As new compounds are now provided N-methyl-3-(3,4-dihydroxyphenyl)serine alkyl esters which are effective as an .alpha.-adrenergic and .beta.-adrenergic agent to stimulate the .alpha.-adrenergic and .beta.-adrenergic functions of the central nervous system of mammalian animals and are expectable to be useful for therapeutic treatment of disorders as invoked by reduced biological activities or functions of the .alpha.- and/or .beta.-adrenergic neurons. N-methyl-L-threo-3-(3,4-dihydroxyphenyl)serine (C.sub.1 -C.sub.6) alkyl esters are preferred amongst the new compounds of this invention.

Abstract: DL- or L-Threo-3-(3,4-dihydroxyphenyl)-N-methyl-serine which may also be termed as DL- or L-threo-adrenalinecarboxylic acid are now provided, which are new compounds useful for therapeutic treatment of Parkinson's disease and mental depression disease.

Abstract: L-aminoacylases S.sub.1 and S.sub.2 derived from actinomycetes and having physicochemical characteristics such that it is a L-aminoacylase which acts on a N-acyl-L-amino acid to give a L-amino acid, its substrate profile is wide, and it acts not only on a N-acyl derivative of a natural L-amino acid, but also on a N-acyl derivative of a synthetic L-amino acid, while it does not act on a N-acyl-D-amino acid, a DL-N-acetyl-.alpha.methylbenzylamine and a N-acetyl-D-glucosamine, etc.

Abstract: N-acyl-DL-3-(3,4-dihydroxyphenyl)serine or a catecholic hydroxyl-protected derivative thereof is stereospecifically de-acylated by reaction with a microorganism of the genus Streptomyces or Streptoverticillium having an acylase or with an extract of said microorganism containing said acylase, to produce L-3-(3,4-dihydroxyphenyl)serine or the hydroxyl-protected derivative thereof, with the N-acyl-D-3-(3,4-dihydroxyphenyl)serine compound remaining unaltered. The L-3-(3,4-dihydroxyphenyl)serine compound so produced can be separated from the N-acyl-D-3-(3,4-dihydroxyphenyl)serine compound owing to the difference in the properties of them.

Abstract: Pterin derivatives are described having the formula (I) ##STR1## wherein R represents a hydroxyphenyl group, a radioiodinated hydroxyphenyl group, a tyraminocarbonyl group, a radioiodinated tyraminocarbonyl group, a proteinocarbonyl group or a carboxy group; Q represents a straight or branched chain alkylene group having 1 to 6 carbon atoms; and R.sub.6 and R.sub.7 each represents a hydrogen, an alkyl group having from 1 to 6 carbon atoms, a hydroxyalkyl group having from 1 to 6 carbon atoms; and a radioimmunoassay method is described using a radioiodinated 4-hydroxy-2-tyraminopteridine derivative or a radioiodinated 4-hydroxy-2-tyraminocarbonylalkylaminopteridine derivative as the tracer.

Abstract: The compound 7-glycylprolylamino-4-methylcoumarin and certain of its derivatives are utilized for the diagnosis of pathological conditions such as hepatic diseases and gastric cancer by measuring the enzymatic activity of X-prolyl dipeptidyl-aminopeptidase.

Abstract: The activity of X-prolyl dipeptidyl-aminopeptidase against X-L-proline-Y wherein X is an amino acid residue and Y is p-nitroaniline, p-phenylazoaniline or 4-phenylazo-1-naphthylamine is used as a measure of human afflictions such as hepatobiliary diseases and carcinomas.

Abstract: The compound 7-glycylprolylamino-4-methylcoumarin and certain of its derivatives are utilized for the diagnosis of pathological conditions such as hepatic diseases and gastric cancer by measuring the enzymatic activity of X-prolyl dipeptidyl-aminopeptidase.

Abstract: The activity of X-prolyl dipeptidyl-aminopeptidase against X-L-proline-Y wherein X is an amino acid residue and Y is p-nitroaniline, p-phenylazoaniline or 4-phenylazo-1-naphthylamine is used as a measure of human afflictions such as hepatobiliary diseases and carcinomas.