Abstract: A known nucleoside, coformycin and its related substances such as isocoformycin, 2'-deoxycoformycin and formycins present as a mixture of them may be separated from each other when an aqueous solution containing them is chromatographed on a column of a cation-exchanger having partially activated carboxylic groups as the ion-exchange function with using water or a buffer solution as the developing solvent.

Abstract: A number of 1N-(.alpha.-hydroxy-.omega.-aminoalkanoyl)-6'N-methyl-3',4'-dideoxykanamyc in B derivatives have been found to possess excellent antibacterial activity against most kanamycin susceptible and resistant organisms. In particular, 1N-(DL-isoseryl)-6'N-methyl-3',4'-dideoxykanamycin B, 1N-(L-isoseryl)-6'-N-methyl-3',4'-dideoxykanamycin B, 1N-(L-4-amino-2-hydroxybutyryl)-6'N-methyl-3',4'-dideoxykanamycin B and 1N-(L-5-amino-2-hydroxyvaleryl)-6'N-methyl-3',4'-dideoxykanamycin B, or an acid addition salt thereof possess these highly desirable attributes.

Abstract: A novel anthracycline antibiotic complex designated herein as baumycin complex is produced by fermentation of a baumycin-producing strain of Streptomyces, e.g. Streptomyces coeruleorubidus ME 130-A4 (FERM-P3540, ATCC 31276). The complex and four bioactive components thereof designated baumycin A.sub.1, A.sub.2, B.sub.1 and B.sub.2 are useful as antibacterial and antitumor agents.

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 aureaus, 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: 1-N-(L-4-amino-2-hydroxybutyryl) derivatives of kanamycin C, 3'-deoxykanamycin C and 3',4'-dideoxykanamycin C have been prepared which possess high antibacterial activity against a wide variety of drug-resistant bacteria. These new derivatives are prepared by reacting L-4-amino-2-hydroxybutyric acid or a functional equivalent thereof with the 1-amino group of kanamycin C, 3'-deoxykanamycin C or 3',4'-dideoxykanamycin C.

Abstract: New antitumor agents designated rhodirubin A and B, which are anthracycline glycosides and inhibit the growth of gram-positive bacteria and mammalian tumors, are produced by fermentation of rhodirubin-producing strains of Streptomyces, e.g. Streptomyces sp. ME 505-HEI (ATCC 31273).

Abstract: The present invention relates to new physiologically active peptides, derivatives thereof and a process for preparation thereof. In particular, it relates to new tetrapeptides designated amastatins A.sub.1, A.sub.2, A.sub.3, B.sub.1 and B.sub.2 and derivatives thereof which have an inhibitory effect on aminopeptidase A and also show stimulation of antibody formation and to a process for preparation thereof by cultivating a strain belonging to the genus Streptomyces.FIELD OF THE INVENTIONThe present invention relates to new physiologically active peptides, derivatives thereof and a process for preparation thereof. In particular, it relates to new tetrapeptides designated amastatins A.sub.1, A.sub.2, A.sub.3, B.sub.1 and B.sub.2 and derivatives thereof which have an inhibitory effect on aminopeptidase A and also show stimulation of antibody formation and to a process for preparation thereof by cultivating a strain belonging to the genus Streptomyces.

Abstract: A 1-N-(.alpha.-substituted-.omega.-aminoacyl)-3'-deoxyribostamycin, which is a useful antibiotic active against various drug-resistant bacteria, can be prepared advantageously by a process starting from a protected derivative of ribostamycin in the form of 1,6-carbamate and comprising the 3'-deoxygenation, the splitting of the carbamate linkage and the 1-acylation.

Abstract: Kanamycin C, 3'-deoxykanamycin C and 3'4'-dideoxykanamycin C are obtained by a new process comprising treating the primary 6'-amino group of a tetra-N-protected derivative of kanamycin B, 3'-deoxykanamycin B and 3', 4'-dideoxykanamycin B with a nitrite to convert said amino group into hydroxyl group and then removing the protective groups. 3'-Deoxykanamycin C and 3', 4'-dideoxykanamycin C are new semi-synthetic aminoglycosidic antibiotics.

