Main description:

Substances belonging to this group of organic compounds are wi,lely distributed in Nature, being found in plants, both higher and lower fungi and, upto the present time, in one animal source, sheep wool-fat. For a long time no real differentiation was possible between the tetra- and penta cyclic triterpenes and the sterols. Then the two latter became disting uishable by their selenium. *dehydrogenation products, i. e. , picene and naphthalene derivatives from the pentacyclic triterpenes and DIELS' hydrocarbon from the sterols. It is now apparent that those compounds yielding predominantly I: 2: 8-trimethylphenanthrene on dehydro genation represent yet another class, and this property is regarded as typical of the tetracyclic triterpenes. The group contains both C and C 30 3l compounds and, although the latter fall outside RUZICKA'S strict definition of triterpenes (I42), it seems desirable to permit this deviation. Members with thirty-two carbon atoms may well be discovered in due course. In a most* valuable account of the triterpenes written in I949, JEGER. (II3) was able to summarize all that was known about the tetra cyclic group in a very small compass. Most of the work discussed in the present article has been published during the last five years and in that time the structures of some twenty compounds have been elucidated. Of outstanding importance is the revelation of close structural relation ships tQ the steroids, and the presence of C and C side-chains, skeletally 8 9 identical with those of cholesterol and ergosterol.

Contents:

/ Contents / Table des matieres.- Sesquiterpenes and Diterpenes.- I. Sesquiterpenes.- 1. Acyclic Sesquiterpenes.- 2. Bisabolene and Cadinene Type Sesquiterpenes.- 3. Eudesmol Type Sesquiterpenes.- 4. Elemol.- 5. Eremophilone.- 6. Iresin.- 7. Azulene Type Sesquiterpenes.- Synthesis and Properties of Azulenes.- 8. Longifolene.- 9. Caryophyllene.- 10. ?-Caryophyllene Alcohol.- 11. Humulene.- 12. Cedrene.- II. Diterpenes.- 1. Structure.- 2. Stereochemistry of the Diterpenes.- III. The Biogenesis of Sesqui- and Diterpenes.- Biogenesis and Nomenclature.- References.- Tetracyclic Triterpenes.- I. Introduction.- II. Lanostane Type Group.- 1. Lanosterol Group.- Occurrence and Isolation.- Nomenclature.- Interrelationship of Lanosterol, Agnosterol and their Dihydro-derivatives.- Structure of Lanosterol.- Location of the Inert Double Bond.- The Side-chain and Ring D.- Stereochemistry of Lanosterol.- Rings A and B.- Rings C and D.- Side-chain Configuration.- Stereochemistry at C(8) and C(9) in Lanostane Derivatives.- Lanost-7-enol.- Synthesis oi Lanostenol.- 2. Eburicoic Acid.- 3. Polyporenic Acid A.- 4. Polyporenic Acid C.- 5. Tumulosic Acid (Polyporenic Acid B).- 6. Pinicolic Acid A.- 7. Trametenolic Acid A.- 8. cycloArtenol.- 9. cycloLaudenol.- III. Euphane Type Group.- 1. Euphol.- 2. Butyrospermol.- 3. Tirucallol.- 4. Euphorbol.- 5. The Acids of Manila Elemi Resin.- IV. Compounds of Unknown Structure.- References.- Neuere Vorstellungen auf dem Gebiete der Biosynthese der Steroide und verwandter Naturstoffe.- I. Einleitung.- II. Steroidbiogenese mit markierten Verbindungen.- 1. Essigsaure als Baustein.- 2. Die Rolle des Squalens.- III. Unsere Kenntnisse der biologischen Beziehungen der Steroide untereinander.- 1. Ein C27-Sterol als Vorstufe der Pflanzensterole mit 28 und 29 C-Atomen.- 2. Gibt es Unterschiede der Biosynthese von Steroiden bei Tieren und Pflanzen?.- 3. Ist ein C27-Sterol obligates Zwischenprodukt bei der Biogenese aller Steroide?.- 4. Die C30- und C31-Steroide.- IV. Die Hypothesen der Steroidbiogenese.- 1. Squalen-Hypothese.- 2. Isosqualen-Hypothese.- 3. Hypothese von Miescher.- 4. Hypothese von Tschesche und Korte.- 5. Neue Vorstellungen.- V. Schlussbetrachtung.- Some Biochemical Aspects of Fungal Carotenoids.- I. Introduction.