Biomolecules aromatic hydrocarbons

A real advantage of working in the FIR is that both polar and non-polar chains may be searched for. Indeed, the lowest bending frequency of C3 has been studied in the laboratory [69], and tentatively detected toward the galactic centre source Sgr B2 [70]. Other large molecules such as polycyclic aromatic hydrocarbons (anthracene, pyrene, perylene, etc) or biomolecules such as glycine or uracil also possess low-frequency FIR vibrations, and can be produced in sizable quantities in supersonic expansions through heated planar nozzles... 

When possible, it can be advantageous to take advantage of an analyte s intrinsie fluorescence. Ideally, native fluorescence would exhibit a high quantum yield and could be excited with readily available excitation sources. Unfortunately, few compounds exhibit fluorescence in the spectral range of the most common lasers, that is, the visible portion of the spectrum. Nonetheless, there are some compounds that fluoresce upon excitation with visible light. Examples include many pharmaceutical compounds,porphyrins, and vitamin B6 metabolites. In contrast, excitation below 300 nm excites quite a number of biomolecules, including proteins and peptides containing Tyr, Tip, or Phe residues, polycyclic aromatic hydrocarbons, as well as nucleosides and DNA. For... 

Capillary electrophoresis (CE) is the fastest growing separation science technique today for the separation and quantitation of peptides and proteins.(lX2) For these biomolecules, the high separation efficiency coupled with the small sample requirements, ease of automation, and the possibility of direct quantitation has placed CE in the forefront of bioanalytical techniques complementing traditional slab gel electrophoresis and liquid chromatography.(3)(4)(5) CE analyses of all the following species have been reported amino acids, peptides, proteins, ions, enantiomers, PCR products, DNA, nucleotides, vitamins, pharmaceuticals, aromatic hydrocarbons, explosive constituents, isoforms, immunoglobulins and dilute biological solutions. (6)(7)... 

We mentioned earlier that some polycyclic aromatic hydrocarbons are strongly carcinogenic. Although all the detdls of this carcinogenesis are not worked out, the broad outlines are known for some molecules. Deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) are huge biomolecules that contain and help transcribe genetic information (Chapter 23). Both DNA and RNA are phosphate-linked sequences of nucleotides, which are sugar molecules attached to heterocyclic bases. 

Biochemical recalcitrance of biomolecules is related to their molecular weight and complexity, as well as, to the presence of ether-bridges, quaternary and tertiary C-atoms, amide groups, phenyl- and heterocyclic N-groups, long-chain hydrocarbons and polymerized aromatic groups (Haider and Martin, 1981 von Liitzow et al.,... 

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