Biotransformation of fluorinated drugs and xenobiotics by the model fungus Cunninghamella elegans.

Some species of the genus Cunninghamella (C. elegans, C. echinulata and C. blaskesleeana) produce the same phase I and phase II metabolites when incubated with xenobiotics as mammals, and thus are considered microbial models of mammalian metabolism. This had made these fungi attractive for metabolism studies with drugs, pesticides and environmental pollutants. As a substantial proportion of pharmaceuticals and agrochemicals are fluorinated, their biotransformation has been studied in Cunninghamella fungi and C. elegans in particular. This article details the methods employed for cultivating the fungi in planktonic and biofilm cultures, and extraction and analysis of fluorinated metabolites. Furthermore, protocols for the heterologous expression of Cunninghamella cytochromes P450 (CYPs), which are the enzymes associated with phase I metabolism, are described.

Endogenous production of 2-phenylethanol by Cunninghamella echinulata inhibits biofilm growth of the fungus.

The filamentous fungus Cunninghamella echinulata is a model of mammalian xenobiotic metabolism. Under certain conditions it grows as a biofilm, which is a natural form of immobilisation and enables the fungus to catalyse repeated biotransformations. Putative signalling molecules produced by other Cunninghamella spp., such as 3-hydroxytyrosol and tyrosol, do not affect the biofilm growth of C. echinulata, suggesting that it employs a different molecule to regulate biofilm growth. In this paper we report that 2-phenylethanol is produced in higher concentrations in planktonic cultures of C. echinulata than when the fungus is grown as a biofilm. We demonstrate that exogenously added 2-phenylethanol inhibits biofilm growth of C. echinulata but has no effect on planktonic growth. Furthermore, we show that addition of 2-phenylethanol to established C. echinulata biofilm causes detachment. Therefore, we conclude that this molecule is produced by the fungus to regulate biofilm growth.

Metabolic pathway of tebuconazole by soil fungus Cunninghamella elegans ATCC36112.

Tebuconazole is the most widely used fungicide in agriculture. Due to its long half-life, tebuconazole residues can be found in the environment media such as in soil and water bodies. Here, the metabolic pathway of tebuconazole was studied in Cunninghamella elegans (C. elegans). Approximately 98% of tebuconazole was degraded within 7 days, accompanied by the accumulation of five metabolites. The structures of the metabolites were completely or tentatively identified by gas chromatography-mass spectrometry (GC-MS) and ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). To identify representative oxidative enzymes that may be involved in the metabolic process, treatment with piperonyl butoxide (PB) and methimazole (MZ) was performed. PB had a strong inhibitory effect on the metabolic reactions, while MZ had a weak inhibitory effect. The results suggest that cytochrome P450 (CYP) and flavin-dependent monooxygenase are involved in the metabolism of tebuconazole. Based on the results, we propose a metabolic pathway for the fungal metabolism of tebuconazole. Data are of interest to gain insight into the toxicological effects of tebuconazole and for tebuconazole bioremediation.

Biodegradation and metabolic pathway of quinalphos by Cunninghamella elegans ATCC36112.

Quinalphos is a long-term, wide-spectrum organophosphate insecticide with residual problems in the natural environment. Cunninghamella elegans (C. elegans) is a member of Mucoromycotina. Since the degradation products of its exogenous compounds are similar to those of mammals, it is often used to simulate the metabolism pathways of mammals. In this study, the detailed metabolic pathways of quinalphos were investigated with C. elegans. Quinalphos was degraded by 92% in 7 days, while ten metabolites were produced. The metabolites were analyzed and identified by GC-MS. To determine the responsible enzymes in quinalphos metabolism, piperonyl butoxide (PB) and methimazole included in the culture flasks, and the kinetic responses of quinalphos and its metabolites by C. elegans were measured. Results indirectly demonstrated that cytochrome P450 monooxygenases were involved in the metabolism of quinalphos, but that methimazole inhibited the metabolism less efficiently. Comprehensive metabolic pathways can be deduced from the detailed analysis of metabolite profiles in control and inhibitor assays.

