Two New Butenolides Produced by an Actinomycete Streptomyces sp.

Two new butenolides, (4S)‐4,10‐dihydroxydodec‐2‐en‐1,4‐olide ( 1 ) and (4S)‐4,8,10‐trihydroxy‐10‐methyldodec‐2‐en‐1,4‐olide ( 2 ), together with three known compounds, MKN‐003B ( 3 ), MKN‐003C ( 4 ), and cyclo(Ala‐Leu) ( 5 ), were isolated from the culture broth of a bacterium of the genus Streptomyces derived from soil environment. The structures of these compounds were elucidated on the basis of spectroscopic analysis. The inhibitory activities of the butenolides against eight pathogenic fungi were evaluated. All of the butenolides showed moderate‐or‐weak antifungal activities in a broth microdilution assay.     

Two New Sesquiterpene Derivatives from the Tunisian Endemic Ferula tunetana Pom.

A new sesquiterpene ester, tunetanin A ( 1 ), a new sesquiterpene coumarin, tunetacoumarin A ( 2 ), together with eight known compounds, i.e., coladin ( 3 ), coladonin ( 4 ), isosmarcandin ( 5 ), 13‐hydroxyfeselol ( 6 ), umbelliprenin ( 7 ) propiophenone ( 8 ), β‐sitosterol ( 9 ), and stigmasterol ( 10 ), were isolated from the roots of Ferula tunetana. Their structures were elucidated on the basis of extensive spectroscopic methods, including 1D‐ and 2D‐NMR experiments and MS analysis, as well as by comparison with published data. The cytotoxicity of compounds 1 – 7 towards two human colon cancer cell lines, HT‐29 and HCT 116, was evaluated. Compounds 3, 4 , and 6 showed weak cytotoxic activities.     

New Pterosin Sesquiterpenes and Antitubercular Constituents from Pteris ensiformis

Two new pterosin sesquiterpenes, (2S)‐13‐hydroxypterosin A ( 1 ) and (2S,3S)‐12‐hydroxypterosin Q ( 2 ), were isolated from the whole plants of Pteris ensiformis, together with six known compounds. The structures of 1 and 2 were determined through extensive 1D/2D‐NMR and MS analyses. Compound 2 exhibited antitubercular activity (MIC 6.25 μg/ml) against Mycobacterium tuberculosis H₃₇Rv in vitro.     

New bisabolane sesquiterpenes and coumarin from Leontopodium longifolium

From the roots of Leontopotium longifolium, three new bisabolane sesquiterpenes, rel-(1S,4R,5S,6R)-4,5-diacetoxy-6-[(R)-1,5-dimethylhexa-3,5-dienyl]-3-methylcyclohex-2-enyl (Z)-2-methylbut-2-enoate (1), rel-(1S,4R,5S,6R)-4,5-diacetoxy-6-[(R)-5-hydroxy-1,5-dimethylhex-3-enyl]-3-methylcyclohex-2-enyl (Z)-2-methylbut-2-enoate (2), rel-(1R,2S,4R,5S)-4-acetoxy-2-[(R)-5-hydroxy-1,5-dimethylhex-3-enyl]-5-methylcyclohexyl (Z)-2-methylbut-2-enoate (3), and a new coumarin, 2,3-dihydro-5-hydroxy-2-(1-methylethenyl)-7H-pyrano[2,3-g][1,4]benzodioxin-7-one (4) together with nine known compounds have been isolated. The structures of these compounds were established by spectroscopic methods. Compounds 1 and 2 exhibited moderate cytotoxic activities against human promyelocytic leukemia (HL-60) cells.     

Four New Nanaomycins Produced by Streptomyces hebeiensis Derived from Lichen

Four new nanaomycins ( 1  –  4 ), together with two known compounds, nanaomycin αA ( 5 ) and nanaomycin βA ( 6 ) were isolated from a fermentation broth of Streptomyces hebeiensis derived from lichen. The structures of the new nanaomycins 1  –  4 were established using comprehensive NMR spectroscopic data analysis as well as UV, IR, and MS data. The antimicrobial activities of 1  –  6 were evaluated against Gram‐positive bacteria and fungus. Compounds 5 and 6 showed antimicrobial activities against the test microorganisms, while 1  –  4 were inactive at 100 μg/ml.     

