Antiviral substance from silkworm faeces: purification and its chemical characterization.

In a previous paper, we reported that an extract of silkworm faeces has a marked antiviral activity on enveloped viruses, but not on a non-enveloped virus, and we showed that it inhibits the synthesis of a viral specific gene of HVJ (Sendai virus) without affecting the viral adsorption and entry into the host cell. In this paper, we accomplished the purification of an antiviral active substance by extraction of a hydrophobic substance and thin layer chromatography. The active substance was found to be a chlorophyll-like substance with a molecular mass of about 530. This substance shows clear antiviral activity against HVJ, HSV (herpes simplex virus type-1), and HIV (human immunodeficiency virus type-1). Its antiviral activity was dependent on light irradiation and temperature. Furthermore, it also possesses a strong hemolytic activity under light.