Biomedical subjects

Ewa Huszcza

Publications and source records attributed to Ewa Huszcza.

6 recordsLinked to original sources

PubMed2005

Biotransformation of 6,7-epoxygeraniol by fungi.

The biotransformation of 6,7-epoxygeraniol by resting cells of selected fungi was investigated. The main product obtained from the transformation in Rhodotorula glutinis and R. marina cultures was 6,7-epoxynerol (5-48% of chloroform extracts), whereas Saccharomyces cerevisiae, Candida parapsilosis and C. kefyr reduced this substrate to 6,7-epoxycitronellol (30-33% of chloroform extracts). Cultures of Yarrowia lipolytica, Botrytis cinerea and S. cerevisiae promoted the cyclisation of 6,7-epoxygeraniol to 2-methyl-2-(2-hydroxyethyl)-5-(2-hydroxyprop-2-yl)tetrahydrofuran (11-99% of chloroform extracts). The biotransformation of 6,7-epoxynerol was also investigated. However, none of the tested micro-organisms converted this compound.

Acyclic Monoterpenes↗

PubMed2005

Steroids' transformations in Penicillium notatum culture.

The application of Penicillium notatum genus for biotransformations of steroids has been investigated. The reactions observed include insertion of an oxygen atom into D-ring of steroids, 15alpha-hydroxylation of 17alpha-methyl testosterone derivatives, ester bond hydrolysis, and degradation of a testosterone derivatives side chain. Microbial production of testolactones, the biologically active compounds, was also achieved using this strain in up to 98% yield.

Androstenedione↗

PubMed2003

Transformations of testosterone and related steroids in Absidia glauca culture.

In the following study, the course of transformations of testosterone and its derivatives with an additional C(1)-C(2) double bond and/or 17alpha-methyl group or without 19-methyl group in Absidia glauca culture was investigated. The fungi were observed to hydroxylate these compounds and to oxidise the 17beta-hydroxyl group. The products of 6beta, 7alpha, 7beta, 11alpha, 12beta or 15beta hydroxylation were obtained. 19-Nortestosterone was also hydroxylated at the 10beta position.The position and stereochemistry of the introduced hydroxyl group was dependent on the presence of the additional C(1)-C(2) double bond, while hydroxylation at the C-6beta was unaffected. The incubation of testosterone with Absidia glauca gave hydroxyderivatives of androstenedione: 7alpha-hydroxyandrostenedione and 6beta,11alpha-dihydroxyandrostenedione. When 1-dehydrotestosterone and 1-dehydro-17alpha-methyltestosterone were used, the products were hydroxylated at 6beta, 7beta or 15beta position while 17alpha-methyltestosterone and 19 nortestosterone products were hydroxylated at 6beta, 7alpha, 11alpha or 12beta position. Two metabolites: 6beta,11alpha-dihydroxyandrostenedione and 6beta,12beta-dihydroxy-17alpha-methyltestosterone were dihydroxylated. The presence of 17alpha-methyl group in 17alpha-methyltestosterone and 1-dehydro-17alpha-methyltestosterone did not influence the position of hydroxylation.

Absidia↗

PubMed2003

Transformations of testosterone and related steroids by Botrytis cinerea.

Botrytis cinerea (strain AM235) was used to investigate the transformations of testosterone and related steroids. It was found that the position and stereochemistry of the introduced hydroxyl group, as well as the yield of products, depended on the structure of the substrate. Botrytis cinerea converts the examined substrates mainly to 7 alpha-hydroxy derivatives. 1-Dehydrotestosterone was also significantly hydroxylated at a 14 alpha-position.

Biotransformation↗

PubMedDate not supplied

Transformations of steroids by Beauveria bassiana.

The course of transformations of testosterone and its derivatives, including compounds with an additional C1,C2 double bond and/or a 17alpha-methyl group, a 17beta-acetyl group or without a 19-methyl group, by a Beauveria bassiana culture was investigated. The fungi promoted hydroxylation of these compounds at position 11alpha, oxidation of the 17beta-hydroxyl group, reduction of the C1,C2 or C4,C5 double bonds and degradation of the progesterone side-chain, leading to testosterone. The structure of 4-ene-3-oxo-steroids had no influence on regio- and stereochemistry of hydroxylation. In a similar manner, dehydroepiandrosterone was hydroxylated by Beauveria bassiana at position 11alpha, however, a small amount of 7alpha-hydroxylation product was also formed.

Ascomycota↗

PubMedDate not supplied

Surfactin isoforms from Bacillus coagulans.

Bacillus coagulans has been found to produce several surfactins that are powerful lipopeptide surfactants. Four main components with molecular weights 1007, 1021 and 1035 Da were separated. Their structures have been confirmed by spectrometric and spectroscopic studies and by acid hydrolysis. The compounds were found to represent two pairs of surfactin isoforms in which beta-hydroxy-iso-C14 or anteiso-C15 fatty acids are linked to the [Leu7] or [Val7] heptapeptide moiety by both an amide group and a lactone bond.

Amino Acids↗