The fungal secondary metabolite panepoxydone has been recently described as an inhibitor of NF-kappaB activation which is a pivotal regulator of the inflammatory and immune response. These findings have led to propose that panepoxydone may be useful as anti-inflammatory agent. In this study we investigated for the first time the effects of panepoxydone on inflammatory gene expression in the monocytic cell line MonoMac6, stimulated with lipopolysaccharide (LPS) and the phorbolester 12-O-tetradecanoylphorbol-13-acetate (TPA). DNA microarray analysis of 110 human genes known to be strongly regulated during inflammation, combined with reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) revealed that low micromolar concentrations (12-24 microM) of panepoxydone strongly inhibited the expression of thirty-three NF-kappaB dependent pro-inflammatory genes such as the chemokines CCL3, CCL4, CCL8; CXCL8, CXCL10, CXCL20, the cytokines IL-1, IL-6, TNF-alpha, pro-inflammatory enzymes like COX-2, and components of the REL/NF-kappaB/IkappaB family without significant effects on the expression of house-keeping genes. Panepoxydone strongly inhibited hTNF-alpha, IL-8 and NF-kappaB promoter activity in LPS/TPA stimulated MonoMac6 cells with IC(50) values of 0.5-1 microg/ml by blocking the phosphorylation of IkappaB and subsequent binding of the activated NF-kappaB transcription factor to the DNA. From our data, panepoxydone may serve as lead structure for the development of transcription-based inhibitors of pro-inflammatory gene expression.
Laschiatrion (1), a new antifungal antibiotic, was isolated from fermentations of Favolaschia sp. 87129. (1) exhibits broad in vitro activity against several human pathogens while no antibacterial and cytotoxic activities could be detected. The structure was elucidated by spectroscopic techniques. As to our knowledge laschiatrion possesses a new steroid skeleton.
5-(2′-oxoheptadecyl)-resorcinol (1) and 5-(2′-oxononadecyl)-resorcinol (2) were isolated from fermentations of an imperfect basidiomycete. The structures of the compounds were determined by spectroscopic techniques. Both compounds exhibit cytotoxic effects against the human colon tumor cell lines COLO-320, DLD-1 and HT-29 and the human promyeloid leukemia cell line HL-60, the human leukemia T cell JURKAT, the human hepatocellular carcinoma cell line HEP-G2 as well as the J774 mouse macrophage cell line. The compounds induce morphological and physiological differentiation of HL-60 cells into granulocytes, which subsequently die by apoptosis. Both compounds show no antibacterial and antifungal activity.
Two novel antifungal agents belonging to the sordarin family have been isolated from fermentations of Sordaria araneosa by bioassay-guided purification and their structures elucidated by NMR techniques. Neosordarin (1) is closely related to the recently discovered hypoxysordarin (2), with only small differences on the aliphatic side chain acylating the hydroxyl in the 3'-position of the sordarose moiety. Hydroxysordarin (3) closely resembles sordarin (4), the only slight difference being the replacement of sordarose with altrose as the sugar unit.
Mariannaeapyrone ((E)-2-(1,3,5,7-tetramethyl-5-nonenyl)-3,5-dimethyl-6-hydroxy-4H-pyran-4-one) is a new fungal metabolite isolated from fermentations of the common mycophilic deuteromycete Mariannaea elegans. The chemical structure of the 4-pyrone was determined by spectroscopic techniques. Mariannaeapyrone is a selective inhibitor of the thromboxane A2 induced aggregation of human platelets, whereas only weak cytotoxic and antimicrobial effects could be observed.
Hypoxysordarin (1), a new sordarin derivative, was isolated from the fermentation broth of the facultative marine Hypoxylon croceum together with a new gamma-lactone, hypoxylactone (2) and sordarin (3). The structures were determined by spectroscopic methods. Sordarin (3) has previously been isolated from the terrestrial Sordaria araneosa (Sordariaceae). Like the parent compound hypoxysordarin exhibits high antifungal activities due to a specific inhibition of protein biosynthesis.
A new meroterpenoid, montadial A (1), has been isolated from the polypore Bondarzewia montana. Its structure was elucidated by spectroscopic techniques. Montadial A exhibits cytotoxic effects and develops a striking yellow color when treated with KOH.
A fungus that grows on pinecones yields a compound with antifungal activity that has become the natural model for a significant innovation in crop protection. Variation and optimization of the lead structure of strobilurin A (1) and selection of derivatives which fulfill all practical requirements, for example, kresoxim-methyl (2), led to an exciting and pan-industrial competition for the development of the strobilurines as a new, highly active, and broadly applicable class of fungicides-a fascinating success story.
The antifungal and cytostatic compound strobilurin M (1) is a new variant of the strobilurins produced by Mycena sp. 96097, a tropical basidiomycete. The same fungus was found to produce tetrachloropyrocatechol (3a) and tetrachloropyrocatechol methyl ether (3b), new natural products, which exhibit antifungal, antibacterial and cytotoxic activities.
