Phenol—water extracts of gram-positivelisteria monocy togenes and gram-negativesalmonella typhimurium. comparison of biological activities

Using phenol—water extraction, a lipopeptidopolysacoharide complex (LPPS) was isolated fromListeria monocytogenes. Some biological and immunological properties of LPPS were compared with lipopolysaccharide isolated by the same procedure fromSalmonella typhimurium. LPPS possesses low pyrogenicity, but the immunological activity is comparable with LPS: slightly lower adjuvant and polyolonal stimulating effect, almost equal mitogenic effect on mouse spleen cells and higher mitogenic effect oh human peripheral blood cells, The results are discussed in connection with the chemical structure of both substances.