Friday, January 7, 2011: 5:30 PM
Marquis - 103 - 105 (Atlanta Marriott Marquis)
A review of the literature of the chemical composition of cellulose raises serious questions about the current paradigm of cellulose. Textbooks and academic courses often present cellulose as a homopolymer of β-D-glucose residues. We submit that no primary data substantiate this model. Investigators in the early 1900’s were very conscientious about their work and clearly gave much thought to the interpretation of their data. Based on the historic literature, we have been unable to find any primary report that concludes that cellulose contains only β-D-glucose residues. However, in some cases, questions remain about the work. In some early analyses, the starting material and isolation procedures are not described in detail, although the chemistry is described in great detail. In reviews, authors summarized the early work but inserted conclusions that are not justified by the data and that were not stated by the original authors. To say that an early investigator only found glucose in an acid hydrolyzate does not mean that other components were not present. In some cases the early investigator did not have the means to detect minor constituents or, as in one case, the researcher re-crystalized the glucose twice. Almost all reviewers avoided discussion of the method of isolation of the extracted sugar(s). Unfortunately, as better methods of analysis became available, investigators did not revisit the issue of cellulose composition using the new tools. Because of changes in terminology, the descriptions of certain products in chemical catalogs and other documents are misleading. We feel that the oversimplification of the commonly-presented model of cellulose may be only one example of a tendency for scientific review to condense complexity. The apparent reductionist presentation of the cellulose model demonstrates the need for investigators to be cautious when using reviews and other literature that do not present experimental data.
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