Structural characterization of the immunoactive and antiviral water-solubilized lignin in an extract of the culture medium of Lentinus edodes mycelia (LEM).

The active principle of EP3, a fraction from an extract of the culture medium of Lentinus edodes mycelia (LEM), which activates murine macrophages, causes proliferation of bone marrow cells, and inhibit the replication of Human Immunodeficiency Virus in vitro, was characterized as a water-solubilized lignin. The detailed structural feature of this water-solubilized lignin was investigated and shown to be a highly condensed and polycarboxylated lignin which is denatured and solubilized by Lentinus edodes from bagasse. The water-solubilized lignin itself was confirmed to have both immunological activities and the antiviral activity.