Chemotaxonomy

Brodo (29) has recently summarized the application of chemical criteria in lichen taxonomy in the following terms chemical investigations now form an integral part of all serious taxonomic studies on lichen forming fungi. In fact within the past decade or so, more and more evidence has accumulated to show that taxonomic units at all levels can be characterized to a greater or lesser extent by their chemical products. One can argue ad nauseam whether these chemically characterised populations represent species, subspecies or whatever, but almost no-one will deny that chemical products do reflect broad or narrow taxonomic relationships.  

Hence it is the taxonomic interpretation of the observed chemical variations that is controversial although Hawksworth (155) has attempted to forward some guidelines for such interpretation. 

Most morphologically defined species have a constant chemistry, usually one cortical substance (e. g. usnic acid, atranorin) and one or more medullary substances, and justify the use of this criterion in lichen taxonomy. The three common patterns of chemical variation are those of replacement type compounds, accessory type compounds and chemosyn-dromic variation. These are discussed in turn. 

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Hegnauer, R., Chemotaxonomie der Pflanzen, Vols. 1, 2, Birk-hauser Verlag, Stuttgart, 1962-63. 

Granger, R. and Passet, J. 1973. Thymus vulgaris spontane de France Races chimiques et chemotaxonomie. Phytochemistry 12 1683-1691. 

Grayer, R. J., Chase, M. W. and Simmonds, M. S. J. 1999. A comparison between chemical and molecular characters for the determination of phylogentic relationships among plant fanrUies An appreciation of Hegnauer s Chemotaxonomie der Pflanzen. Biochem. Syst. Ecol. 27 369-393. 

Hawksworth, D. L. 1976. Lichen chemotaxonomy. Pages 139-184 in D. H. Brown, D. L. Hawksworth, and R. H. Bailey (eds.), Lichenology Progress and Problems. Academic Press, New York. 

Howard, B. M., Nonomura, A. M. and Fenical, W. 1980. Chemotaxonomy in marine algae secondary metabolite synthesis by Laurencia in unialgal culture. Biochem. Syst. Ecol. 8 329-336. 

Smallfield, B. M. 1997b. Essential oils from New Zealand manuka and kanuka Chemotaxonomy of Kunzea. Phytochemistry 45 1605-1612. 

Takahashi, K., Nagahama, S., Nakasbima, T. and Suenaga, H. 2003. Chemotaxonomy on the leaf constituents of Thujopsis dolabrata Sieb. et Zucc.—analysis of acidic extracts. Biochem. Syst. Ecol. 31 723-738. 

Brondz, I. Olsen, I. Chemotaxonomy of selected species of the Actinobacillus-Haemophilus-Pasteurella group by means of gas chromatography, gas chromatography-mass spectrometry and bioenzymatic methods. J. Chromatogr. 1986,380,1-17. 

Hotta-Hara, H. Yabuuchi, E. Mizuno, S. Yano, I. Application of FAB/MS analysis of bacterial membrane lipids to the chemotaxonomy. Nippon Iyo Masu Supeku-toru Gakkai Koenshu. 1991,16, 223-226. 

Drucker, D. B. Fast atom bombardment mass spectrometry of phospholipids for bacterial chemotaxonomy. ACS Symp. Ser. 1994, 541,18-35. 

Bergquist PR, Wells RJ (1983) Chemotaxonomy of the porifera The development and current status of the field. In Scheuer PJ (ed) Marine Natural Products. Chemical and biological perspectives. Academic, New York, vol 5... 

Karuso P, Hagadone MR, Scheuer PJ, Bergquist PR (1990) Chemotaxonomy of the Porifera by infrared spectroscopy. In Rutzler K (ed) New perspectives in sponge biology. Smithsonian Institution, Washington, DC, p 55... 

OLESZEK, W., Alfalfa saponins structure biological activity and chemotaxonomy. In Saponins Used in Food and Agriculture Advances in Experimental Medicine and Biology, (G. R. Waller and K. Yamasaki, eds.), Plenum Press, New York. 1996, pp. 155-170... 

During the past two decades a great number of papers have been published on the isolation, structure elucidation, synthesis and transformation, biogenesis, chemotaxonomy, and pharmacology of indole alkaloids. In this chapter we summarize the new results that appeared from 1968 to mid 1984 for the cory-nantheine-yohimbine group of monoterpene indole alkaloids with greater emphasis on their chemistry, excluding the related oxindoles and heteroyohimbines. 

GC and GC-MS (see Chapter 2), are ideal for the separation and characterization of individual molecular species. Characterization generally relies on the principle of chemotaxonomy, where the presence of a specific compound or distribution of compounds in the ancient sample is matched with its presence in a contemporary authentic substance. The use of such 6molecular markers is not without its problems, since many compounds are widely distributed in a range of materials, and the composition of ancient samples may have been altered significantly during preparation, use and subsequent burial. Other spectroscopic techniques offer valuable complementary information. For example, infrared (IR) spectroscopy and 13C nuclear magnetic resonance (NMR) spectroscopy have also been applied. 

Similar data evaluation problems exist in other scientific fields and can also be treated by multivariate statistical data analysis, for instance, in economics (econometrics), sociology, psychology (psychometrics), medicine, biology (chemotaxonomy),... 

This example belongs to chemotaxonomy, a discipline that tries to classify and identify organisms (usually plants, but also bacteria, and even insects) by the chemical or biochemical composition (e.g., fingerprint of concentrations of terpenes, phenolic compounds, fatty acids, peptides, or pyrolysis products) (Harbome and Turner 1984 Reynolds 2007 Waterman 2007). Data evaluation in this field is often performed by multivariate techniques. 

The problem is much more difficult when the defensive compounds are distributed throughout the insect body and no clues are available as to which type of compounds are present. In this case, a H NMR spectrum on the insect total extract will usually not be helpful, and a reliable bioassay is needed to follow the biological activity through the fractionation process. Repellency bioassays using ants [9] or spiders [10] have been successfully used for this purpose. Chemotaxonomy can also be very helpful, as taxonomically related insects tend to produce the same kind of defensive chemicals. Thus, once the latter have been identified for a few species, the study of other species belonging to the same group is usually much simplified. A good example is provided by coc-... 

Kinghom, A.D. and Balandrin, M.F. (1984). Quinolizidine alkaloids of the Leguminosae Structural types, analysis, chemotaxonomy and biological activities, in Pelletier, S.W., Ed., Alkaloids chemical and biological perspectives, John Wiley and Sons, New York, pp. 105-148. 

Scora RW, Kumamoto J (1983) Chemotaxonomy of the genus Citrus. In Waterman PG Gmndon MF (eds) Chemistry and chemical taxonomy of the rutales. Academic Press, London, pp 343-351... 

Jensen SR, Schripsema J. (2002) Chemotaxonomy and pharmacology of Gentianaceae. In Struwe L, Albert V (eds), Gentianaceae — Systematics and Natural History, pp. 573-631. Cambridge University Press. 

Classification based on chemotaxonomy The field of chemotaxonomy attempts to review plant constituents according to plant taxa. Namely, constituents are regarded as markers for evolution as well as the classification of plants. 

Deedat, Y.D. Ellis, C.R. J. Econ. Eta tomol. 1983, 76, 1055. Gibbs, R.D. "Chemotaxonomy of Flowering Plants" McGlll-Queens University Press Montreal and London, 197 4, 4 volunes. 

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