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: There are disclosed two new antibiotics formerly denominated MC916-A and MC916-B and now called neothramycin A and neothramycin B which are potent inhibitors of the growth of leukemia cells, e.g. Leukemia L-1210 cells in mice. They are produced by controlled fermentation of Streptomyces FERM-P 2452 (A.T.C.C. 31123).

Abstract: 1-N-(.alpha.-hydroxy-.omega.-aminoalkanoyl)-derivatives of 3'-deoxykanamycin A or 6'-N-methyl-3'-deoxykanamycin A are provided as new and useful compounds which are active against gram-negative and gram-positive bacteria, including drug-resistant strains of these bacteria. Examples of these compounds include 1-N-((SR)-.beta.-amino-.alpha.-hydroxypropionyl)-3'-deoxykanamycin A, 1-N-((S)-.gamma.-amino-.alpha.-hydroxybutyryl)-3'-deoxykanamycin A, 1-N-((S)-.delta.-amino-.alpha.-hydroxyvaleryl)-3'-deoxykanamycin A and 1-N-((S)-.gamma.-amino-.alpha.-hydroxybutyryl)-6'-N-methyl-3'-deoxykanamyc in A. The compounds may be prepared by selective acylation of the 1-amino group of 3'-deoxykanamycin A or 6'-N-methyl-3'-deoxykanamycin A with a corresponding .alpha.-hydroxy-.omega.-amino-alkanoic acid.

Abstract: There is provided a process for producing a stable macromomycin (hereinafter often referred to as MCR) powder which comprises adding a stablilizer selected from the group consisting of saccharides, amino acids and salts thereof, organic acid salts, inorganic acid salts and a chelating agent to a solution of macromomycin purified from fermentation broth prior to dehydration as by lyophilization.

Abstract: Increased duration of inhibition of secretion of pepsin in man by oral administration of pepstatin is achieved by the use of a formulation in which pepstatin is coated on very small granules of sodium bicarbonate to form floating minicapsules.

Abstract: Compounds having the general formula ##STR1## wherein R.sup.2 is substituted either at the 4'-position or at the 5'-position and is hydrogen, fluoro, bromo, chloro, hydroxy or lower alkyl; R.sup.3 is chloro, bromo or lower alkyl; R.sup.4 is hydroxy, amino or lower alkoxy, and Z is hydrogen or lower alkyl and the nontoxic, pharmaceutically acceptable metal salts of said compounds when Z is hydrogen exhibit strong activities in inhibiting histidine decarboxylase and anthine oxidase.

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',4'-.alpha.-Epoxyneamine and its related aminoglycosidic antibiotic derivatives containing 3',4'-.alpha.-epoxyneamine moiety in the molecule thereof are now provided, which may be in the form of their amino-protected and partially hydroxyl-protected product and which are useful as intermediates for use in the synthetic production of therapeutically valuable 3'-deoxy derivatives of aminoglycosidic antibiotics.

Abstract: Compounds having the formula ##STR1## (the meanings of R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are indicated hereinafter) exhibit suppressive activity to various immune responses and can be employed in the therapy of immunological diseases, especially autoimmune diseases.

Abstract: New antitumor agents named aclacinomycins A and B, which are anthracycline glycosides and inhibit the growth of various microorganisms e.g., Staphylococcus aureus, Micrococcus flavus, Corynebacterium bovis and inhibit the growth of animal tumors such as leukemia L1210 and P388 and lymphoma 6C3HED in mice and hepatomas in rats are produced by the fermentation of a microorganism belonging to the genus Streptomyces which has been designated Streptomyces galilaeus (MA144-M1 and A.T.C.C. 31133); they are recovered from the broth by conventional methods for recovering antibiotics.

Abstract: A novel physiologically active peptide Val-X-Ala-X, in which X is 4-amino-3-hydroxy-6-methylheptanoic acid, which is prepared from R-Val-Val-X-Ala-X by the action of a microbial enzyme, N-acyl derivatives thereof which are produced by acylating said new peptide, and the processes for producing thereof and the microbial enzyme are disclosed.