Adaptive conditions and safety of the application of Penicillium frequentans as a biocontrol agent on stone fruit.

Penicillium frequentans (Pf909) reduces brown rot caused by Monilinia spp. in stone fruit. The registration of a microbial biocontrol agent in Europe requires information on the risks and safety of a biological product. This study focused on the impact of the physical environment on Pf909 survival and growth, Pf909 mycotoxin production on fruit surface, and the Pf909 resistance to commercial antifungal compounds used in animal and human medicine. The effect of temperature (4 to 37°C), water activity (0.999 to 0.900), pH (3 to 11), light intensity (0, 90 and 180lm) and photoperiod (0/24, 12/12, 16/8, 24/0; light/dark) on mycelial growth and sporulation of Pf909 were monitored for 10days in vitro on culture medium. Antifungal activity of antifungal compounds on mycelial growth of Pf909 was also measured by a quantitative micro spectrophotometric assay after 72h of incubation. The presence or absence of four non-volatile mycotoxins (patulin, penicillic acid, ochratoxin A and citrinin) on nectarine surfaces treated with Pf909 was determined by HPLC. Growth rate was significantly influenced by water activity, temperature and light exposure conditions. Pf909 showed maximum growth and sporulation at 22°C and 25°C, in wet conditions (0.999 water activity), with a pH5.6 to 9, and in darkness or a short light photoperiod. Our results showed all antifungal compounds used reduced significantly Pf909 mycelial growth at tested commercial doses. HPLC data analysis showed that 7days after biofungicide (Pf909) application there were no mycotoxin products on the surface of nectarine. Finally, no phylogenetic relationship has been shown among Pf909 and other species of Penicillium that produce mycotoxins. In conclusion, from an ecological point of view, Pf909 would establish and survive actively over a broad range of climatic conditions. The probability of risks to human and animal health is considered very low.

Ligerin, an antiproliferative chlorinated sesquiterpenoid from a marine-derived Penicillium strain.

A new chlorinated sesquiterpenoid analogue of fumagillin, ligerin (1), was isolated from a marine-derived strain of Penicillium, belonging to the subgenus Penicillium, along with the known compounds penicillic acid (2), orcinol, and orsellinic acid. Chemical structures were established by an interpretation of spectroscopic data including IR, UV, and HRESIMS, together with analyses of 1D and 2D NMR spectra and X-ray analysis for the determination of the absolute configuration. Ligerin (1) displayed strong inhibitory activity against an osteosarcoma cell line. This is the first report of the isolation of a fumagillin analogue from a marine-derived Penicillium strain.

Cytotoxic activity of fungal strains isolated from the ascidian Eudistoma vannamei.

The cytotoxic activity at 50 µg/ml of extracts obtained from eleven fungal strains associated to Eudistoma vannamei, an endemic ascidian from Northeast Brazil, against two cell lines, i.e., the HCT-8 (colon cancer) and the MDA-MB-435 (melanoma) cell lines, was investigated. The most promising extract (EV10) was obtained from a fungus identified as Aspergillus sp. by molecular analysis and was selected for bioassay-guided isolation of its active principals. Large-scale fermentation of EV10 in potato-dextrose broth followed by chromatographic purification of the active extract from the liquid medium allowed the isolation of the isocoumarins mellein, cis-4-hydroxymellein, and trans-4-hydroxymellein, besides penicillic acid. All isolated compounds were tested for their cytotoxicity against the tumor cell lines MDA-MB-435 and HCT-8 and revealed penicillic acid as the only cytotoxic compound (cell growth inhibitions >95%).

Cytotoxic and other metabolites of Aspergillus inhabiting the rhizosphere of Sonoran desert plants.

In a study to discover potential anticancer agents from rhizosphere fungi of Sonoran desert plants cytotoxic EtOAc extracts of four Aspergillus strains have been investigated. Two new metabolites, terrequinone A (1) and terrefuranone (2), along with Na-acetyl aszonalemin (LL-S490beta) (3) were isolated from As. terreus occurring in the rhizosphere of Ambrosia ambrosoides, whereas As. terreus inhabiting the rhizosphere of an unidentified Brickellia sp. afforded dehydrocurvularin (4), 11-methoxycurvularin (5), and 11-hydroxycurvularin (6). As. cervinus isolated from the rhizosphere of Anicasanthus thurberi contained two new compounds, 4R*,5S*-dihydroxy-3-methoxy-5-methylcyclohex-2-enone (7) and 6-methoxy-5(6)-dihydropenicillic acid (8), in addition to penicillic acid (9). Penicillic acid was also isolated from As. wentii occurring in the rhizosphere of Larrea tridentata. The structures of 1-9 were elucidated by spectroscopic methods and chemical derivatizations. Acetylation of 2 afforded 14-acetylterrefuranone (13) and 14-deoxy-13(14)-dehydroterrefuranone (14). Metabolites 1-9, the dienone 14, and 5(6)-dihydropenicillic acid (16) were evaluated for cytotoxicity in a panel of four human cancer cell lines and in normal human primary fibroblast cells. Compounds 4 and 5 displayed considerable cytotoxicity, whereas 1, 6, 9, and 14 were found to be moderately active, with 6 and 9 exhibiting selective cytotoxicity against cancer cell lines compared with the normal fibroblast cells.

Three new chlorine containing antibiotics from a marine-derived fungus Aspergillus ostianus collected in Pohnpei.

A marine bacterium Ruegeria atlantica (designated as strain TUF-D) was isolated from a glass plate submerged in the coastal water. Three new chlorine containing compounds (1 to approximately 3), together with penicillic acid (4) were obtained from a marine-derived fungus Aspergillus ostianus strain TUF 01F313 isolated from a marine sponge at Pohnpei as antibacterial components against R. atlantica. The structures of three new antibiotics were determined based on their spectral data as 8-chloro-9-hydroxy-8,9-deoxyasperlactone (1), 9-chloro-8-hydroxy-8,9-deoxyasperlactone (2), and 9-chloro-8-hydroxy-8,9-deoxyaspyrone (3). Compound 1 inhibited the growth of R. atlantica at 5 microg/disc (inhibition zone: 12.7 mm), while 2 and 3 were active at 25 microg/disc (10.1 and 10.5 mm, respectively).

[Studies on chemical constituents of mycelium of fungus Cephalosporium sp. AL031(II)].

Three compounds were isolated from the mycelium of the fungus Cephalosporium sp. AL031 whose metabolites have been proven to possess antifungal and antibacterial activities. Based on the spectral data and elemental analysis, they were identified as 3-hydroxy-ergosta-7,22-dien-6-one(A), penicillic acid(B), 4-hydroxy-3,6-dimethyl-2-pyrone(C). All of these compounds were obtained from the culture medium of this fungus for the first time.