Evidence that phomopsins A and B are not the only toxic metabolites produced by Phomopsis leptostromiformis

✍ Scribed by J. G. Allen; G. R. Hancock

• Book ID: 102873660
• Publisher: John Wiley and Sons
• Year: 1989
• Tongue: English
• Weight: 545 KB
• Volume: 9
• Category: Article
• ISSN: 0260-437X
• DOI: 10.1002/jat.2550090203

✦ Synopsis

The toxicities of up to four different toxic preparations containing metabolites of Phomopsis leptostromiformis were examined in two experiments with sheep and one with rats. It was shown that the different toxic preparations containing similar amounts of phomopsin A varied substantially in toxicity. Crystalline phomopsin A was the least toxic. It is suggested that the increased toxicity of the other three preparations was due to the presence of toxic metabolites additional to phomopsins A and B. Evidence to support this suggestion is presented.

Animal experiments

Toxicity ratings using a sheep bioassay. The toxicity ratings of various dose rates of phomopsin A in each of the toxic preparations were evaluated using a sheep b i o a ~s a y . ~ This bioassay has been extensively used previously to determine the toxicity of lupin stubbles. lupin hays and lupin seeds. It involves the oral administration of 300, 300, 300, 200 and 200 g of the test sample to each of three sheep over five consecutive days. The sheep are killed 72 h after the last administration and the microscopic pathology present in each liver awarded a score on a scale of 0-45.