Abstract:
The present invention relates to a coupled biotransformation process of converting chenodeoxycholic acid (CDCA) and related compounds to ursodeoxycholic acid (UDCA) and related compounds. It also relates to the cloning, expression, and biochemical characterization of a novel NADP + -dependent 7α-hydroxysteroid dehydrogenase (7α-HSDH) from Clostridium difficile , cofactor switch mutants thereof, and their application for the oxidation of bile acids. A further aspect of the invention relates to novel NADP-dependent cofactor switch mutants of the NADP + -dependent 7α-HSDH of E. coli and their application for the oxidation of bile acids.
Abstract:
New process for the regioselective enzymatic oxidation of bile acids, salts or derivatives thereof, such as cholic acid, chenodeoxycholic acid or cholic acid methyl ester, by NAD (P) + -dependent hydroxysteroid dehydrogenase (HSDH) in the presence of an alcohol dehydrogenase (ADH) and of methyl acetoacetate as a co- substrate for the regeneration of the cofactor NAD(P) + .
Abstract:
A process for producing 1-methyl-1,4-androstadiene-3,17-dione characterized by the fact that 1-methyl-5alpha-androst-1-ene-3,17-dione (Metenolon) is fermented with a micro-organism culture of the genera Norcardia, Mycobacterim or Fusarium.
Abstract:
The invention relates to 12 a-hydroxysteroid dehydrogenases, nucleic acid sequences coding for the same, expression cassettes and vectors, recombinant microorganisms containing the corresponding coding nucleic acid sequences, a method for producing said 12 a-hydroxysteroid dehydrogenases, a method for enzymatic oxidation of 12 a-hydroxysteroids using said enzyme, a method for enzymatic reduction of 12-ketosteroids using said enzyme, a method for qualitative or quantitative determination of 12-ketosteroids and/or12a-hydroxysteroids using said 12a-hydroxysteroid dehydrogenases and a method for production of ursodesoxycholic acid, comprising the enzyme-catalysed cholic acid oxidation using said 12 a-hydroxysteroid dehydrogenases.
Abstract:
The invention relates to technology of microorganism. The invention declares a method of using cloud point system in biological transforming. The method forms a cloud point system below the microbiological transformating culturing temperature using one kind or more than one kind of nonionic surfactant solution, and said system acts as transformation medium of microorganism. The system is suitable to microbiological transformating of hydrophobe compound. The method of the invention has advantages of excluding the inhibition to the growing of cells with substrates and products. It also can exclude the decompound of products. The cloud point system in this invention forming a microcosmic emulsion in the state of oil in water and water in oil. The drop of surfactant can improve the solubility and the biological use ratio of substrates and exclude the inhibition to the growing of cells with substrates, and it is the storehouse of substrates and the extractant of products. There is some bleb in the continuous surfactant, which like a microreactor. The bleb can let the microorganism beyond the poisoning of surfactant, and improve the biological compatibility.
Abstract:
The description relates to a process for producing 4-pregnene-3,20-dione and its derivatives of general formula (I) in which: R1 is a hydrogen or fluorine atom or a methyl group; R2 is a hydrogen atom of a hydroxy group; and R3 and R4 together represent a carbon-carbon bond or R3 is a hydrogen atom, a hydroxy group or an alkanoyloxy group with up to 6 carbon atoms; and R4 is a hydrogen atom or a methyl group; whereby a pregnane derivative of general formula (II) in which: R1, R3 and R4 have the significance given above, ..... represents a single or double bond, R5 is a hydrogen atom, a hydroxy group or an alkanoyloxy group with a maximum of 6 carbon atoms, and R6 is a hydrogen atom or an alkanoyl group with a maximum of 6 carbon atoms, is fermented with a bacterial culture of the mycobacterium species, NRRL B-3805.
Abstract:
Die Erfindung betrifft neuartige 3α-Hydroxysteroid Dehydrogenase-Mutanten, die für diese Enzym-Mutanten kodierenden Sequenzen, Verfahren zur Herstellung der Enzym-Mutanten und deren Verwendung bei enzymatischen Umsetzungen von Cholsäureverbindungen, und insbesondere bei der Herstellung von Ursodesoxycholsaure (UDCS); Gegenstand der Erfindung sind auch neuartige Verfahren zur Synthese von UDCS unter Verwendung der Enzym-Mutanten; sowie die Herstellung von UDCS unter Verwendung rekombinanter, mehrfach modifizierter Mikroorganismen.
Abstract:
Ein Verfahren zur enantioselektiven enzymatischen Reduktion von Verbindungen, die eine Steroidstruktur (ABCD), einschließlich eines oder mehrerer Heteroatome, einer oder mehrerer Doppelbindungen und/oder eines Aromaten in der Ringstruktur, umfassen und mindestens eine Oxogruppe an der Position 3, 7, 11, 12 oder 17 des Steroidringsystems oder in α-Stellung an irgendeinem Kohlenstoffrest am Steroidgerüst aufweisen (=Oxosteroidverbindung/Hydroxysteroidverbindung), wobei die Oxosteroidverbindung mit einer Hydroxysteroiddehydrogenase in Gegenwart eines Cofactors NADH oder NADPH reduziert wird, ist dadurch gekennzeichnet, dass, a) die Oxosteroidverbindung in einer Konzentration von >50 g/l im Reaktionsansatz vorliegt, b) der durch die Hydroxysteroiddehydrogenase gebildete oxidierte Cofactor NAD oder NADP kontinuierlich durch Oxidation eines sekundären Alkohols der allgemeinen Formel R x R y CHOH, wobei R x , R y unabhängig voneinander Wasserstoff, verzweigtes oder unverzweigtes Cl-C8-Alkyl darstellen und C insgesamt ≥ 3, oder durch Oxidation eines C4-C6-Cycloalkanols regeneriert wird, und, c) zur Oxidation des sekundären Alkohols der allgemeinen Formel R X R Y CHOH bzw. des Cycloalkanols eine zusätzliche Oxidoreduktase/Alkoholdehydrogenase eingesetzt wird.