Abstract: The present invention is a novel process for the transformation of 17&agr;-hydroxy-6&agr;-methylpregn-4-ene-3,20-dione 17-acetate (I) to 11&bgr;,17&agr;,21-trihydroxy-6&agr;-methylpregna-1,4-diene-3,20-dione 21-acetate (VI)

Abstract: An expression cassette, operable in a recombinant host, comprising a heterologous DNA coding sequence encoding a protein, which is functional, alone or in cooperation with one or more additional proteins of catalyzing an oxidation step in the biological pathway, for conversion of cholesterol into hydrocortisone, which step is selected from the group consisting of: the conversion of cholesterol to pregnenolone; the conversion of pregnenolone to progesterone; the conversion of progesterone to 17&agr;-hydroxyprogesterone; the conversion of 17&agr;-hydroxyprogesterone to cortexolone; the conversion of cortexolone to hydrocortisone, and the corresponding control sequences effective in that host.

Abstract: An expression cassette, operable in a recombinant host, comprising a heterologous DNA coding sequence encoding a protein, which is functional, alone or in cooperation with one or more additional proteins, of catalyzing an oxidation step in the biological pathway for conversion of cholesterol into hydrocortisone, which step is selected from the group consisting a of:

Abstract: Novel cell lines and methods are provided for inducibly expressing the Hepatitis B virus (HBV) genome within cultured cells. Cells are stably transformed with an HBV genome under control of an operator/promoter target sequence which can activate expression of the HBV genome when bound by a cognate transactivator protein. The cell lines are also stably transformed with a gene that encodes and expresses a suitable transactivator protein. Cells may be maintained under non-inducing conditions whereby the transactivator protein is unable to interact with the operator/promoter target sequence, so the HBV genome is not expressed. Under appropriate inducing conditions, the transactivator protein is enabled to interact with the operator/promoter target sequence, thereby activating expression of the HBV genome. The inducible system provides an effective and rapid cell-based assay to screen compounds for anti-hepadnaviral activity.

Abstract: Disclosed herein is a method for preparing 11.beta., 17.alpha., 20, 21-tetrahydroxy steroids of the pregnane class. This method comprises incubating the corresponding 17.alpha., 20.alpha. or .beta., 21-trihydroxy steroid in the presence of a culture medium capable of effecting the 11.beta.-hydroxylation, such medium comprising a fungal culture of the genus Curvularia. Also disclosed herein is a method for preparing 11.beta., 17.alpha., 21-trihydroxy-20-oxo steroids of the pregnane class. This method comprises the hydroxylation method described hereinabove followed by conversion of the resulting 11.beta., 17.alpha., 20.alpha. or .beta., 21-tetrahydroxy steroid into the corresponding 11.beta., 17.alpha., 21-trihydroxy-20-oxo steroid.

Abstract: A biocatalyst contains microorganisms, e.g., of the species Arthrobacter simplex, Aspergillus ochraceus, Bacillus sphaericus, Curvularia lunata, Flavobacterium dehydrogenans, Mycobacterium spec., or Saccharaomyces uvarum, immobilized on a copolymer of acrolein and 1-vinyl-2-pyrrolidone, crosslinked by reaction with an alkylenedioxydiamine of the formulaH.sub.2 NO--(CH.sub.2).sub.n ONH.sub.2wherein n is a number of 2 to 12. The preparation of steroids is also disclosed.

Abstract: Microbiological conversions of cyclodextrins are intensified by adding to the reaction mixture 0.2 to 3 moles of .alpha.-, .beta.- or .gamma.-cyclodextrin or an optical mixture thereof pro mole of the steroid substrate, before, at the beginning or during the conversion. The cyclodextrin if desired, can be removed after the reaction. In this way the reaction velocity can be increased, the reaction time is reduced, the substrate concentration in the solution, i.e. its solubility is increased or the so called product inhibition may be avoided. In certain cases of more alternatives the desired reaction can be catalyzed and in this manner the selectivity is increased.

Abstract: A process for preparing an 11.beta.-hydroxy steroid of the formula ##STR1## wherein represents a single bond or a double bond;X is hydrogen, fluorine, chlorine or methyl; andV is methylene, ethylene, ethylidene or vinylidene;comprises fermenting an 11-deoxy steroid of the formula ##STR2## wherein , X and V are as defined above,R.sub.1 is hydrogen or C.sub.1-6 -alkyl; andR.sub.2 is C.sub.1-6 -alkyl;with a fungal culture of a genus Curvularia.

Abstract: A method for activating immobilized living microorganisms applied to transformations of steroids, antibiotics and other compounds characterized by the addition of peptone, glucose or a mixture of peptone and glucose to the reaction mixture.