Phalloin

Phalloin and gamma-amanitin were detected within the 1st day and phalloidin within the 2nd day in the urine of rats after the administration of amanita phalloides extracts. [HSDB] Intraperitoneal LD50 (mouse) = 1 mg/kg; [RTECS] See Phalloidin.

THE HISTORY OF TOXIC COMPONENTS MAY BE DIVIDED INTO 2 PERIODS. THE 1ST STUDIES BEGAN IN THE LATE 18TH CENTURY AND RESULTED IN DISTINGUISHING BETWEEN NON-TOXIC HEMOLYSIN OR PHALLINE, AND A POORLY DEFINED TOXIC COMPOUND. THE 2ND PERIOD BEGAN WITH THE ISOLATION OF PHALLOIDINE IN 1937, FOLLOWED BY ISOLATION OF ALPHA, BETA AND GAMMA AMANITINE AND PHALLOINE. CLASSIFICATION, STRUCTURE, CONCENTRATIONS, TOXICITY IN ANIMALS AND STRUCTURE-ACTIVITY RELATIONSHIPS ARE DISCUSSED FOR THESE. ALSO REVIEWED ARE DATA ON SYNTHESIS OF TOXIN CONSTITUENTS, RESEARCH ON THE ANTITOXIN, ANTAMANIDE.[THEVENIN M ET AL; AMANITA PHALLOIDES AND ITS TOXINS: I. REVIEW OF RESEARCH ON THE IDENTITY OF THE TOXIC COMPONENTS; EUR J TOXICOL ENVIRON HYG 9(4) 197 (1976)]

Phallotoxins bind actin, preventing its depolymerization and poisoning the cell. They bind specifically at the interface between F-actin subunits, locking adjacent subunits together. This leads to a decrease in the rate constant for the dissociation of actin subunits from filament ends, which essentially stabilizes actin filaments through the prevention of filament depolymerization. Moreover, they inhibit the ATP hydrolysis activity of F-actin. (L1183, A2465)

Oligopeptide similar to phalloidin. [ChemIDplus]

Prophalloin is one of a group of toxins from the death cap (Amanita phalloides) known as phallotoxins. (L996)

COUPLING OF THE S-CHLORIDE OF BOC TERT-BUTYLOXYCARBONYL-ALANYL-D-THREONYL-CYSTEINYL-ALLO-HYDROXYPROLINE WITH ALANYL-TRYPTOPHYL-GAMMA-HYDROXYLEUCINE LACTONE GAVE A THIOETHER, WHICH ON CYCLIZATION YIELDED BOC-SECOPHALLOIN LACTONE. REMOVAL OF THE BOC RESIDUE, OPENING OF THE LACTONE RING AND A 2ND CYCLIZATION LED TO PHALLOIN, WHICH PROVED IDENTICAL WITH THE NATURAL TOXIN IN PHYSICAL AND TOXICOLOGICAL RESPECTS.