The Ability of Chlorophyll to Trap Carcinogen Aflatoxin B1: A Theoretical Approach

• Published in: International journal of molecular sciences Vol. 23; no. 11; p. 6068
• Main Authors: Vázquez-Durán, Alma, Téllez-Isaías, Guillermo, Hernández-Rodríguez, Maricarmen, Ruvalcaba, René Miranda, Martínez, Joel, Nicolás-Vázquez, María Inés, Aceves-Hernández, Juan Manuel, Méndez-Albores, Abraham
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 28-05-2022; MDPI
• Subjects: Aflatoxin B1; Aflatoxins; Carcinogens; Charge transfer; Chemical activity; Chlorophyll; chlorophyll a; density functional theory; Electrostatic properties; intermolecular interactions; M06-2X functional; Mass spectrometry; molecular modeling; Molecular orbitals; Nitrogen; Performance evaluation; Porphyrins; Scientific imaging
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms23116068

The coordination of one and two aflatoxin B1 (AFB1, a potent carcinogen) molecules with chlorophyll a (chl a) was studied at a theoretical level. Calculations were performed using the M06-2X method in conjunction with the 6-311G(d,p) basis set, in both gas and water phases. The molecular electrostatic potential map shows the chemical activity of various sites of the AFB1 and chl a molecules. The energy difference between molecular orbitals of AFB1 and chl a allowed for the establishment of an intermolecular interaction. A charge transfer from AFB1 to the central cation of chl a was shown. The energies of the optimized structures for chl a show two configurations, unfolded and folded, with a difference of 15.41 kcal/mol. Chl a appeared axially coordinated to the plane (α-down or β-up) of the porphyrin moiety, either with the oxygen atom of the ketonic group, or with the oxygen atom of the lactone moiety of AFB1. The complexes of maximum stability were chl a 1-α-E-AFB1 and chl a 2-β-E-AFB1, at −36.4 and −39.2 kcal/mol, respectively. Additionally, with two AFB1 molecules were chl a 1-D-2AFB1 and chl a 2-E-2AFB1, at −60.0 and −64.8 kcal/mol, respectively. Finally, biosorbents containing chlorophyll could improve AFB1 adsorption.