Abstract: Four new antibiotics which are denominated istamycin A, istamycin B, istamycin A.sub.o and istamycin B.sub.o, and which are useful as antibacterial agents, are produced by fermentation of a new microorganism, Streptomyces tenjimariensis.

Abstract: Disclosed is 3'-deamino-3'-morpholino-carminomycin, a new anthracycline glycoside having both antimicrobial and antitumor activity. Also disclosed is a new N-alkylation procedure for preparing the above compound as well as the known anthracyclines, 3'-deamino-3'-morpholino-adriamycin and 3'-deamino-3'-morpholino-daunomycin, in high yield.

Abstract: New anthracycline compounds, 2-hydroxy-aclacinomycins M, N, S and T having potent antitumor activity and low toxicity, and the processes for the preparation thereof from 2-hydroxy-aclacinomycin A by reduction or acid hydrolysis are disclosed.

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: A new and improved process for the preparation of C-4' etherified anthracycline glycoside derivatives is provided. The new process involves fewer steps than the prior art process and gives the antibiotic end-products in higher yield.

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 physiologically active substances, ebelactone A and ebelactone B which are generally termed ebelactone are produced from a new microorganism, Streptomyces MG7-G1 strain identified FERM-P 5363 or ATCC No. 31860 and ATCC No. 31880. Ebelactone is useful as a host defense stimulator having an activity to enhance cell-mediated immunity, and also as an anti-inflammatory agent.

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: 3'-Deoxykanamycin A useful as antibacterial agent is produced from a protected kanamycin A derivative either by a process comprising imidazolylthiocarbonylation of the 3'- and 2"-hydroxyl groups of 4",6"-O-cyclohexylidene-4'-0:6'-N-carbonyl-5,2'-O-isopropylidene-1,3,3"-tr i-N-tosylkanamycin A, preferential removal of the 3'-imidazolylthiocarbonyloxy group with tributyltin hydride for the 3'-deoxygenation, followed by removal of the 2"-O-imidazolylthiocarbonyl group with aqueous ammonia, removal of the N-tosyl groups with alkali or alkaline earth metal in liquid ammonia, hydrolytic fission of the 4',6'-cyclic carbamate ring and concurrent removal of the 5,2'-O-isopropylidene group and 4",6"-O-cyclohexylidene group, or by a process comprising selective acetylation of the 2"-hydroxyl group of said protected kanamycin A derivative with acetyl chloride in pyridine, trifluoromethanesulfonylation of the 3'-hydroxyl group, followed by concurrent removal of the 3'-trifluoromethanesulfonyloxy group and N-tosyl groups w

Abstract: New 4-demethoxy-11-deoxydaunomycin and 4-demethoxy-11-deoxyadriamycin anthracycline derivatives have been prepared and found to be useful antimicrobial and antitumor agents.

Abstract: 3'-Deoxykanamycin B, namely tobramycin is produced in an improved yield with a reduced reaction time under moderate reaction conditions, starting from a penta-N-protected 3'-mono-O-alkyl-, aralkyl- or arylsulfonylated derivative of kanamycin B in which all the 1, 3, 2' and 3"-amino groups and possibly the 6'-amino group have been protected by an arylsulfonyl group, especially tosyl group; the 3'-hydroxyl group of kanamycin B has been alkyl-, aralkyl- or arylsulfonylated; the 4"- and 6"-hydroxyl groups have been blocked with a di-valent hydroxyl-protecting group; and possibly the 4'-hydroxyl group and 6'-amino group have been blocked by being converted into the form of a 4', 6'-cyclic carbamate formed between the 4'-hydroxyl group and the 6'-amino group, by subjecting to a process essentially comprising reaction of said protected kanamycin B derivative with a metal halide for a reaction time of 30 min. to 2 hours at a reaction temperature of 0.degree. C..about.150.degree. C.

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: The invention is to provide a new process for producing daunomycin and baumycins having potent antitumor activity and low toxicity by microbial conversion of anthracyclinones such as aklavinone and .epsilon.-rhodomycinone.

