Microbiological transformation of diosgenin by resting cells of filamentous fungus, Cunninghamella echinulata CGMCC 3.2716

New adipate esters from Cunninghamella echinulata: isolation, identification, biosynthesis and in silico prediction of potential opioid/anti-opioid and antidiabetic activities

Metabolites of the fungus Cunninghamella echinulata NRRL 1382 were investigated under the effect of fusidic acid (1) feeding. In addition to ergosterol (2) which is a fungal sterol, two novel adipate esters (3, 4) were isolated, and their structures were fully investigated using various spectroscopic analyses, including 1 D, 2 D NMR and HRESIMS. In silico biological target prediction and molecular docking investigation revealed a potential agonist/antagonist activity for compound 3 by binding to µ opioid receptor and antidiabetic effect by aldose reductase inhibitory activity for compound 4.

Recent advances in chemical synthesis, biocatalysis, and biological evaluation of diosgenin derivatives - A review

Extracting organic compounds from plants and developing derivatives are essential methods for drug discovery. Diosgenin, extracted from Dioscoreaceae plants, is a type of spirostan steroid with various biological effects, including anti-inflammation, neuro-protection, and apoptosis-induction. Many researchers committed their work to the chemical semi-synthesis of diosgenin derivatives to improve diosgenin's therapeutic bioavailability and expand its range of applications in disease treatment and prevention. Biotransformation, a mild whole-cell biocatalysis method, also made crucial contributions to the structural diversity of diosgenin analogs in recent years. Although the structural modification of diosgenin has made significant progress, it lacks a comprehensive review. Here, we review the chemical modification and biotransformation of diosgenin along with the biological evaluation of diosgenin derivatives to provide a reference for the structural modification strategy and pharmaceutical application of diosgenin derivatives.

Fungal mediated biotransformation of melengestrol acetate, and T-cell proliferation inhibitory activity of biotransformed compounds

Glomerella fusaroide, and Rhizopus stolonifer were effectively able to transform the steroidal hormone melengestrol acetate (MGA) (1) into four (4) new metabolites, 17α-acetoxy-11α-hydroxy-6-methyl-16-methylenepregna-4,6-diene-3,20-dione (2), 17α-acetoxy-11α-hydroxy-6-methyl-16-methylenepregna-1,4,6-triene-3,20-dione (3), 17α-acetoxy-6,7α-epoxy-6β-methyl-16-methylenepregna-4,6-diene-3,20-dione (4), and 17α-acetoxy-11β,15β-dihydroxy-6-methyl-16-methylenepregna-4,6-diene-3,20-dione (5). All these compounds were structurally characterized by different spectroscopic techniques. The objective of the current study was to assess the anti-inflammatory potential of melengestrol acetate (1), and its metabolites 2-5. The metabolites and the substrate were assessed for their inhibitory effects on proliferation of T-cells in vitro. The substrate (IC₅₀ = 2.77 ± 0.08 µM) and its metabolites 2 (IC₅₀ = 2.78 ± 0.07 µM), 4 (IC₅₀ = 2.74 ± 0.1 µM), and 5 (IC₅₀ = < 2 µM) exhibited potent T- cell proliferation inhibitory activities, while compound 3 (IC₅₀ = 29.9 ± 0.09 µM) showed a moderate activity in comparison to the standard prednisolone (IC₅₀ = 9.73 ± 0.08 µM). All the metabolites were found to be non-toxic against 3T3 normal cell line. This study thus identifies some potent compounds active against T-cell proliferation. Their anti-inflammatory potential, therefore, deserves to be further investigated.

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 β -dihydroxy-19-nor-4-androsten-3-one (2), together with three known compounds, 10 β -hydroxy-19-nor-4-androsten-3,17-dione (3), 6 β,10 β,17 β -trihydroxy-19-nor-4-androsten-3-one (4) and 10 β,17 β -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.