- II. Occurrence of Carotenoids in Fungi.- 1. Carotenes with Formula C40H56.- 2. Carotenoid Hydrocarbons more Saturated than C40H56.- 3. Neutral Xanthophylls.- 4. Acidic Xanthophylls.- III. Carotenoid Formation in Fungi.- 1. Interrelationships of the C40-Polyenes.- a) Mutant Studies.- b) Inhibitor Studies.- c) Studies of Light-Activated Carotenoid Synthesis.- d) Temperature Studies.- 2. Precursors of the C40-Polyenes.- IV. Physiological Role of Fungal Carotenoids.- 1. Carotenoids in Sexual and Reproductive Processes.- 2. Carotenoids as Photosensitizers.- V. Conclusion.- References.- The Pyrrolizidine Alkaloids.- I. Introduction: Origin, Occurrence and Nature of the Pyrrolizidine Alkaloids.- Nature of the Pyrrolizidine Alkaloids.- Isolation.- II. The Basic Hydrolysis Products.- Retronecine, Platynecine and Heliotridine as Derivatives of Heliotridane.- The Degradation of Heliotridane.- The Structure of Retronecine and Platynecine.- The Structure of Heliotridine.- Monohydroxy-methylpyrrolizidines : Trachelanthamidine and Supinidine.- N-Oxides: Trachelanthidine and Isatinecine.- Syntheses of Pyrrolizidine Bases.- Stereochemistry and Syntheses of Heliotridane, Pseudo-heliotridane and their Derivatives.- Trihydroxy-methylpyrrohzidine: Rosmarinecine.- Bases of Unknown Structure: Mikanecine, Hastanecine, Turneforcidine and Otonecine.- Summary of the Structures of the Bases.- III. The Acid Hydrolysis Products.- C10-Acids.- Isatinecic and Retronecic Acids.- Senecic, Integerrinecic and Usaramoensinecic Acids.- Seneciphyllic and isoSeneciphyllic Acids.- Riddellic Acid.- Sceleranecic and Sceleratinic Acids.- Jaconecic Acid and the Neutral Lactone from Jaconine.- C10-Acids of Undetermined Structure.- Senecifolic, Squalinecic, Mikanecic, Grantianic and Hastanecic Acids.- Monocrotalic and Dicrotalic Acids.- Acids having Seven-Carbon Skeleton Structures.- Trachelanthic Acid.- Viridifloric Acid.- Heliotrinic Acid.- Lasiocarpic Acid.- Acid from Makrotomine.- Acid from Trichodesmine.- IV. The Structures of the Alkaloids.- Alkaloids from Monohydroxy-methylpyrrolizidines.- A. Alkaloids of Trachelanthamidine.- Trachelanthamine.- Viridiflorine.- Makrotomine.- B. Alkaloids from Supinidine.- Supinine.- 'Base C'.- C. Alkaloids from D-isoRetronecanol.- Lindelofine.- Lindelofamine.- Alkaloids from Heliotridine: Heliotrine, 'Base G' Lasiocarpine.- C18-Alkaloids from Retronecine, Platynecine and Rosmarinecine.- Retrorsine, Isatidine.- Riddelliine.- Senecionine.- Integerrimine.- Usaramoensine.- Platyphylline.- Rosmarinine.- Seneciphylline.- Grantianine.- Sarracine.- Sceleratine.- Senecifoline.- Alkaloids from Senecio brasiliensis.- Monocrotaline.- Dicrotaline.- The Alkaloids as N-Oxides.- V. Pharmacology (with M. E. Von Klemperer).- References.- Paper Chromatography in the Study of the Structure of Peptides and Proteins.- I. Principles of Paper Chromatography.- II. Paper Chromatographic Techniques.- 1. Choice of Paper.- 2. Preparation of the Material for Chromatography.- 3. Application of the Material to the Paper.- 4. Effect of pH.- 5. Apparatus.- 6. Solvents.- 7. Drying of Chromatograms.- 8. Detection of Amino Acids, Peptides and Proteins on Paper.- a) General Reagents.- b) Non-Specific Reagents.- c) Specific Colour Reactions for Some Amino Acids and Peptides.- III. The Determination of the Amino Acid Composition of Peptides and Proteins.- 1. Qualitative Analysis.- 2. Quantitative Analysis.- a) Measurements Applied Directly on the Paper.- b) Methods Involving Elution from the Paper after Reaction with a Reagent.- c) Methods Involving Elution from the Paper before Reaction.- IV. Identification of Terminal Sequences in Peptides and Proteins.- 1. N-Terminal Sequences.- a) Dinitrofluorobenzene Method.- b) Isothiocyanate Method.- c) Other Methods.- 2. C-Terminal Sequences.- a) Carboxypeptidase Method.- b) Reduction Methods.- c) Other Methods.- 3. Conclusion.