TY - JOUR

T1 - Selective Interactions of Cyclodextrins with Isomeric 1,2,4-Thiadiazole Derivatives Displaying Pharmacological Activity

T2 - Spectroscopy Study

AU - Brusnikina, Maria

AU - Chibunova, Ekaterina

AU - Silyukov, Oleg

AU - Chislov, Mikhail

AU - Volkova, Tatyana

AU - Proshin, Alexey

AU - Terekhova, Irina

PY - 2017/11/1

Y1 - 2017/11/1

N2 - Complex formation of α-, β- and γ-cyclodextrins with 1,2,4-thiadiazole derivatives, which are structural isomers displaying an activity in the treatment of Alzheimer’s disease, was examined by the use of 1H NMR and UV-spectroscopy. Stability constants of the complexes formed between cyclodextrins and thiadiazoles in two different buffers (pH 1.2 and 7.4) were calculated and analyzed. The temperature dependences of the stability constants were used to evaluate the enthalpy and entropy changes of complex formation. It was demonstrated that selectivity of the interactions between cyclodextrins and isometric 1,2,4-thiadiazole derivatives is determined by the size of macrocyclic cavity and relative position of the side groups in the benzene ring of the guest molecules. Higher stability of the complexes in the acidic medium (pH 1.2) in comparison with the slightly alkaline solution (pH 7.4) is caused by the important role of surface interactions.

AB - Complex formation of α-, β- and γ-cyclodextrins with 1,2,4-thiadiazole derivatives, which are structural isomers displaying an activity in the treatment of Alzheimer’s disease, was examined by the use of 1H NMR and UV-spectroscopy. Stability constants of the complexes formed between cyclodextrins and thiadiazoles in two different buffers (pH 1.2 and 7.4) were calculated and analyzed. The temperature dependences of the stability constants were used to evaluate the enthalpy and entropy changes of complex formation. It was demonstrated that selectivity of the interactions between cyclodextrins and isometric 1,2,4-thiadiazole derivatives is determined by the size of macrocyclic cavity and relative position of the side groups in the benzene ring of the guest molecules. Higher stability of the complexes in the acidic medium (pH 1.2) in comparison with the slightly alkaline solution (pH 7.4) is caused by the important role of surface interactions.

KW - Complex formation

KW - Cyclodextrin

KW - Spectroscopy

KW - Thermodynamics

KW - Thiadiazole

UR - http://www.scopus.com/inward/record.url?scp=85031926761&partnerID=8YFLogxK

U2 - 10.1007/s10953-017-0684-x

DO - 10.1007/s10953-017-0684-x

M3 - Article

AN - SCOPUS:85031926761

VL - 46

SP - 1970

EP - 1980

JO - Journal of Solution Chemistry

JF - Journal of Solution Chemistry

SN - 0095-9782

IS - 11

ER -