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ARS Home » Southeast Area » Dawson, Georgia » National Peanut Research Laboratory » Research » Publications at this Location » Publication #175303


item Sobolev, Victor

Submitted to: Journal of Association of Official Analytical Chemists International
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/22/2005
Publication Date: 11/10/2005
Citation: Sobolev, V. 2005. Determination of pka and log p of cyclopiazonic acid. Journal of Association of Official Analytical Chemists International. 88:367-370

Interpretive Summary: Cyclopiazonic acid (CPA) is an important toxin produced by several molds. It may naturally contaminate peanuts and corn and has been found in cheese and poultry meat. CPA is toxic to animals and has been reported in kodo millet seeds that caused toxicosis in humans. The ability to form electrically charged molecules (pKa) and the fat-water distribution ratio (log P), the most important parameters in toxin research, have not been reported for CPA. Absorption, distribution, toxic buildup in fatty tissues, and excretion of CPA can be predicted if pKa and log P are known. Such knowledge also is very useful in CPA analytical method development. With the present research, pKa and log P of CPA were determined, and its possible absorption properties were suggested.

Technical Abstract: The ionization constant (pKa) and the octanol-water partition coefficient (log P) of the important mycotoxin cyclopiazonic acid (CPA) were determined by means of potentiometric titration, and the lipophilicity profile (log D) was calculated. Under the experimental conditions, pKa of CPA = 2.97±0.09; log P = 3.83±0.10; and log D at pH 7.4 = -0.58.