Hydroxylation of Progesterone and Its Derivatives by the Entomopathogenic Strain Isaria farinosa KCh KW1.1.

Progesterone biotransformation is worth studying because of the high industrial value of its derivatives. This study investigated the catalytic ability of the entomopathogenic filamentous fungus strain Isaria farinosa KCh KW1.1 to transform progesterone derivatives: 11α-hydroxyprogesterone, 17α-hydroxyprogesterone, 16α,17α-epoxyprogesterone and pregnenolone. In the culture of Isaria farinosa KCh KW1.1, 11α-hydroxyprogesterone was effectively transformed into only one product: 6ß,11α-dihydroxyprogesterone. Transformation of 17α-hydroxyprogesterone gave three hydroxy derivatives: 6ß,17α-dihydroxyprogesterone, 12ß,17α-dihydroxyprogesterone and 6ß,12ß,17α-trihydroxyprogesterone. Two products: 6ß-hydroxy-16α,17α-epoxyprogesterone and 6ß,11α-dihydroxy-16α,17α-epoxyprogesterone, were obtained from the 16α,17α-epoxyprogesterone transformation. We isolated two compounds from the biotransformation medium with pregnenolone: 11α-hydroxy-7-oxopregnenolone and 5α,6α-epoxy-3ß,11α-dihydroxypregnan-7,20-dione. In this study, we observed only mono- and dihydroxy derivatives of the tested substrates, and the number of obtained products for each biotransformation did not exceed three.

Metallacarborane Derivatives Effective against Pseudomonas aeruginosa and Yersinia enterocolitica.

Pseudomonas aeruginosa is an opportunistic human pathogen that has become a nosocomial health problem worldwide. The pathogen has multiple drug removal and virulence secretion systems, is resistant to many antibiotics, and there is no commercial vaccine against it. Yersinia pestis is a zoonotic pathogen that is on the Select Agents list. The bacterium is the deadliest pathogen known to humans and antibiotic-resistant strains are appearing naturally. There is no commercial vaccine against the pathogen, either. In the current work, novel compounds based on metallacarborane cage were studied on strains of Pseudomonas aeruginosa and a Yersinia pestis substitute, Yersinia enterocolitica. The representative compounds had IC50 values below 10 µM against Y. enterocolitica and values of 20-50 µM against P. aeruginosa. Artificial generation of compound-resistant Y. enterocolitica suggested a common mechanism for drug resistance, the first reported in the literature, and suggested N-linked metallacarboranes as impervious to cellular mechanisms of resistance generation. SEM analysis of the compound-resistant strains showed that the compounds had a predominantly bacteriostatic effect and blocked bacterial cell division in Y. enterocolitica. The compounds could be a starting point towards novel anti-Yersinia drugs and the strategy presented here proposes a mechanism to bypass any future drug resistance in bacteria.

Biological Potential and Chemical Profile of European Varieties of Ilex.

Plants of the genus Ilex are widespread throughout the world, with its best-known representative being Ilex paraguraiensis from South America. The European species Ilex aquifolium shows similarities in its terpenoid, sugar and phenolic acid profiles. Using aqueous extracts of Ilex aquifolium as a supplement in Wistar rats showed that, despite the lack of caffeine, it had strong hypocholesterolemic effects. In addition, a reduction in oxidative lipid degradation and a decrease in hepatic steatosis in histopathological studies were observed. The results of this study suggest that extracts from the European species Ilex aquifolium may have potential as an alternative treatment for hyperlipidemia.

New 6,19-oxidoandrostan derivatives obtained by biotransformation in environmental filamentous fungi cultures.

