Lophyrotomin, a new toxic octapeptide from the larvae of sawfly, Lophyrotoma interrupta.

Lophyrotomin, a new toxic octapeptide, has been isolated from sawfly (Lophyrotoma interrupta) larvae using solvent extraction, dialysis, adsorption on polyamide, ion exchange chromatography on DEAE cellulose and silica gel G chromatography. On the basis of evidence from chemical methods, pmr and mass spectrometry, a partial structure is proposed. Lophyrotomin has an approximate intraperitoneal LD50 of 2 mg/kg for mice.