Abstract: A new analgesic agent is now provided, which comprises as the active ingredient 3-amino-2-hydroxy-4-phenylbutanoic acid and some related compounds thereof. These compounds have now found to be effective as inhibitor against enkephalinase and as an agent for enhancing analgesic activity of morphine.

Abstract: 3-Amino-2-hydroxy-4-phenylbutanoic acid and esters thereof as well as new derivatives thereof which are related to bestatin in their chemical structure are active to enhance the immune response in living animals.

Abstract: 3'-Deoxykanamycin A useful as an antibacterial agent can be produced by a new process comprising reacting a 2',2"-di-O-acylated-3'-O-sulfonylated-tetra-N-protected derivative of kanamycin A with a base such as alkali metal alcoholate in a lower alkanol to effect 2',3'- and 3',4'-epoxidation and concurrently removal of the 2'- and 2"-acyl groups, reducing the resultant N-protected 2',3'-anhydro-3'-epi derivative and 3',4'-anhydro-3'-epi derivative of kanamycin A either with hydrogen in the presence of a known hydrogenation catalyst or with sodium borohydride to afford the corresponding N-protected 3'-deoxygenated derivative of kanamycin A and then removing the residual amino-protecting groups therefrom to give 3'-deoxykanamycin A.

Abstract: New routes are provided for the synthesis of 3',4'-dideoxykanamycin B which is effective in inhibiting kanamycin-resistant organisms from kanamycin B through new intermediate, of which a fundamental process comprises a new reaction of a 3',4'-epoxy derivative of amino- and hydroxyl-protected kanamycin B with a xanthate to form a corresponding 3',4'-dideoxy-3'-eno derivative followed by removal of the amino- and hydroxyl-protecting groups thereof and by hydrogenation of the resulting 3',4'-dideoxy-3'-eno-kanamycin B. A 3',4'-episulfide derivative corresponding to the 3',4'-epoxy derivative which is formed as second product in the reaction of 3',4'-epoxy derivative with xanthate is also used as intermediate for the preparation of 3',4'-dideoxykanamycin B.

Abstract: There are provided new compounds, 3',4'-anhydro-4'-epi derivatives of kanamycin A of the formula: ##STR1## wherein R represents an alkyl, aralkyl or aryl group and Y represents an alkylidene, aralkylidene, cycloalkylidene or tetrahydropyranylidene group which are useful as an intermediate for the synthesis of 3',4'-dideoxykanamycin A and 4'-deoxykanamycin A from kanamycin A. The compounds of formula (I) can be prepared by treating the corresponding 4'-O-sulfonyl derivative with an alkali metal alcoholate in a lower alkanol under an alkaline condition.

Abstract: Penicillin compounds and methods for the production thereof are described, said penicillin compounds being represented by the formula (I) ##STR1## wherein R.sub.1, R.sub.2, and R.sub.3 each represents hydrogen, a lower alkyl group, a halogen atom, a lower alkoxy group, a hydroxyl group, or a substituted or unsubstituted phenylalkoxy group except that R.sub.1, R.sub.2, and R.sub.3 cannot all represent hydrogen simultaneously; R.sub.4 represents hydrogen or a lower alkyl group; and R.sub.5 represents hydrogen or a hydroxyl group.

Abstract: 4-Amino-2-hydroxybutyric acid or 2,4-diaminobutyric acid may be readily produced by a new process comprising reacting a propionic acid compound containing a .beta.-carboxamido substituent (-CONH.sub.2) on the carbon atom at the 3-position and optionally containing hydroxyl substituent and protected or unprotected amino substituent on the .alpha.-carbon atom thereof, with an alkanoic acid anhydride in liquid pyridine to convert the carboxamido group into a nitrile group, with occasional acylation of a .alpha.-hydroxyl group, occasionally removing the alkanoyl group from the .alpha.-acyloxyl group of the resulting nitrile intermediate, and then reducing the resultant nitrile compound with hydrogen to convert the nitrile group into an aminomethyl group, and further optionally removing the residual amino-protecting group from the resultant 4-aminobutyric acid compound.

Abstract: A novel ester of a cephem compound having a carboxyl group at the 4-position in the nucleus; a process for preparing the same by reacting a cephem carboxylic acid or its salt with a halogenide; and a method for removing the protective group for the carboxyl group in the nucleus of a cephem compound by contacting it with an alcohol, or with an organic solvent in the presence of a Lewis acid.

Abstract: New routes are provided for the synthesis of 3',4'-dideoxykanamycin B which is effective in inhibiting kanamycin-resistant organisms from kanamycin B through new intermediate, of which a fundamental process comprises a new reaction of a 3',4'-epoxy derivative of amino- and hydroxyl-protected kanamycin B with a xanthate to form a corresponding 3',4'-dideoxy-3'-eno derivative followed by removal of the amino- and hydroxyl-protecting groups thereof and by hydrogenation of the resulting 3',4'-dideoxy-3'-eno-kanamycin B. A 3',4'-episulfide derivative corresponding to the 3',4'-epoxy derivative which is formed as second product in the reaction of 3',4'-epoxy derivative with xanthate is also used as intermediate for the preparation of 3',4'-dideoxykanamycin B.