链霉菌FIM-080014产生的核苷类代谢产物研究

本文采用大孔吸附树脂、硅胶柱色谱、反相柱色谱、凝胶sephadex LH-20及HPLC等方法对链霉菌FIM-080014发酵液及菌丝体中的代谢产物进行分离,得到7个核苷类化合物。通过NMR及MS等方法鉴定了上述化合物的结构,分别为尿嘧啶(1)、尿嘧啶核苷(2)、2'-脱氧尿嘧啶核苷(3)、5'-C-甲基尿嘧啶核苷(4)、2'-脱氧胸腺嘧啶核苷(5)、2'-脱氧鸟嘌呤核苷(6)和次黄嘌呤(7),其中化合物4首次从微生物代谢产物中分离得到。活性分析表明化合物1～7对神经氨酸酶具有一定的抑制活性,其IC50值分别为3.7、2.1、4.4、1.4、3.6、2.5和2.4 mM。     

Kalafungin, a New Antibiotic Produced by Streptomyces tanashiensis Strain Kala

Kalafungin is a new antimicrobial agent obtained from the culture broth of a soil isolate of Streptomyces tanashiensis, designated Streptomyces tanashiensis strain Kala UC-5063. Kalafungin is a chemically stable, nonpolyene agent which is ex-extremely inhibitory in vitro against a variety of pathogenic fungi, yeasts, protozoa, gram-positive bacteria, and, to a lesser extent, gram-negative bacteria.     

Actinomycetes from Moroccan habitats: isolation and screening for cytotoxic activities

In our screening for actinomycetes showing cytotoxic activities, 8 samples were collected from various Moroccan habitats, 136 isolates were tested for their capacity to produce antibacterial compounds against gram positive bacteria. Thirty-seven strains of these isolates were active against Gram-positive bacteria. Using the following steps of primary screening: antibacterial activity, confrontation between the isolates and toxicity to Artemia salina; fifteen different isolates were used for further investigation. The aqueous extracts of Streptomyces sp. T5 and Streptomyces sp. AS8 were selected for their cytotoxic activity against Hep2, BSR and P815 cell lines, and two active compounds were observed on HPLC. The two isolates exhibited high activity against human cancer cell lines and were inactive on PBMC cell lines. Furthermore, the Streptomyces sp. T5 extract showed a proliferative activity.     

Two new isocoumarins isolated from a mangrove-derived Penicillium sp.

Two new isocoumarins named peniciisocoumarins I and J (1−2), together with four known analogues (3−6), were obtained from Penicillium sp. GXIMD 03001, an endophytic fungus derived from the rhizophoraceous mangrove Kandelia candel. The structures and absolute configurations of 1 and 2 were determined by detailed analysis of their NMR, MS spectroscopic data, a modified Mosher’s method and electronic circular dichroism data. All isolated isocoumarins were evaluated for their cytotoxic activity against four human cancer cell lines (SPCA-1, BEL-7402, GSC-7901 and MCF-7). However, none of the compounds exhibited any appreciable activity (IC₅₀ > 50 μM).     

Chemical Structures of New Piericidins Produced by Streptomyces pactum

Chemical structures of new piericidins produced by Streptomyces pactum are elucidated on the basis of mass, PMR and CMR spectral analyses. Consequently, these piericidins were shown to be constructed by a combination of variations in each four functionalities and carbon skeletons.     

New chemical constituents from the endophyte Streptomyces species LR4612 cultivated on Maytenus hookeri

From solid cultures of the biologically important endophyte Streptomyces species LR4612, cultivated on Maytenus hookeri, four new and two known compounds were isolated. The new compounds were identified as (2S*,3S*)-5-amino-3-hydroxy-5-oxopentan-2-yl 3-(formylamino)-2-hydroxybenzoate (1), N-[(3R*,4R*)-3-amino-3,4-dihydro-4-methyl-2,6-dioxo-2H,6H-1,5-benzodioxocin-10-yl]formamide (2), (5beta,6alpha)-6,11-dihydroxyeudesmane (3), and 5-(6,7-dihydroxy-6-methyloctyl)furan-2(5H)-one (4); the known compounds were elucidated as sorbicillin (5) and N-acetyltyramine (6). The structures were established by HR-ESI-MS and in-depth NMR analyses.     

