Complexation of AAPH (2,2′-azobis(2-methylpropionamidine) dihydrochloride) with cucurbit[7]uril enhances the yield of AAPH-derived radicals
Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
Standard
Complexation of AAPH (2,2′-azobis(2-methylpropionamidine) dihydrochloride) with cucurbit[7]uril enhances the yield of AAPH-derived radicals. / Forero-Girón, Angie C.; Fuentealba, Denis; Mariño-Ocampo, Nory; Gutiérrez-Oliva, Soledad; Herrera, Barbara; Toro-Labbé, Alejandro; Fuentes-Lemus, Eduardo; Davies, Michael J.; Aliaga, Margarita E.; López-Alarcón, Camilo.
I: Journal of Molecular Liquids, Bind 389, 122840, 2023.Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
Harvard
APA
Vancouver
Author
Bibtex
}
RIS
TY - JOUR
T1 - Complexation of AAPH (2,2′-azobis(2-methylpropionamidine) dihydrochloride) with cucurbit[7]uril enhances the yield of AAPH-derived radicals
AU - Forero-Girón, Angie C.
AU - Fuentealba, Denis
AU - Mariño-Ocampo, Nory
AU - Gutiérrez-Oliva, Soledad
AU - Herrera, Barbara
AU - Toro-Labbé, Alejandro
AU - Fuentes-Lemus, Eduardo
AU - Davies, Michael J.
AU - Aliaga, Margarita E.
AU - López-Alarcón, Camilo
N1 - Publisher Copyright: © 2023 Elsevier B.V.
PY - 2023
Y1 - 2023
N2 - AAPH (2,2′-azobis(2-methylpropionamidine) dihydrochloride), a water-soluble azo compound is widely employed to produce peroxyl radicals for chemical and biological studies. This compound is shown herein to form a stable inclusion complex with cucurbit[7]uril (CB7), a well-established supramolecular host. Competitive binding assays using berberine dye, isothermal titration calorimetry (ITC), and nuclear magnetic resonance (1H NMR) experiments, provided evidence for the inclusion of AAPH inside the CB7 cavity with a binding constant of 2.51 ± 0.76 × 105 M−1 (determined by ITC). Computational analysis at B3LYP-D3BJ/6-311G(d,p) of the complex (AAPH@CB7) showed interactions of the positively-charged amino groups of AAPH with carbonyl functions at the CB7 entrances. Photolysis of AAPH@CB7 by illumination at 365 nm, gave a higher yield of carbon-centered radicals when compared to the absence of CB7, as evidenced by electron paramagnetic resonance spin trapping using α-phenyl-N-t-butylnitrone. Enhanced radical formation was corroborated by increased consumption of pyrogallol red, free Trp and Trp-containing peptides when these were exposed to AAPH@CB7 in the presence of light. The increased yield of radicals generated by AAPH@CB7 is believed to arise from a pull effect of CB7 portals on initial AAPH-derived carbon-centered radicals generated by photolysis. It is proposed that these radicals are exposed and released to the bulk solution and react with O2 to give peroxyl radicals. These results suggest that the AAPH@CB7 complex can be used to generate high yields of peroxyl radicals for their use in studying these species in material, environmental and biomedical sciences amongst others.
AB - AAPH (2,2′-azobis(2-methylpropionamidine) dihydrochloride), a water-soluble azo compound is widely employed to produce peroxyl radicals for chemical and biological studies. This compound is shown herein to form a stable inclusion complex with cucurbit[7]uril (CB7), a well-established supramolecular host. Competitive binding assays using berberine dye, isothermal titration calorimetry (ITC), and nuclear magnetic resonance (1H NMR) experiments, provided evidence for the inclusion of AAPH inside the CB7 cavity with a binding constant of 2.51 ± 0.76 × 105 M−1 (determined by ITC). Computational analysis at B3LYP-D3BJ/6-311G(d,p) of the complex (AAPH@CB7) showed interactions of the positively-charged amino groups of AAPH with carbonyl functions at the CB7 entrances. Photolysis of AAPH@CB7 by illumination at 365 nm, gave a higher yield of carbon-centered radicals when compared to the absence of CB7, as evidenced by electron paramagnetic resonance spin trapping using α-phenyl-N-t-butylnitrone. Enhanced radical formation was corroborated by increased consumption of pyrogallol red, free Trp and Trp-containing peptides when these were exposed to AAPH@CB7 in the presence of light. The increased yield of radicals generated by AAPH@CB7 is believed to arise from a pull effect of CB7 portals on initial AAPH-derived carbon-centered radicals generated by photolysis. It is proposed that these radicals are exposed and released to the bulk solution and react with O2 to give peroxyl radicals. These results suggest that the AAPH@CB7 complex can be used to generate high yields of peroxyl radicals for their use in studying these species in material, environmental and biomedical sciences amongst others.
KW - AAPH
KW - Azocompounds
KW - Cucurbit[7]uril complexes
KW - Peroxyl radicals
KW - Supramolecular radical chemistry
UR - http://www.scopus.com/inward/record.url?scp=85168423432&partnerID=8YFLogxK
U2 - 10.1016/j.molliq.2023.122840
DO - 10.1016/j.molliq.2023.122840
M3 - Journal article
AN - SCOPUS:85168423432
VL - 389
JO - Journal of Molecular Liquids
JF - Journal of Molecular Liquids
SN - 0167-7322
M1 - 122840
ER -
ID: 365958857