Patents by Inventor Hans-Peter Schar

Hans-Peter Schar has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5183749
    Abstract: The present invention relates to a one-step microbial process for the preparation of 13.beta.-hydroxy- or 14,15-epoxy-milbemycins of the following formulae I and II ##STR1## in which R.sub.1 and R.sub.1 ' represent methyl, ethyl, isopropyl or sec.-butyl or represent the group ##STR2## in which X represents methyl, ethyl or isopropyl, and A and A' represent the group ##STR3## in which R.sub.2 represents hydrogen, --C(O)-CH.sub.2 O-C(O)-CH.sub.2 CH.sub.2 -COOH or --C(O)-CH.sub.2 CH.sub.2 -COOH, or mixtures of compounds of the formulae I and II, which process comprises bringing a milbemycin of the formula III ##STR4## dissolved in a liquid phase, in which R.sub.3 represents R.sub.1 or R.sub.1 ' and R.sub.4 represents A or A', and R.sub.1, R.sub.1 ', A and A' have the meanings given for formulae I and II, into contact with a microorganism that is capable of 13.beta.-hydroxylation or 14,15-epoxidation or of both reactions, or into contact with active constituents thereof.
    Type: Grant
    Filed: March 20, 1990
    Date of Patent: February 2, 1993
    Assignee: Sankyo Company, Ltd.
    Inventors: Gerado Ramos, Oreste Ghisalba, Hans-Peter Schar, Bruno Frei, Peter Maienfisch, Anthony C. O'Sullivan
  • Patent number: 5098841
    Abstract: The invention relates to a preferably continuous process for the preparation of R- or S-2-hydroxy-4-phenylbutyric acid in very high enantiomeric purity, which comprises reducing 2-oxo-4-phenylbutyric acid with the enzyme D-lactate dehydrogenase from Staphylococcus epidermidis or with the enzyme L-lactate dehydrogenase from bovine heart, respectively, in the presence of NAD(H) and formate or ethanol and formate dehydrogenase or alcohol dehydrogenase, respectively. R-2-hydroxy-4-phenylbutyric acid is a valuable intermediate in the preparation of ACE inhibitors or their precursors.
    Type: Grant
    Filed: June 2, 1989
    Date of Patent: March 24, 1992
    Assignee: CIBA-GEIGY Corporation
    Inventors: Oreste Ghisalba, Daniel Gygax, Rente Lattmann, Hans-Peter Schar, Elke Schmidt, Gottfried Sedelmeier