Abstract: A new compound is produced which has the general formula: ##STR1## wherein R represents hydrogen atom or a lower alkyl group and which exhibits an immunopotentiating activity. This new compound as well as its pharmaceutically acceptable salts and hydrates are useful for immunotherapy and treatment of immune diseases and disorders in living animals including human beings. The new compound can be produced by reduction of a hydroxyterephthalic acid alkyl ester or by esterification of the corresponding 3-hydroxy-4-(hydroxymethyl)-benzoic acid.

Abstract: New compounds, 6"-deoxydibekacin, 4", 6"-dideoxydibekacin, 1-N-(L-4-amino-2-hydroxybutyryl)-6"-deoxydibekacin and 1-N-(L-4-amino-2-hydroxybutyryl)-4",6"-dideoxydibekacin are now produced semi-synthetically from dibekacin, i.e. 3',4'-dideoxykanamycin B. These four new compounds are each useful as an antibacterial agent. Production of 6"-deoxydibekacin or 4",6"-dideoxydibekacin is made by removal of the 6"-hydroxyl group or by removal of the 4"- and 6"-hydroxyl groups from an amino-protected and hydroxyl-protected derivative of dibekacin. Production of 1-N-(L-4-amino-2-hydroxybutyryl)-6"-deoxydibekacin or -4",6"-dideoxydibekacin is made by acylating the 1-amino group of 6"-deoxydibekacin or 4",6"-dideoxydibekacin with the L-4-amino-2-hydroxybutyryl group, or alternatively by removal of the 6"-hydroxyl group or the 4"- and 6"-hydroxyl groups from a known compound, 1-N-(L-4-amino-2-hydroxybutyryl)-dibekacin.

Abstract: Novel antibiotics cleomycins represented by the formula ##STR1## wherein R is a terminal amino residue of the cleomycin. These compounds are useful as a chemotherapeutic agent for treating cancer and bacterial infections.

Abstract: This invention provides tetrapeptide derivatives of the formula (I): ##STR1## wherein R.sup.1 and R.sup.2 are methyl, 1-methylethyl, 2-methylpropyl, 1-hydroxyethyl, 2-carboxyethyl or 4-aminobutyl and Y is ##STR2## wherein R.sup.3 is methyl, 1-methylethyl, 2-methylpropyl, 1-methylpropyl, hydroxymethyl, 1-hydroxyethyl, carboxymethyl, 2-carboxyethyl, 4-aminobutyl, 3-guanidinopropyl, benzyl or p-hydroxybenzyl excluding the compounds in which R.sup.1 and R.sup.2 are each 1-methylethyl and also R.sup.3 is carboxymethyl or 2-carboxyethyl, the first and leftmost .beta.-amino acid moiety in said tetrapeptide derivatives having the (2S,3R)-configuration and a primary amino group and the second, third and fourth .alpha.-amino acid moieties in said tetrapeptide derivatives having the L-configuration. These compounds have an inhibitory activity on several types of aminopeptidases.

Abstract: New anthracycline glycoside derivatives of rhodomycin-group, .epsilon.-rhodomycin RDC, .epsilon.-isorhodomycin RDC, .beta.-rhodomycin RDC, .gamma.-rhodomycin RDC, .gamma.-rhodomycin RDRs and .beta.-pyrromycin RDC having potent anticancer activities and lower toxicities and a process for the production thereof by microbiological conversion method are disclosed.

Abstract: New anthracycline derivatives of adriamycin and daunomycin prepared by the etherification of the C-4' and/or C-14 hydroxyl groups of the starting material glycosides are found to be useful antimicrobial and antitumor agents.

Abstract: 3',4'-Dideoxy derivative and 1-N-((S)-.alpha.-hydroxy-.omega.-aminoalkanoyl)-3',4'-dideoxy derivative of kanamycin A are now synthetized from kanamycin A and show a wider and/or higher antibacterial activity than the parent kanamycin A so that they are useful in therapeutic treatment of infections by gram-negative and gram-positive bacteria, including drug-resistant strains thereof.