Phenolic Compounds Introduction

In Table 15 are recorded the dissociation constants of certain phenolic compounds. From these data it becomes obvious that the introduction of aldehyde groups, or other substituents, changes the dissociation constant of phenolic hydroxyls by over one-hundred fold. Moreover, oxidation studies carried out in this laboratory have shown that the native lignins from bagasse, white Scots pine and birch contain... 

In contrast, both gas and liquid chromatography enable the samples of interest to be separated into individual components prior to introduction into the mass spectrometer ion source. Gas chromatography involves sample introduction with the requisite that the sample components must be volatilized prior to separation, and results in a gas sample being introduced to the mass spectrometer (i.e. El, Cl). Figure 5-2 shows the chromatogram obtained after a mixture of three simple phenolic compounds - phenol,... 

Many foods obtained from plants contain tannins. These are phenolic compounds that bind proteins, such as mammalian enzymes. It has been shown in vitro that tannic acid significantly reduces the lubricating qualities of human saliva both by decreasing its viscosity and increasing friction [55], This effect depends on the presence of salivary PRPs, which have a high affinity for tannins [56], It has been shown that the introduction of tannins into the diet can stimulate the production of PRPs in the saliva of rats [57], PRPs are a major component of salivary pellicle, and thus it would not be surprising to find that dietary tannins affect the viscosity of pellicle. 

Mass spectrometry and gas-phase ion chemistry of phenols concerns this class of compounds and, in particular, the various types of gaseous ions formed from them, as objects of fundamental interest and analytical signihcance. However, in the special case of phenols, a mass spectrometry with phenols has been developed. As mentioned in the Introduction, one of the modern methodologies for the formation of ions from polar and/or high-molecular mass, and thus non-volatile, organic and bioorganic compounds, relies on the use of various phenolic compounds as matrices for ion generation. Matrix-assisted laser ionization/desorption has become one of the major essential ioniza-... 

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