Microbial biotransformation of some novel hydantoin derivatives: Perspectives for bioremediation of potential sunscreen agents

Having identified novel hydantoin derivatives (compounds 1-5) demonstrating promising photoprotective capacity against UV radiation, and understainding the problem of the biotic and abiotic degradation of UV filters, the aim of the study was to evaluate their metabolic fate with the environmental fungus Cunninghamella echinulata. In parallel, compound 1 in vitro microsomal metabolic pattern was evaluated. Finally, in silico toxicity of test compounds and their biotransformation products was estimated, and parent compounds photostability was assessed. The study demonstrated the capacity for C. echinulata to metabolize 1-5, which were biotransformed to a greater extent than the standard UV filter. O-dealkylation of the side chains attached to the phenyl or hydantoin rings, and hydroxylation of the phenyl ring occurred during microbial transformation. O-dealkylation product was a unique metabolite observed in microsomal biotransformation of 1, being its intrinsic clearance in the medium category range. In silico study demonstrated that compounds 1-5 have low toxicity risk. Among the resulting metabolites, four can increase the risk of reproductive effects as shown by OSIRIS prediction. Noteworthy, all indicated metabolites belong to minor metabolites, except for compound 3 major metabolite. Moreover, the results of the photostability study showed that 1-5 were considered to be photostable. To sum up, the obtained in vitro biotransformation, photostability, and in silico toxicity results encourage further studies on hydantoin derivatives as potential UV photoprotective agents. The presented biotransformation profile of compounds 1-5 by C. echinulata suggests that these compounds may follow a similar biodegradation fate when released into the environment.

Evaluation of Microbial Transformation of 10-deoxoartemisinin by UPLC-ESI-Q-TOF-MSE

10-deoxoartemisinin is a semisynthetic derivative of artemisinin that lacks a lactone carbonyl group at the 10-position, and has stronger antimalarial properties than artemisinin. However, 10-deoxoartemisinin has limited utility as a therapeutic agent because of its low solubility and bioavailability. Hydroxylated 10-deoxoartemisinins are a series of properties-improved derivatives. Via microbial transformation, which can hydroxylate 10-deoxoartemisinin at multiple sites, the biotransformation products of 10-deoxoartemisinin have been investigated in this paper. Using ultra-performance liquid chromatography-electrospray ionization-quadrupole time-of-flight mass spectrometry (UPLC-ESI-Q-TOF-MS^E) combined with UNIFI software, products of microbial transformation of 10-deoxoartemisinin were rapidly and directly analyzed. The hydroxylation abilities of nine microorganisms were compared using this method. All of the microorganisms evaluated were able to hydroxylate 10-deoxoartemisinin, and a total of 35 hydroxylated products were identified. These can be grouped into dihydroxylated 10-deoxoartemisinins, monohydroxylated 10-deoxoartemisinins, hydroxylated dehydrogenated 10-deoxoartemisinins, and hydroxylated hydrogenated 10-deoxoartemisinins. Cunninghamella echinulata and Cunninghamella blakesleeana are able to hydroxylate 10-deoxoartemisinin, and their biotransformation products are investigated here for the first time. Cunninghamella elegans CICC 40250 was shown to most efficiently hydroxylate 10-deoxoartemisinin, and could serve as a model organism for microbial transformation. This method could be used to generate additional hydroxylated 10-deoxoartemisinins for further research.

Biotransformation of progestonic hormone dydrogesterone with Macrophomina phaseolina, and study of the effect of biotransformed products on phagocytes oxidative burst

Biotransformation of a synthetic progestonic hormone dydrogesterone (1), C₂₁H₂₈O₂, with a plant pathogenic fungus Macrophomina phaseolina yielded two new 2 and 3, and a known 4 metabolites. These analogues were identified as, 3β,11α-dihydroxy-5β,9β,10α-pregna-7-ene-6,20-dione (2), 15β-hydroxy-9β,10α-pregna-4,6-diene-3,20-dione (3), and 8α-hydroxy-9β,10α-pregna-4,6-diene-3,20-dione (4). Major structural changes were observed in metabolite 2. New metabolite 3 showed anti-inflammatory potential, and was found to be the potent inhibitor of intracellular reactive oxygen species (ROS) from whole blood phagocytes (IC₅₀ = 4.2 ± 0.3 μg/mL), as compared to standard drug Ibuprofen (IC₅₀ = 11.2 ± 1.9 μg/mL). The metabolites 2, 3, and 4 were found to be non-toxic to NIH-3T3 (CRL-1658) normal cell line. This indicated anti-inflammatory potential of resulting metabolites.

