Abstract: Aminoglycosidic antibiotic comprising a 6-0-(3"-aminoglycosyl)-2-deoxystreptamine optionally having a 4-0-(aminogycosyl) group, such as kanamycins, gentamicins, sisomicin, forms reversible complex with zinc cations by association of the zinc cations with some pairs of aminohydroxyl groups in the aminoglycoside, and the zinc-complexed amino groups are blocked from acylation. Reaction of this zinc complex with an acylation reagent having an amino-blocking acyl group brings about acylation of the non-complexed amino groups to give an N-acylated zinc complex, namely a complex of zinc cation with an N-acylated aminoglycosidic antibiotic derivative. Removal of zinc cations from N-acylated zinc complex yields a partially N-acylated aminoglycosidic antibiotic where 1- and 3"-amino groups are unprotected but all other amino groups protected with acyl group.

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: A process for producing threo-3-amino-2-hydroxybutanoylaminoacetic acids comprises the steps of allowing to react a starting compound represented by the general formula: ##STR1## wherein R.sub.1 represents a naphthyl or a group of the formula: ##STR2## in which R.sub.6 and R.sub.7 represent individually hydrogen, halogen, amino or a protected amino, hydroxy or a protected hydroxy, a lower alkoxy or a lower alkyl and R.sub.2 represents a protected amino, with a starting compound represented by the general formula: ##STR3## wherein R.sub.3 represents hydrogen or an ester residue, to obtain threo-3-protected amino-2-hydroxy-4-oxobutanoic acid or its ester represented by the general formula: ##STR4## wherein R.sub.1, R.sub.2 and R.sub.3 have the same meanings as above, and then reducing the same into threo-3-protected amino-2-hydroxybutanoic acid or its ester represented by the general formula: ##STR5## wherein R.sub.1, R.sub.2 and R.sub.

Abstract: Aminoglycoside antibiotics biochemically transformed from Kanamycin A or Kanamycin B, which are represented by the formula ##STR1## wherein R.sub.1 represents a hydrogen atom or a methyl group and R.sub.2 represents an amino group or a hydroxyl group.

Abstract: 1-N-Isoseryl- or 1-N-(L-4-amino-2-hydroxybutyryl)-3',4'-dideoxykanamycin B is prepared through a new route starting from 3',4'-dideoxy-3',4'-didehydrokanamycin B, which comprises the steps of protecting all or some of the four amino groups other than the 1-amino group of the starting material with an amino-protecting group, reacting the partially amino-protected derivative or derivatives thus formed with isoserine or L-4-amino-2-hydroxybutyric acid or a reactive derivative thereof having the amino group unprotected or protected whereby to acylate the 1-amino group of the former, eliminating the amino-protecting group or groups from the acylated product and reducing the 3',4'-olefinic double bond of the product by catalytic hydrogenation, the last two steps being effected in order or simultaneously or in the reverse order. Also provided are new, useful intermediate compounds during the process.

Abstract: N-methylbleomycins represented by the general formula ##STR1## which are useful as antitumor agents and bactericides; a method of preparing the same; and intermediate products in the preparation thereof.

Abstract: New anthracycline derivatives, 1-hydroxy-13-dihydrodaunomycin and N-formyl-1-hydroxy-13-dihydrodaunomycin are produced by microbial transformation of .epsilon.-pyrromycinone and .epsilon.-isorhodomycinone with daunomycin-producing streptomyces and their mutants. The derivatives herein are useful as cancer chemotherapeutic agents.

Abstract: A new antibiotic designated as auromomycin is prepared from the culture broth of Streptomyces macromomyceticus, a macromomycin-producing strain, as yellow crystals. Auromomycin is recovered in pure form from the culture broth by using hydrophobic chromatography with Octyl Sephalose CL-4B or Phenyl Sepharose CL-4B.

Abstract: By protecting the aldehyde group of a macrolide series antibiotics with a cyclic acetal or thioacetal, novel macrolide derivatives can be produced from the macrolide series antibiotics by releasing successively, the sugar moieties bonded to the macrolide antibiotics.The novel marcolide derivatives obtained by this invention, that is, the derivatives of a macrolide series antibiotics produced by releasing partially or wholly the sugar moieties bonded are useful as intermediates for producing novel macrolide series antibiotics.

Abstract: New anthracycline glycosides designated MA 144-G1, -G2, -L, -S1, -N1, -U1 and -Y which inhibit the growth of gram-positive bacteria and mammalian tumors are produced by fermentation of certain species of Streptomyces and by the chemical or enzymatic conversion of certain anthracycline glycosides. New microbiological and chemical processes are also provided for preparation of the anthracycline glycosides MA 144-S2 and -U2 which have been found to be identical with the previously reported anthracyclines, marcellomycin and musettamycin.