BACKGROUND: Steroid compounds with a 6,19-oxirane bridge possess interesting biological activities including anticonvulsant and analgesic properties, bacteriostatic activity against Gram-positive bacteria and selective anti-glucocorticoid action, while lacking mineralocorticoid and progestagen activity. RESULTS: The study aimed to obtain new derivatives of 3ß-acetyloxy-5α-chloro-6,19-oxidoandrostan-17-one by microbial transformation. Twelve filamentous fungal strains were used as catalysts, including entomopathogenic strains with specific activity in the transformation of steroid compounds. All selected strains were characterised by high biotransformation capacity for steroid compounds. However, high substrate conversions were obtained in the cultures of 8 strains: Beauveria bassiana KCh BBT, Beauveria caledonica KCh J3.4, Penicillium commune KCh W7, Penicillium chrysogenum KCh S4, Mucor hiemalis KCh W2, Fusarium acuminatum KCh S1, Trichoderma atroviride KCh TRW and Isaria farinosa KCh KW1.1. Based on gas chromatography (GC) and nuclear magnetic resonance (NMR) analyses, it was found that almost all strains hydrolysed the ester bond of the acetyl group. The strain M. hiemalis KCh W2 reduced the carbonyl group additionally. From the P. commune KCh W7 and P. chrysogenum KCh S4 strain cultures a product of D-ring Baeyer-Villiger oxidation was isolated, whereas from the culture of B. bassiana KCh BBT a product of hydroxylation at the 11α position and oxidation of the D ring was obtained. Three 11α-hydroxy derivatives were obtained in the culture of I. farinosa KCh KW1.1: 3ß,11α-dihydroxy-5α-chloro-6,19-oxidoandrostan-17-one, 3ß,11α,19-trihydroxy-5α-chloro-6,19-oxidoandrostan-17-one and 3ß,11α-dihydroxy-5α-chloro-6,19-oxidoandrostan-17,19-dione. They are a result of consecutive reactions of hydrolysis of the acetyl group at C-3, 11α- hydroxylation, then hydroxylation at C-19 and its further oxidation to lactone. CONCLUSIONS: As a result of the biotransformations, seven steroid derivatives, not previously described in the literature, were obtained: 3ß-hydroxy-5α-chloro-6,19-oxidoandrostan-17-one, 3ß,17α-dihydroxy-5α-chloro-6,19-oxidoandrostane, 3ß-hydroxy-5α-chloro-17α-oxa-D-homo-6,19-oxidoandrostan-17-one, 3ß,11α-dihydroxy-5α-chloro-17α-oxa-D-homo-6,19-oxidoandrostan-17-one and the three above-mentioned 11α-hydroxy derivatives. This study will allow a better understanding and characterisation of the catalytic abilities of individual microorganisms, which is crucial for more accurate planning of experiments and achieving more predictable results.

Identification of a potent inhibitor of type II secretion system from Pseudomonas aeruginosa.

Pseudomonas aeruginosa is an opportunistic pathogen infecting human population. The pathogen is becoming a serious health problem due to its ability to evade normal immune response of the host and multiple drug resistance to many antibiotics. The pathogen has 2 major virulence systems of which the type III secretion system (T3SS) is of major concern to humans. A third system, type 2 secretion system (T2SS), is common to bacteria and used to secrete exotoxin A (ExoA) responsible for human cell destruction. To help bypass the drug resistance, a strategy to block the T2SS based on a low similarity between human ATPases and the essential ATPases of the T3SS and T2SS of P. aeruginosa, was used. An in silico-optimized inhibitor of T3SS, made directly from the computer-optimized of previously published compounds and their combinatorial libraries, showed IC50 = 1.3 ±â€¯0.2 µM in the T2SS ExoA secretion blocking test. The compound was non-toxic to human lung epithelial cell line A549 and could block cellular destruction of those cells in a cell infection model at 200 µM for at least 24 h. The compound could be a lead candidate for the development of T2SS virulence blockers of Pseudomonas aeruginosa.

Biotransformation of steroids by entomopathogenic strains of Isaria farinosa.

BACKGROUND: Steroid compounds are very interesting substrates for biotransformation due to their high biological activity and a high number of inactivated carbons which make chemical modification difficult. Microbial transformation can involve reactions which are complicated and uneconomical in chemical synthesis, and searching for a new effective biocatalyst is necessary. The best known entomopathogenic species used in steroid modification is Beauveria bassiana. In this study we tested the ability of Isaria farinosa, another entomopathogenic species, to transform several steroids. RESULTS: Twelve strains of the entomopathogenic filamentous fungus Isaria farinosa, collected in abandoned mines located in the area of the Lower Silesian Voivodeship, Poland, from insects' bodies covered by fungus, were used as a biocatalyst. All the tested strains effectively transformed dehydroepiandrosterone (DHEA). We observed 7α- and 7ß-hydroxy derivatives as well as changes in the percentage composition of the emerging products. Due to the similar metabolism of DHEA in all tested strains, one of them was selected for further investigation. In the culture of the selected strain, Isaria farinosa KCh KW1.1, transformations of androstenediol, androstenedione, adrenosterone, 17α-methyltestosterone, 17ß-hydroxyandrost-1,4,6-triene-3-one and progesterone were performed. All the substrates were hydroxylated with high yield and stereoselectivity. We obtained 6ß-hydroxyandrost-4-ene-3,11,17-trione, 15α,17ß-dihydroxy-6ß,7ß-epoxyandrost-1,4-diene-3-one and 6ß,11α-dihydroxyprogesterone. There is no evidence of either earlier microbial transformation of 17ß-hydroxyandrost-1,4,6-triene-3-one or new epoxy derivatives. CONCLUSIONS: Isaria farinosa has a broad spectrum of highly effective steroid hydroxylases. The obtained 7-hydroxydehydroepiandrosterone has proven high biological activity and can be used in Alzheimer's disease and as a key intermediate in the synthesis of aldosterone antagonists. Transformation of progesterone leads to high yield of 6ß,11α-dihydroxyprogesterone and it is worth further study.