Does the degree of substitution on the cyclodextrin hosts impact their affinity towards guest binding?
Photochem Photobiol Sci
; 19(7): 956-965, 2020 Jul 01.
Article
em En
| MEDLINE
| ID: mdl-32519735
ABSTRACT
Although cyclodextrins have been extensively utilized in various branches of supramolecular chemistry due to their numerous attractive attributes, however, to achieve even advanced applications, they often need structural modification through substitutions of suitable functional groups at their rims. A systematic investigation on how the degree of substitution on the cyclodextrin rims affects the binding affinity for a given guest molecule has however rarely been reported, especially from the perspective of photophysical studies. Herein, we report the non-covalent interaction of a styryl based dye, LDS-798, with three different sulfobutylether beta cyclodextrin (SBEnßCD) derivatives bearing varying degrees of substitution (n), using ground state absorption, steady-state emission, excited-state lifetime and time-resolved fluorescence anisotropy measurements. The dye-host binding constant values indicate that the strength of the interaction between LDS-798 and SBEnßCD derivatives follows an increasing trend with an increasing number of tethered sulfobutylether substituents on the cyclodextrin rims, which is attributed to the gradual increase of the electrostatic interaction between the negatively charged sulfobutylether groups and the positively charged LDS-798. Excited state lifetime measurements and ionic strength dependent studies on the dye-SBEnßCD complexes further support the increased affinity between the dye and the host in the supramolecular complexes, with an increasing number of sulfobutylether substituents on the ßCD rims. The obtained results suggest that the molecular recognition of LDS-798 with SBEnßCD derivatives can be tuned very effectively by varying the number of sulfobutylether substituents on the cyclodextrin rims. Considering that SBE7ßCD is one of the FDA approved agents for drug formulations, the obtained results with other SBEnßCD hosts may be useful in designing selective drug delivery applications, drug formulations, and effective fluorescence on-off switches.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Compostos de Quinolínio
/
Ciclodextrinas
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Corantes Fluorescentes
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Compostos de Anilina
Idioma:
En
Revista:
Photochem Photobiol Sci
Assunto da revista:
BIOLOGIA
/
QUIMICA
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
Índia