Beschreibung
Wood as found in trees and bushes was of primary importance to ancient humans in their struggle to control their environment. Subsequent evolution through the Bronze and Iron Ages up to our present technologically advanced society has hardly diminished the importance of wood. Today, its role as a source of paper products, furniture, building materials, and fuel is still of major significance. Wood consists of a mixture of polymers, often referred to as lignocellulose. The cellulose micro fibrils consist of an immensely strong, linear polymer of glucose. They are associated with smaller, more complex polymers composed of various sugars called hemicelluloses. These polysaccharides are embedded in an amorphous phenylpropane polymer, lignin, creating a remarkably strong com posite structure, the lignocellulosic cell wall. Wood also contains materials that are largely extraneous to this lignocellulosic cell wall. These extracellular substances can range from less than 1070 to about 35% of the dry weight of the wood, but the usual range is 2% -10%. Among these components are the mineral constituents, salts of calcium, potassium, sodium, and other metals, particularly those present in the soil where the tree is growing. Some of the extraneous components of wood are too insoluble to be ex tracted by inert solvents and remain to give extractive-free wood its color; very often these are high-molecular-weight polyphenolics.
Autorenportrait
Inhaltsangabe1 Introduction and Historical Background.- 1.1 Historical Uses of Extractives and Exudates.- 1.1.1 Introduction.- 1.1.2 Major Uses of Extractives and Exudates.- 1.1.2.1 The Use of Durable Woods.- 1.1.2.2 Exudates.- 1.1.2.2.1 Varnishes.- 1.1.2.2.2 Lacquers.- 1.1.2.2.3 Gums.- 1.1.2.3 Tannins.- 1.1.2.4 Dyes.- 1.1.2.5 Perfumes.- 1.1.2.6 Rubber.- 1.1.2.7 Medicines.- 1.1.3 Lessons from History.- References.- 1.2 Natural Products Chemistry - Past and Future.- 1.2.1 Introduction.- 1.2.2 Isolation and Purification.- 1.2.3 Structure Determination.- 1.2.4 The Future of Natural Products Science.- References.- 2 Fractionation and Proof of Structure of Natural Products.- 2.1 Introduction.- 2.2 Novel Techniques and Recent Developments in Fractionation and Isolation.- 2.2.1 Countercurrent Chromatography.- 2.2.1.1 Coil Countercurrent Chromatography.- 2.2.1.2 Droplet Countercurrent Chromatography.- 2.2.1.3 Rotation Locular Countercurrent Chromatography.- 2.2.1.4 Centrifugal Partition Chromatography.- 2.2.1.5 Comparison of Partition Chromatographic Methods.- 2.2.2 Adsorption Chromatography.- 2.2.2.1 Ion-Pair Chromatography.- 2.2.2.2 Other New Methods of Column Chromatography.- 2.2.2.3 Supercritical Fluid Chromatography.- 2.3 Nuclear Magnetic Resonance Spectroscopy.- 2.3.1 Proton Nuclear Magnetic Resonance.- 2.3.1.1 Difference Decoupling.- 2.3.1.2 Difference NOE.- 2.3.1.3 Contact Shifts.- 2.3.1.4 Partial Relaxation.- 2.3.2 Carbon Nuclear Magnetic Resonance.- 2.3.2.1 J-Modulated Spin Echo.- 2.3.2.2 Insensitive Nuclei Enhanced by Polarization Transfer.- 2.3.2.3 Distortionless Enhancement by Polarization Transfer.- 2.3.2.4 Carbon-Proton Heteronuclear Coupling.- 2.3.2.5 Carbon-Proton Heteronuclear NOE.- 2.3.2.6 Deuterium Isotopic Shifts.- 2.3.3 Two-Dimensional NMR Spectroscopy.- 2.3.3.1 Two Dimensional J-Resolved Proton NMR Spectroscopy.- 2.3.3.2 Two Dimensional Correlation Spectroscopy.- 2.3.3.3 Two Dimensional-INADEQUATE (Incredible Natural Abundance Double Quantum Transfer Experiment).- 2.4 Other Spectroscopic Techniques.- 2.4.1 Mass Spectrometry.- 2.4.1.1 Techniques That Enhance Sample Volatilization.- 2.4.1.2 Modern Techniques of Ionization/Desorption.- 2.4.1.3 Tandem Mass Spectrometry.- 2.4.2 Ultraviolet-Visible Spectroscopy.- 2.4.3 Infra-Red Spectroscopy.- 2.4.4 Circular Dichroism.- 2.4.4.1 The Nature of Circular Dichroism.- 2.4.4.2 The Additivity Relation in A Values.- 2.5 General Conclusions.- References.- 3 Evolution of Natural Products.- 3.1 Convergent Synthesis and the Origin of RNA-Based Life.- 3.2 Expansion of the Acetate, Mevalonate, and ?-Aminolevulinate Pathways in Bacteria and Algae.- 3.3 Expansion of the Shikimate Pathway in Terrestrial Plants.- 3.4 Phytochemistry and Plant Defense.- 3.5 Oxidation Levels of Angiospermous Micromolecules.- 3.6 Skeletal Specialization of Angiospermous Micromolecules.- 3.7 Quantification of Micromolecular Parameters.- 3.8 Phytochemical Gradients in Angiosperms.- 3.9 Future Perspectives.- References.- 4 Carbohydrates.- 4.1 Introduction.- 4.2 Sucrose.- 4.3 Higher Oligosaccharides Related to Sucrose.- 4.4 Other Oligosaccharides.- 4.5 Monosaccharides.- 4.6 Alditols.- 4.7 Cyclitols.- 4.7.1 myo-Inositol.- 4.7.2 D-chiro-Inositol.- 4.7.3 Quebrachitol.- 4.7.4 D-Quercitol.- 4.7.5 Conduritol.- 4.7.6 Quinic Acid.- 4.8 Plant Glycosides.- 4.9 Starch.- 4.10 Extractable Polysaccharides.- 4.10.1 Arabinogalactans.- 4.10.1.1 Larch Arabinogalactans.- 4.10.1.2 Other Extractable, Nonexudate Arabinogalactans.- 4.10.2 Other Extractable Polysaccharides; The Pectic Polysaccharides.- 4.10.3 Exudate Gums.- 4.10.3.1 Acacia Gums.- 4.10.3.2 Exudate Gums of Other Rosales Genera.- 4.10.3.3 Gums of Combretaceae (Myrtiflorae) Genera.- 4.10.3.4 Exudate Gums of Anacardiaceae (Sapindales).- 4.10.3.5 Exudate Gums of Families in the Orders Rutales, Parietales, and Malvales.- 4.10.3.6 Exudate Gums from Other Orders.- 4.10.3.7 Exudate Gums with Xylan Cores.- References.- 5 Nitrogenous Extractives.- 5.1 Amino Acids, Proteins, Enzymes, and Nu
