The use of and search for drugs and dietary supplements derived from plants have accelerated in recent years. Ethnopharmacologists, botanists, microbiologists, and natural-products chemists are combing the Earth for phytochemicals and “leads” which could be developed for treatment of infectious diseases. While 25 to 50% of current pharmaceuticals are derived from plants, none are used as antimicrobials. Traditional healers have long used plants to prevent or cure infectious conditions; Western medicine is trying to duplicate their successes. Plants are rich in a wide variety of secondary metabolites, such as tannins, terpenoids, alkaloids, and flavonoids, which have been found in vitro to have antimicrobial properties. This review attempts to summarize the current status of botanical screening efforts, as well as in vivo studies of their effectiveness and toxicity. The structure and antimicrobial properties of phytochemicals are also addressed. Since many of these compounds are currently available as unregulated botanical preparations and their use by the public is increasing rapidly, clinicians need to consider the consequences of patients self-medicating with these preparations.

Plant Products as Antimicrobial Agents

Antimicrobial properties of tannins

https://zenodo.org/record/1259683/files/article.pdf

The conversion of procyanidins and prodelphinidins to cyanidin and delphinidin

Eating five servings of fruits and vegetables per day! This is what is highly recommended and heavily advertised nowadays to the general public to stay fit and healthy! Drinking green tea on a regular basis, eating chocolate from time to time, as well as savoring a couple of glasses of red wine per day have been claimed to increase life expectancy even further! Why? The answer is in fact still under scientific scrutiny, but a particular class of compounds naturally occurring in fruits and vegetables is considered to be crucial for the expression of such human health benefits: the polyphenols! What are these plant products really? What are their physicochemical properties? How do they express their biological activity? Are they really valuable for disease prevention? Can they be used to develop new pharmaceutical drugs? What recent progress has been made toward their preparation by organic synthesis? This Review gives answers from a chemical perspective, summarizes the state of the art, and highlights the most significant advances in the field of polyphenol research.

Plant Polyphenols: Chemical Properties, Biological Activities, and Synthesis

Preface Wood and Society, Christopher D. Risbrudt STRUCTURE AND CHEMISTRY Structure and Function of Wood, Alex C. Wiedenhoeft and Regis B. Miller Cell Wall Chemistry, Roger M. Rowell, Roger Pettersen, James S. Han, Jeffrey S. Rowell, and Mandla A. Tshabalala PROPERTIES Moisture Properties, Roger M. Rowell Biological Properties, Rebecca E. Ibach Thermal Properties, Roger M. Rowell and Susan L. LeVan-Green Weathering of Wood, R. Sam Williams Surface Characterization, Mandla A. Tshabalala WOOD COMPOSITES Wood Adhesion and Adhesives, Charles R. Frihart Wood Composites, Lars Bergland and Roger M. Rowell Chemistry of Wood Strength, Jerrold E. Winandy and Roger M. Rowell Fiber Webs, Roger M. Rowell, James S. Han and Von Y. Byrd Wood Thermoplastic Composites, Daniel F. Caulfield, Craig Clemons, Rodney E. Jacobson, and Roger M. Rowell PROPERTY IMPROVEMENTS Chemical Modification of Wood, Roger M. Rowell Lumen Modifications, Rebecca E. Ibach and W. Dale Ellis Plasma Treatment of Wood, Ferencz S. Denes, L. Emilio Cruz-Barba, and Sorin Manolache

Handbook of Wood Chemistry and Wood Composites

Hemlock and Spruce Tannins: An Odyssey.- Biogenesis.- Tannins - Their Place in Plant Metabolism.- The Enzymology of Proanthocyanidin Biosynthesis.- Biogenesis of Condensed Tannins: An Overview.- Structure.- Structural Variations in Proanthocyanidins and Their Derivatives.- Chemical Nature of Phlobaphenes.- Conformational Analysis of Oligomeric Proanthocyanidins.- An Overview of Condensed Tannin Structure.- Analytical Methods.- Chromatography of Proanthocyanidins.- New NMR Experiments Applicable to Structure and Conformational Analysis.- FAB-MS Applications in the Elucidation of Proanthocyanidin Structures.- Analytical Methods: An Overview.- Reactions.- MNDO Molecular Orbital Analyses of Models for Proanthocyanidin-Methylolphenol Reactions.- Reactions at the A-Ring of Proanthocyanidins.- Chemistry of the Condensed Tannin B-Ring.- Reactions at the Interflavanoid Bond of Proanthocyanidins.- Base-Catalyzed Pyran Rearrangements of Profisetinidins.- Key Reactions in Developing Uses for Condensed Tannins: An Overview.- Complexation.- Carbohydrate - Polyphenol Complexation.- Chemistry of Tannin-Protein Complexation.- Interaction of Condensed Tannins with Biopolymers.- Biological Significance.- Microscopic Studies of Tannin Formation and Distribution in Plant Tissues.- Condensed Tannins in Southern Pines and Their Interactions with the Ecosystem.- Effects of Condensed Tannin on Animal Nutrition.- Tannin as a Carcinogen in Bush-Tea: Tea, Mate', and Khat.- Tannin-Insect Interactions.- Are Tannins Resistance Factors against Rust Fungi?.- The Biological Significance of Tannins: An Overview.- Specialty Chemicals.- Tannin-Based Wood Adhesives.- Adhesives Containing Pine Bark Tannin for Bonding Nylon Cord to Rubber.- Using Tannins to Produce Leather.- Condensed Tannins as a Source of Novel Biocides.- Tannins as Specialty Chemicals: An Overview.- Concluding Remarks.- Future Conferences.- Indexes.- Participants.- Author Index.

