Patents by Inventor Roelof W. Liebenberg

Roelof W. Liebenberg 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: 5609874
    Abstract: This invention relates to a method and means for the treatment of a viral infection and for reducing the rate of decrease in CD4 lymphocyte counts in a subject having a viral infection. It relates, in particular, to a use of an extract of corms of the family Hypoxidaceae in the preparation of a medicament for the treatment of a viral infection; to the use of the said extract in the preparation of a medicament for reducing the rate of decrease of CD4 lymphocyte counts in a subject with a viral infection; to a method of treating a viral infection, to a method of reducing the rate of decrease in CD4 lymphocyte counts in a subject having a viral infection; to a medicament for the treatment of a viral infection, and to a medicament for reducing the rate of CD4 lymphocyte counts in a subject having a viral infection.
    Type: Grant
    Filed: March 6, 1995
    Date of Patent: March 11, 1997
    Assignee: Virostat (NA) NVQ
    Inventors: Roelof W. Liebenberg, Petrus B. Kruger, Patrick J. D. Bouic, Carl F. De Vos Albrecht
  • Patent number: 4652636
    Abstract: The invention relates to the treatment and prevention of cancerous conditions by the administration of a composition including the compound of the formula: ##STR1## or of an aqueous, alcoholic or aqueous alcoholic or other extracts of plants of the Hypoxidaceae family and particularly the plants of the genus Hypoxis and the genus Spiloxene.
    Type: Grant
    Filed: May 2, 1985
    Date of Patent: March 24, 1987
    Assignee: Roecar Holdings
    Inventors: Siegfrid Drewes, Roelof W. Liebenberg
  • Patent number: 4644085
    Abstract: The invention relates to a new anti-cancer chemical compound which has been called rooperol and certain derivatives thereof of the general formula ##STR1## in which A is chosen from the group including a phenyl group, a substituted phenyl group and --CH.sub.2 --O--R.sup.5 where R.sup.5 =H, an alkyl (C.sub.1 -C.sub.5), aralkyl or acyl substituent; R.sup.1 and R.sup.2 are chosen from substituents including H for both or singly if one of them is --OH, --NH.sub.2, --SH, ##STR2## or taken together R.sup.1 and R.sup.2 are =0; R.sup.3 is H or ##STR3## where R.sup.6 is an alkyl group (C.sub.1 -C.sub.7); either of R.sup.4 or B are chosen from substituents including H, ##STR4## a phenyl group, substituted phenyl group or a furyl group.
    Type: Grant
    Filed: June 4, 1985
    Date of Patent: February 17, 1987
    Assignee: Rooperol (NA) NV
    Inventors: Siegfried Drewes, Roelof W. Liebenberg