Biotransformation of Neoruscogenin by the Endophytic Fungus Alternaria eureka

Biotransformation of neoruscogenin (NR, 1, spirosta-5,25(27)-diene-1β,3β-diol), the major bioactive sapogenin of Ruscus preparations, was carried out with the endophytic fungus Alternaria eureka. Fourteen new biotransformation products (2-15) were isolated, and their structures were elucidated by NMR and HRESIMS data analyses. A. eureka affected mainly oxygenation, oxidation, and epoxidation reactions on the B and C rings of the sapogenin to afford compounds 8-15. In addition to these, cleavage of the spiroketal system as in compounds 2-7 and subsequent transformations provided unusual metabolites. This is the first study reporting conversion of the spirostanol skeleton to cholestane-type metabolites 2-5. Additionally, the cleavage of the C-22/C-26 oxygen bridge yielding a furostanol-type steroidal framework and subsequent formation of the epoxy bridge between C-18 and C-22 in 7 was encountered for the first time in steroid chemistry.

Natural product driven diversity via skeletal remodeling of caryophyllene β-lactam

(-)-β-Caryophyllene was decorated with a privileged β-lactam motif and subsequently converted into highly diverse scaffolds via remodeling of the ring system. The structures were defined by spectroscopic data, X-ray diffraction analysis, and experimental and calculated ECD data. Compound 19 displayed the most potent activity against the rice blast fungus, while 6 had a more potent α-glucosidase inhibition than the drug acarbose. These findings demonstrate a concise protocol to exploit natural product-driven diversity.

Microbial transformation of mestanolone byMacrophomina phaseolinaandCunninghamella blakesleeanaand anticancer activities of the transformed products

The microbial transformation of anabolic androgenic steroid mestanolone (1) with Macrophomina phaseolina and Cunninghamella blakesleeana has afforded seven metabolites. The structures of these metabolites were characterized as 17β-hydroxy-17α-methyl-5α-androsta-1-ene-3,11-dione (2), 14α,17β-dihydroxy-17α-methyl-5α-androstan-3,11-dione (3), 17β-hydroxy-17α-methyl-5α-androstan-1,14-diene-3,11-dione (4), 17β-hydroxy-17α-methyl-5α-androstan-3,11-dione (5), 11β,17β-dihydroxy-17α-methyl-5α-androstan-1-ene-3-one (6), 9α,11β,17β-trihydroxy-17α-methyl-5α-androstan-3-one (7), and 1β,11α,17β-trihydroxy-17α-methyl-5α-androstan-3-one (8). All the metabolites, except 5 and 6, were identified as new compounds. Substrate 1 (IC₅₀ = 27.6 ± 1.1 μM), and its metabolites 2 (IC₅₀ = 19.2 ± 2.9 μM) and 6 (IC₅₀ = 12.8 ± 0.6 μM) exhibited moderate cytotoxicity against the HeLa cancer cell line (human cervical carcinoma). All metabolites were noncytotoxic to 3T3 (mouse fibroblast) and H460 (human lung carcinoma) cell lines. The metabolites were also evaluated for immunomodulatory activity, and all were found to be inactive.

The microbial transformation of anabolic androgenic steroid mestanolone (1) with Macrophomina phaseolina and Cunninghamella blakesleeana has afforded seven metabolites. Some of them have exhibited moderate cytotoxicity against HeLa cancer cell line.