The Study of a Novel Paeoniflorin-Converting Enzyme from Cunninghamella blakesleeana.

Paeoniflorin is a glycoside compound found in Paeonia lactiflora Pall that is used in traditional herbal medicine and shows various protective effects on the cardio-cerebral vascular system. It has been reported that the pharmacological effects of paeoniflorin might be generated by its metabolites. However, the bioavailability of paeoniflorin by oral administration is low, which greatly limits its clinical application. In this paper, a paeoniflorin-converting enzyme gene (G6046, GenBank accession numbers: OP856858) from Cunninghamella blakesleeana (AS 3.970) was identified by comparative analysis between MS analysis and transcriptomics. The expression, purification, enzyme activity, and structure of the conversion products produced by this paeoniflorin-converting enzyme were studied. The optimal conditions for the enzymatic activity were found to be pH 9, 45 °C, resulting in a specific enzyme activity of 14.56 U/mg. The products were separated and purified by high-performance counter-current chromatography (HPCCC). Two main components were isolated and identified, 2-amino-2-p-hydroxymethyl-methyl alcohol-benzoate (tirs-benzoate) and 1-benzoyloxy-2,3-propanediol (1-benzoyloxypropane-2,3-diol), via UPLC-Q-TOF-MS and NMR. Additionally, paeoniflorin demonstrated the ability to metabolize into benzoic acid via G6046 enzyme, which might exert antidepressant effects through the blood-brain barrier into the brain.

Fluorotelomer alcohols are efficiently biotransformed by Cunninghamella elegans.

Cunninghamella elegans is a well-studied fungus that biotransforms a range of xenobiotics owing to impressive cytochrome P450 (CYP) activity. In this paper, we report the biotransformation of 6:2 fluorotelomer alcohol (6:2 FTOH) by the fungus, yielding a range of fluorinated products that were detectable by fluorine-19 nuclear magnetic resonance spectroscopy (19F NMR), gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS). Upon incubation with the pre-grown cultures, the substrate (100 mg/L) was completely consumed within 48 h, which is faster biotransformation than other fungi that have hitherto been studied. The main metabolite formed was the 5:3 fluorotelomer carboxylic acid (5:3 FTCA), which accumulated in the culture supernatant. When the cytochrome P450 inhibitor 1-aminobenzotriazole was included in the culture flasks, there was no biotransformation of 6:2 FTOH, indicating that these enzymes are key to the catalysis. Furthermore, when exogenous 5:3 FTCA was added to the fungus, the standard biotransformation of the drug flurbiprofen was inhibited, strongly suggesting that the main fluorotelomer alcohol biotransformation product inhibits CYP activity and accounts for its accumulation.

Phospholipid and antioxidant responses of oleaginous fungus Cunninghamella echinulata against hydrogen peroxide stress.

Hydrogen peroxide (H2O2) is one of the major oxidative stress intracellularly and extracellularly, which may affect lipid membrane or cell membrane. However, the mechanism remains unclear. The present study investigated phospholipid and antioxidant responses of Cunninghamella echinulata under exogenous H2O2 stress by integrating lipidomics and transcriptomics. H2O2 significantly affected phospholipid profile of C. echinulata exposed to exogenous H2O2. The phospholipid content was reduced from 6.41% to 2.47% on the first day, and to 1.03% on the 7th day, which was 5-6 times lower than that in the control. Phosphatidyl choline was reduced significantly from 29.71% to 2.73% on the 7th day. The lipid-related metabolic maps of C. echinulata responding to H2O2 were constructed based on transcriptomics, lipidomics and biochemical analysis. Results showed that H2O2 almost mobilized all the signaling pathways in the cell, especially the AMPK and cAMP signaling pathway, which regulated the metabolism of proteins and fatty acids. H2O2-stress triggered the high expression of heat shock genes. The antioxidant enzymes were activated to supply more NADPH, which contributed to the modulation of intracellular redox balance, and continuously scavenged active substances, thus improving the mycelial resistance to oxidative stress.

