Supramolecular Interaction of Primaquine with Native
β-Cyclodextrin
M. Murugan
1,3
·
A. Anitha
1,4
·
K. Sivakumar
5
·
R. Rajamohan
1,2
Received: 19 September 2017 / Accepted: 27 March 2018 / Published online: 22 May 2018
© Springer Science+Business Media, LLC, part of Springer Nature 2018
Abstract The supramolecular host–guest inclusion complex of Primaquine (PQ) with the
nano-hydrophobic cavity of beta-cyclodextrin (β-CD) was prepared by physical mixing,
kneading and co-precipitation methods. The formation of an inclusion complex in PQ with
β-CD in the solution phase has been confirmed by UV–visible and fluorescence spec-
troscopy. The stoichiometry of the inclusion complex is 1:1; the Primaquine molecule is
deeply entrapped in the cavity of β-cyclodextrin, which was confirmed by analysis of
spectral shifts and corresponding absorbance and fluorescence intensities. The Benesi–
Hildebrand plot was used to calculate the binding constant of the inclusion complex of PQ
with β-CD at room temperature. The Gibbs energy change of the inclusion complex
process has been calculated. The pK
a
and pK
Ã
a
for the monocation and neutral equilibrium
of PQ in aqueous and β-CD media are discussed. The thermal stability for the inclusion
complex of PQ with β-CD has been analyzed using differential scanning calorimetry. The
modification of the crystal structure to amorphous for the solid inclusion complex was
confirmed by powder X-ray diffraction. The structure of the complex is proposed by
docking studies using the Patch-Dock server. A cytotoxic analysis was also carried out for
the pure PQ and its solid complex on the MDA MB 231 cell line and showed that the
activity is good for both substances. The cytotoxicity neither improved nor decreased with
the formation of the inclusion complex with β-CD.
Keywords Primaquine · β-CD · Acidity constants · DSC · Patch-Dock server · In-vitro
anticancer activity
& R. Rajamohan
rajmohanau@gmail.com
1
Research and Development Centre, Bharathiar University, Coimbatore, Tamil Nadu 641 046, India
2
Department of Chemistry, SKP Engineering College, Tiruvannamalai, Tamil Nadu 606 611, India
3
Department of Chemistry, IFET College of Engineering, Villupuram, Tamil Nadu 605 108, India
4
Department of Chemistry, Government Arts College, Chidambaram, Tamil Nadu 608 102, India
5
Department of Chemistry, SCSVMV University, Kanchipuram, Tamil Nadu 631 561, India
123
J Solution Chem (2018) 47:906–929
https://doi.org/10.1007/s10953-018-0768-2
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