Biotransformation of drospirenone, a contraceptive drug, with Cunninghamella elegans

Biotransformation of an orally active contraceptive drug, drospirenone (1), by Cunninghamella elegans ATCC 36114 yielded four new metabolites, 6β,7β,15β,16β-dimethylene-3-oxo-14α-hydroxy-17α-pregn-4-ene-21,17-carbolactone (2), 6β,7β,15β,16β-dimethylene-3,11-dioxo-17α-pregn-4-ene-21,17-carbolactone (3), 6β,7β,15β,16β-dimethylene-3,12-dioxo-17α-pregn-4-ene-21,17-carbolactone (4), and 6β,7β,15β,16β-dimethylene-3-oxo-11β,14α-dihydroxy-17α-pregn-4-ene-21,17-carbolactone (5), along with a known metabolite, 6β,7β,15β,16β-dimethylene-3-oxo-11α-dihydroxy-17α-pregn-4-ene-21,17-carbolactone (6). This study provides not only new analogues of orally active contraceptive drug, drospirenone, but also help in understanding the metabolism of this important drug.

Microbial transformation of contraceptive drug etonogestrel into new metabolites with Cunninghamella blakesleeana and Cunninghamella echinulata

Biotransformation of a steroidal contraceptive drug, etonogestrel (1), (13-ethyl-17β-hydroxy-11-methylene-18,19-dinor-17α-pregn-4-en-20-yn-3-one) was investigated with Cunninghamella blakesleeana and C. echinulata. Five metabolites 2-6 were obtained on incubation of 1 with Cunninghamella blakesleeana, and three metabolites, 2, 4, and 6 were isolated from the transformation of 1 with C. echinulata. Among them, metabolites 2-4 were identified as new compounds. Their structures were deduced as 6β-hydroxy-11,22-epoxy-etonogestrel (2), 11,22-epoxy-etonogestrel (3), 10β-hydroxy-etonogestrel (4), 6β-hydroxy-etonogestrel (5), and 14α-hydroxy-etonogestrel (6). Compounds 1-6 were evaluated for various biological activities. Interestingly, compound 5 was found to be active against β-glucuronidase enzyme with IC₅₀ value of 13.97±0.12μM, in comparison to standard compound, d-saccharic acid 1,4-lactone (IC₅₀=45.75±2.16μM). Intestinal bacteria produce β-glucuronidase. Increased activity of β-glucuronidase is responsible for the hydrolyses of glucuronic acid conjugates of estrogen and other toxic substances in the colon, which plays a key role in the etiology of colon cancer. Inhibition of β-glucoronidase enzyme therefore has a therapeutic significance. Compounds 1-6 were also found to be non cytotoxic against 3T3 mouse fibroblast cell lines.

Production of biologically active oxidized derivatives of finasteride through metabolism by Aspergillus niger culture

CONTEXT

Among the 4-azasteroids, finasteride is biologically the most important compound having preventive effect against male pattern baldness (MPH) and benign prostatic hyperplasia commonly called enlargement of prostate gland.

OBJECTIVE

The microbial transformation of finasteride by fungus Aspergillus niger (ATCC 10549) has been investigated to obtain biologically more potent derivatives.

MATERIALS AND METHODS

Fermentation of finasteride was performed with filamentous fungus Aspergillus niger (ATCC 10549). This transformation resulted in the production of two transformed products, which were purified through column chromatography. In vitro lipoxygenase inhibitory potential was determined by incubating 20 mL of the enzyme with 10 mL of test sample (100 μM) in 0.1 mM (pH 7.0) phosphate buffer for 5 min at 258 °C followed by addition of 10 μL of substrate (linolenic acid) to reaction mixture and measuring the formation of complex spectrophotometrically.

RESULTS

Structure elucidation of biotransformed metabolites was ascertained through extensive 1D and 2D spectroscopic techniques. This study established the fact that A. niger promoted stereospecific dihydroxylation at C-11 and C-15 of finasteride. The resulting biotransformed metabolites were characterized as 11α-hydroxyfinasteride and 15β-hydroxyfinasteride, respectively. Finasteride along with transformed metabolites were analyzed for their in vitro lipoxygenase (LOX) inhibition assay. Among the tested compounds 15β-hydroxyfinasteride showed good activity with IC₅₀ value 112.56 ± 2.23 μM while inhibitory effect in case of 11α-hydroxyfinasteride was low with IC₅₀ value 186.05 ± 1.34 μM. Standard compound baicalein revealed IC₅₀ value being 22.0 ± 0.05 μM.

