Carbohydrate-based nucleic acids

Allen, D., and El Rassl, Z. (2004). Capillary electrochromatography with monolithic silica columns III. Preparation of hydrophilic silica monoliths having surface-bound cyano groups chromatographic characterization and application to the separation of carbohydrates, nucleosides, nucleic acid bases and other neutral polar species.. Chromatogr. A 1029, 239—247. 

Lipids are defined as water-insoluble compounds extracted from living organisms by weakly polar or nonpolar solvents. This definition is based on a physical property, in contrast to the definitions of proteins, carbohydrates, and nucleic acids, which are based on chemical structure. Consequently, the term lipid covers a structurally diverse group of compounds, and there is no universally accepted scheme for classifying lipids. 

The most successful applications of CE-LIF detection have been in the analysis of carbohydrates and nucleic acids. Carbohydrates can be derivatized with agents such as aminopyrene trisulfonic acid, which introduces a fiuorophore and also confers electrophoretic mobility to the analyte. Double-stranded nucleic acids can be detected using intercalating dyes and by covalent attachment of nucleotides carrying fluorophores. The fluorescently labeled primers or chain terminating nucleotides which are widely used in automated slab gel-based DNA sequencers are also used in capillary-based sequencers. In one multicapillary sequencer, a novel sheath flow system is used for LIF excitation of separated bands with imaging of emitted fluorescence on a charge-coupled device (CCD) detector. 

Nucleic acids are acidic substances present m the nuclei of cells and were known long before anyone suspected they were the primary substances involved m the storage transmission and processing of genetic information There are two kinds of nucleic acids ribonucleic acid (RNA) and deoxyribonucleic acid (DNA) Both are complicated biopolymers based on three structural units a carbohydrate a phosphate ester linkage between carbohydrates and a heterocyclic aromatic compound The heterocyclic aro matic compounds are referred to as purine and pyrimidine bases We 11 begin with them and follow the structural thread... 

Even if It could be shown that RNA preceded both DNA and proteins in the march toward living things that doesn t automatically make RNA the first self replicating molecule Another possibility is that a self replicating polynucleotide based on some carbo hydrate other than o ribose was a precursor to RNA Over many generations natural selection could have led to the replacement of the other carbohydrate by D ribose giving RNA Recent research on unnatural polynucleotides by Professor Albert Eschenmoser of the Swiss Federal Institute of Technology (Zurich) has shown for example that nucleic acids based on L threose possess many of the properties of RNA and DNA... 

Sephadex. Other carbohydrate matrices such as Sephadex (based on dextran) have more uniform particle sizes. Their advantages over the celluloses include faster and more reproducible flow rates and they can be used directly without removal of fines . Sephadex, which can also be obtained in a variety of ion-exchange forms (see Table 15) consists of beads of a cross-linked dextran gel which swells in water and aqueous salt solutions. The smaller the bead size, the higher the resolution that is possible but the slower the flow rate. Typical applications of Sephadex gels are the fractionation of mixtures of polypeptides, proteins, nucleic acids, polysaccharides and for desalting solutions. 

The compounds that are identifiable in the sea represent a vast array of biochemicals attributable to the life and death of marine plants and animals. They are generally grouped into six classes based on structural similarities hydrocarbons, carbohydrates, lipids, fatty acids, amino acids, and nucleic acids. Because they represent compounds that can be quantified and understood for their chemical properties and known role in biological systems, a great deal of information has been accumulated over the years about these groups and the specific compounds found within them.7... 

The growing interest for the identification and characterization of polar and large compounds caused the development and the introduction of new ionization techniques, such as electrospray ionization (ESI)[4], and matrix assisted laser desorption ionization (MALDI),[5] and their more recent improvements, thus establishing new MS based approaches for studying large molecules, polymers and biopolymers, such as proteins, carbohydrates, nucleic acids. 

Tipson always enjoyed and took great pride in precise scientific writing. When the Advances in Carbohydrate Chemistry series was launched in 1945 under the editorship of W. W. Pigman and M. L. Wolfrom, he wrote a comprehensive article for Volume 1 on the chemistry of the nucleic acids that is to this day a model of historical accuracy, careful and economical use of language, and clear interpretation of experimental data based on thoroughly characterized crystalline compounds. 

The nucleotides of RNA and DNA consist of three components a carbohydrate, a phosphate group and an organic nitrogenous base. There are two types of carbohydrate molecule in nucleic acids, both of which are D-pentoses, i.e. contain five carbon atoms. The carbohydrate in RNA is ribose, while DNA contains deoxyribose, which has a hydrogen atom instead of a hydroxyl group attached to the carbon in the 2 position (Figure 13.1). 

The nutrients discussed in this section are carbohydrate, fat, protein and nucleic acids. The nucleic acids, upon digestion, provide phosphate, bases and nucleosides (Chapters 10 and 20). Each is discussed under four separate headings ... 

Nucleic acids, proteins, some carbohydrates, and hormones are informational molecules. They carry directions for the control of biological processes. With the exception of hormones, these are macromolecules. In all these interactions, secondary forces such as hydrogen bonding and van der Waals forces, ionic bonds, and hydrophobic or hydrophilic characteristics play critical roles. Molecular recognition is the term used to describe the ability of molecules to recognize and interact bond—specifically with other molecules. This molecular recognition is based on a combination of the interactions just cited and on structure. 

The molecules that form the foundation of living systems are often organized into four categories. They are the primary metabolites nucleic acids, proteins, carbohydrates, and lipids. The categories can be grouped together in different ways, based on features that they have in common. For example, nucleic acids, proteins, and polysaccharides are polymeric. Nucleic acids and proteins are further related because they are templated polymers. Other classification systems are also possible.1 Interest in the development of size-expanded versions of biomolecules has grown over the past... 

The phosphoproteins and the nucleoproteins contain also the element phosphorus in the former, probably combined directly with one of the constituents of the protein molecule in the latter, combined with a purine base or a carbohydrate, which substances constitute nucleic acid. 

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