The new antifungal strobilurins I (1) and K (19) are 3,4-dihydro-2H-benzo[b][1,4]dioxepin derivatives. Their structure and stereochemistry was determined by degradation to aldehyde 3. Both enantiomers of 3 were synthesised and the absolute configurations assigned by the high-field 1H NMR variant of Mosher's method. (S)-3 is identical with the compound derived from the natural products. In the course of these investigations the epoxide structures 15, 16 and 17 previously assigned to strobilurin D, hydroxystrobilurin D and 9-methoxystrobilurin K have to be changed in 18, 21 and 20, respectively. All these compounds possess the same benzodioxepin core structure and (S)-configuration as strobilurin I (1).
A new antifungal (E)-β-methoxyacrylate, noroudemansin A (1), was isolated from cultures of Pterula sp. 82168. Its biological activities were investigated and compared with oudemansin A. The structure was elucidated by spectroscopic methods. Three semisynthetic noroudemansin A derivatives were synthesized from the natural product.
Strobilurin N (1), a new member of the strobilurin family of antibiotics, has been isolated from the toadstool Mycena crocata, together with dehydrochorismic acid lactane (5) and 3-[1-carboxyvinyl)oxy]benzoic acid (6), which are closely related to chorismic acid (10). Their structures were determined mainly by H-1 and C-13 NMR spectroscopy. Interestingly strobilurin N is the first strobilurin without antifungal activity.
Panaeolus sphinctrinus, Panaeolus papilionaceus, and Coprinus friesii are described as producers of ligninolytic enzymes. P. papilionaceus and P. sphinctrinus both produced a laccase. In addition, P. sphinctrinus produced a manganese peroxidase, C. friesii secreted a laccase and two peroxidases similar to the peroxidase of Coprinus cinereus. The purified laccases and peroxidases were characterized by broad substrate specificities, significant enzyme activities at alkaline pH values, and remarkably high pH optima. The two peroxidases of C. friesii remained active at pH 7.0 and 60 degrees C for up to 60 min of incubation, The peroxidases were inhibited by sodium azide and ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA), whereas the laccases were inhibited by sodium azide and N,N-diethyldithiocarbamic acid. As determined by native polyacrylamide gel electrophoresis and isoelectric focusing, all three fungi produced laccase isoenzymes.
Arthrosporone (1) and eight new triquinane-type sesquiterpenoids have been isolated from mycelial cultures of the agaric Macrecystidia cucumis. The cucumins A-D (2, 4-6) are highly unsaturated hirsutane derivatives, whereas the cucumins E-G (7-9) represent a new type of linear triquinanes. Cucumin H (10) is a new member of the ceratopicane group. The absolute configuration of cucumin F (8) was assigned by H-1-NMR analysis of the corresponding Mosher esters. Two further metabolites were identified as cycle(phenylalanylprolyl) (12) and cyclo(leucylprolyl) (13). Cucumin A (2) exhibits antibacterial and cytotoxic activities.
Penidiamide, a new tripetide containing dehydrotryptamine, glycine and anthranilic acid linked together by two amide bonds, and oxindole were isolated from submerged cultures of Penicillium sp. 62-92. Both compounds preferentially inhibited human synovial phospholipase A2, penidiamide with an IC50 of 30 microM and oxindole of 380 microM. With the exception of U 937 cells (leukemia, human), no cytotoxic activities were detected against HL-60- (leukemia, human), HeLa S3- (epitheloid carcinoma, human), BHK 21- (kidney fibroblasts, hamster), and L1210-cells (leukemia, mouse). No antimicrobial activity was detected for oxindole, and only weak antibacterial activity for penidiamide. The structure of penidiamide was elucidated by spectroscopic methods.
Among the sources of bioactive metabolites, less intensively investigated organisms like the higher fungi seem to hold an excellent promise for new structures with interesting biological activities. In the last decades interesting compounds of different biogenetic origin with antibacterial, antifungal, phytotoxic, nematocidal, cytostatic, antiviral, and other pharmacological activities were isolated from basidiomycetes. In the following review we will concentrate on metabolites isolated from submerged cultures.
The influence of the pellet morphology of the basidiomycete Cyathus striatus on the production of the antibiotics striatals A, B, and C was investigated. The main operating parameters in fermenters of different sizes were the tip speed and the volumetric power input. Different methods were developed for quantification of morphological characteristics. The apparent viscosity of the suspension was measured with a cylinder rheometer. Sediment density was measured with a sedimentation apparatus. Particle size distributions were recorded with an image analysis system. By means of the presented measuring methods, morphological characteristics could be determined and enabled an early assessment of the fermentation course and the antibiotics production. During the exponential growth phase of the fungus the relative sediment height correlated with the biomass concentration. The pellet morphology at this stage influenced the later production of striatals. The yield of the striatals was markedly influenced by pellet size and sediment density. Since these morphological characteristics determine the rheological properties of the culture the measurement of the apparent viscosity of the culture in the production phase allowed predictions of the production yield.
Five yellow 2-hydroxy-5-methoxybenzoquinones with C(15)and C-17 alkyl side chains were isolated from fruitbodies of the wood-rotting fungus Phlebia chryoscrea. The compounds, named phlebiachrysoic acids A-E are strong inhibitors of leukotriene biosynthesis and are responsible for the red colour reaction when the fruitbodies are touched with aqueous alkali.