RT Journal Article
SR Electronic
T1 Covalent Binding of Reactive Anhydride of Cantharidin to Biological Amines
JF Drug Metabolism and Disposition
JO Drug Metab Dispos
FD American Society for Pharmacology and Experimental Therapeutics
SP 775
OP 784
DO 10.1124/dmd.123.001637
VO 52
IS 8
A1 Fan, Yaya
A1 Chen, Lin
A1 Jing, Qiuyi
A1 Li, Xiaoli
A1 Pan, Hong
A1 Fang, Chao
A1 Zhang, Jianyong
A1 Shi, Fuguo
YR 2024
UL http://dmd.aspetjournals.org/content/52/8/775.abstract
AB Cantharidin is a terpenoid from coleoptera beetles. Cantharidin has been used to treat molluscum contagiosum and some types of tumors. Cantharidin is highly toxic, and cantharidin poisoning and fatal cases have been reported worldwide. The mechanisms underlying cantharidin-induced toxicity remain unclear. Cantharidin contains anhydride, which may react with biologic amines. This study aimed to examine the chemical reactivity of cantharidin toward nucleophiles and characterize adducts of cantharidin with biologic amines in vitro and in mice. Here two types of conjugates were formed in the incubation of cantharidin under physiologic conditions with free amino acids, a mimic peptide, or amine-containing compounds, respectively. Amide-type conjugates were produced by the binding of cantharidin anhydride with the primary amino group of biologic amines. Imide-type conjugates were generated from the dehydration and cyclization of amide-type conjugates. The structure of the conjugates was characterized by using high-resolution mass spectrometry. We introduced the 14N/15N and 79Br/81Br isotope signatures to confirm the formation of conjugates using L-(ε)15N-lysine, L-lysine-15N2, and bromine-tagged hydrazine, respectively. The structure of imide conjugate was also confirmed by nuclear magnetic resonance experiments. Furthermore, the amide and imide conjugates of cantharidin with amino acids or N-acetyl-lysine were detected in mouse liver and urine. Cantharidin was found to modify lysine residue proteins in mouse liver. Pan–cytochrome P450 inhibitor 1-aminobenzotriazole significantly increased the urine cantharidin-N-acetyl-lysine conjugates, whereas it decreased cantharidin metabolites. In summary, cantharidin anhydride can covalently bind to biologic amines nonenzymatically, which facilitates a better understanding of the role of nonenzymatic reactivity in cantharidin poisoning.SIGNIFICANCE STATEMENT Anhydride moiety of cantharidin can covalently bind to the primary amino group of biological amines nonenzymatically. Amide and imide conjugates were generated after the covalent binding of cantharidin anhydride with the primary amino groups of amino acids, a mimic peptide, and protein lysine residues. The structure of conjugates was confirmed by 14N/15N and 79Br/81Br isotope signatures using isotope-tagged reagents and nuclear magnetic resonance experiments. This study will facilitate the understanding of the role of nonenzymatic reactivity in cantharidin poisoning.