Kettapeptin: isolation, structure elucidation and activity of a new hexadepsipeptide antibiotic from a terrestrial Streptomyces sp

The ethyl acetate extract of the Streptomyces sp. isolate GW99/1572 exhibited significant biological activity against Gram-positive bacteria and delivered kettapeptin (1), a new hexadepsipeptide antibiotic of the azinothricin type. The structure was elucidated by various 1D and 2D NMR techniques, mass spectrometry and by comparison of the NMR data with those of closely related antibiotics. The absolute configuration of the compound was derived by crystal structure analysis and by comparison with the optical rotation data of related compounds.     

Bhimamycin A to approximately E and bhimanone: isolation, structure elucidation and biological activity of novel quinone antibiotics from a terrestrial Streptomycete

From the ethyl acetate extract of a terrestrial Streptomycete isolate, five new quinone antibiotics, bhimamycin A (2a), B (2b), C (3c), D (5a), E (7) and the new tetralone bhimanone (8) were isolated together with the known microbial products chrysophanol (1a), aloesaponarin II (1b), 3,8-dihydroxy-1-methylanthraquinone-2-carboxylic acid (1c), adenosine, 2'-deoxyadenosine, phenylacetamide, and 2-(p-hydroxyphenyl)ethanol. The structures of these natural products were deduced from the spectral data and confirmed by comparison with related compounds from the literature and by synthesis.     

A new tetracycline antibiotic from a Dactylosporangium species. Fermentation, isolation and structure elucidation

An actinomycete identified as a Dactylosporangium sp. produces a new tetracycline, 4a-hydroxy-8-methoxychlortetracycline (Sch 34164). The addition of magnesium ions to complex fermentation media increased the antibiotic titers. Sch 34164 was isolated by solvent extraction and Sephadex G-25 column chromatography. The novel structure was proposed based on spectroscopic analysis. The shift of C-4a (35 to 77 ppm) and C-8 (140 to 163 ppm) in the 13C NMR as compared to chlortetracycline was indicative of the novel hydroxyl and methoxy substituents, respectively.     

Altersetin,a new antibiotic from cultures of endophytic Alternaria spp. Taxonomy,fermentation, isolation,structure elucidation and biological activities

A novel antibacterial antibiotic, for which the name altersetin is proposed, was isolated from the culture broth of two endophytic Alternaria species. The relative and absolute configuration were assigned by NOESY or CD data, respectively. Altersetin is chemically related to equisetin and showed potent MIC against several pathogenic gram-positive bacteria, whereas gram-negative bacteria and pathogenic yeast were not or much less susceptible. Moderate in vivo efficiacy was observed for altersetin in a murine sepsis model.     

Porothramycin, a new antibiotic of the anthramycin group: production, isolation, structure and biological activity

A new antitumor antibiotic porothramycin was produced by a new strain of Streptomyces albus. The antibiotic was isolated in two active forms, the natural free hydroxyl form (porothramycin A) or the crystalline methyl ether form (porothramycin B) depending upon the isolation process used. Structural studies established that porothramycin is a new member of the pyrrolo[1,4]benzodiazepine group antibiotics having only one substituent on the benzene ring. The antibiotic exhibited antimicrobial activity against Gram-positive bacteria and anaerobes and significantly prolonged the survival times of mice implanted with experimental tumors.     

Two new beta-class milbemycins from streptomyces bingchenggensis: fermentation, isolation, structure elucidation and biological properties

Two new beta-class milbemycins from Streptomyces bingchenggensis, named milbemycin beta(13) and beta(14), have been isolated and characterized. The producing organism has been deposited at the China General Microbiology Culture Collection Center (Accession No: CGMCC1734). On the basis of detailed spectroscopic analysis and comparison with reported data, their structures were determined to be the hydroxyl derivatives at C-27 of milbemycin beta(3) and 25-ethylmilbemycin beta(3), respectively. Milbemycins beta(13) and beta(14) possess potent acaricidal and nematocidal activity. The discovery of these two compounds plays an important role in understanding and perfecting the proposed pathways of milbemycins.     

Sultriecin, a new antifungal and antitumor antibiotic from Streptomyces roseiscleroticus. Production, isolation, structure and biological activity.

Streptomyces roseiscleroticus L827-7 (ATCC 53903) produced a novel antifungal and antitumor antibiotic, sultriecin. It exhibited in vitro antifungal activity and potent in vivo antitumor activity against P388 and L1210 leukemias, and B16 melanoma. Sultriecin is composed of several unique structural units; a conjugated triene, an alpha,beta-unsaturated delta-lactone, and a sulfate functionality.     

Butalactin, a new butanolide antibiotic. Taxonomy, fermentation, isolation and biological activity

Butalactin, [2-(4',5'-epoxy-hex-2'(E)-en)oyl-2-hydroxy-3-hydroxymethyl-2, 3-(Z)-butanolide] is a new antibiotic produced by Streptomyces sp. HIL Y-86,36923. Taxonomically, the producing organism most closely resembles Streptomyces corchorusii. The strain also produces cineromycin B. Though butalactin is structurally related to 'signal molecules' such as A-factor, the anthracycline inducing factors and the virginiae butanolides, it does not show inducing activity for antibiotic production or aerial mycelium formation in the indicator strain. Butalactin possesses a weak antibiotic activity against Gram-positive and Gram-negative bacteria.     

Pyrroxamycin, a new antibiotic taxonomy, fermentation, isolation, structure determination and biological properties

A strain of streptomycete was found to produce a new antibiotic pyrroxamycin. This compound was isolated from the culture broth of Streptomyces sp. S46506. The chemical structure was determined to be 4,5-dichloro-2-(6',8'-dichloro-4'H-1',3'-benzodioxin-4'-yl)-3-nitr opyrrole by its chemical character and 1H and 13C NMR spectral analysis. Pyrroxamycin was active against Gram-positive bacteria and dermatophytes.     

