Pyrimidines linkage isomers

Purpureocobalt — see Cobalt, chloropentaammine-Purpureocobaltic chloride —see Cobalt, chloropentaammine-, chloride Pyridine, 2-hydroxy-5-methyl-dodecacobalt complexes, 168 Pyridine complexes linkage isomers, 186 Pyrimidine complexes... 

Since Nielsen et al introduced peptide nucleic acids (PNA), this area has received vast attention, and continues to do so. More recently, the main area of interest has been in novel analogues, and many new ones have been reported. The solid phase synthesis of DNA-3 -PNA chimeras have been described, in which the DNA is attached to the amino terminal of the PNA via the 3 -phosphate or thiophosphate. All chimeras were shown to have superior thermal stability towards either DNA or RNA than a DNA oligomer, and the phosphodiester linkage was more stable than the phosphorothioate. Hybridisation studies with PNA and PNA-DNA chimeras demonstrate that there is a sequence effect for the junction between PNA and DNA on duplex stability. A decamer pyrimidine bis-PNA oligomer, separated by a linker, when targeted to complementary dsDNA formed three distinct structures. One structure contained two bis-PNA units, and the other two were believed to be structural isomers. 

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