Abstract: New antitumor agents designated MA 144-M.sub.1 and MA 144-M.sub.2, which are anthracycyline 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: Three, new physiologically active derivatives of esterastin are now provided, which inhibit the activity of esterase similarly to the parent esterastin and further exhibit a higher inhibiting activity against cholesterol esterase than the parent esterastin. These three new derivatives are tetrahydroesterastin which is produced by catalytic hydrogenation of esterastin; 3,5-di-hydroxy-2-hexylhexadeca-7,10-dienoic 1,3-lactone which is produced by alkaline hydrolysis of esterastin; and 3,5-di-hydroxy-2-hexylhexadecanoic 1,3-lactone which is produced either by alkaline hydrolysis of said tetrahydroesterastin or by catalytic hydrogenation of the product of the alkaline hydrolysis of esterastin.

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: 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 macrolide 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: 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: 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: 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: Coriolin derivatives having antitumor activity and low toxicity represented by the following general formula: ##STR1## where R: --CO(CH.sub.2).sub.6 CH.sub.3 or --COCH(OH)(CH).sub.2).sub.5 CH.sub.3,X: .dbd.CH.sub.2 or --COOR',R': H or lower alkyl group.Y: OH or .dbd.O andZ: --OH or OCH.sub.3,as well as the process for producing the above derivatives are disclosed.

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: 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 microorganism 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: The compounds of this invention represented by the following formula: ##STR1## (wherein R is hydrogen atom, an alkyl group having C.sub.1 to C.sub.4, a hydroxy group or a halogen atom) can be obtained by condensing the compounds represented by the following formula: ##STR2## wherein R is as defined above, X is hydrogen atom, and Y is hydrogen atom or an amino protecting group or reactive derivatives thereof with (S)-arginine according to a method commonly employed in the peptide chemistry.The peptides according to this invention have strong inhibitory activity against aminopeptidase B, can raise immunity of the organisms and prove useful for inhibiting transfer of cancer and relapse thereof. Also, when used jointly with Bleomycin which is an antitumor agent, they can greatly enhance the antitumor effect of said agent.

Abstract: This invention provides the amino acid (2S,3R)-3-amino-2-hydroxy-4-phenylbutanoic acid which is prepared by hydrolysis of bestatin. Bestatin is a chemical which inhibits aminopeptidase B, leucine aminopeptidase and bleomycin hydrolase, enhances the antitumor effect of bleomycin, has the chemical name [(2S,3R)-3-amino-2-hydroxy-4-phenylbutanoyl]-L-leucine, has the following structure ##STR1## and is prepared by cultivating a strain of streptomyces which produces bestatin in a nutrient medium under aerobic conditions until substantial activity inhibitory to aminopeptidase B is imparted to said cultured medium and then recovering said bestatin from said cultured medium. A preferred strain is Streptomyces olivoreticuli FERM-P No. 2590 (A.T.C.C. 31159).

Abstract: A new 1-N-(.omega.-aminoalkanesulfonyl) derivative of an aminoglycosidic antibiotic such as ribostamycin, 3'-deoxy- or 3',4'-dideoxy-ribostamycin, kanamycin A or B, and 3'-deoxy- or 3',4'-dideoxy-kanamycin B exhibits a broader, antibacterial spectrum than the parent aminoglycosidic antibiotic and is useful in the therapeutic treatment of infections caused by gram-positive and gram-negative bacteria including drug-resistant strains thereof. The aforesaid derivative may be made by reaction between the parent antibiotic and an amino-protected .omega.-aminoalkanesulfonic acid halide and removal of the amino-protecting group from the condensation product.

Abstract: Novel derivatives of kanamycin, 1-N-(L-4-amino-2-hydroxy butyryl)-6'-N-alkylkanamycins, have been prepared which possess improved antibacterial activity against gram-positive and gram-negative bacteria including kanamycin-resistant strains.

Abstract: A process for preparing a novel antibiotic, 5"-amino-3',5"-dideoxy-ribostamycin, which comprises subjecting a ribostamycin derivative represented by the formula: ##STR1## to selective sulfonylation to form a 3',5"-O-disulfonyl derivative, SUBJECTING THE THUS PRODUCED DERIVATIVE TO AZIDE-FORMING REACTION WITH SODIUM AZIDE,Subjecting the thus produced ribostamycin 3'-O-sulfonyl-5"-azido derivative to deoxylation by treating it with sodium borohydride in an aprotic and polar solvent,Subjecting the thus obtained 3' deoxy derivative to catalytic hydrogenation in the presence of a catalyst to form a 5"-amino derivativeAnd then, removing the remaining protective groups of the last-mentioned derivative.

Abstract: A clinically valuable antibiotic, 3',4'-dideoxykanamycin B is now produced by a reduced number of consecutive steps in an improved overall yield by new processes starting from kanamycin B via intermediate derivatives of kanamycin B in which all the five amino groups are protected with an unsubstituted or substituted benzyloxycarbonyl group and possibly the 2"-hydroxyl group may be protected with a lower alkylsufonyl, arylsulfonyl or aralkylsulfonyl group.

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.

Abstract: There is provided a process for recovering macromomycin (hereinafter referred to as MCR) which comprises adding coagulants or coagulants and neutralizers to a culture filtrate saturated with ammonium sulfate and collecting the resulting precipitate containing MCR in a high yield at low centrifugal force. From the precipitate obtained, MCR powders can be prepared according to the methods described in U.S. Pat. No. 3,595,954 and others.

Abstract: A novel, unique nucleoside, 3-.beta.-D-ribofuranosyl-3,6,7,8-tetrahydroimidazo[4,5-d][1,3]diazepin-7-o l, named isocoformycin, of the formula ##STR1## is provided by ring expansion of derivatives of 9-.beta.-D-ribofuranosyl-6-hydroxymethyl-1,6-dihydropurine. Isocoformycin markedly inhibits deaminating enzymes which inactivate formycin and adenine arabinoside (also known as ara-A and Vidarabine). Formycin and adenine arabinoside are used as antiviral and antitumor agents in mammals and birds and isocoformycin is advantageous to prolong the activity and effect of formycin and adenine arabinoside.

Abstract: A useful antibiotic, 3',4'-dideoxykanamycin B can be prepared in shortened steps and in an improved overall yield by a new process starting from kanamycin B via new intermediate derivatives of kanamycin B in which all the amino groups and possibly the 2"-hydroxyl group are protected with sulfonyl-type protecting groups selected from lower alkyl-, aryl- and aralkyl-sulfonyl groups.