Polylysine Produced by Streptomyces

The xylitol dehydrogenase gene (xdh) of Bacillus pallidus was cloned and overexpressed in Escherichia coli using pQE60 vector, for the first time. The open reading frame of 759 bp encoded a 253 amino acid protein with a calculated molecular mass of 27,333 Da. The recombinant xylitol dehydrogenase (XDH) was purified to homogeneity by three-step column chromatography, producing a single SDS–PAGE band of 28 kDa apparent molecular mass. The enzyme exhibited maximal activity at 55 °C in glycine-NaOH buffer pH 11.0, with 66% of initial enzyme activity retained after incubation at 40 °C for 1 h. In further application of the recombinant bacterium to L-xylulose production from xylitol (initial concentration 5%) using a resting cell reaction, 35% L-xylulose was produced within 24 h. This result indicates that this recombinant XDH is applicable in the large-scale production of L-xylulose.     

Lomofungin,a New Antibiotic Produced by Streptomyces lomondensis sp. n

Lomofungin is a new antimicrobial agent obtained from the culture broth of Streptomyces lomondensis sp. n. UC-5022. Lomofungin is an acidic, olive-yellow, crystalline compound which inhibits, in vitro, a variety of pathogenic fungi, yeasts, and gram-positive and gram-negative bacteria.     

Acremoxanthone E,a Novel Member of Heterodimeric Polyketides with a Bicyclo[3.2.2]nonene Ring,Produced by Acremonium camptosporum W. Gams (Clavicipitaceae) Endophytic Fungus

Bioactivity‐directed fractionation of the organic mycelium extract of the endophytic fungus Acremonium camptosporum W. Gams (Clavicipitaceae), isolated from the leaves of Bursera simaruba (Burseraceae), led to the isolation of six major heterodimeric polyketides, including one not previously characterized acremoxanthone derivative. In addition, the already known acremoxanthone C, acremonidins A and B, and acremoxanthones A and B were obtained. The structure of the new compound was established by extensive NMR studies, including DEPT, COSY, NOESY, HSQC, and HMBC methods. The trivial name proposed for this compound is acremoxanthone E. In addition, the structure of acremoxanthone C was unequivocally established for the first time, through X‐ray crystal‐structure analysis. The anti‐oomycete activities of the pure compounds were tested against four economically important phytopathogenic oomycetes. Inhibitory concentration for 50% diameter growth reduction, IC₅₀, values for the four phytopathogens ranged from 6 to 38 μM . Also, in parallel, the cytotoxic activities against six cancer cell lines were evaluated showing IC₅₀ values similar to those of cisplatin. To the best of our knowledge, this is the first report on three different groups of heterodimeric polyketides, linked by a bicyclo[3.2.2]nonene, such as xanthoquinodins, acremonidins, and acremoxanthones, which are isolated from an endophytic fungus. In addition, a common biosynthetic origin could be proposed.     

A New Toxic Substance,Teleocidin, Produced by Streptomyces

The production and isolation of a new toxic substance, Teleocidin, and its biological properties were previously reported^1,2). Thereafter it has been found that an other strain of Streptomyces produced such specific toxic substance as Teleocidin in its cultured mycellium. Comparative tests of these two purified crystalline powders showed the new toxic substance resembles Teleocidin closely though differs in certain chemical properties. Therefore, the original Teleocidin is designated Teleocidin A, whereas that produced by a new strain of Streptomyces is named Teleocidin B, which had been tentatively called as the SK-toxic substance.

From the results of the chemical studies of Teleocidin B and its hydrogenated derivative, which was easily obtained as a crystalline form by the catalytic hydrogenation of Teleocidin B with Adam’s catalyst, molecular formula, C₂₈H_39~41N₃O₂ was postulated for Teleocidin B.

It was also recognized that an alcoholic hydroxyl, a lactam ring and a heterocyclic ring like indole or pyrrole structure existed as the functional groups of Teleocidin B.     

Metabolites Produced by Streptomyces mobaraensis

New metabolites, A-, B- and X-substance and piericidin X, were isolated from mycellia of Streptomyces mobaraensis. Structure of A-substance was decided as VII and B-substance was identified as reticulol (VIII).