Main description:

Sulfonium compounds have been known to the organic chemist for almost 90 years. During most of this period they remained curiosities, well suited for didactic purposes to illustrate certain similarities to ether adducts and to organic ammonium compounds. Their exploration remained largely in the academic realm, because no unusual practical applications were found in spite of a steady increase in the attention paid to them. An event that occasionally puts a class of compounds into the center of interest is the recognition of its occurrence in nature and of special biological significance. The first natural sulfonium compound was discovered less than 20 years ago, somewhat by chance rather than as the climax of some coveted biochemical problem. Gradually, however, the unique role of sulfonium compounds, especially of S-adenosyl methionine, in enzymatic group transfer reactions such as trans methylation was recognized, and the recent upsurge of interest has been exceptional. The present review is directed toward an interpretation of the properties and functions of biological sulfonium compounds with frequent reference to their structural chemistry. The data presented here may suggest novel or improved analytical techniques and new interpretations of the mechanism of group transfer. Furthermore, a stimulus may be derived for the design of sulfonium compound analogues. The availability of competitive analogues of biochemical key compounds has aided in the understanding of the function of virtually all metabolic intermediates, prosthetic groups of enzymes, vitamins, amino acids, and other compounds. The pattern will be similar in sulfonium biochemistry.

Contents:

