Drug – bio-affecting and body treating compositions – Antigen – epitope – or other immunospecific immunoeffector – Recombinant or stably-transformed bacterium encoding one or...
Patent
1981-12-30
1984-04-03
Waltz, Thomas A.
Drug, bio-affecting and body treating compositions
Antigen, epitope, or other immunospecific immunoeffector
Recombinant or stably-transformed bacterium encoding one or...
564154, 564151, 564197, 564198, 2605005H, 546245, 548188, 548540, A61K 3116, C07C14923, C07C103183
Patent
active
044407882
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
This invention relates to cysteine derivatives useful as therapeutic agents for hepatic failures and a process for preparing same.
BACKGROUND ART
The liver is the single organ that is largest in the body and is said to have more than one hundred different kinds of functions including, in addition to metabolism of carbohydrates, lipids, proteins and amino acids, bile production, detoxication, foreign matter treatment, control of hormones, production of prothrombin, one of blood coagulating agents, storage of various constituents of organisms (such as fat, glycogen, proteins, vitamines, etc.) and the like. This organ which has such precise and well-balanced functions possesses a large self-restorative ability and hence is expected to heal spontaneously even if it is functionally disordered. Nevertheless the liver may suffer an acute or chronic lesion due to one or more of various factors such as alcohol, undernutrition, virus infection, medicaments, poisons, biliary obstruction, disorder of the enterohepatic circulatory system and the like and such lesion is manifested as one or more of diseases such as fatty liver, drug-toxic hepatic failure, drug-hypersensitive hepatic failure, alcoholic hepatitis, viral hepatitis, congestive hepatitis, hepatopathy due to biliary engorgement, jaundice, and hepatocirrhosis which is the final picture of the foregoing diseases.
When these hepatic failures are induced, a medication can be employed with the intention of accelerating restoration of cells of the liver parenchyma or alleviating the damage of liver cells with the aid of protection against various hepatopathy-inducing factors, thereby accelerating the recovery from its functional disorder or preventing aggravation.
The inventors have found that paticular cysteine derivatives are effective for the above-mentioned purpose and accomplished the present invention.
DISCLOSURE OF INVENTION
In brief, the present invention resides in
(1) a cysteine derivative of the formula: ##STR1## wherein R.sup.1 is methyl or ethyl, R.sup.2 and R.sup.3 are each hydrogen or a lower alkyl having 1 to 6 carbon atoms, or one of R.sup.2 and R.sup.3 is amino, monomethylamino, dimethylamino or hydroxyl and the other is hydrogen or a lower alkyl having 1 to 6 carbon atoms, or R.sup.2 and R.sup.3, taken together, may stand for an alkylene chain or a hetero-atom containing alkylene chain, thereby forming a ring along with the nitrogen atom, and R.sup.4 is hydrogen or acetyl;
(2) a process for preparing a cysteine derivative of the foregoing formula (I) which comprises reacting a cysteine alkyl ester of the formula: ##STR2## wherein R.sup.1 and R.sup.4 are as defined in formula (I) and R.sup.5 is methyl or ethyl, with an amino compound of the formula: ##STR3## wherein R.sup.2 and R.sup.3 are as defined in formula (I);
(3) a process for preparing a cysteine derivative of the formula: ##STR4## wherein R.sup.1, R.sup.2 and R.sup.3 are as defined in formula (I), which comprises reacting an S-alkyl-cysteine of the formula: ##STR5## wherein R.sup.1 is as defined in formula (I) and R.sup.6 is an amino-protecting group, or its reactive derivative with an amino compound of the formula: ##STR6## wherein R.sup.2 and R.sup.3 are as defined in formula (I), then eliminating the amino-protecting group, if necessary, followed by neutralization; and
(4) a process for preparing a cysteine derivative of the foregoing formula (I) which comprises reacting an S-alkyl-N-acetyl-cysteine of the formula: ##STR7## wherein R.sup.1 is as defined in formula (I), or its reactive derivative with an amino compound of the foregoing formula (III).
Now the present invention is described in detail.
The compounds according to this invention are cysteine derivatives of the foregoing formula (I).
In formula (I), R.sup.1 is methyl or ethyl and R.sup.2 and R.sup.3 are each hydrogen or a lower alkyl having 1 to 6 carbon atoms such as methyl, ethyl, propyl, butyl, pentyl, hexyl or the like, or one of R.sup.2 and R.sup.3 is amino, monomethylamino, dimethylamino or hydrox
REFERENCES:
patent: 2940933 (1960-06-01), Jezl
patent: 3340147 (1967-09-01), Martin et al.
patent: 4216225 (1980-08-01), Shiratsuchi et al.
Morita Yoshiharu
Terayama Hiroshi
Umezu Kohei
Mitsubishi Chemical Industries Limited
Waltz Thomas A.
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