Abstract: A 9,3"-di-acyl derivative of a macrolide antibiotic can be readily produced by reacting a macrolide antibiotic or an acyl derivative thereof with an organic acid halide, particularly an alkanoic acid halide, in a solvent and in the presence of a molecular sieve consisting of a synthetic zeolite and then de-acylating partially the resultant acylation products by a partial hydrolysis in an aqueous alcohol to give the 9,3"-di-acyl derivative of the macrolide antibiotic.

Abstract: A process for preparing a cephalosporanic acid derivative or a 7-acylaminocephalosporanic acid derivative which comprises subjecting an esterifying agent to reaction in liquid sulfur dioxide in the presence of a base with an N-protected-cephalosporin C to obtain a diester, subjecting the diester to reaction in an inert solvent with an iminohalide forming agent to produce an iminohalide, subjecting the iminohalide with a lower alcohol to produce an iminoether, subjecting the product produced, after subjecting the iminoether to reaction with a reactive derivative of an organic acid, to hydrolysis and further eliminating the ester group of the carboxylic acid.

Abstract: A process for preparing a cephalosporin ester which comprises subjecting an organic halide or an alcohol to reaction with a cephalosporin acid, a cephalosporin acid halide or a salt thereof in the presence of liquid sulfur dioxide.

Abstract: A new and useful 1-N-[(S)-.alpha.-hydroxy-.omega.-aminoacyl] derivative of an aminoglycosidic antibiotic, including its deoxy derivative, such as kanamycin B, 3'-deoxyneamine, 3',4'-dideoxyneamine, 3',4'-dideoxyribostamycin or 3',4'-dideoxykanamycin B is now synthetized from the parent substance, aminoglycosidic antiobiotic. The new 1-N-[(S)-.alpha.-hydroxy-.omega.-aminoacyl] derivative shows a wider and/or higher antibacterial activity than the parent substance and is useful in the treatment of infections by gram-negative and gram-positive bacteria, including drug-resistant strains thereof. The preparation of this new derivative may be made by 1-N-acylating the parent aminoglycosidic antibiotic with (S)-.alpha.-hydroxy-.omega.-aminocarboxylic acid with the amino group being protected, and chromatographically separating the acylated products to isolate the desired 1-N-acyl derivative, followed by the removal of the amino-protecting group.

Abstract: As new semi-synthetic antibiotic derivative are provided N-methanesulfonic acid derivatives of 3',4'-dideoxykanamycin B which are less toxic than the parent antibiotic and have useful high antibacterial activity. They are produced by interacting 3',4'-dideoxykanamycin B, an aldehyde such as paraformaldehyde and sulfurous acid or an alkali metal sulfite reagent.

Abstract: 3'-Deoxy derivatives of neamine, 6'-N-alkylneamine, kanamycin B, 6'-N-alkylkanamycin B, ribostamycin, 6'-N-alkylribostamycin and paromamine may be produced by a new process comprising reducing the 3',4'-.alpha.-anhydro derivative (namely, the 3',4'-epoxide derivative) of the aminoglycosidic antibiotics with hydrogen in an alkaline lower alkanol medium containing an alkali metal hydroxide or alkoxide dissolved therein and in the presence of a reducing catalyst such as Raney nickel. The 3',4'-.alpha.-anhydro derivative may be prepared by treating the 3'-sulfonylated derivative of the amino-protected and hydroxyl-protected neamine, 6'-N-alkylneamine, kanamycin B, 6'-N-alkylkanamycin B, ribostamycin, 6'-N-alkylribostamycin or paromamine with an alkali metal hydroxide or alkoxide in a lower alkanol to effect epoxidation between the 4'-hydroxyl group and the carbon atom substituted by the 3'-sulfonic ester group.

Abstract: A new and useful 1-N-[(S)-.alpha.-hydroxy-.omega.-aminoacyl]derivative of an aminoglycosidic antiobiotic, including its deoxy derivative, such as kanamycin B, 3'-deoxyneamine, 3',4'-dideoxyneamine, 3',4'-dideoxyribostamycin or 3', 4'-dideoxykanamycin B is now synthetized from the parent substance, aminoglycosidic antibiotic. The new 1-N-[(S)-.alpha.-hydroxy-.omega.-aminoacyl] derivative shows a wider and/or higher antibacterial activity than the parent substance and is useful in the treatment of infections by gram-negative and gram-positive bacteria, including drug-resistant strains thereof. The preparation of this new derivative may be made by 1-N-acylating the parent aminoglycosidic antibiotic with (S)-.alpha.-hydroxy-.omega.-aminocarboxylic acid with the amino group being protected, and chromatographically separating the acylated products to isolate the desired 1-N-acyl derivative, followed by the removal of the amino-protecting group.

Abstract: A new cyclic ureido-derivative of a deoxystreptamine-containing antibiotic represented by the general formula: ##SPC1##Wherein R.sub.a, R.sub.b and R.sub.c stand for the residues present in the molecule of said antibiotic other than the deoxystreptamine moiety thereof is produced.