Taxonomic applications

The taxonomic application of the ability of enteric organisms to grow with 4-hydroxy-phenylacetate (Cooper and Skinner 1980) and 3-hydroxyphenylpropionic acid (Burlingame and Chapman 1983) has been established. In addition, it has been demonstrated that the enzyme that carries out the hydroxylation has a wide substrate range extending to 4-meth-ylphenol, and even to 4-chlorophenol (Prieto and Garcis 1994). 

The digestion patterns are often highly reproducible and can be used as a kind of fingerprint , dependent only on structural features of the RNA, and offer possibilities of taxonomic applications (Gould et al. 1966 Gould 1968). Thus not only can evolutionary changes... 

Although the applications described here have concerned diverse macromolecular samples, pyrolysis is also of utility in the analysis of smaller molecules, particularly quaternary ammonium compounds, which undergo quantitative thermal fragmentation to volatile products. For example, the specificity and sensitivity afforded by Py-GC/MS with mass fragmentography renders the technique suitable for the analysis of endogenous neurotransmitters such as acetylcholine at the l-2pmol level. However, in all cases, analytical throughput is limited by the retention times of the pyrolysis products, a condition that is particularly severe in taxonomic applications. Automation allows extended use, but direct Py-MS... 

A New Semi-Automatic Morphometric Protocol for Conodonts and a Preliminary Taxonomic Application... 

The stndies of variation patterns in Lasthenia and Brickellia hardly break the snrface of a vast and complex literatnre on chemical variation within Asteraceae. The snbject has been discnssed in detail, with reviews focnsing on polyacetylenes (Bohlmann et al., 1973), sesqniterpene derivatives (Seaman, 1982), and flavonoids (Bohm and Stnessy, 2001). The next examples come from the sesqniterpene lactone literatnre and, again, represent only a sample of the applications that have been made nsing those data. Examples covering the taxonomic hierarchy within Asteraceae np to the early 1980s can be fonnd in the monumental review of the family prepared by Seaman (1982). 

Icacinaceae are a moderate-sized, primarily tropical family consisting of 52 genera, many of which are monotypic, and 300 species. Additional background on taxonomic problems surrounding the family can be found in the 1991 paper by Kaplan et al. Chemical data have been used by Dahlgren (1980) to assess these relationships with related families, but the application involved simple presence or absence data (iridoids) and did not touch upon the dynamic nature of the pathways involved. 

L. M. Mallory and G. S. Sayler, Application of FAME (fatty acid methyl ester) analysis in the numerical taxonomic determination of bacterial guild structure, Mi-croh. Ecol. t0 l%2 (1984). 

Drucker, D. B. Jenkins, S. A. Applications of mass spectrometry including combined gas chromatography-mass spectrometry in taxonomic studies of bacteria. Biochem. Soc. Trans. 1989,17, 245-249. 

As noted above, whole-cell MALDI-TOF MS was intended for rapid taxonomic identification of bacteria. Neither the analysis of specific targeted bacterial proteins, nor the discovery of new proteins, was envisioned as a routine application for which whole cells would be used. An unknown or target protein might not have the abundance or proton affinity to facilitate its detection from such a complex mixture containing literally thousands of other proteins. Thus, for many applications, the analysis of proteins from chromatographically separated fractions remains a more productive approach. From a historical perspective, whole-cell MALDI is a logical extension of MALDI analysis of isolated cellular proteins. After all, purified proteins can be obtained from bacteria after different levels of purification. Differences in method often reflect how much purification is done prior to analysis. With whole-cell MALDI the answer is literally none. Some methods attempt to combine the benefits of the rapid whole cell approach with a minimal level of sample preparation, often based on the analysis of crude fractions rather... 

Related Compounds. LXXV. Alkaline Nitrobenzene Oxidation of Plant Materials and Application to Taxonomic Classification. J. Amer. chem. Soc. 66, 32 (1944). 

Cypermethrin Winter Wheat 0.595 (drift rate) and 25 g a.i./ha (2 app at 14 day intervals) Effects reported on a wide range of species studies at both 0.595 and 25 g a.i./ha Recovery reported for all taxonomic groups 38-40 days after 2nd application of both 0.595 and 25 g a.i./ha... 

Santos, L.C. et al.. Application of HPLC-NMR coupling using C30 phase in the separation and identification of flavonoids of taxonomic relevance, Fresen. J. Anal. Chem., 368, 540, 2000. 

Phenolic compounds are of interest due to their potential contribution to the taste (astrin-gency, bitterness, and sourness) and formation of off-flavor in foods, including tea, coffee, and various fruit juices, during storage. Their influence on the appearance of food products, such as haze formation and discoloration associated with browning in apple and grape products, is also significant. Furthermore, analysis of these phenolic compounds can permit taxonomic classification of the source of foods. The importance of each phenolic compound and its association with the quality of various foods is described further in Sec. IV, on food applications. 

Consideration of sample preparation also leads to the question of whether for some applications at least sensors would be more effectively constructed as a collection of modules each with a different function (sample preparation, transduction, detection, data collection) on a platform, large, small or miniaturised, rather than the old ideal of a small, self-contained device with intimately appressed layers which could return a rapid answer from a bucket of slime or some other spectacularly heterogeneous matrix. It is accepted that those with a taxonomic bent... 

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