Chemistry and Significance of Condensed Tannins

Introduction: Reflections on the Chemistry and Affinities of the Major Commercial Tannins in the Context of their Industrial Use D.G. Roux. Biogenesis and Synthesis: Enzymes in the Biosynthesis of Hydrolyzable Tannins G.G. Gross. Biosynthesis of Flavenoids G. Hrazdina. Chemical Properties: Gallic Acid at its Metabolites E. Haslam. Chinquapinic Acid M. Adamczeski, et al. Biological Significance: Plant Phenolics as Expressions of Biological Diversity O.R. Gottlieb. Pharmacologically Active Tannins Isolated from Medicinal Plants T. Okuda, et al. Commercial Significance: Flavor, Color, and Stability in Fruit Products A.G.H. Lea. Tannins and the Qualities of Wines V.L. Singleton. Conclusions: Concluding Remarks P.E. Laks, R.W. Hemmingway. 54 additional articles. Index.

Plant polyphenols : synthesis, properties, significance

Summary The condensed tannins are natural wood preservatives found in high concentrations in the bark and wood of some tree species Condensed tannin-containing bark extracts from loblolly pine (Pinus taeda) were evaluated as wood preservatives using standard methods Bark extracts by themselves did not cause any reduction in weight loss of pressure-treated wood blocks at the retentions tested However, they do have efficacy as wood preservatives when complexed with copper (II) ions The best experimental wood preservative formulation was a dual treatment using a sulphited bark extract first, followed by a Cu~ treatment At some retentions, this method yielded wood blocks with greater resistance to decay by Corio/us versicolor than pentachlorophenol A single stage treatment of extract plus copper using an aqueous ammoniacal solvent was also successful but not as effective as the dual treatment

/pdf/flavonoid-biocides-wood-preservatives-based-on-condensed-5dtbg5yh5g.pdf

Flavonoid Biocides: Wood Preservatives Based on Condensed Tannins

Adhesives from Renewable Resources: Historical Perspective and Wood Industry Needs Lignin in Adhesives: Introduction and Historical Perspective Search for Lignin Condensation Reactions with Modern NMR Techniques Cross-Linking Options for Lignins Modification of Lignins for Use in Phenolic Resins Adhesive Feedstocks from Lignin: Mechanistic Studies on the Oxidative-Cleavage Reaction of Some Lignin Model Compounds Soda Bagasse Lignin Adhesives for Particleboard: Preliminary Results Effects of Phenol-Formaldehyde Copolymer on Gluebond Performance of Lignin-Phenolic Resin Systems Durable Wood Adhesives from Kraft Lignin Room-Temperature Curing Adhesives Based on Lignin and Phenoloxidases Biomass Pyrolysis Oil Feedstocks for Phenolic Adhesives Condensed Tannins in Adhesives: Introduction and Historical Perspectives Viscosity and Formaldehyde Consumption of Procyanidin Solutions Reactions of Tannin Model Compounds with Methylolphenols Tannin-Based Adhesives for Finger-Jointing Wood Activation of Some Condensed Tannins via Facile Ring Isomerizations: Potential Adhesive Applications Modification of Diisocyanate-Based Particleboard and Plywood Glues with Natural Polymers: Polyphenols, Carbohydrates, and Proteins Condensed Tannins as Substitutes for Resorcinol in Bonding Polyester and Nylon Cord to Rubber Research vs. Industrial Practice with Tannin-Based Adhesives Carbohydrates in Adhesives: Introduction and Historical Perspective Cellulosic Adhesives Utilization of Soda Bagasse Hemicellulose as Corrugated Board Adhesives Starch- and Dextrin-Based Adhesives Cullulose Graft Copolymers for Potential Adhesive Applications: Bonding of Plastics to Wood Carbohydrate-Modified Phenol-Formaldehyde Resins Formulated as Neutral Conditions Glucose, Urea, and Phenol-Based Adhesive for Bonding Wood Fast-Curing Carbohydrate-Based Adhesives Thermosetting Adhesive Resins from Whey and Whey Byproducts Chemistry of Furan Polymers Polyurethanes from Renewable Resourses Blood and Casein Adhesives for Bonding Wood Development of a Microbial System for Production of Mussel Adhesive Protein Adhesives from Marine Mussels Opportunities for Future Development of Adhesives from Renewable Resources

Adhesives from renewable resources

https://www.srs.fs.usda.gov/pubs/ja/ja_williams008.pdf

Richard W. Hemingway

Papers

Chemistry and Significance of Condensed Tannins

Plant polyphenols : synthesis, properties, significance

Flavonoid Biocides: Wood Preservatives Based on Condensed Tannins

Adhesives from renewable resources

Molecular weight profiles of proanthocyanidin polymers