Universität zu Köln

Hohnsen, Johannes (2026). Functionalization of Thiosemicarbazones for Biomedical Applications. PhD thesis, Universität zu Köln.

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Abstract

Thiosemicarbazones (TSCs) are organosulfur compounds which are frequently investigated as multidentate ligands in coordination chemistry. The huge interest in these compounds is based on their biological activity which includes antimicrobial and antitumor properties. Especially the latter are often of interest since several TSCs have entered clinical trails in the past. However, most of the compounds have a limited selectivity and water solubility, which needs further optimization. During this research a total of 83 new TSCs and 24 metal complexes (Cu(II), Pt(II) and Fe(III)) have been synthesized, whereby the N1 and N4 positions were functionalized. In addition, many new isothiocyanates and thiosemicarbazides have been synthesized. Beside this investigation of the ligand design, the idea of this work was to investigate concepts for improving the medical performance of TSCs: 1) by their conjugation to nanoparticles and 2) biomolecules, 3) their labeling with fluorescence markers, 4) their design towards amphiphilic structures, 5) increasing their coordination sphere to hexadentate ligands and 6) tuning the Fe(II)/(III) redox potential of α-pyridyl TSC as well as their conjugation to TiO2 nanoparticles.

Item Type:	Thesis (PhD thesis)
Translated title:	Title Language Funktionalisierung von Thiosemicarbazonen für biomedizinische Anwendungen German
Creators:	Creators Email ORCID ORCID Put Code Hohnsen, Johannes JohannesHohnsen@web.de UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-798229
Date:	2026
Language:	English
Faculty:	Faculty of Mathematics and Natural Sciences
Divisions:	Faculty of Mathematics and Natural Sciences > Department of Chemistry > Institute of Inorganic Chemistry
Subjects:	Chemistry and allied sciences Medical sciences Medicine
Uncontrolled Keywords:	Keywords Language Thiosemicarbazones English Bioconjugation English Nanoconjugation English Anticancer English Fluorescent tag English Metal complexes English
Date of oral exam:	4 February 2026
Referee:	Name Academic Title Klein, Axel Prof. Dr. Mathur, Sanjay Prof. Dr.
Refereed:	Yes
URI:	http://kups.ub.uni-koeln.de/id/eprint/79822