Thomas P. Abbott

Solid state analysis of plant polymers by FTIR

Abstract Wheat straw, kenaf, oak, and pine were extracted to give samples with various contents of lignin, hemicellulose, and cellulose. Precise amounts of these samples were blended with KBr and pressed into discs, and their FTIR spectra were determined. Two-spectra subtraction, and combination of multiple spectra by matrix inversion and least squares matrix methods were used to give spectra of individual lignin, hemicellulose, and cellulose components in all 4 plant types. They are the most complete IR spectra available for lignin in plant matrices.

SOLVENT SELECTION GUIDE FOR COUNTER-CURRENT CHROMATOGRAPHY

Abstract Thirteen two-phases counter-current chromatography solvent systems (five not previously described for high-speed counter-current chromatography) were evaluated for relative polarity by using Reichardts dye to measure solvachromatic shifts and by using solubility of index compounds. Three groups of systems were classified as lipophilic, polar or intermediate and a solvent selection guide was developed. Several intermediate systems appeared to have similar characteristics based on these evaluations. A method for making alternative solvent systems and determining composition of the two phases without concentration standards was described. Three of the lipophilic systems were tested for the separation of a 180-mg mixture of dimethylphthalate, dioctylphthalate and dodecyl acetate, and the hexane—acetonitrile (1:1) system was found to work best.

Ion exchange reactions of quaternary ammonium halides with wheat straw. Preparation of oil-absorbents

Abstract Products useful for removing emulsified oil from water were prepared by first heating wheat straw with sodium hydroxide solution and then subjecting the resulting product to an ion exchange reaction with hexadecyltrimethylammonium bromide (CTAB). Comparison of sodium hydroxide solutions of varying concentrations showed that sufficient NaOH is needed to disrupt straw particles and produce a high surface area product; however, NaOH concentration must not be so high as to remove large amounts of hemicellulose, since the uronic acid substituents of hemicellulose are responsible for much of the ion exchange capacity of straw. Infrared spectroscopy of a typical straw-CTAB adduct indicated a C16 quaternary ammonium cation content of 3·9% by weight (13·7 meq per 100 g of adduct).

Major extractable components in Asclepias linaria (Asclepiadaceae) and Ilex verticillata (Aquifoliaceae), two potential hydrocarbon crops.

The major extractable components of two species identified as having high oil or polyphenol contents were characterized in detail.Asclepias linaria, a desert milkweed, contains 30.3% extractable material on a dry-weight basis, andIlex verticillata contains 41.5% extractable material on a dry-weight basis. Important components inA. linaria oil fractions are triterpene alcohols and esters, wax, and natural rubber; fatty acid triglycerides were nearly absent.Ilex verticillata oil fractions were predominantly triglycerides with some triterpene fatty acid esters. The more polar polyphenol fraction contained sugars and sugar esters of fatty acids and triterpene acids. The polyphenol fraction from these plants is better described as a saponin fraction. Because the crude saponin fraction represents 10.7% of the dry weight of A. linaria and 18.9% of the dry weight ofI. verticillata and because the saponin fractions showed good emulsifying properties, the refined extract of these plants might be used as a biodegradable surfactant.ResumenLos componentes mayores que se pueden extraer de dos especies identificadas como teniendo cantidades de mucha esencia o cantidades de polifenolfueron caracterizados en detalle.Asclepias linaria, un vencetósigo del desierto, tiene 30.3% material que se puede extraer en un base de peso seco, yIlex verticillata tiene 41.5% material que se puede extraer en un base de peso seco. Componentes importantes enA. linaria fracciones de esencia son alcoholes de triterpenos y ésteres, cera, y goma natural. Triglicéridos de acidos grasos casifueron no existentes.Ilex verticillata fracciones de esencia fueron triglicéridos predominantemente con algunas ésteres triterpenos de acidos grasos. La fractión polifenol mas polar contuvi azucares y ésteres de azucar de acidos grasos y acidos triterpenos. La fractión polifenol de estas plantas esta describida como una fractión saponina. Porque la fractión saponina cruda representa 10.7% del peso seco deA. linaria y 18.9% del peso seco deI. verticillata y porque las fracciónes saponinas muestraron buenas propiedades de emulsiar, es posible usar el extracto refinado de estas plantas como un detergente biogradable.