Cytochrome P450 5208A3 is a promiscuous xenobiotic biotransforming enzyme in Cunninghamella elegans.

Cunninghamella elegans is a long-established microbial model of mammalian drug and xenobiotic metabolism enabled by the actions of cytochrome P450 enzymes that are poorly characterised. In this paper we describe the identification of a new cytochrome P450 (CYP) monooxygenase in the fungus that catalyses the biotransformation of a range of structurally distinct xenobiotic substrates. The fungal enzyme was heterologously expressed in the yeast Pichia pastoris X-33 alone and in combination with previously identified C. elegans CYP reductases (CPRs A, B and C). Enzyme activity was assessed against a panel of drugs (flurbiprofen, diclofenac and ibuprofen), pesticides (transfluthrin, ß-cyfluthrin and λ-cyhalothrin) and a perfluoroalkyl substance (6:2 fluorotelomer alcohol) that were incubated with whole yeast cells expressing CYP5208A3. The biotransformation products were determined by gas chromatography-mass spectrometry (GC-MS) revealing the same metabolites that had been previously observed in the fungus. Co-expression of the CPRs improved metabolite production and the degree of improvement depended on the substrate and the CYP/CPR combination. Optimal pyrethroid biotransformation was achieved with CYP/CPR_C, whereas the best combination for non-steroidal anti-inflammatory drug hydroxylation was CYP/CPR_A; fluorotelomer alcohol oxidation was only observed with CYP/CPR_B. The change in substrate specificity observed with CYP5208A3 in combination with the different CPRs might help explain how C. elegans can biotransform such a broad spectrum of xenobiotics.

Production, immobilization and application of invertase from new wild strain Cunninghamella echinulata PA3S12MM.

AIMS: The objective of this study was to determine the best conditions to produce invertase by Cunninghamella echinulata PA3S12MM and to immobilize and apply the enzyme. METHODS AND RESULTS: The maximum production was verified in 8 days of cultivation at 28°C supplemented with 10 g L-1 apple peel, reaching 1054.85 U ml-1 . The invertase was purified from the DEAE-Sephadex column. The derivative immobilized in alginate-gelatin-calcium phosphate showed reusability >50% for 19 cycles. The derivative immobilized in glutaraldehyde-chitosan showed greater thermostability and at a different pH. The hydrolysis of 15 ml of sucrose 500 g L-1 in a fixed bed reactor (total volume of 31 ml) produced 24.44 µmol min-1 of glucose and fructose at a residence time of 30 min and a conversion factor of 0.5. CONCLUSIONS: The new wild strain C. echinulata PA3S12MM presents high invertase production in medium supplemented with an agro-industrial residue and the immobilized enzyme showed high thermal stability and resistance at a different pH. SIGNIFICANCE AND IMPACT OF THE STUDY: The fungus C. echinulata PA3S12MM is an excellent producer of invertases in Vogel medium supplemented with apple peel. The enzyme is promising for industrial application since it has good performance in reusability and inverted sugar production.

Controlled Production of Zearalenone-Glucopyranoside Standards with Cunninghamella Strains Using Sulphate-Depleted Media.

