cortodoxone and phenanthrene

The metabolism of phenanthrene and the mammalian corticosteroid hormone cortexolone by the fungus Cunninghamella elegans was studied. The amounts of the cortexolone transformation products, cortisol and epicortisol, were affected by the presence of phenanthrene. Approximately 40% more cortisol was produced by C. elegans in cultures with phenanthrene. In contrast, epicortisol formation decreased. C. elegans transformed phenanthrene to phenanthrene trans-1,2-,3,4-, and 9,10-dihydrodiols, phenols, diphenols (diols) and glucoside conjugates of 1-, 2-, 3-, 4-, and 9-phenanthrols. Almost all of the phenanthrene initially added was metabolized to ethyl acetate extractable metabolites. In the mycelia and culture medium extracts, phenanthrol glucosides represented 80% and 94% of the total metabolites, respectively. The major metabolite was the glucoside conjugate of 1-phenanthrol. The presence of cortexolone affected the biodegradation of phenanthrene by decreasing the amounts of phenanthrene metabolites compared to control cultures.

Topics: Biodegradation, Environmental; Biotransformation; Cortodoxone; Cunninghamella; Environmental Pollutants; Gas Chromatography-Mass Spectrometry; Phenanthrenes; Spectrometry, Mass, Electrospray Ionization

The expression of cytochrome P-450 and cytochrome P-450 reductase (CPR) genes in the conterminous biotransformation of corticosteroids and PAHs was studied in Cunninghamella elegans 1785/21Gp. We had previously used this strain as a microbial eucaryotic model for studying the relationship between mammalian steroid hydroxylation and the metabolization of PAHs. We reported that cytochrome P-450 reductase is involved in the biotransformaton of cortexolone and phenanthrene. RT-PCR and Northern blotting analyses indicated that the cytochrome P-450 and CPR genes appear to be inducible by both steroids and PAHs. The expression of the cytochrome P-450 gene was increased ninefold and the expression of the CPR gene increased 6.4-fold in cultures with cortexolone and/or phenanthrene in comparison with controls. We conclude that the increase in cytochrome P-450 gene expression was accompanied by an increase in cytochrome P-450 enzymatic activity levels.

Topics: Biotransformation; Blotting, Northern; Cortodoxone; Cunninghamella; Cytochrome P-450 Enzyme System; NADPH-Ferrihemoprotein Reductase; Phenanthrenes; Reverse Transcriptase Polymerase Chain Reaction

A filamentous fungus Cunninghamella elegans IM 1785/21Gp which displays ability of 17alpha,21-dihydroxy-4-pregnene-3,20-dione (cortexolone) 11-hydroxylation (yielding epihydrocortisone (eF) and hydrocortisone (F)) and polycyclic aromatic hydrocarbons (PAHs) degradation, was used as a microbial eucaryotic model to study the relationships between mammalian steroid hydroxylation and PAHs metabolization. The obtained results showed faster transformation of phenanthrene in Sabouraud medium supplemented with steroid substrate (cortexolone). Simultaneously phenanthrene stimulated epihydrocortisone production from cortexolone. In phenanthrene presence the ratio between cortexolone hydroxylation products (hydrocortisone and epihydrocortisone) was changed from 1:5.1-6.2 to 1:7.6-8.4 in the culture without phenanthrene. Cytochrome P-450 content significantly increased after the culture supplementation by the second substrate, phenanthrene or cortexolone, adequately. To confirm the involvement of cytochrome P-450 in phenanthrene metabolism, the inhibition studies were performed. The cytochrome P-450 inhibitors SKF 525-A (1.5mM) and 2-methyl-1,2-di-3-pyridyl-1-propanone (metyrapone) (2mM) inhibited phenanthrene transformation by 80 and 62%, respectively. 1-aminobenzotriazole (1mM) completely blocked phenanthrene metabolism. The obtained results suggest a presence of connections between steroid hydroxylases and enzymes involved in PAH degradation in C. elegans.

Topics: Biotransformation; Cortodoxone; Cunninghamella; Cytochrome P-450 Enzyme Inhibitors; Cytochrome P-450 Enzyme System; Enzyme Inhibitors; Metyrapone; Phenanthrenes; Proadifen; Triazoles

Nine fungal strains showing ability of cortexolone hydroxylation to epicortisol and/or cortisol were screened in this work for anthracene and phenanthrene elimination (250 mg/l). All of the strains (Cylindrocladium simplex IM 2358, C. simplex IM 2358/650, Monosporium olivaceum IM 484, Curvularia lunata IM 2901, C. lunata IM 2901/366, C. tuberculata IM 4417, Cunninghamella elegans IM 1785, C. elegans IM 1785/21Gp, C. elegans IM 1785/10Gi) significantly removed anthracene and phenanthrene. During incubation with anthracene formation of intermediate products was observed. The amount of the main intermediate product, identified as 9, 10-anthraquinone, was not greater than 22.2% of the anthracene introduced to the fungal cultures. C. elegans IM 1785/21Gp was the best degrader of both anthracene and phenanthrene, removing 81.6 and 99.4% of these compounds after 7 days, respectively. Phenanthrene removal by C. elegans IM 1785/21Gp was preceded by PAHs accumulation in mycelium and growth inhibition. Elimination of phenanthrene started after one day of incubation and was related to the fungus growth.

Topics: Anthracenes; Cortodoxone; Fungi; Hydroxylation; Phenanthrenes