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Strain C39217-R109-7 (ATCC 53791) is an actinomycete strain isolated from a soil sample collected at Puerto Viejo, Peru. It produces a new antitumor antibiotic, designated pyrrolosporin A. Taxonomic studies on its morphological, cultural and physiological characteristics identified this producing strain as Micromonospora sp. C39217-R109-7. Pyrrolosporin A shows antimicrobial activity against Gram-positive bacteria and it is weakly active against Gram-negative bacteria. Pyrrolosporin A prolongs the life span of mice inoculated with P388 leukemia cells.

A new strain of Microtetraspora parvosata subsp. kistnae subsp. nov. (ATCC 55076) was found to produce new antiviral antibiotics, designated kistamicins A and B. These antibiotics exhibited activity against influenza virus type A and moderate activity against Gram-positive bacteria.

Three new 5-lipoxygenase inhibitors, designated as BU-4601 A, B and C, were found in the fermentation broth of Streptomyces sp. strain No. AA2807. Their structures were identified as isodecyl, isoundecyl and isolauryl esters of 5-hydroxyanthranilic acid, respectively. Based on their structures, five related esters were synthesized and evaluated for biological activity as inhibitors of 5-lipoxygenase. Both naturally-occurring and chemically-synthesized compounds exhibited almost equal levels of 5-lipoxygenase inhibitory activities in vitro.

A new antitumor antibiotic verucopeptin was isolated from the culture broth of Actinomadura verrucosospora Q886-2. It should potent cytotoxicity and specific in vivo activity against B16 melanoma. Maximum T/C value (162%) was obtained by Q1D x 1 treatment schedule.

A strain of Amycolatopsis orientalis No. Q427-8 (ATCC 53884) was found to produce a complex of new antiviral antibiotics, quartromicin which consisted of at least six components A1, A2, A3, D1, D2 and D3. Structural studies suggested that they are a novel type of molecules unrelated to any known antibiotics. Each component of quartromicin exhibited antiviral activity against herpes simplex virus type 1, influenza virus type A and human immunodeficiency virus.

An actinomycete strain No. Q996-17 produced a novel compound, epoxomicin, which exhibited in vivo antitumor activity against B16 melanoma. Structural studies indicated that it is a new member of the epoxy-beta-aminoketone group, and is closely related to eponemycin.

The morphology, chemotaxonomy, and cultural and physiological characteristics were examined on the five strains of actinomycetes which produce antiviral antibiotics, fluvirucin congeners. All strains have meso-2,6-diaminopimelic acid in the cell wall. Four strains, Q464-31, L407-5, R359-5 and R516-16, belong to the maduromycetes since they have madurose in the whole cell. The remaining one strain, R869-90, has rhamnose but no madurose, and is a nocardioform actinomycete. These five strains were classified and designated as follows: Strain Q464-31 (fluvirucin A1 producer): Microtetraspora tyrrhenii sp. nov. (Actinomadura pusilla group). Strain L407-5 (fluvirucin B2 producer): A maduromycete. Strain R359-5 (fluvirucin B1 producer): Microtetraspora pusilla (Actinomadura pusilla group). Strain R869-90 (fluvirucin A2 producer): Saccharothrix mutabilis. Strain R516-16 (fluvirucins B2, B3, B4 and B5 producer): A maduromycete.

Maduropeptin, a complex of new macromolecular antitumor antibiotics, is a metabolite of Actinomadura madurae H710-49. The active components maduropeptins A1, A2 and B are acidic chromopeptides with MW of around 22, 500 and composed of 14 types of amino acids and an unstable chromophore. The antibiotics are active in vitro against Gram-positive bacteria and highly cytotoxic to tumor cells. They produced significant prolongation of survival time of mice implanted with P388 leukemia and B16 melanoma.

A novel screening method for melanin biosynthesis inhibitors using Streptomyces bikiniensis NRRL B-1049 as the indicator organism has been developed. Several known compounds, including tyrosinase inhibitors, were found to inhibit melanin production of S. bikiniensis on agar plates. This screening method was applied to fermentation broths of actinomycetes and several cultures with melanin biosynthesis inhibitory activity were found.

Streptomyces hygroscopicus No. P247-71 (ATCC 53709) produced a novel antibiotic eponemycin which exhibited specific in vivo antitumor effect against B16 melanoma. Structural studies assigned (4S)-1, 2-epoxy-2-hydroxymethyl-4-(N-isooctanoyl-L-serylamino)-6-methylhept-6-ene-3-one to eponemycin which is unrelated to the known antitumor antibiotics.

Strains of Bacillus cereus produced a complex of new antibiotics, glysperins A, B and C. They are basic, water-soluble antibiotics and active against Gram-positive and Gram-negative bacteria including aminoglycoside-resistant organisms. Glysperin A is a major component of the antibiotic complex and approximately two to four times more active than components B and C.