- Table des matieres.- Polysaccharides of Marine Algae.- I. Introduction.- II. Skeletal Polysaccharides of the Algal Cell-Wall.- 1. Cellulose in Algae.- 2. Mannans.- 3. Xylans.- 4. Conclusions.- III. Food Reserve Polysaccharides.- 1. Starch (Green Algae).- 2. Floridean Starch (Red Algae).- 3. Laminarin (Brown Algae).- 4. Conclusions.- IV. Polysaccharides Containing Sulphate Esters.- 1. Fucoidin (Brown Algae).- 2. Galactan Sulphates of Red Algae.- (a) Agarose Type.- (i) Agar.- (ii) Funori.- (iii) Porphyran.- (b) x-Carrageenan Type.- (i) Carrageenan.- (ii) Furcellaran.- (iii) Other Carrageenan Types.- (c) Miscellaneous.- (i) The Mucilage of Dilsea edulis.- (ii) Polysiphonia fastigiata.- 3. Polysaccharide Sulphates of Green Algae.- (a) Heteropolysaccharides Containing Sulphated Arabogalactans.- (i) Cladophora rupestris.- (ii) Caulerpa filiformis.- (iii) Codium fragile.- (b) Heteropolysaccharides Containing Glucuronic Acid.- (i) Ulva lactuca.- (ii) Acrosiphonia centralis.- (iii) Enteromorpha compressa.- 4. Conclusions.- V. Alginic Acid.- References.- Der Kohlenhydratstoffwechsel in Gerste, Hafer und Rispenhirse.- I. Die loeslichen Kohlenhydrate in der Gerste und ihre Konstitution.- II. Die loeslichen Kohlenhydrate im Hafer und ihre Konstitution.- III. Die loeslichen Kohlenhydrate in der Rispenhirse und ihre Konstitution.- IV. Die enzymatische Steuerung des Kohlenhydratstoffwechsels in den Getreidearten.- V. Zur Geschichte der Kultur der Getreidearten.- The Chemistry of Biological Sulfonium Compounds..- I. Introduction.- II. The Discovery of Sulfonium Compounds.- III. The Chemistry of Sulfonium Compounds.- 1. Formation and Structure.- 2. Mechanisms of Decomposition and Rearrangement.- 3. Stereoisomerism of the Sulfonium Group.- IV. In vitro Synthesis and Properties of Biological Sulfonium Compounds.- 1. Dimethyl-?-propiothetin.- 2. S-Methylsulfonium Salt of Methionine (S-Methylmethionine).- 3. S-Adenosylmethionine and Related Compounds.- a. In vitro Synthesis of S-Adenosylmethionine.- b. S-Adenosyl-3-methylmercaptopropylamine.- c. Hydrolysis of S-Adenosylmethionine.- d. Effect of Alkali on S-Adenosylmethionine and Related Compounds.- e. Diastereoisomers of S-Adenosylmethionine.- V. Origin and Metabolism of Biological Sulfonium Compounds.- 1. Dimethyl-?-propiothetin.- 2. S-Methylsulfonium Salt of Methionine (S-Methylmethionine).- 3. S-Adenosylmethionine.- VI. Metabolic Functions of Biological Sulfonium Compounds.- 1. Transmethylations.- a. General Considerations.- b. The Diversity of Methyl Acceptors.- c. Analytical Techniques.- d. Attempts to Explain the Mechanism of Transmethylation.- 2. Biosynthesis of Spermidine and Spermine.- 3. Formation of Homoserine Lactone and Homoserine from S-Adenosylmethionine.- VII. Derivatives and Analogues of Biological Sulfonium Compounds.- 1. Analogues for Metabolic Studies.- 2. Sulfonium Derivatives of Protein-bound Methionine.- References.- Some Aspects of the Chemistry and Function of Human and Animal Hemoglobins..- I. Introduction.- II. Nomenclature.- III. The Amino Acid Sequence of Human Hemoglobins A and F.- 1. Hemoglobin A.- a. The Amino Acid Sequence of the ?AChain.- b. The Amino Acid Sequence of the ?AChain.- 2. Hemoglobin F.- a. The Amino Acid Sequence of the ?F Chain.- b. The Amino Acid Sequence of the ?F Chain.- 3. A Comparison of Hemoglobins A and F.- 4. A Comparison of the ? and ? Chains.- IV. Other Hemoglobins in the Normal Human Individual.- 1. The Hemoglobin Components of the New-born Infant.- 2. The Hemoglobin Components of the Adult.- V. The Abnormal Human Hemoglobins.- 1. Methods.- 2. Nomenclature.- 3. Some General Genetic Considerations.- 4. Hemoglobins with Abnormalities in the ? Chain.- 5. Hemoglobins with Abnormalities in the ? Chain.- 6. Hemoglobins with Abnormalities in the ? Chain.- 7. Hemoglobins with Abnormalities in the ? Chain.- 8. Hemoglobins with Other Abnormalities.- 9. General Remarks.- VI Animal Hemoglobins.- 1. Gross Structure of Animal Hemoglobins.- 2. Adult and Fetal Forms.- 3. Nomenclature of the Animal Hemoglobins.- 4. Sequences in the Animal Hemoglobins.- a. ? Chains.- b. ? Chains.- c. ? Chains.- VII. Hemoglobin in Three Dimensions.- 1. Introduction.- 2. The Relationship between Hemoglobin and Myoglobin.- 3. Pertinent Aspects of the Structure of Myoglobin.- 4. The ? and ? Chains - Secondary and Tertiary Structure.- 5. The Quaternary Structure.- 6. The Three-dimensional Structure of Hemoglobins from Different Species.- 7. Oxygenation and Structural Alterations.- VIII. Chemical Modifications of Hemoglobin.- 1. Introduction.- 2. Reactions of the Heme Group.- 3. Titration Curves and their Interpretation.- 4. Reactions of the Sulfhydryl Group.- 5. Other Reactions.- 6. Conclusions.- IX. Reversible Dissociation and Subunit Hybridization of Hemoglobin.- 1. Introduction.- 2. Possible Modes of Dissociation.- 3. Evidence for Dissociation.- 4. Mechanism of Dissociation and Subunit Hybridization.- 5. Other Factors which Influence Dissociation and Subunit Hybridization.- 6. Comments on Dissociation and Hybridization.- X. The Biosynthesis of Hemoglobin.- 1. Introduction.- 2. Genetic Control of Hemoglobin Structure.- 3. Biosynthesis of the Polypeptide Chains of Globin.- a. The Activation of Amino Acids for Protein Biosynthesis.- b. DNA and the Role of m-RNA.- c. The Function of the Ribosomes.- d. The Assembling of the Polypeptide Chain.- e. The Final Release of the Protein.- 4. Biosynthesis of Heme.- 5. The Attachment of Heme to Globin Chains.- 6. Assembly of Chains into the Whole Hemoglobin Molecule.- References.- Kollagen.- I. Einleitung.- II. UEbersicht.- III. Aminosaurezusammensetzung.- 1. Kollagene der Wirbeltiere.- 2. Kollagene im niederen Tierreich.- IV. Primarstruktur.- 1. Aminosauresequenzen des Kollagens.- a. Partielle Saure- und Alkali-Hydrolyse.- b. Enzymatische Methoden.- ?) Abbau des denaturierten Kollagens mit Trypsin.- ?) Kollagenase - der Schlussel fur die apolaren Bereiche.- ?) Isolierung der apolaren Bereiche.- ?) Isolierung der polaren Bereiche.- 2 Alkali- und Hydroxylamin-empfindliche Bindungen, Endgruppen und Acetylgruppen.- 3. Quervernetzungen.- V. Sekundar- und Tertiarstruktur.- 1. Ergebnisse der Roentgenstruktur-Untersuchung.- 2. Physikalische Eigenschaften des nativen Kollagenmolekuls.- 3. Denaturiertes loesliches Kollagen.- VI. Zerfall und Ruckbildung der Sekundar- und Tertiarstruktur (De- und Renaturierung).- 1. Denaturierung in Loesung.- 2. Denaturierung im festen Zustand (Schrumpfung).- 3. Renaturierung in Loesung.- 4. Der De- und Renaturierung des Kollagens analoge Umwandlungen von (Pro * Gly * Pro)n in Loesung.- VII. Bau und Bildung der Fibrillen und Segmente (Quartarstrukturen).- 1. Die nativen Fibrillen.- a. Das Querstreifungsmuster.- b. Die Ursache der Querstreifung.- 2. Der molekulare Bau der verschiedenen Kollagenstrukturen.- a. Das Querstreifungsmuster der Long-spacing-Segmente (SLS).- b. Die Anordnung der Kollagenmolekule in den Fibrillen des nativen Typs.- c. Die Anordnung der Molekule in den Long-spacing-Fibrillen (FLS).- d. Die End-an-End-Zusammenlagerung der Kollagenmolekule.- 3. Die Fibrillenbildung.- 4. Die Beeinflussung der Fibrillenbildung in vitro.- VIII. Stoffwechsel des Kollagens.- 1. Biosynthese.- 2. Reifung und Alterung.- 3. Abbau im Koerper.- 4. Mineralisierung.- 5. Kollagenosen.- Some Applications of Nuclear Magnetic Resonance Spectroscopy in Natural Product Chemistry.- I. Introduction.- II. Principles of Application.- 1. Determination of Empirical Formulae.- 2. Determination of the Classes of Protons in a Molecule. The Chemical Shift.- 3. The Number of Protons in a Given Class. Intensities.- 4. The Sequence of Groups in Molecules. Electron Coupled Spin-Spin Interaction.- 5. An Example of Application to Structure Determination.- 6. Applications to the Elucidation of Relative Stereochemistry and Conformation.- III. Examples in Natural Product Chemistry.- 1. Steroids.- 2. Carbohydrates.- 3. Carotenoids and Acyclic Terpenes.- 4. Flavonoids and Related Compounds.- 5. Alkaloids.- References.- Namenverzeichnis. Index of Names. Index des Auteurs.- Sachverzeichnis. Index of Subjects. Index des Matieres.