In recent years, conjugated mycotoxins have gained increasing interest in food safety, as their hydrolysis in human and animal intestines leads to an increase in toxicity. For the production of zearalenone (ZEN) glycosides reference standards, we applied Cunninghamellaelegans and Cunninghamella echinulata fungal strains. A sulphate-depleted medium was designed for the preferred production of ZEN glycosides. Both Cunninghamella strains were able to produce zearalenone-14-ß-D-glucopyranoside (Z14G), zearalenone-16-ß-D-glucopyranoside (Z16G) and zearalenone-14-sulphate (Z14S). In a rich medium, Cunninghamellaelegans preferably produced Z14S, while Cunninghamellaechinulata preferably produced Z14G. In the sulphate-depleted medium a dramatic change was observed for Cunninghamellaelegans, showing preferred production of Z14G and Z16G. From 2 mg of ZEN in sulphate-depleted medium, 1.94 mg of Z14G and 0.45 mg of Z16G were produced. Following preparative Liquid Chromatography-Mass Spectrometry (LC-MS) purification, both fractions were submitted to 1H and 13C NMR and High-Resolution Mass Spectrometry (HRMS). These analyses confirmed that the purified fractions were indeed Z14G and Z16G. In conclusion, the presented research shows that a single Cunninghamella strain can be an effective and efficient tool for the controlled biotransformation of ZEN glycosides and other ZEN metabolites. Additionally, the biotransformation method was extended to zearalanone, ß-zearalenol and other mycotoxins.

Biodegradation of Chloroxylenol by Cunninghamella elegans IM 1785/21GP and Trametes versicolor IM 373: Insight into Ecotoxicity and Metabolic Pathways.

Chloroxylenol (PCMX) is applied as a preservative and disinfectant in personal care products, currently recommended for use to inactivate the SARS-CoV-2 virus. Its intensive application leads to the release of PCMX into the environment, which can have a harmful impact on aquatic and soil biotas. The aim of this study was to assess the mechanism of chloroxylenol biodegradation by the fungal strains Cunninghamella elegans IM 1785/21GP and Trametes versicolor IM 373, and investigate the ecotoxicity of emerging by-products. The residues of PCMX and formed metabolites were analysed using GC-MS. The elimination of PCMX in the cultures of tested microorganisms was above 70%. Five fungal by-products were detected for the first time. Identified intermediates were performed by dechlorination, hydroxylation, and oxidation reactions catalysed by cytochrome P450 enzymes and laccase. A real-time quantitative PCR analysis confirmed an increase in CYP450 genes expression in C. elegans cells. In the case of T. versicolor, spectrophotometric measurement of the oxidation of 2,20-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) showed a significant rise in laccase activity during PCMX elimination. Furthermore, with the use of bioindicators from different ecosystems (Daphtoxkit F and Phytotoxkit), it was revealed that the biodegradation process of PCMX had a detoxifying nature.

Oxidative biotransformation of stemofoline alkaloids.

Biotransformations of stemofoline (1a), (2'S)-hydroxystemofoline (2a), (11Z)-1',2'-didehydrostemofoline (3a) and stemocurtisine (4) were studied through fermentation with Cunninghamella elegans TISTR 3370. Three new stemofoline derivatives; 6 R-hydroxystemofoline (1b), (2'S, 6 R)-dihydroxystemofoline (2b) and (11Z,6R)-1',2'-didehydro-6-hydroxystemofoline (3b), together with the known compound 1',2'-didehydrostemofoline-N-oxide (3c), were produced by C-hydroxylation and N-oxidation reactions. Stemocurtisine was not biotransformed under these conditions. The transformed product 1b was four times more potent (IC50 = 11.01 ± 1.49 µM) than its precursor 1a (IC50 = 45.1 ± 5.46 µM) as an inhibitor against acetylcholinesterase.

Oligochitosan Synthesized by Cunninghamella elegans, a Fungus from Caatinga (The Brazilian Savanna) Is a Better Antioxidant than Animal Chitosan.

Animal chitosan (Chit-A) is gaining more acceptance in daily activities. It is used in a range of products from food supplements for weight loss to even raw materials for producing nanoparticles and hydrogel drug carriers; however, it has low antioxidant activity. Fungal oligochitosan (OChit-F) was identified as a potential substitute for Chit-A. Cunninghamella elegans is a fungus found in the Brazilian savanna (Caatinga) that produces OligoChit-F, which is a relatively poorly studied compound. In this study, 4 kDa OChit-F with a 76% deacetylation degree was extracted from C. elegans. OChit-F showed antioxidant activity similar to that of Chit-A in only one in vitro test (copper chelation) but exhibited higher activity than that of Chit-A in three other tests (reducing power, hydroxyl radical scavenging, and iron chelation). These results indicate that OChit-F is a better antioxidant than Chit-A. In addition, Chit-A significantly increased the formation of calcium oxalate crystals in vitro, particularly those of the monohydrate (COM) type; however, OChit-F had no effect on this process in vitro. In summary, OChit-F had higher antioxidant activity than Chit-A and did not induce the formation of CaOx crystals. Thus, OChit-F can be used as a Chit-A substitute in applications affected by oxidative stress.

