Naphthoquinone-like polyketide isolated from Streptomyces sp. RI-77 and its predicted biosynthetic pathway.

A novel naphthoquinone-like polyketide, JBIR-85 (1), with a unique skeleton and antioxidative activity was isolated from a culture of Streptomyces sp. RI-77. The planar structure of 1 was established on the basis of extensive NMR and MS analyses.

JBIR-56 and JBIR-57, 2(1H)-pyrazinones from a marine sponge-derived Streptomyces sp. SpD081030SC-03.

Strain SpD081030SC-03, representing a novel species of Streptomyces, was isolated from a marine sponge. Two 3,5,6-trisubstituted 2(1H)-pyrazinones, JBIR-56 (1) and JBIR-57 (2), were isolated from a culture of SpD081030SC-03. The planar structures of 1 and 2 were assigned on the basis of extensive NMR and MS analyses.

JBIR-66, a new metabolite isolated from tunicate-derived Saccharopolyspora sp. SS081219JE-28.

In the course of our chemical screening program for new secondary metabolites, we isolated a new compound JBIR-66 (1) from the culture broth of the tunicate-derived actinomycete, Saccharopolyspora sp. SS081219JE-28. The structure of 1 was determined to be (3Z,6E,8E)-N-(4-acetamido-3-hydroxybutyl)-2-hydroxy-4,8-dimethylundeca-3,6,8-trienamide on the basis of extensive NMR and MS spectroscopic data.

Streptomyces associated with a marine sponge Haliclona sp.; biosynthetic genes for secondary metabolites and products.

Terrestrial actinobacteria have served as a primary source of bioactive compounds; however, a rapid decrease in the discovery of new compounds strongly necessitates new investigational approaches. One approach is the screening of actinobacteria from marine habitats, especially the members of the genus Streptomyces. Presence of this genus in a marine sponge, Haliclona sp.

Anti-influenza virus compound from Streptomyces sp. RI18.

Screening for anti-influenza virus activity in compounds isolated from Streptomyces sp. RI18, which was isolated using the membrane filter method, uncovered a novel compound, JBIR-68 (1), which contains a unique skeleton. Its structure was established by extensive NMR and MS analyses.

A new angucycline and a new butenolide isolated from lichen-derived Streptomyces spp.

A new 1,1-dichlorocyclopropane-containing angucycline, JBIR-88 (1), and a new butenolide, JBIR-89 (2), respectively, were isolated from the fermentation broths of two lichen-derived actinomycetes identified as a new species of Streptomyces (strains RI104-LiC106 and RI104-LiB101) using phylogenetic methods. The structures of 1 and 2 were elucidated on the basis of 1D and 2D NMR spectroscopy and MS analyses. Compound 1 showed cytotoxic activities against cancer cells and antimicrobial activity against Micrococcus luteus.

Terpenoids produced by actinomycetes: isolation, structural elucidation and biosynthesis of new diterpenes, gifhornenolones A and B from Verrucosispora gifhornensis YM28-088.

New terpenoids named gifhornenolones A (1) and B (2) were isolated from the culture broth of Verrucosispora gifhornensis YM28-088, and their structures were established as hydroxylated isopimaradiene derivatives on the basis of extensive NMR and MS spectral analyses. In addition, a known sesquiterpene compound cyperusol C (3) was isolated. The absolute configuration of 1 was determined by nuclear Overhauser effect spectroscopy (NOESY) and CD spectra as 4R, 5S, 9R, 10S, 13R, and that of 2 was determined by NOESY experiments as 3R, 4R, 5R, 9R, 10S, 13R.

Tetracenoquinocin and 5-iminoaranciamycin from a sponge-derived Streptomyces sp. Sp080513GE-26.

Two new anthracyclines, tetracenoquinocin (1) and 5-iminoaranciamycin (2), together with the known compounds aranciamycin (3) and antibiotic SM 173B were isolated from the culture of Streptomyces sp. Sp080513GE-26 associated with a marine sponge, Haliclona sp. The structures of 1 and 2 were established on the basis of extensive NMR and MS analyses along with (13)C-labeling experiments.

Tetrapeptides possessing a unique skeleton, JBIR-34 and JBIR-35, isolated from a sponge-derived actinomycete, Streptomyces sp. Sp080513GE-23.