- V. The Determination of Amino Acid Sequences in Long Chain Polypeptides and Proteins.- 1. Separation of Component Chains.- 2. Methods for the Partial Hydrolysis of Peptides and Proteins.- 3. Isolation and Purification of Peptides.- 4. Deduction of Polypeptide Sequence from the Structure of Lower Peptides.- VI. Concluding Remarks.- References.- Acides amines iodes et iodoproteines.- I. Introduction.- II. Les acides amines iodes.- 1. Caracteres analytiques generaux des acides amines iodes.- 2. Iodotyrosines et iodohistidines.- a) Iodotyrosines.- 1 Degrees L-3-Monoiodotyrosine.- 2 Degrees L-3 : 5-Diiodotyrosine.- b) Iodohistidines.- c) Reaction d'ioduration de la L-tyrosine, de la L-histidine et de leurs derives.- 3. Iodothyronines et derives.- a) Iodothyronines.- 1 Degrees Monoiodothyronines.- 2 Degrees Diiodothyronines.- 3 Degrees Triiodothyronines.- 4 Degrees Thyroxine.- b) Derives de la thyronine.- 1 Degrees Derives substitues sur les noyaux.- 2 Degrees Derives substitues sur le phenol.- 3 Degrees Modification de la liaison entre les deux noyaux.- c) Derives de la thyronine avec modifications de la chaine laterale.- 1 Degrees Acides amines et derives.- 2 Degrees Acides.- 4. Acides amines marques par I131.- a) Iodotyrosines marquees.- b) Iodothyronines marquees.- III. Iodoproteines.- 1. Proteines artificiellement iodees.- a) Ioduration des proteines et reactions de substitution.- b) Formation de thyroxine au cours de l'ioduration des proteins.- c) Mecanisme chimique de formation de la thyroxine et de la 3 : 5 : 3?-triiodothyronine.- 2. Thyroglobuline.- a) Preparation.- b) Proprietes et composition en acides amines.- c) Iode et acides amines iodes.- 3. Scleroproteines iodees.- a) Gorgpnines et antipathines.- b) Spongines.- Bibliographie.- Chemistry and Biochemistry of Snake Venoms.- I. Introduction.- II. Snakes and Venoms.- 1. Zoological Classification of Poisonous Snakes.- 2. Poison Apparatus.- 3. Extraction of Venom.- 4. Drying and Conservation of Venom.- III. The Action of Venoms.- 1. Pharmacological Activity.- a) "Curare" Group.- b) Circulation Group.- c) Hemorrhagic Group.- d) Toxic Value.- 2. Enzymic Activity.- IV. Enzymes from Snake Venoms.- 1. Esterases.- a) Phospholipase A (Lecithinase A).- b) Phospholipases B and C.- c) Phosphoesterases.- d) 5-Nucleotidase.- e) Adenosine triphosphatase (ATPase).- f) Ophio-cholinesterase (OChEase).- 2. Carbohydrases : Hyaluronidase.- 3. Proteases.- a) Proteinases.- b) Peptidases.- c) Proteolytic Enzymes and Coagulation.- 4. Oxidases.- a) Catalase.- b) Ophio-L-Amino Acid Oxidase (OAAO).- 5. Inhibiting Enzymes.- V. Separation, Purification, and Crystallization of Biologically Active Venom Constituents.- 1. Non-proteins.- 2. First Attempts, to Separate Active Proteins.- 3. The Active Principles from Naja Venoms.- a) Neurotoxin.- b) Constitution of Neurotoxin.- c) Hemolysin.- d) Properties and Composition of Crystalline Hemolysin.- e) Cholinesterase.- f) Cardiotoxin.- g) Inhibitor.- 4. Neurotoxin from Bungarus fasciatus Venom.- 5. The Neurotoxic and Coagulating Principles from Vipera russellii Venom.- 6. Active Proteins from Crotalus t. terrificus Venom.- a) Coagulin.- b) Preparation of Crotoxin.- c) Composition, Chemical Properties and Homogeneity of Crotoxin.- d) Biological Properties of Crotoxin.- e) The Structure of Crotoxin.- VI. Electrophoresis of Snake Venoms.- References.- Gene Structure and Gene Action.- The Gene as a Biological Unit.- The Chemistry of the Genetic Material.- Transforming Principles.- The Genetics of Viruses.- The Structure of DNA.- Gene Specificity.- Gene Reproduction.- Gene Mutation.- Gene Function.- Genetics of Hemoglobin Structure.- Genes and Enzymes.- Genes and Aromatic Amino Acids.- Summarizing Discussion.- References.- Namenverzeichnis. Index of Names. Index des Auteurs.- Sachverzeichnis. Index of Subjects. Index des Matieres.