An unidentified oligosporic actinomycete strain, No. E864-61, produced two new antibiotics, Bu-2313 A (C27H35NO9) and Bu-2313 B (C26H33NO9). Bu-2313 A and B each exhibited a broad antibiotic spectrum against Gram-positive and Gram-negative anaerobic bacteria, and showed in vivo activity against experimental infections produced by B. fragilis and C. perfringens. Bu-2313 also inhibited some aerobic bacteria such as streptococci. Bu-2313 B was approximately two-fold more active than Bu-2313 A.

A strain of Bacillus circulans produced a complex of basic peptide antibiotics designated Bu-2470, which was found to contain four active components, A, B1, B2a and B2b. Bu-2470 A specifically inhibited various Pseudomonas species including P. aeruginosa, P. maltophilia and P. putida, but otherwise its antibacterial spectrum was limited to certain Gram-negative organisms. Bu-2470 B1 and B2 (B2a + B2b) showed broad antibiotic activity against Gram-positive and Gram-negative bacteria including Pseudomonas species. The physicochemical and biological properties of Bu-2470 B1 and B2 are very similar to those of the octapeptin group of antibiotics.

A new genus Streptoalloteichus is proposed in the family Actinoplanaceae to distinguish species of actinomycetes which form short or long spore-chains on aerial mycelium, bears oval sporangia with motile spores and has a characteristic cell-wall composition of strain C677-91 type. Strain C677-91 (ATCC 31217, FERM-P No. 4070) was named Streptoalloteichus hindustanus gen. nov. and sp. nov. The actinomycete strain C677-91 produces spore-chain clusters and sclerotia in the aerial mycelium which are morphologically similar to those found in some species of Streptomyces. The cultural characteristics of the strain on agar media also resemble those of Streptomyces species and the colonies have no distinct color. Strain C677-91 produces sporangia or sporangia-like vesicles which contain one to several spores in the vegetative mycelium. The sporangiospores possess a single long polar flagellum and are motile. The cell wall of strain C677-91 contains meso-alpha,epsilon-diaminopimelic acid, alanine, glutamic acid, galactose, mannose, rhamnose and glucosamine. Strain C677-91 has several important characteristics in common with Streptomyces tenebrarius including the production of nebramycin factors but the latter strain does not produce sporangia.

An aerobic actinomycete strain isolated from an Indian soil sample and designated No. E864-61 was found to produce in submerged fermentation a new antibiotic complex, Bu-2313 (components A and B). Strain E864-61 forms single, pairs or chains of three to eight spores on the aerial mycelium and its aerial mass color is grayish blue-green. The cell wall of strain E864-61 contains meso-diaminopimelic acid and galactose. Strain E864-61 has been classified as a new species of the genus Microtetraspora and designated as Microtetraspora caesia sp. nov.

Empedopeptin is a new antibiotic produced by empedobacter haloabium nov. sp. (ATCC 31962). It is a water-soluble depsipeptide antibiotic containing eight amino acid residues and a C14-fatty acid moiety in the molecule. Although structurally unrelated, empedopeptin and vancomycin have similar antimicrobial spectra against aerobic and anaerobic Gram-positive bacteria including antibiotic-resistant strains. Empedopeptin is highly active in vivo in mice against systemic infections of Staphylococcus aureus, Streptococcus pyogenes and Clostridium perfringens. Empedopeptin is not absorbed orally.

In the course of our search for new antibiotics, a strain of Bacillus circulans No. YQW-B6 was isolated from a soil sample collected in Taiwan. This organism produced a complex of aminoglycoside antibiotics designated Bu-1709, and the two major components, A1 and A2, were identified as butirosins A (I) and B (II)2-4), respectively. This paper reports the bioactive degradation products from butirosins and the semi-synthesis of butirosin analogs.

The oxamicetin-producing organism designated as Arthrobacter oxamicetus TOMITA and KAWAGUCHI sp. nov. is described. The morphological, cultural and physiological characteristics of the organism as well as its taxonomic relationship to other species of Arthrobacter are also discussed. The type strain is No. B302-B75 by virtue of its being a single isolate.

Cirramycin A, a macrolide antibiotic, has been found to consist of one major (A1) and several minor components (A2, A3, A4 and A5). The majoractive substance, cirramycin A1 (C31H51NO10), was isolated as a single component and characterized in detail. It has a strong ultraviolet absorption peak at 241mμ and its chromophore is suggested to be an α, β-unsaturated γ, δ-depoxide carbonyl system. Cirramycin A1 contains the basic sugar mycaminose but lacks a neutral sugar in the molecule.