الفهرس 
Chemistry of rutheniumOnly 14 pages are availabe for public view
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Abstract
In this thesis, we studied binding of [Ru(NO)(Et2NpyS4)]Br complex
(RuNOTSP) and its ligand (TSP) as drugs with biomolecules BSA and DNA
using UV-Vis, fluorescence spectroscopy, Stopped-flow and molecular docking.
The thesis consists of three chapters as follows:
Chapter 1 provides a general information about ruthenium metal and their
complexes, ligand substitution, the kinetics of ruthenium compounds, and
different mechanisms of action. This gives them advantages over platinum-
based complexes. Then, we discuss the application of ruthenium in diverse
fields along with its physical and chemical properties. We focus on the
biomedical application which divided into treatment and diagnostic aspects.
Ruthenium and their complexes have anticancer, antimicrobial and
immunosuppressant activity. Also, they are used in determination of
cyclosporine, ferritin and folate level in human body. This study has focused
attention on the interaction between ruthenium nitrosyl complexes and BSA and
DNA as biological targets. Also, this chapter outlined importance of serum
albumin and deoxyribonucleic acid.
Chapter 2 includes the experimental details of the current study, which
includes: i) The material used in the current work; ii) Synthesis of ligand and
ruthenium nitrosyl complex; iii) Instruments and equipment. Also, details of the
biological investigations as Serum albumins and deoxyribonucleic acid binding
measurements, antibacterial activity and cytotoxicity. In addition, spectroscopic
technique, kinetic experiments details and computational studies are described.
Chapter 3 presents results and discussion. Our findings can be
summarized as follows:
Nitrosyl ruthenium complex RuNOTSP were synthesized in our lab as
reported previously via template alkylation of Bu4N[Ru(NO)(S2C6H4)2] with
Et2Npy(CH2Br)2 in boiling THF. RuNOTSP was characterized using UV-Vis,
IR, Mass spectroscopies conductivity measurements and compared with
published data. The interaction of the nitrosyl ruthenium complex RuNOTSP
and its ligand TSP with BSA were studied using stopped-flow, fluorescence
quenching, UV-Vis absorption studies, and molecular docking. Kinetic studies
of interaction of ligand and its complex with BSA using stopped-flow can be
summarized as follow: a first fast second-order binding and reversible step of
BSA binding including complex dissociation and formation was suggested for
all compounds. For the second reaction steps, a slow first-order isomerization
reaction, a reversible reaction step was observed for TSP whereas, an
irreversible reaction with RuNOTSP indicates that ligand-BSA complex is
more stable kinetically than complex-BSA complex. The ?G values for the
overall reaction are -10.5 kJ mol-1 for RuNOTSP and -7.4 kJ mol-1 for
RuNOTSP and TSP indicated the reaction is spontaneous for both compounds.
Fluorescence quenching of both compounds observed the presence of the static
quenching mechanism through complex formation. The quenching constant
(Ksv) of RuNOTSP calculated as 1.5 × 105 M-1 at 298 K is higher than the
corresponding Ksv of TSP, which is 9.4 × 104 M-1 that indicates high affinity of
the ligand towards BSA. TSP and its complex were checked for their
antibacterial activity against E. coli, P. aeruginosa, S. aureus and E. faecalis
bacteria where important activities were obtained with a good relationship to the
coordination affinity and the binding constants. The cytotoxic activity of both
compounds was tested against Hepatocellular carcinoma (HepG2) and normal
liver cell lines (BNL) at different concentrations by WST-1 assay. The results
showed that the survival of tumor cells increased with increasing concentration
and the cytotoxicity trend found Ru-NO complex is higher than ligand. The
molecular docking study illustrated that van der Waal, Pi-Alkyl interaction, and
the hydrogen bonding play an important role in BSA binding.
Also, the interaction of DNA with RuNOTSP and its ligand TSP are
studied by fluorescence quenching, UV-Vis absorption, stopped-flow, and
molecular docking. Fluorescence enhancement spectra of both compounds is
controlled by a static enhancement mechanism. The dynamic constant (KD) of
RuNOTSP calculated as 2.4 × 104 M-1 at 298 K is slight lower than the
corresponding KD of TSP, which is 2.7 × 104 M-1. The absorption spectra of
RuNOTSP and TSP decrease with increasing concentration of DNA. The
binding constant (kb) of RuNOTSP calculated as 4.05 × 104 L.mol-1 when TSP
is 1.77 × 104 L.mol-1. Kinetic studies of interaction of RuNOTSP and TSP with
DNA using stopped-flow via two different mechanisms, a fast reversible
followed by slow reversible steps were observed for RuNOTSP and TSP. The
optimized geometric structures of ligand and its metal complexes are in good
agreement with the experimental results. Molecular docking shows that
RuNOTSP and TSP interact in a parallel manner with the major groove of
DNA backbone through non-covalent interaction such as hydrogen bonding, van
der Waals and hydrophobic interactions. The obtained data indicate that
RuNOTSP has a higher activity than TSP.