Abstract: A new physiologically active substance named esterastin is now provided, which inhibits the activity of esterase and is useful as an immunosuppressive drug. Esterastin is produced by cultivating a micro-organism Streptomyces MD4-C1 identified as FERM-P 3723 or ATCC. 31336 in a culture medium under aerobic conditions and recovering it from the resulting culture.

Abstract: Bestatin, which is [(2S,3R)-3-amino-2-hydroxy-4-phenylbutanoyl]-L-leucine, and related compounds which inhibit aminopeptidase B, leucino aminopeptidase and Bleomycin hydrolase, enhance the anti-tumor effect of Bleomycin and exhibit an antifertility effect were synthesized and tested.

Abstract: Novel 3-[(S)-1'-phenylethylamino]propylaminobleomycin obtained by reacting a reactive derivative of the carboxyl group of bleomycinic acid with N-[(S)-1'-phenylethyl]-1,3-diaminopropane, a non-toxic salt of said novel bleomycin, and a method for producing the novel bleomycin. Because of much reduction in the side effect causing pulmonary fibrosis, the novel bleomycin is more useful than a commercial bleomycin complex which gives rise to said undesirable side effect.

Abstract: A new compound having the formula ##STR1## and now designated forphenicinol is produced, 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 hydrolysis of the corresponding aminonitrile compound of the formula ##STR2## or by reduction of forphenicine.

Abstract: New antitumor agents designated MA 144-M.sub.1 and MA 144-M.sub.2, which are anthracycline glycosides and inhibit the growth of gram-positive bacteria, e.g. Staphyococcus aureus, Bacillus subtilis and Sarcina lutea, and inhibit the growth of animal tumors such as leukemia L 1210, P 388 and sarcoma 180 are produced by fermentation of MA 144-producing strains of streptomyces and by the chemical or enzymatic conversion of aclacinomycin A or cinerubin A.

Abstract: Aminoglycoside antibiotics biochemically transformed from Kanamycin A or Kanamycin B, which are represented by the formula ##STR1## wherein R.sub.1 represents a hydrogen atom or a methyl group and R.sub.2 represents an amino group or a hydroxyl group.

Abstract: New anthracycline glycosides designated MA 144-G1, -G2, -L,-S1, -N1, -U1 and -Y which inhibit the growth of gram-positive bacteria and mammalian tumors are produced by fermentation of certain species of Streptomyces and by the chemical or enzymatic conversion of certain anthracycline glycosides. New microbiological and chemical processes are also provided for preparation of the anthracycline glycosides MA 144-S2 and -U2 which have been found to be identical with the previously reported anthracyclines, marcellomycin and musettamycin.

Abstract: New anthracycline glycosides designated MA 144-G1, -G2, -L, -S1, -N1, -U1 and -Y which inhibit the growth of gram-positive bacteria and experimental animal tumors are produced by fermentation of certain species of Streptomyces and by the chemical or enzymatic conversion of certain anthracycline glycosides. New microbiological and chemical processes are also provided for preparation of the anthracycline glycosides MA 144-S2 and -U2 which have been found to be identical with the previously reported anthracyclines, marcellomycin and musettamycin.

Abstract: A process for preparing bleomycinic acid having a melting point of 228.degree.-230.degree. C. (decomposition) and an analysis of C: 40.80%, H: 5.29%, N: 16.45%, O: 24.78%, S: 4.53%, Cl: 3.37%, and Cu: 4.78% which is characterized by being soluble in water, difficultly soluble in methanol, acetic acid and dimethylsulfoxide, and insoluble in ethanol, ethyl acetate, acetone and ether, and which tests positive to Pauly and Ehrlich reactions but tests negative to ninhydrin, Sakaguchi, Dragendorf, Tollens, ferric chloride, Fehling and Molish reactions, and which has a maximum ultraviolet absorption spectrum at 246 m.mu. and 292 m.mu. and which has an infrared absorption spectrum bands at 3350, 1720, 1670, 1640, 1580, 1460, 1365, 1050, 770 (cm.sup.-1), and which can be hydrolyzed to yield 2'-(2-aminoethyl)-2,4'-bithiazole-4-carboxylic acid, L-threonine, 4-amino-3-hydroxy-2-methyl-.eta.-valeric acid, .beta.-hydroxy-histidine, .beta.-amino-.beta.-(4-amino-6-carboxy-5-methylpyrimidine-2-yl)-propionic acid, L-.beta.

Abstract: A novel process for producing antibiotics bleomycins by innoculating and aerobically culturing in a nutrient source-containing medium a bleomycin-producing strain belonging to the actinomyces, wherein the culture is effected in the presence of an amino compound having at least one ##STR1## group and at least one basic group selected from amino, imino, guanidino, amidino and sulfonium groups and nitrogen-containing cyclic compounds, or in the presence of a compound convertible in the culture liquor to such amino compound as mentioned above, thereby selectively producing a known or novel bleomycin component corresponding to the said amino compound or to an amino compound derived from the above-mentioned compound, and then the known or novel bleomycin is recovered by known means from the culture medium.