A new isobenzofuranone derivative from a marine Streptomyces sp.

One new isobenzofuranone derivative,1,4-dimethoxy-3-(3R*-hydroxy-3R*-methyl-1-tetralone)-1(3H)-isobenzofuran(1),was isolated from the broth of marine Streptomyces sp.M268.The structure was elucidated by spectroscopy characteristics as well as comparison with the literature.Compound 1 exhibited cytotoxicities against human cancer cell,HL-60,A549,and BEL-7402.     

Hainanmycin A,a cyclo-heptadeca macrolide bearing a cyclopentenone moiety from the mangrove-derived Streptomyces sp. 219807

A macrocyclic polyketide with novel carbon skeleton, namely hainanmycin A, was isolated from the mangrove-derived Streptomyces sp. 219807. This polycyclic compound featured a cyclo-heptadeca framework possessing a 5,6-disubstituted-4-hydroxy-2-pyrone moiety in conjunction with a 2-cyclopentenone residue. The structure was established by spectroscopic analyses, and the stereochemistry was determined by NMR chemical shifts calculations and time-dependent density functional theory (TDDFT) calculation of electronic circulardichroism (ECD). A possible biogenetic pathway for hainanmycin A was proposed.     

A New Virginae Butanolide from Streptomyces sp.

A novel butanolide, named virginaebutanolide F (1), was isolated from the lyophilized culture broth of Slreptomyces sp., along with a known compound virginaebutanolide C (2). Their structures including the stereochemistry were elucidated on the basis of extensive 1D and 2D NMR as well as HRESI-MS and CD spectroscopic analysis.     

One new anthraquinone from marine Streptomyces sp. FX-58

One new anthraquinone, 1,8-dihydroxy-2-ethyl-3-methylanthraquinone (1), together with two known compounds octadecanoic acid (2) and cholest-4-en-3-one (3) was isolated from marine actinomycete Streptomyces sp. FX-58. The structure of 1 was elucidated on the basis of spectroscopic methods, especially, the 2D-NMR spectral analysis. The cytotoxic activities of 1 were evaluated in vitro.     

Amphidinolide W, a new 12-membered macrolide from dinoflagellate Amphidinium sp

A new cytotoxic 12-membered macrolide, amphidinolide W (1), has been isolated from a marine dinoflagellate Amphidinium sp., and the structure was elucidated by spectroscopic data including (13)C-(13)C INADEQUATE correlations for its (13)C-enriched sample. The absolute stereochemistry of 1 was assigned by combination of J-based configuration analysis and modified Mosher method. Amphidinolide W (1) is the first macrolide without an exomethylene unit among all amphidinolides obtained so far.     

Izumiphenazine D, a new phenazoquinoline N-oxide from Streptomyces sp. IFM 11204

A new phenazine derivative named izumiphenazine D (1), together with three known metabolites, 1-hydroxyphenazine (2), phenazine-1-carboxylic acid (3) and 6-hydroxyphenazine-1-carboxylic acid (4) has been isolated from the ethyl acetate extract of culture of Streptomyces sp. IFM 11204. The structure of 1 was established via spectroscopic methods, including 1D- and 2D-NMR measurements.     

A new diketopiperazine derivative from a deep sea-derived Streptomyces sp. SCSIO 04496

A new diketopiperazine (DKP) derivative, (6R,3Z)-3-benzylidene-6-isobutyl-1-methyl piperazine-2,5-dione (1), as well as five known DKPs 2–6 was isolated from a deep sea-derived Streptomyces sp. SCSIO 04496. The structure of 1 was elucidated using a combination of 1D and 2D NMR, HR-ESI-MS and chiral-phase HPLC techniques. Compounds 1–6 did not show cytotoxic activity at a concentration of 100 μM in bioactivity assay.     

Iromycins: a new family of pyridone metabolites from Streptomyces sp. II. Convergent total synthesis

The total synthesis of iromycin A (1a), a microbial metabolite combining a novel structure with an interesting biological activity as a NO synthase inhibitor, was accomplished using a flexible and highly convergent approach. Thus, the ring fragment was prepared as 6-bromomethylpyrone 27 by acylation of the respective beta-ketoester 13 and subsequent lactonization of the thus-obtained beta,delta-diketoester 11, followed by bromination of the 6-methyl group. In addition, the unsaturated side chain was efficiently prepared as terminal alkyne 34 which was then carboaluminated to furnish the alkenyldimethylalane 35. The assembly of these two fragments was thoroughly studied using nickel, palladium, and copper catalysts yet only succeeded in the absence of any transition metal after formation of the respective lithium alkenyltrialkylalanate. Treatment of the coupled product 41 with liquid ammonia then completed the total synthesis which furnished an 18% overall yield over the nine steps of the longest linear sequence.     

Total synthesis of rutamycin B, a macrolide antibiotic from Streptomyces aureofaciens.

Rutamycin B (2) was synthesized from three principal subunits, spiroketal 75, keto aldehyde 83, and aldehyde 108. First, triol 62 was assembled by Julia coupling of sulfone 56 with aldehyde 58 followed by an acid-catalyzed spiroketalization. The three hydroxyl functions of 62 were successfully differentiated, leading to phosphonate 75. The latter was condensed in a Wadsworth-Emmons reaction with 83, prepared in six steps from (R)-aldehyde 76, to give 92. Coupling of the titanium enolate of 92 with 108 afforded Felkin product 109 with high stereoselectivity in a process that is critically dependent on the presence of the p-methoxybenzyl ether in the aldehyde. Transformation of 109 via aldehyde 116 to vinylboronate 122 was followed by macrocyclization under Suzuki conditions to yield 123. Exhaustive desilylation of the latter yielded rutamycin B.     

