Flavoglaucin

J Nat Prod. 2011 Jul 22;74(7):1636-9.

Benzyl derivatives with in vitro binding affinity for human opioid and cannabinoid receptors from the fungus Eurotium repens.[Pubmed: 21667972]

METHODS AND RESULTS:
Bioassay-guided fractionation of the fungus Eurotium repens resulted in the isolation of two new benzyl derivatives, (E)-2-(hept-1-enyl)-3-(hydroxymethyl)-5-(3-methylbut-2-enyl)benzene-1,4-diol (1) and (E)-4-(hept-1-enyl)-7-(3-methylbut-2-enyl)-2,3-dihydrobenzofuran-2,5-diol (2), along with seven known compounds (3-9) including five benzaldehyde compounds, Flavoglaucin (3), tetrahydroauroglaucin (4), dihydroauroglaucin (5), auroglaucin (6), and 2-(2',3-epoxy-1',3'- heptadienyl)-6-hydroxy-5-(3-methyl-2-butenyl)benzaldehyde (7), one diketopiperazine alkaloid, echinulin (8), and 5,7-dihydroxy-4-methylphthalide (9). The chemical structures of these compounds were established on the basis of extensive 1D and 2D NMR and HRMS data.
CONCLUSIONS:
Compounds 1-4 and 6 showed good binding affinity for human opioid or cannabinoid receptors. These findings have important implications for psychoactive studies with this class of compounds.

Biosci Biotechnol Biochem. 2010;74(5):1120-2.

Evaluation of flavoglaucin, its derivatives and pyranonigrins produced by molds used in fermented foods for inhibiting tumor promotion.[Pubmed: 20460698]

METHODS AND RESULTS:
Flavoglaucin, its derivatives, and pyranonigrins, which are antioxidants produced by the molds used in fermented foods, were examined for their inhibition of tumor promotion by the Epstein-Barr virus early antigen activation test. Flavoglaucin and its derivatives exhibited high activity.
CONCLUSIONS:
Flavoglaucin and such a derivative as isodihydroauroglaucin inhibited mouse skin tumor promotion in a two-stage carcinogenesis test and appear to be antitumor promoters.

Chem Pharm Bull (Tokyo). 2006 Jun;54(6):882-3.

A new radical scavenging anthracene glycoside, asperflavin ribofuranoside, and polyketides from a marine isolate of the fungus microsporum.[Pubmed: 16755063]

METHODS AND RESULTS:
A new anthracene glycoside, asperflavin ribofuranoside (1), and the previously described polyketides, Flavoglaucin (2), isodihydroauroglaucin (3), and citrinin (4) have been isolated from the marine-derived fungus Microsporum sp. The structure and absolute stereochemistry of a new compound (1) was assigned on the basis of physicochemical data. Compounds 1-3 exhibited a significant radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) with IC(50) values of 14.2, 11.3, and 11.5 microM, respectively, which are more potent than the positive control, ascorbic acid (IC(50), 20 microM).
CONCLUSIONS:
Compound 1 also showed a moderate antibacterial activity against the methicillin-resistant and multidrug-resistant Staphylococcus aureus (MRSA and MDRSA) with MIC value of 50 microg/ml.

Int J Mol Sci. 2014 Dec 19;15(12):23749-65.

Inhibitory effects of benzaldehyde derivatives from the marine fungus Eurotium sp. SF-5989 on inflammatory mediators via the induction of heme oxygenase-1 in lipopolysaccharide-stimulated RAW264.7 macrophages.[Pubmed: 25535073 ]

Two benzaldehyde derivatives, Flavoglaucin (1) and isotetrahydro-auroglaucin (2), were isolated from the marine fungus Eurotium sp. SF-5989 through bioassay- and 1H NMR-guided investigation.
METHODS AND RESULTS:
In this study, we evaluated the anti-inflammatory effects of these compounds in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. We demonstrated that compounds 1 and 2 markedly inhibited LPS-induced nitric oxide (NO) and prostaglandin E2 (PGE2) production by suppressing inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) protein expression without affecting cell viability. We also demonstrated that the compounds reduced the secretion of pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6). Furthermore, compounds 1 and 2 inhibited LPS-induced nuclear factor-κB (NF-κB) activation by suppressing phosphorylation of IkappaB (IκB). These results indicated that the anti-inflammatory effects of these benzaldehyde derivatives in LPS-stimulated RAW264.7 macrophages were due to the inactivation of the NF-κB pathway. In addition, compounds 1 and 2 induced heme oxygenase-1 (HO-1) expression through the nuclear transcription factor-E2-related factor 2 (Nrf2) translocation. The inhibitory effects of compounds 1 and 2 on the production of pro-inflammatory mediators and on NF-κB binding activity were reversed by HO-1 inhibitor tin protoporphyrin (SnPP).
CONCLUSIONS:
Thus, the anti-inflammatory effects of compounds 1 and 2 also correlated with their ability of inducing HO-1 expression.

J Microbiol Biotechnol. 2013 Sep 28;23(9):1206-11.

PTP1B inhibitory secondary metabolites from marine-derived fungal strains Penicillium spp. and Eurotium sp.[Pubmed: 23770564]

The selective inhibition of PTP1B has been widely recognized as a potential drug target for the treatment of type 2 diabetes and obesity.
CONCLUSIONS:
In the course of screening for PTP1B inhibitory fungal metabolites, the organic extracts of several fungal species isolated from marine environments were found to exhibit significant inhibitory effects, and the bioassay-guided investigation of these extracts resulted in the isolation of fructigenine A (1), cyclopenol (2), echinulin (3), Flavoglaucin (4), and viridicatol (5). The structures of these compounds were determined mainly by analysis of NMR and MS data.
CONCLUSIONS:
These compounds inhibited PTP1B activity with 50% inhibitory concentration values of 10.7, 30.0, 29.4, 13.4, and 64.0 micrometer, respectively. Furthermore, the kinetic analysis of PTP1B inhibition by compounds 1 and 5 suggested that compound 1 inhibited PTP1B activity in a noncompetitive manner, whereas compound 5 inhibited PTP1B activity in a competitive manner.