Anti-viral isolates obtainable from leeches

A method for obtaining an extract having inhibiting activity towards a human immunodeficiency virus, comprising:

• preparing a suspension from tissue of a leech from the family hirudinidae;
• fractionating the suspension;
• and
• selecting as the extract a protein-free fraction which exhibits a molecular weight in the range of 300 to about 600 Dalton and exhibits inhibiting activity towards a human immunodeficiency virus;
• and wherein said fraction is selected from the group of

A method of obtaining an extract having inhibiting activity toward a human immunodeficiency virus, comprising:

• preparing a suspension from tissue of a leech from the family hirudinidae;
• fractionating the suspension;
• and
• selecting as the extract a protein-free fraction which exhibits a molecular weight in the range of 300 to about 600 Daltons and exhibits inhibiting activity towards a human immunodeficiency virus;
• and wherein said extract is of the formula Ar1-spacer-Ar2, wherein Ar1 is a six ring aromatic which is substituted with one or more of a hydroxyl group, an amino group, a C1-4 alkyl group, or a halogen wherein—spacer—is a C3-8 alkyl alkylene group coupled through a hydrophilic group to said Ar1 group, and further wherein Ar2 is a heteroaromatic 2-ringsystem of carbon and nitrogen atoms, said 2-ringsystem having form 9 to 10 atoms in a purine-like or naphthalene-like ringsystem, and said 2-ringsystem is substituted with one or more of a C3-8 alkyl group, a hydroxy group, an amino group, or a halogen group.