ABSTRACT
Thionucleotides, especially 4-thiouridine and 6-thioguanosine, are photosensitive molecules that photocrosslink to both proteins and nucleic acids, and this feature is a major reason for their application in various investigations. To get insight into the thermodynamic and structural contributions of 6-thioguanosine to the properties of RNA duplexes a systematic study was performed. In a series of RNA duplexes, selected guanosine residues located in G-C base pairs, mismatches (G-G, G-U, and G-A), or 5' and 3'-dangling ends were replaced with 6-thioguanosine. Generally, the presence of 6-thioguanosine diminishes the thermodynamic stability of RNA duplexes. This effect depends on its position within duplexes and the sequence of adjacent base pairs. However, when placed at a dangling end a 6-thioguanosine residue actually exerts a weak stabilizing effect. Furthermore, the structural effect of 6-thioguanosine substitution appears to be minimal based on NMR and Circular Dichroism (CD) data.
Subject(s)
Guanosine/analogs & derivatives , RNA/chemistry , Thionucleosides/chemistry , Base Sequence , Circular Dichroism , Guanine Nucleotides/chemistry , Guanosine/chemistry , Magnetic Resonance Spectroscopy , Nucleic Acid Conformation , Organophosphorus Compounds/chemistry , RNA, Double-StrandedABSTRACT
We describe synthesis of novel acyclic nucleoside analogues which are building blocks for CuAAC reaction and their activity against two types of human cancer cell lines (HeLa, KB). Three of chosen compounds show promising cytotoxic activity. Synthesis pathway starting from simple and easily accessible substrates employing DMT or TBDPS protective groups is described. Adenosine and thymidine analogues containing alkyne moiety and adenosine analogue containing azido group were synthesized. The obtained units showed ability of forming triazole motif under the CuAAC reaction conditions.
Subject(s)
Adenosine/chemical synthesis , Antineoplastic Agents/chemical synthesis , Thymidine/chemical synthesis , Acids, Acyclic/chemistry , Adenosine/pharmacology , Alkynes/chemistry , Antineoplastic Agents/pharmacology , Cell Line, Tumor , Cell Survival , Click Chemistry , Humans , Magnetic Resonance Spectroscopy/methods , Molecular Structure , Spectrometry, Mass, Electrospray Ionization/methods , Thymidine/pharmacology , Triazoles/chemistryABSTRACT
Herein, we describe synthesis of novel acyclic dinucleotide analogues connected via triazole linkage in CuAAC reaction. Synthesis pathway starting from previously obtained building blocks containing alkyne or azide functional group is described. Further functionalization and application of dinucleotide analogues in DNA phosphoramidite solid-phase synthesis is also explained. Additionally, we have examined the influence of novel modifications on DNA duplex thermodynamic stability.