CONCLUSION

The present investigation highlighted the fact that potentially active compound can be produced through the technology of biotransformation.

Microbial transformation of danazol with Cunninghamella blakesleeana and anti-cancer activity of danazol and its transformed products

Biotransformation of danazol (1) (17β-hydroxy-17α-pregna-2,4-dien-20-yno-[2,3-d]-isoxazole) with Cunninghamella blakesleeana yielded three new metabolites 2-4 and a known metabolite 5. These metabolites were identified as 14β,17β-dihydroxy-2-(hydroxymethyl)-17α-pregn-4-en-20-yn-3-one (2), 1α,17β-dihydroxy-17α-pregna-2,4-dien-20-yno-[2,3-d]-isoxazole (3), 6β,17β-dihydroxy-17α-pregna-2,4-dien-20-yno-[2,3-d]-isoxazole (4), and 17β-hydroxy-2-(hydroxymethyl)-17α-pregn-1,4-dien-20-yn-3-one (5). Danazol (1) and its derivatives were evaluated against cervical cancer cell line (HeLa). Compound 1 showed a potent cytotoxicity with IC50=0.283±0.013 μM, as compared to doxorubicin (IC50=0.506±0.015 μM), where compound 3 was also found to be significantly active with IC50=13.427±0.819 μM.

Microbial transformation of oxandrolone with Macrophomina phaseolina and Cunninghamella blakesleeana

Microbial transformation of oxandrolone (1) was carried out by using Cunninghamella blakesleeana and Macrophomina phaseolina. Biotransformation of 1 with M. phaseolina yielded four new metabolites, 11β,17β-dihydroxy-17α-(hydroxymethyl)-2-oxa-5α-androstan-3-one (2), 5α,11β,17β-trihydroxy-17α-methyl-2-oxa-androstan-3-one (3), 17β-hydroxy-17α-methyl-2-oxa-5α-androstan-3,11-dione (4), and 11β,17β-dihydroxy-17α-methyl-2-oxa-5α-androstan-3-one (5). Whereas a new metabolite, 12β,17β-dihydroxy-17α-methyl-2-oxa-5α-androstan-3-one (6), was obtained through the microbial transformation of oxandrolone (1) with C. blakesleeana. The structures of isolated metabolites were characterized on the basis of MS and NMR spectroscopic data.

Endophyte inspired chemical diversity from beta-caryophyllene

The natural product (−)-β-caryophyllene is considered as an ideal initiator to generate diverse scaffolds by transannular cyclization due to its macrocyclic structure and abundant availability in nature.

Microbial transformation of diosgenin by Cunninghamella blakesleana AS 3.970 and potential inhibitory effects on P-glycoprotein of its metabolites

Microbial transformation of diosgenin ((25R)-spirost-5-en-3β-ol) using Cunninghamella blakesleana AS 3.970, afforded eleven polyhydroxylated derivatives. Compounds 4 and 6 could increase the accumulation of adriamycin in MCF-7/ADR cells.

Microbial transformations of diosgenin by the white-rot basidiomycete Coriolus versicolor

Microbial transformation of diosgenin (3β-hydroxy-5-spirostene) using white-rot fungus Coriolus versicolor afforded four previously unreported polyhydroxylated steroids, 25(R)-spirost-5-en-3β,7α,15α,21-tetraol (5), 25(R)-spirost-5-en-3β,7β,12β,21-tetrol (6), (25R)-spirost-5-en-3β,7α,12β,21-tetraol (7), and (25R)-spirost-5-en-3β,7β,11α,21-tetraol (8), along with three known congeners, 25(R)-spirost-5-en-3β,7β-diol (2), 25(R)-spirost-5-en-3β,7β,21-triol (3), and 25(R)-spirost-5-en-3β,7β,12β-triol (4). These structures were elucidated by 1D and 2D NMR as well as HR-ESIMS analysis. In addition, we provide evidence for two new microbial hydroxylations of diosgenin: C-21 primary carbon hydroxylation and C-15 hydroxylation. The 3β-hydroxyl group and double bond in the B-ring of diosgenin were found to be important structural determinants for their activity.