Spectroscopic Techniques to StuOptical Properties and Interaction of Some Drugs With Bioactive Compound of Coffee Beans
No Thumbnail Available
Date
2018-06-22
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Ababa University
Abstract
Drug-drug/food interactions are major source of patient’s inconvenience and non-adherence
through disruption in a patient’s daily schedule. Hence, lack of knowledge of potentially
significant drug-drug/food interactions lead to poor clinical outcomes. Thus, investigation
of different incompatibilities of drugs using spectroscopic techniques is most
important inquiry of solving these problems. For this reason, the optical transition probabilities
and interactions of some drugs (nicotinamide (NIC), neomycin sulfate (NOMS),
norfloxacin (NOR) and ciprofloxacin (CIP)) with biologically active compounds of coffee
beans (chlorogenic acid (CGA) and caffeine (CAF)) have been investigated using
Ultraviolet visible (UV-Vis) absorption and fluorescence spectroscopic techniques. From
the UV-Vis spectroscopic technique, the self-, hetero-association, thermodynamic properties,
and optical transition probabilities of the drugs were investigated in aqueous solution.
The parameters were analysed using Dimer model and Bensi-Hildebrand equations
respectively for the self-and hetero-associations. The obtained equilibrium dimerization
constant (KC) values are 2.379 _ 104, 1.06 _ 105, 5.424 _ 103, 4.377 _ 103, 4.3135 _
103 and 6.67 _ 103M1 for NIC, NOMS, NOR, CIP, interaction of nicotinamide with
chlorogenic acid (NIC-CGA), and interaction of norfloxacin with caffeine (NOR-CAF)
respectively. In order to understand the interaction mechanisms of the self and heteroassociations,
thermodynamic properties were determined using Vant’s Hoff’s equation.
The molar enthalpy changes were found to be 4.826_0.415, 3.76_0.66, (5.35_0.459),
(1.98 _ 0.25),(16.927 _ 0.836) and (1.277 _ 0.103)kJ.mol1 for NIC, NOMS, NOR,
CIP, NIC-CGA and NOR-CAF respectively. Thus, hydrophobic interactions are dominant
for the interaction of NIC and NOMS molecules, and electrostatic forces play the
major role in the interactions of NOR, CIP, NIC-CGA and NOR-CAF molecules. The op-
(Copyright C Ataklti Abraha June 22, 2018) vi
vii
tical transition probabilities of the drugs were determined using integrating absorption
technique from the absorption spectra of the drugs. The values of the oscillator strengths
are 0.07, 0.1,0.37 and 0.46 for NIC, NOMS, NOR and CIP respectively. Besides, the binding
of CAF with NIC using fluorescence quenching technique was analysed at temperatures
of 295 and 303 K and it was confirmed with the absorption spectra of the binding
molecules. From this fluorescence quenching spectral analysis the quenching constant
(1.775_104L/mol), quenching rate constant (5.052_1013L/mol/s) and number of binding
sites 0.88 were determined at 295 K. The thermodynamic properties of interaction of
nicotinamide with caffeine (NIC-CAF) indicates that electrostatic forces play the major
rule in the binding of the molecules. The effect of solvent polarity on the absorption and
fluorescence spectra of NIC were investigated. The ground state and excited state dipole
moments of NIC are estimated from solvatochromic shifts of absorption and fluorescence
spectra as a function of the dielectric constant and refractive index functions. Thus, the
ground and excited dipole moments were found to be 0.02D and 0.268D respectively using
Bilot-Kawski method. The excited state dipole moment is found to be higher than
those of ground state for all of the used methods, and the higher values are attributed
to more polar excited state of NIC. Therefore, the results of the study are very important
for understanding the binding reaction in biological system, nature and strength of the
transition, absorption spectral interpretation, and in providing stringent test of atomic
and molecular structure calculations for theoretical work of the compounds. Thus, understanding
the interaction properties of the drugs may help in the field of pharma technology
and food companies in improving the efficiency and the capabilities of absorption
of the drugs in biological system and in induce rapid recovery of patient’s.
Description
Keywords
Spectroscopic, Techniques to Study the Optical Properties, Interaction, Some Drugs With Bioactive, Compound of Coffee Beans