Experimental plant material

Lineweaver and Ballou49 have proposed a pectinesterase unit ( PE. u. ) for expressing PM activity. One such unit is equivalent to 1/930 PMU under the same experimental conditions or the quantity of enzyme that, at 30° and optimum pH, will catalyze the hydrolysis of pectin at an initial rate of one milliequivalent ester bonds per minute in a standard substrate (0.5% citrus pectin containing 8-11% methoxyl) and 0.15 M sodium chloride. The use of the latter unit is unfortunate since the values obtained for the activity in ordinary plant materials are obtained in the third decimal place and because the experimental conditions are so... 

Chloro-ort/2o-toluidine has been identified in field samples of plant materials treated with chlordimeform, e.g., in young bean leaves at concentrations of less than 0.1-0.2 ppm [mg/kg], in grape stems at 0.02-0.3 ppm [mg/kg], in a mixture of grape stems and berries at 0.02-0.5 ppm [mg/kg] and in prunes and apples at less than 0.04 ppm [mg/kg] (Kossmann et al., 1971). In an experimental field application (one to three treatments with chlordimeform, harvesting 42 days after last treatment), 4-chloro-ort/zo-toluidine was found in rice grains at 3-61 ppb [ Xg/kg] and in straw parts at 80-7200 ppb [pg/kg] (lizuka Masuda, 1979). 4-Chloro-ort/70-toluidine was detected as a metabolic product in cotton plants following treatment with chlordimeform (Bull, 1973). 

Finally, the experimenter should be aware that the cell walls from each plant and each plant tissue are different and require their own cell wall isolation and fractionation protocols. Hence for any given plant material, modifications of the basic procedures described in this unit will probably be required. 

All cells have to be broken open to remove the cell contents. To accomplish cell lysis the authors use a combination of homogenizing and grinding steps. For recalcitrant tissue a small rock grinder (i.e., ring grinder) is used. The authors advise the experimenter to perform a trial run on their plant material to establish the number and duration of homogenization steps. These should always be the minimum required to break open the cells. Excessive... 

An accurate sample weight before extraction and the amount of final extract after sample cleanup should be known for an accurate quantification of phenolic compounds extracted from plant materials by HPLC analysis. The characteristic wavelengths for detection of polyphenolics can be selected at the discretion of the experimenter. The solvent gradients described in the Basic and Alternate Protocols can be modified for better resolution. 

Plant materials often contain triterpenoid saponin in considerable amounts. With regard to plants with antiulcer activity, licorice root contains about 2 to 12% of glycyrrhizic acid and the seeds of the horse chestnut up to 13% of aescin. Several plants containing high amounts have been shown to possess antiulcer activity in several experimental ulcer models (Table 64.2). 

Presently it is mostly used as a fuel, but as petroleum becomes increasingly scarce and expensive, proposals and experimental plants for using this material begin to appear. One such process uses fluid-bed hydrocracking and dealkylation to produce phenols and benzene. 

Bianchi, T.S., Findlay, S., and Fontvieille, D. (1991) Experimental degradation of plant materials in Hudson River sediments. I. Heterotrophic transformations of plant pigments. Biogeochemistry 12, 171-187. 

For all analytical methods the quality of the results ultimately relates back to the chemical purity of the very best available SRM and to the linearity of the correlation curve for the experimentally measured property vs. the SRM concentration. For substances that are naturally chiral there is the additional very serious concern about enantiomeric purity. The determination of an enantiomer whether for an enantiomeric purity test, or for an enantiomeric ratio or excess test in the study of a partial racemic mixture, is one of the more difficult analytical problems. To actually report the enantiomeric purity of an enantiomer as better than 99% is truly beyond the capability of current analytical methodology [31], for after all few substances ever have a chemical purity that is guaranteed to be greater than 99%. So, as mentioned earlier, one has to accept the fact that the results are measured relative to an enantiopurity of an SRM that is defined to be 100%. This limitation of course impacts on the true meaning of a calculated enantioexcess, and to a much lesser degree perhaps, in assays of chiral substances extracted from plant materials using calibration data that were obtained for synthetic SRM s. 

Eventually, through experimentation with lots of plant materials, it was found in the mid-1800s that soft wood pulp was a very efficient and economical paper material. 

This chapter would not have been possible without the detailed information supplied by B. Baldwin, M. Chase, D. Crawford, S. Downie, J. Doyle, R. Olmstead, J. Palmer, R. Price, J. Rodman, D. Soltis, and D. Stein. Experimentation on methods of collecting and shipping tropical plant material was made possible by National Science Foundation Grants BSR 8516573, 8806520, 8815173, 9007293, and 9016260, and by grants from the National Geographic Society and the Nave Fund (University of Wisconsin, Madison, WI). 

Cody, R.D. (1979) Lenticular gypsum occurrences in nature, and experimental determinations of effects of soluble green plant material on its formation. Journal of Sedimentary Petrobgy 49, 1015-1028. 

It is not possible to set up an exact energy balance because such functions as material feeding, removal, transport and the like were performed manually in the experimental plant. An estimate shows, however, that the pyrolytic treatment of the available energy in the waste transformed... 

Plant materials Burley tobaccos (Nicotiana tabacum L. cv KY 14 and cv KY 17) were grown at various times in the soil floor of a greenhouse. Recommended cultural and fertilization practices were followed (11). A randomized complete block experimental design... 

However, in experimental trials with decomposition of fresh litter in special lit-terbags, these C N and C P ratios decline as decomposition of organic matter proceeds. These may be connected to an increase in the relative part of microbial biomass in litterbags in comparison with the remaining plant materials and remineralization of this biomass (Table 5). 

Many of the fundamental studies of the pan agglomerator were carried out in connection with the pelletizing of cement raw meal [Section 13.3, Ref. 2], which was widely investigated in the 1950s and 60s. Some experimental plants were built, but later this approach was abandoned in favor of preheating fine raw materials in fluidized bed heat exchangers. 

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