A revised amino group pK a for prymnesins does not provide decisive evidence for a pH-dependent mechanism of Prymnesium parvum’s toxicity

Abstract: A reconsideration of the pKa values proposed by Valenti et al. (Theodore W. Valenti et al., A mechanistic explanation for pH-dependent ambient aquatic toxicity of Prymnesium parvum carter. Toxicon (2010) 55, 990–998) suggests that the ionization status of the C-14 amino group in prymnesins will not substantially influence the toxicity of these compounds over a pH range of 6.5–8.5. A revised pKa value and ionization state distribution for the prymnesins in aqueous systems is proposed. [Copyright &y& Elsevier]