FR112123, a new oligopeptide antibiotic from Streptomyces viridochromogenes. Taxonomy, fermentation, isolation, physico-chemical properties, structure and biological activity

FR112123 is a new oligopeptide antibiotic produced by Streptomyces viridochromogenes No. 7587. The structure of FR112123 is elucidated as N-(N6-(N2-glycyl-L-glutaminyl)-D-lysyl)-D-alanine (1) by spectroscopic and chemical evidence. It resembles a partial structure of peptidoglycan in bacteria. The compound has a superior activity against an Escherichia coli mutant sensitive to inhibitors of cell wall synthesis, although it has a weak activity against the parent strain. These suggest that FR112123 might act on the biosynthesis of bacterial cell wall.     

Oxetin, a new antimetabolite from an actinomycete. Fermentation, isolation, structure and biological activity

A new amino acid-antimetabolite, oxetin, was isolated from a fermentation broth of a Streptomyces sp. OM-2317, a soil isolate. The chemical structure was elucidated as (2R,3S)-3-amino-2-oxetane carboxylic acid by analysis of the spectral data and by X-ray diffraction methods. The antibiotic is the first natural product possessing an oxetane ring. Certain microorganisms were inhibited by oxetin only when cultivated in minimal media. The inhibitory action was reversed by several amino acids such as L-isoleucine, L-methionine, L-valine and L-glutamine. It also exhibited herbicidal activity and inhibited glutamine synthetase from spinach leaves.     

A new anthracycline antibiotic, cinerubin R. Taxonomy, structural elucidation and biological activity.

A novel anthracycline antibiotic, cinerubin R, was isolated from the fermentation broth of Streptomyces eurythermus strain H1715MY2. The structure of cinerubin R was elucidated to be 4"-aculosyl-4'-rhodinosyl-7-rhodosaminyl-epsilon-py rromycinone. Cinerubin R was active against Gram-positive bacteria and inhibited the growth of divergent multi-drug-resistant cells to the same extent as their parental cells.     

New aminophenoxazinones from a marine Halomonas sp.: fermentation, structure elucidation, and biological activity

The addition of anthranilic acid to the culture medium of the marine derived Halomonas sp. strain GWS-BW-H8hM completely altered the secondary metabolite pattern relative to the standard conditions. The red-orange color of the culture filtrate extract was the result of the production of 2-aminophenoxazin-3-one (1), chandrananimycin C (5) and three new derivatives of 1 with a previously unknown substitution pattern: 2-amino-, 2-amino-8-benzoyl-, and 2-amino-8-(4-hydroxybenzoyl)-6-hydroxyphenoxazin-3-one (2-4). The compounds were determined to have antibacterial and cytotoxic activities; a mode of action other than DNA intercalation is discussed.     

Agrochelin, a new cytotoxic antibiotic from a marine Agrobacterium. Taxonomy, fermentation, isolation, physico-chemical properties and biological activity

Agrochelin, a new alkaloid cytotoxic substance, was produced by the fermentation of Agrobacterium sp. The compound was obtained from the bacterial cells by solvent extraction and purified by silica gel chromatography. Agrochelin (1) and its acetyl derivative (2) exhibited cytotoxic activity.     

Aranorosinol A and aranorosinol B, two new metabolites from Pseudoarachniotus roseus: production, isolation, structure elucidation and biological properties.

Two new secondary metabolites, aranorosinol A (1) and aranorosinol B (2), were isolated from a strain of Pseudoarachniotus roseus. Their structures were elucidated on the basis of their spectral properties and chemical transformations and were found to be similar to aranorosin (3) isolated from the same strain.     

FR109615, a new antifungal antibiotic from Streptomyces setonii. Taxonomy, fermentation, isolation, physico-chemical properties and biological activity

FR109615, a new antibiotic active against Candida, was isolated from Streptomyces setonii No. 7562. Based on the spectroscopic data, the structure of FR109615 was elucidated as cis-2-aminocyclopentane-1-carboxylic acid (1). The compound showed the excellent in vivo efficacy in a generalized infection test of mice.     

免疫抑制剂SIPI-029-1的研究——发酵、分离、结构鉴定和生物活性

用筛选微生物来源的免疫抑制活性化合物的酵母筛选系统，筛选出的吸水链霉菌（Streptomyces hygroscopcus)sp.SIPI-029的发酵液具有免疫抑制活性，应用乙酸乙酯提取，硅胶柱层析和结晶等方法，从其上清液中分离出活性化合物SIPI-029-1；通过理化性质，质谱，紫外，红外和核磁共振等图谱数据的分析。确定SIPI-029-1化合物为安莎类抗生素，与文献报道的HerbimycinA结构一致，生物学活性研究，发现其具有中等强度的免疫抑制新活性。     

Pedein A and B: production, isolation, structure elucidation and biological properties of new antifungal cyclopeptides from Chondromyces pediculatus (Myxobacteria)

Two new secondary metabolites, named pedein A and B, were isolated from the cell mass of the myxobacterium Chondromyces pediculatus. Their planar structures were elucidated by spectroscopic methods, in particular 2D NMR as 24-membered cyclic hexapeptides composed of a variable tryptophan residue, glycine, sarcosine and three unusual hydroxy beta- and gamma-amino acids. The main component, pedein A, strongly inhibited the growth of yeasts and fungi, induced hemolysis of erythrocytes, and caused changes in membrane permeability of Rhodotorula glutinis. The structures of the pedeins are closely related to the large family of the microsclerodermins, which have been isolated from lithistid sponges of Microscleroderma and Theonella species.