Date of Award
Master of Science (MS)
Dr. Mohammad Ahmad Khasawneh
Haythem Ali Mohammad Saadah
Extensive literature survey reveals that 8-Hydroxyquinoline (8-HQ), urea, thiourea and piperazine exhibit wide biological activity profile such as anticancer, anti-Alzheimer, anti-viral, antibacterial and antifungal activity. Novel urea and thiourea-quinoline derivatives connected by piperazine moiety have been synthesized and purified using appropriate techniques (extraction, crystallization and column chromatography) followed by characterization using IR spectroscopy and NMR spectroscopy (both ³H and ¹³C).
Biological activity, metal chelation properties and the photo-physical properties were studied for these novel compounds. Anti-bacterial study shows moderate activity for most of the compounds against P.aereginosa, S.aureus and Enterococcus at concentration 250 μM. Antifungal study showed high potency activity for only compound, N-(4-chlorophenyl)-4-((8-hydroxyquinolin-5- yl)methyl)piperazine-1-carboxamide 62c against Botrytis cinerea which considered a high-risk of development of fungicide resistance.
Metal chelation studies showed strong interaction between these compounds and Cu²⁺ and Zn²⁺ metal ions. The trend of chelation strength for all compounds follows the trend (Cu²⁺ > Zn²⁺ > Fe³⁺), where the Cu²⁺ forms the most stable complex with all compounds. The stability of Fe³⁺complexes was the weakest among all of them. In the photophysical study, the compounds showed a photo-induced electron transfer (PET) occurring from the 8-HQ ring (donor) to urea and thiourea groups (acceptor) with the piperazine moiety serving as a spacer between them. It was assumed that the efficiency varied according to the molecular stacking, where the smaller size ring substituent resulted in higher PET efficiency. For the same reason, the efficiency of urea compounds was higher than those of thiourea.
The metal chelation and photophysical studies of these compounds are excellent indicators of the potential of these compounds in other biological activity which are to be done in the near future including anticancer, anti-Alzheimer, and anti- Parkinson diseases.
Jaarouf Alkaabi, Aysha Mohammed Subaih, "SYNTHESIS AND BIOLOGICAL APPLICATIONS OF SOME NOVEL UREA AND THIOUREA-QUINOLINE DERIVATIVES" (2019). Theses. 781.