Abstract: A protein with immuno-suppressive activity and with the following physico-chemical properties:isoelectric point: 4.25,ultraviolet absorption spectrum: as shown in FIG. 1, with a maximum at 260 nm,molecular mass: about 90,000 daltons,can be strained by Coomasie blue, but not by Methylene blue or PAS,desoxyribonuclease, ribonuclease A and neuraminidase proof, and degraded by .alpha., .gamma. and .delta. chymotrypsins and trypsine.

Abstract: This invention relates to compounds having the formula: ##STR1## in which R.sub.1 and R.sub.2 are independently hydrogen, a C.sub.1-4 alkyl group or an aliphatic or aromatic acyl group, provided R.sub.1 and R.sub.2 are not simultaneously hydrogen, or, together with the nitrogen atom to which they are attached, R.sub.1 and R.sub.2 form a 5- or 6-membered ring which may carry another heteroatom; R.sub.3 is a C.sub.1-4 alkyl group; and R.sub.4 and R.sub.5 represent independently a hydrogen or halogen atom, a C.sub.1-4 alkyl group or a C.sub.1-4 alkoxy group; and the acid addition salts of the above compounds. Said new compounds have an anxiolytic and diuretic action, together with a spasmolytic action of non-.alpha.-adrenalytic nature on the unstriated muscle fibers.