Two new modified indole-containing peptides, JBIR-34 (1) and JBIR-35 (2), were isolated from the fermentation broth of a sponge-derived actinomycete identified by phylogenetic methods as a Streptomyces sp. (strain Sp080513GE-23). The planar structures of 1 and 2 were assigned on the basis of 1D and 2D NMR spectroscopy and MS analyses.

Distribution of the 3-hydroxyl-3-methylglutaryl coenzyme A reductase gene and isoprenoid production in marine-derived Actinobacteria.

During the course of our screening program to isolate isoprenoids from marine Actinobacteria, 523 actinobacterial strains were isolated from 18 marine sponges, a tunicate, and two marine sediments. These strains belonged to 21 different genera, but most were members of Streptomyces, Nocardia, Rhodococcus, and Micromonospora. Some Actinobacteria have been reported to use the mevalonate pathway for the production of isoprenoids as secondary metabolites.

Screening and evaluation of new inhibitors of hepatic glucose production.

In the course of our screening program for inhibitors of hepatic glucose production in rat hepatoma H4IIE-C3 cells, which were used as model liver cells, five naphtoquinone derivatives-javanicin, solaniol, 9-O-methylfusarubin, 5,10-dihydroxy-1,7-dimethoxy-3-methyl-1H-naphtho[2,3-c]pyran-6,9-dione, 9-O-methylbostrycoidin-and vanillin were selected from our natural product library. These naphtoquinone derivatives inhibited hepatic glucose production at IC(50) values of 3.8-29 microM, but showed cytotoxicity against hepatic cells after incubation for 48 h.

JBIR-15, a new aspochracin derivative, isolated from a sponge-derived fungus, Aspergillus sclerotiorum Huber Sp080903f04.

In the course of our chemical screening program for novel metabolites by LC-MS monitoring, we isolated a new aspochracin derivative, JBIR-15 (1), together with aspochracin, from the culture broth of a sponge-derived fungus, Aspergillus sclerotiorum Huber Sp080903f04. The structure of 1 was determined to be N-demethyl aspochracin at the alanyl residue on the basis of extensive NMR and MS analyses.

New sesquiterpenes, JBIR-27 and -28, isolated from a tunicate-derived fungus, Penicillium sp. SS080624SCf1.

In the course of our screening program for novel metabolites from tunicate-derived fungi, novel sesquiterpenoids, named JBIR-27 (1) and -28 (2), together with known sporogen-AO1 and phomenone, were isolated from the culture broth of Penicillium sp. SS080624SCf1. The structures of 1 and 2 were determined to be eremophilane analogs on the basis of extensive NMR and MS analyses.

JBIR-23 and -24, novel anticancer agents from Streptomyces sp. AK-AB27.

The screening for active compounds against malignant pleural mesothelioma (MPM) cells produced by Streptomyces sp. AK-AB27 resulted in the isolation of two compounds with a dodecahydrodibenzo[b,d]furan skeleton named JBIR-23 (1) and -24 (2). Their structures were established on the basis of extensive NMR and MS analyses.

Studies on terpenoids produced by actinomycetes. 5-dimethylallylindole-3-carboxylic Acid and A80915G-8"-acid produced by marine-derived Streptomyces sp. MS239.

As a result of screening for terpenoids produced by marine-derived Streptomyces sp. MS239, two new terpenoids named 5-dimethylallylindole-3-carboxylic acid and A80915G-8''-acid were isolated and their structures were determined mainly by NMR analyses.

Terpenoids Produced by Actinomycetes: Napyradiomycins from Streptomyces antimycoticus NT17.

Napyradiomycin SR ( 1), 16-dechloro-16-hydroxynapyradiomycin C2 ( 2), 18-hydroxynapyradiomycin A1 ( 3), 18-oxonapyradiomycin A1 ( 4), 16-oxonapyradiomycin A2 ( 5), 7-demethyl SF2415A3 ( 6), 7-demethyl A80915B ( 7), and ( R)-3-chloro-6-hydroxy-8-methoxy-alpha-lapachone ( 8) were isolated from the culture broth of Streptomyces antimycoticus NT17. These compounds are derivatives of the napyradiomycins isolated previously from Chainia rubra or Streptomyces aculeolatus. The structures of the new compounds, some of which exhibit antibacterial activities, were established by comparing their NMR data with data of related known compounds.