The first section of this work describes the synthesis of a library of novel rhein analogues that are potential anticancer agents. The design of these compounds takes advantage of the ability for rhein to intercalate into DNA and as the incorporation of an alkylating agent, which serves to covalently modify DNA. In three cell lines, these compounds showed potent cytotoxicity with IC50 in the low to mid-μM range. The second project was focused on the development of an efficient synthesis of 6H-Isoindolo[2,1-α]indol-6-one (24), a core structure for a number of biologically active compounds. The approach is metal-free and uses a Beckmann rearrangement followed by an intramolecular cyclization.

Our laboratory has used the 1,4,5,8 Naphthalenetetracarboxylic diimine (NDI) unit to develop threading polyintercalators that bind DNA with the NDI units intercalated in between GpG steps and two different peptide linkers, which connect the NDI units, situated in either the major or minor grooves. The first generation bisintercalators, G₃K and [beta]Ala₃K, were shown to bind two different sequences of DNA, where the peptide linkers reside in the major and minor grooves respectively. These binding modules were then combined to generate threading polyintercalators that bound different DNA sequences with simultaneous occupation of both grooves. In particular, a cyclic bisintercalator was designed and DNAse I footprinting revealed a strong preference for the sequence 5'-GGTACC-3'. NMR structural studies of the complex with d(CGGTACCG)₂ verified a pseudocatenane structure in which the NDI units reside four base pairs apart, with one linker located in the minor groove and the other in the major groove. This was the first structurally well-characterized pseudocatenane complex between a sequence-specific cyclic bisintercalator and its preferred binding sequence. The ability to simultaneously occupy both groves of the same sequence is interesting for several reasons. Most significantly, it raises questions about a complex DNA intercalator's ability to locate its preferred sequence within a long strand of DNA. In order to directly assess this, the intercalator was modified (CBI-Cys) to incorporate a gold nanoparticle probe to allow for the direct visualization of the intercalator locating its preferred sequence within a long DNA strand. The appropriate protocols to visualize DNA using electron and atomic force microscopy were unsuccessful; however, the foundation has been set for future work to develop the appropriate method to determine the mechanism by which the cyclic bisintercalator locates its preferred sequence. Additionally, the bisintercalators developed in our laboratory offered a unique opportunity to exploit their sequence specificity for controlled nanoparticle assembly. Over the past decade, nanoparticles and DNA have been used to develop novel nanoparticle assembly systems with the goal of developing electronic devices and nanomaterials. The G₃K bisintercalator was synthetically modified to incorporate a gold nanoparticle probe. This intercalator-nanoparticle conjugate, BisKC·Au, maintained its binding specificity (5'-GGTACC-3') to a modified DNA fragment containing multiple G₃K binding sites. The atomic force microscope has become the most promising tool in visualizing individual DNA molecules. A modified procedure utilized APS to allow for the direct visualizing of plasmid DNA. The framework is now in place to confirm the controlled assembly of the gold nanoparticles. This protocol can then be used for the [beta]Ala₃K bisintercalator to lead to the development of a nanoparticle assembly system that can precisely control the organization of multiple types of nanoparticles. / text

This work deals with carborane and metallacarborane clusters, in terms of their fundamental chemistry and complexation with cyclodextrins, and in the context of emerging pharmacophores applicable in medicinal chemistry. Arguably, the most important part of this work is the preparation of cobalt bis(dicarbollide) sulfamide derivatives. The sulfamido group is attached to the metallacarborane carbon vertex by an alkyl chain that may be modified in its length. This was accomplished by, firstly, the abstraction of the acidic hydrogen, located on the {CH}-vertex from the metallacarborane, by reaction with lithium base, followed by, secondly, reaction with electrophilic agents (PFA, oxirane and oxetane), which leads to a cascade of reactions to give the desired sulfamide derivatives. These compounds were then tested by collaborators in other institutes for in vitro and in vivo activity towards Carbonic Anhydrase IX (CA IX), which is an enzyme associated with tumour growth. In vivo tests on mice have shown that these types of substances are able to effectively reduce tumour size by 30%. The synthetic research continued with the preparation of sulfonamide compounds of the isomers of the carborane series. The reactions began exclusively with propylhydroxy carborane starting materials, which provide optimum...

This work deals with carborane and metallacarborane clusters, in terms of their fundamental chemistry and complexation with cyclodextrins, and in the context of emerging pharmacophores applicable in medicinal chemistry. Arguably, the most important part of this work is the preparation of cobalt bis(dicarbollide) sulfamide derivatives. The sulfamido group is attached to the metallacarborane carbon vertex by an alkyl chain that may be modified in its length. This was accomplished by, firstly, the abstraction of the acidic hydrogen, located on the {CH}-vertex from the metallacarborane, by reaction with lithium base, followed by, secondly, reaction with electrophilic agents (PFA, oxirane and oxetane), which leads to a cascade of reactions to give the desired sulfamide derivatives. These compounds were then tested by collaborators in other institutes for in vitro and in vivo activity towards Carbonic Anhydrase IX (CA IX), which is an enzyme associated with tumour growth. In vivo tests on mice have shown that these types of substances are able to effectively reduce tumour size by 30%. The synthetic research continued with the preparation of sulfonamide compounds of the isomers of the carborane series. The reactions began exclusively with propylhydroxy carborane starting materials, which provide optimum...