A new metabolite from Cunninghamella blakesleeana-mediated biotransformation of an oral contraceptive drug, levonorgestrel.

Cunninghamella blakesleeana-mediated biotransformation of an oral contraceptive drug, levonorgestrel (1), yielded a new metabolite, 13ß-ethyl-17α-ethynyl-10,17ß-dihydroxy-4,6-dien-3-one (2), and two known metabolites 3 (13ß-ethyl-17α-ethynyl-10ß,17ß-dihydroxy-4-en-3-one), and 4 (13ß-ethyl-17α-ethynyl-6ß,17ß-dihydroxy-4-en-3-one) at an ambient temperature using aqueous media. Hydroxylation and dehydrogenation of compound 1 was observed during the bio-catalytic transformation. The structure of a new metabolite 2 was determined by 1H, 13C, and 2DNMR and HR-EIMS spectroscopic techniques.

Single Cell Oil (SCO)-Based Bioactive Compounds: I-Enzymatic Synthesis of Fatty Acid Amides Using SCOs as Acyl Group Donors and Their Biological Activities.

Fatty acid amides (FAAs) are of great interest due to their broad industrial applications. They can be synthesized enzymatically with many advantages over chemical synthesis. In this study, the fatty acid moieties of lipids of Cunninghamella echinulata ATHUM 4411, Umbelopsis isabellina ATHUM 2935, Nannochloropsis gaditana CCAP 849/5, olive oil, and an eicosapentaenoic acid (EPA) concentrate were converted into their fatty acid methyl esters and used in the FAA (i.e., ethylene diamine amides) enzymatic synthesis, using lipases as biocatalysts. The FAA synthesis, monitored using in situ NMR, FT-IR, and thin-layer chromatography, was catalyzed efficiently by the immobilized Candida rugosa lipase. The synthesized FAAs exhibited a significant antimicrobial activity, especially those containing oleic acid in high proportions (i.e., derived from olive oil and U. isabellina oil), against several human pathogenic microorganisms, insecticidal activity against yellow fever mosquito, especially those of C. echinulata containing gamma-linolenic acid, and anticancer properties against SKOV-3 ovarian cancer cell line, especially those containing EPA in their structures (i.e., EPA concentrate and N. gaditana oil). We conclude that FAAs can be efficiently synthesized using microbial oils of different fatty acid composition and used in specific biological applications.

Filamentous fungi with high paraquat-degrading activity isolated from contaminated agricultural soils in northern Thailand.

The contamination of paraquat (1,1'-dimethyl-4,4'-bipyridylium dichloride) herbicide from the farming area has become a public concern in many countries. This herbicide harms to human health and negatively effects the soil fertility. Several methods have been introduced for the remediation of paraquat. In this study, 20 isolates of the paraquat-tolerant fungi were isolated from the contaminated soil samples in northern Thailand. We found that isolate PRPY-2 and PFCM-1 exhibited the highest degradation activity of paraquat on synthetic liquid medium. About 80 and 68% of paraquat were removed by PRPY-2 and PFCM-1 respectively after 15 days of cultivation. Based on the morphological characteristic and molecular analysis, the fungal isolate PRPY-2 and PFCM-1 were identified as Aspergillus tamarii and Cunninghamella sp. respectively. The biosorption of paraquat on these fungal mycelia was also investigated. It was found that only 8-10% of paraquat could be detected on their mycelia, while 24-46% of paraquat was degraded by fungal mycelia. This is the first report on paraquat degrading ability by A. tamarii and Cunninghamella sp. It is demonstrated that these filamentous fungi are promising microorganisms available for remediation of paraquat contaminated environment.

