Isopanepoxydone inhibits oxidative damage in murine alveolar macrophages via NRF2 and NLRP3 inflammasome.

BACKGROUND: Respiratory diseases due to particulate matter are a serious health issue. We sought to investigate the efficacy of isopanepoxydone (ISO) isolated from the Panus rudis as a therapeutic against particulate matter-induced respiratory complications. MATERIALS AND METHODS: ISO was isolated from a culture broth of Panus rudis using solvent partition, silica gel, and column chromatography, and high-performance liquid chromatography. Its chemical structure was determined spectroscopically. Murine alveolar macrophages (MH-S) were treated with ISO to investigate the inhibition of nitric oxide (NO) while cytotoxicity was investigated via a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay. The expression of pro-inflammatory mediators, cytokines, and protein expression levels in the oxidative protective and inflammasome pathway were also investigated. Reactive oxygen species in MH-S cells were investigated using 2',7'-dichlorofluorescein diacetate while immunofluorescence was performed to investigate the expression of activated apoptosis-associated speck-like proteins (ASC) containing a caspase recruitment domain in MH-S cells. RESULTS: ISO effectively inhibited CFA-induced NO production with no cytotoxicity on MH-S cells and pro-inflammatory mediators and cytokines were also inhibited (except tumor necrosis factor α and interleukin-6). ISO enhanced the protein expression of nuclear factor erythroid 2-related factor 2, while suppressing proteins in the inflammasome pathway, but did not suppress the expression of nuclear factor-kappa B. ISO also reduced detectable ROS other than preventing the activation of ASC. CONCLUSION: Pathways of action of ISO in MH-S cells that prevent oxidative damage and suppress the expression of proteins in the inflammasome pathway were investigated. ISO may be developed as a treatment for respiratory inflammation.

Consoramides A-C, New Zwitterionic Alkaloids from the Fungus Irpex consors.

In our ongoing search for new secondary metabolites from fungi, a basidiomycete fungus Irpex consors was selected for mycochemical investigation, and three new zwitterionic alkaloids (1-3) and five known compounds (4-8) were isolated from the culture broth (16 l) of I. consors. The culture filtrate was fractionated by a series of column chromatography including Diaion HP-20, silica gel, and Sephadex LH-20, Sep-Pak C18 cartridge, medium pressure liquid chromatography (MPLC), and high pressure liquid chromatography (HPLC) to yield eight compounds (1-8). The structures of the isolated compounds were elucidated by the interpretation of nuclear magnetic resonance (NMR) spectra and high-resolution mass spectrometry (HR-MS). Their antioxidant and antibacterial activities were examined. The zwitterionic structures of three new sesquiterpene alkaloids (1-3) were determined together with five known compounds identified as stereumamide E (4), stereumamide G (5), stereumamide H (6), stereumamide D (7), and sterostrein H (8). This is the first report of the zwitterionic alkaloids in the culture broth of I. consors. Three new zwitterionic alkaloids were named as consoramides A-C (1-3).

Dentipellin, a new antibiotic from culture broth of Dentipellis fragilis.

In our effort to find antimicrobial agents from higher fungi, we isolated a new compound, dentipellin (1), along with three known glycosylated diterpenes, erinacines A-C (2-4) from culture broth of Dentipellis fragilis. Their chemical structures were determined by spectroscopic methods including NMR and mass measurements. These compounds exhibited weak antibacterial and antifungal activities.

Chemical Constituents of the Culture Broth of Panus rudis.

In our ongoing search for new secondary metabolites from fungal strains, one novel compound (1) and nine known compounds (2-10) were isolated from the EtOAc-soluble layer of the culture broth of Panus rudis. The culture broth of P. rudis was extracted in acetone and fractionated by solvent partition; column chromatography using silica gel, Sephadex LH-20, and Sephadex G-10; MPLC; and HPLC. The structures of isolated compounds were elucidated by one- and two-dimensional NMR and LC-ESI-mass measurements. One new compound, panepoxydiol (1), and nine known compounds, (E)-3-(3-hydroxy-3-methylbut-1-en-1-yl)-7-oxabicyclo[4.1.0]hept-3-ene-2,5-diol (2), isopanepoxydone (3), neopanepoxydone (4), panepoxydone (5), panepophenanthrin (6), 4-hydroxy-2,2-dimethyl-6-methoxychromane (7), 6-hydroxy-2,2-dimethyl-3-chromen (8), 2,2-dimethyl-6-methoxychroman-4-one (9), 3,4-dihydroxy-2,2-dimethyl-6-methoxychromane (10), were isolated from the culture broth of P. rudis. This is the first report of isolation of a new compound panepoxydiol (1) and nine other chemical constituents (2-5, 7-10) from the culture broth of P. rudis.

Rhizophins A and B, new sesquiterpenes from the culture broth of Coprinus rhizophorus.

Two new sesquiterpenes (1 and 2) together with one known compound (3) were isolated from the culture broth of Coprinus rhizophorus. Chemical structures of these compounds were deduced by spectroscopic methods. Compound 1 exhibited free-radical-scavenging activity against the 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical. Compounds 2 and 3 exhibited antimicrobial activities against Saccharomyces cerevisiae, Propionibacterium acnes, and Staphylococcus epidermidis.

Oregonensins A and B, new meroterpenoids from the culture broth of Ganoderma oregonense and their antioxidant activity.

Two new meroterpene derivatives (1 and 2), together with three known compounds (3-5) were isolated from the culture broth of fungus Ganoderma oregonense. Chemical structures of compounds 1-5 were determined using spectroscopic methods. All compounds were tested for 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging efficacy. Compound 1 exhibited significant antioxidant activities with IC50 values of 31.2 and 65.4 µM in the ABTS and DPPH radical scavenging activities, respectively.

Neuraminidase Inhibitors from the Fruiting Body of Glaziella splendens.

Neuraminidase (NA) cleaves the glycosidic bond linkages of sialic acids to release the mature virions from infected cells and has been an attractive therapeutic target for anti-influenza agents. In our ongoing investigation of NA inhibitors in mushroom extracts, we found that the extract the fruiting body of Glaziella splendens potently inhibited neuraminidase. The fruiting bodies of G. splendens were extracted and partitioned successively with hexane, ethyl acetate, and butanol. The ethyl acetate soluble-layer was subjected to silica gel and Sephadex LH-20 column chromatographies, and MPLC to obtain five compounds (1-5). Their structures were determined by spectroscopic methods. NA inhibitory activity of these compounds was evaluated using NAs from recombinant rvH1N1, H3N2, and H5N1 influenza A viruses. One compound (1) was elucidated as a new azaphilone derivative, and four compounds (2-5) were identified as entonaemin A, comazaphilone D, rubiginosin A, and entonaemin B, respectively. Compounds 3 and 4 showed considerable inhibitory activity against three types of neuraminidases with the IC50 values of 30.9, 41.8, and 35.7 µM for 3 and 46.5, 50.4, and 29.9 µM for 4, respectively. This study reveals that the fruiting bodies of G. splendens possess azaphilone derivatives with the NA inhibitory activity. This is the first report on the isolation of neuraminidase inhibitors from the fruiting bodies of G. splendens.

Three new meroterpenoids from culture broth of Perenniporia medulla-panis and their antioxidant activities.

Three new meroterpenoids (1-3) together with one known compound (4) were isolated from the culture broth of Perenniporia medulla-panis, a wood-rotting fungus in the family Polyporaceae. Their structures were elucidated by NMR and HRESIMS analyses. These compounds exhibited antioxidant activity with IC50 values ranging from 12.8 to 190.3 µM in the 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical-scavenging assay.