Quantitation of estolides by Fourier transform infrared spectroscopy

Estolides were produced from meadowfoam oil fatty acids, oleic, linoleic, petroselinic, andcis-5,cis-13 docosadienoic acids. Estolide reaction mixtures were quantitated by Fourier transform infrared spectroscopy and compared to the area percentages determined by high-performance liquid chromatography. The absorbance frequency of estolide carbonyl (1737 cm−1) is different than the lactone carbonyl (1790 cm−1) and the acid carbonyl (1712 cm−1). Estolide standards were obtained by wiped-film molecular-still distillations and column chromatography.

Microbial Transformation of 12-Hydroxyoctadecanoic Acid to 5-n-Hexyl-Tetrahydrofuran-2-Acetic Acid'

Stationary-phase cells of a corynebacterium (FUI-2) and a bacillus (NRRL B-14864) isolate, when grown aerobically in 1% YE medium at 25°C, converted 12-hydroxystearic acid to a major compound, 5-n-hexyl-tetrahydrofuran-2-acetic acid, and other intermediate and minor compounds (6-hydroxydodecanoic acid, 4-hydroxydecanoic acid, 4-ketodecanoic acid and γ-decanolactone). The yields of 5-n-hexyl-tetrahydrofuran-2-acetic acid, 4-hydroxydecanoic acid, and γ-decanolactone, byBacillus lentus NRRL B-14864 were 43%, 18% and 5%, respectively, after 2.5 d of incubation.

A 14C Balance on Nitrobenzene Oxidized Kenaf Lignin

Abstract Kenaf, containing unlabeled or 14C-labeled lignin was oxidized by nitrobenzene. Reaction products were separated, the 14C-content measured, and the products identified by mass spectroscopy (MS) and high pressure liquid chromatography (HPLC). Principal products and their approximate percentage of “original-lignin-14C-content” were: syringaldehyde 20%, oxalic acid 20%, high-molecular-weight species 16%, vanillin 8.2%, benzoic acid and 4-hydroxy-azobenzene 10.7%, neutral species 3% or less, syringic acid 2.4%, vanillic acid 1.5%, and malic acid (trace). Numerous aromatic products at about the 1% concentration level remain unidentified.

Evidence of A and E1 normal mode absorbances in the infrared spectrum of hemoglobin

In an FT-IR study of the secondary structure of proteins, several concentrations, cell pathlengths, resolution values, and machine parameters were investigated. During this investigation we observed that 1-cm−1 resolution spectra of hemoglobin enhanced by second derivatives revealed an additional band in the α-helix region. Krimm and co-workers predicted the existence of two absorbances in the infrared amide I region (1600-1700 cm−1) of α-helical proteins in solution that correspond to the A and E1 amide carbonyl vibrational modes. However, they observed only one band in the α-helix region at 2 cm−1 resolution.

Oxidation and Quantification of 14C-lignin at Different Ages in Wheat, Pine, Oak, and Kenaf

Abstract Plant materials, containing 14C-labeled lignins, were harvested at intervals up to 1 year after labeling. They were oxidized with sodium chlorite (NaC102) and nitrobenzene. Age of lignin appears to limit the degree of solubilization of lignin by NaC102. Nitrobenzene oxidation solubilized all lignins in wheat, oak, and kenaf but not all lignin in some pine samples. Klason and UV analysis of lignin content were compared with 14C-content to determine percent lignin soluble in 3% sulfuric acid (Klason analysis solvent), corrected lignin contents, and UV absorptivity of lignin. Ten to 20% of most lignins were soluble in 3% sulfuric acid. When corrected Klason lignin contents were used, UV absorptivities at 280 nm were about 38 g−1 1 cm−1 for wheat straw and kenaf lignins and 11 g−1 1 cm−1 for pine lignin.