Medroxyprogesterone derivatives from microbial transformation as anti-proliferative agents and acetylcholineterase inhibitors (combined in vitro and in silico approaches).

The fungal transformations of medroxyrogesterone (1) were investigated for the first time using Cunninghamella elegans, Trichothecium roseum, and Mucor plumbeus. The metabolites obtained are as following: 6ß, 20-dihydroxymedroxyprogesterone (2), 12ß-hydroxymedroxyprogesterone (3), 6ß, 11ß-dihydroxymedroxyprogesterone (4), 16ß-hydroxymedroxyprogesterone (5), 11α, 17-dihydroxy-6α-methylpregn-4-ene-3, 20-dione (6), 11-oxo-medroxyprogesterone (7), 6α-methyl-17α-hydroxypregn-1,4-diene-3,20-dione (8), and 6ß-hydroxymedroxyprogesterone (9), 15ß-hydroxymedroxyprogesterone (10), 6α-methyl-17α, 11ß-dihydroxy-5α-pregnan-3, 20-dione (11), 11ß-hydroxymedroxyprogesterone (12), and 11α, 20-dihydroxymedroxyprogesterone (13). Among all the microbial transformed products, the newly isolated biotransformed product 13 showed the most potent activity against proliferation of SH-SY5Y cells. Compounds 12, 5, 6, 9, 11, and 3 (in descending order of activity) also showed some extent of activity against SH-SY5Y tumour cell line. The never been reported biotransformed product, 2, showed the most potent inhibitory activity against acetylcholinesterase. Molecular modelling studies were carried out to understand the observed experimental activities, and also to obtain more information on the binding mode and the interactions between the biotransformed products, and enzyme.

The oxygenated products of cryptotanshinone by biotransformation with Cunninghamella elegans exerting anti-neuroinflammatory effects by inhibiting TLR 4-mediated MAPK signaling pathway.

Cryptotanshinone (1), a major bioactive constituent in the traditional Chinese medicinal herb Dan-Shen Salvia miltiorrhiza Bunge, has been reported to possess remarkable pharmacological activities. To improve its bioactivities and physicochemical properties, in the present study, cryptotanshinone (1) was biotransformed with the fungus Cunninghamella elegans AS3.2028. Three oxygenated products (2-4) at C-3 of cryptotanshinone (1) were obtained, among them 2 was a new compound. Their structures were elucidated by comprehensive spectroscopic analysis including HRESIMS, NMR and ECD data. All of the biotransformation products (2-4) were found to inhibit significantly lipopolysaccharide-induced nitric oxide production in BV2 microglia cells with the IC50 values of 0.16-1.16 µM, approximately 2-20 folds stronger than the substrate (1). These biotransformation products also displayed remarkably improved inhibitory effects on the production of inflammatory cytokines (IL-1ß, IL-6, TNF-α, COX-2 and iNOS) in BV-2 cells via targeting TLR4 compared to substrate (1). The underlying mechanism of 2 was elucidated by comparative transcriptome analysis, which suggested that it reduced neuroinflammatory mainly through mitogen-activated protein kinase (MAPK) signaling pathway. Western blotting results revealed that 2 downregulated LPS-induced phosphorylation of JNK, ERK, and p38 in MAPK signaling pathway. These findings provide a basal material for the discovery of candidates in treating Alzheimer's disease.

Biotransformation of contraceptive drug desogestrel with Cunninghamella elegans, and anti-inflammatory activity of its metabolites.