Peloruside A: a potent cytotoxic macrolide isolated from the new zealand marine sponge Mycale sp

A novel, polyoxygenated, pyranose ring containing 16-membered macrolide peloruside A (1) exhibiting cytotoxic activity in the nanomolar range was isolated from the New Zealand marine sponge Mycale sp. The structure of 1 and relative stereochemistry of the 10 stereogenic centers were determined on a 3 mg sample using a variety of spectroscopic methods. Compound 1 was isolated along with the previously reported cytotoxins mycalamide A (2) and pateamine (3) from a single specimen of this sponge.     

Symbiodinolactone A,a new 12-membered macrolide from symbiotic marine dinoflagellate Symbiodinium sp.

A new 12-membered macrolide, symbiodinolactone A, was isolated from the culture broth of symbiotic marine dinoflagellate Symbiodinium sp. The gross structure of symbiodinolactone A was elucidated by spectroscopic analyses, and the relative configuration was elucidated by the J-based configuration analysis and density-functional theory calculations. Symbiodinolactone A is the new 12-membered macrolide possessing an E double bond between C-4 and C-5, a branched methyl group at C-7, and a 1,2,3-trihydroxybutyl group at C-11. Symbiodinolactone A is the first usual size macrolide and the first non-nitrogen-containing macrolide from dinoflagellate Symbiodinium sp. Symbiodinolactone A might be generated by the unexplained dinoflagellate polyketide biosynthetic machinery.     

Four new anthraquinones from a soil actinomycete Streptomyces sp. WS-13394 and their bioactivities

Further chemical study of secondary metabolites from the soil actinomycete Streptomyces sp. WS-13394 resulted in the isolation of four new alkylated anthraquinone analogues (5–8). Their structures were elucidated on the basis of extensive spectroscopic analysis, including HR-ESI-MS, 1D and 2D NMR. The new compounds, together with analogues obtained before (1–4), were tested for their in vitro cytotoxicity against Huh-7 and SGC-7901.     

Antimicrobial and antioxidant activities of a new benzamide from endophytic Streptomyces sp. YIM 67086

A new benzamide (1) and four known compounds (2–5) were isolated from endophytic Streptomyces YIM67086, and their structures were determined as 2-amino-3,4-dihydroxy-5-methoxybenzamide (1), 4-hydroxy-3-methoxybenzoic acid (2), phenylacetic acid (3), N-acetyltyramine (4) and p-hydroxytruxinic acid (5). Compound 5 was first found in the microorganism. The antimicrobial activities of compounds 1–5 and antioxidant activity of compound 1 were investigated.     

Novel Polyketides Isolated from Streptomyces sp.

From the endophytic strain Streptomyces sp. CS of Maytenus hookeri, five novel type III polyketides, compounds 1 – 5 , were isolated. Their structures were elucidated by spectroscopic analyses including 1D‐ and 2D‐NMR experiments, and by HR‐ESI‐MS.     

Aspergillolide,a new 12-membered macrolide from sea cucumber-derived fungus Aspergillus sp. S-3-75

Abstract

A new 12-membered macrolide, aspergillolide (1), along with nine known compounds (2–10), were isolated from the fungus Aspergillus sp. S-3-75 associated with the sea cucumber Holothuria nobilis Selenka. The structure and absolute stereochemistry of 1 were elucidated on the basis of extensive spectroscopic methods and single crystal X-ray diffraction analysis.     

Bioactive isocoumarins from a terrestrial Streptomyces sp. ANK302

Four isocoumarins have been isolated from the terrestrial Streptomyces sp. ANK302, namely 6,8-dimethoxy-3-methylisocoumarin (1), 6,8-dihydroxy-3-methylisocoumarin (2), 6,8-dihydroxy-7-methoxy-3-methylisocoumarin (3), and 6,7,8-trimethoxy-3-methylisocoumarin (4). Compound 1 is a new naturally-occurring isocoumarin, and 2 was isolated as a new bacterial product. The structures 1-4 were deduced from high resolution mass, 1D and 2D NMR spectra and by comparison with related compounds from the literature. Compound 2 showed a strong zoosporicidal activity at a concentration of 5 microg/mL against a phytopathogenic oomycete, Plasmopara viticola, and 1 was active against     

Colubricidin A, a novel macrolide antibiotic from a Streptomyces sp.

A new 34-membered macrolide antibiotic, colubricidin A (1), was isolated from the fermentation broth of a new streptomyces species. Its structure was elucidated on the basis of analysis of the spectroscopic data and chemical degradation. It was identified as a glycomacrolide with an unprecedented aromatic chromophore. Colubricidin A showed excellent activity against Gram-positive bacteria.     

Three new 2,5-diketopiperazines from the fish intestinal Streptomyces sp. MNU FJ-36

The gut actinobacteria of marine-inhabited fish is one of the most important reservoirs of novel natural products. Currently, the Streptomyces sp. MNU FJ-36 was isolated from the intestinal fabric of Katsuwonus sp. and determined by 16S rRNA analysis. From the cultures of the S. sp. MNU FJ-36, three new 2,5-diketopiperazines (2,5-DKPs) were discovered and identified as 3-(3-hydroxy-4-methoxybenzyl)-6-isobutyl-2,5-diketopiperazine (1), 3-(1,3-benzodioxol-5-ylmethyl)-6-isobutyl-2,5-diketopiperazine (2) and 3-(1,3-benzodioxol-5-ylmethyl)-6-isopropyl-2,5-diketopiperazine (3). Their structures were elucidated on the basis of spectroscopic data analysis. All the compounds were also evaluated for their inhibitory activity against P388, A-549 and HCT-116 cell lines with the MTT assay.