Biotransformation of an orally active contraceptive drug, desogestrel (1), with Cunninghamella elegans yielded a new metabolite, 13ß-ethyl-11-methylene-18,19-dinor-17α-pregn-4-en-20-yn-17ß-ol-3,6-dione (2), along with five known metabolites, i.e., 13ß-ethyl-11-methylene-18,19-dinor-17α-pregn-4-en-20-yn-3ß,6ß,17ß-triol (3), 13ß-ethyl-11-methylene-18,19-dinor-17α-pregn-4-en-20-yn-6ß,17ß-diol-3-one (4), 13ß-ethyl-11-methylene-18,19-dinor-17α-pregn-4-en-20-yn-17ß-ol-3-one (5), 13ß-ethyl-11-epoxy-18,19-dinor-17α-pregn-4-en-20-yn-17ß-ol-3-one (6), and 13ß-ethyl-11-methylene-18,19-dinor-17α-pregn-4-en-20-yn-10ß,17ß-diol-3-one (7). The structure of new metabolite 2 was elucidated by using 1H-, 13C-, and 2D-NMR, EI-, and HREI-MS, IR, and UV spectroscopic data. Compounds 1-7 were evaluated for anti-inflammatory activities, i.e., inhibition of T-cell proliferation, and pro-inflammatory cytokine (TNF-α). Compounds 1 (IC50 = 1.12 ± 0.03 µg/mL), 2 (IC50 = 1.15 ± 0.05 µg/mL), 3 (IC50 = 1.15 ± 0.05 µg/mL), 4 (IC50 = 1.40 ± 0.03 µg/mL), 5 (IC50 = 1.78 ± 0.08 µg/mL), and 6 (IC50 = 1.36 ± 0.07 µg/mL) were identified as potent inhibitors of T-cells proliferation, in comparison to the standard drug, prednisolone (IC50 = 3.51 ± 0.03 µg/mL). Compound 7 (IC50 = 6.18 ± 0.04 µg/mL) showed a good activity. In addition, substrate 1 (IC50 ≤ 1 µg/mL), and its metabolites 2 (IC50 = 4.1 ± 0.60 µg/mL), and 6 (IC50 = 6.8 ± 0.8 µg/mL) also showed a potent inhibition of pro-inflammatory cytokine (TNF-α) production, as compared to the standards drug, pentoxifilline (IC50 = 94.8 ± 2.1 µg/mL). Whereas compounds 3 (IC50 = 57.9 ± 7.6 µg/mL), and 5 (IC50 = 27.2 ± 6.8 µg/mL) showed a moderate inhibition of TNF-α production, while compounds 4 and 7 showed no inhibition. Compounds 1-7 were found to be non-cytotoxic to 3T3 normal cell line (mouse fibroblast).

Fungal transformation of norandrostenedione with Cunninghamella blakesleeana and anti-bacterial activity of the transformed products.

Although the discovery of antibiotics has decreased the spread and severity of infectious diseases, their uncontrolled use has lead to the emergence of bacterial resistance to existing chemotherapeutic agents. Bacterial disease thus remains a challenge for health authorities in worldwide and especially in sub-Saharan Africa. Despite their efficacy, the miss-use of medicinal plants for the treatment of infectious diseases couple to the farming and hunting activities has contribute enormously to the destruction of many medicinal plant species. In search of an alternative for new and effective agents against bacterial infection, norandrostenedion (19-nor-4-androsten-3,17-dione) (1), was biotransformed by Cunninghamella blakesleeana ATCC 8688A and yielded a new metabolite, 6α,10 ß -dihydroxy-19-nor-4-androsten-3-one (2), together with three known compounds, 10 ß -hydroxy-19-nor-4-androsten-3,17-dione (3), 6 ß,10 ß,17 ß -trihydroxy-19-nor-4-androsten-3-one (4) and 10 ß,17 ß -dihydroxy-19-nor-4-androsten-3-one (5). Their structures were elucidated on the basis ofspectroscopic techniques: NMR analysis (1D and 2D) and HRIE-MS and by comparison with previously reported data. In addition, the agar diffusion method was used to evaluate the diameter of the inhibition zone and INT colorimetric assay for MIC values. All metabolites obtained showed a potent and varied activity against tested bacteria. These results support the uses of biotransformation to develop new antimicrobial compounds for clinical application.