Naturally Occurring Organohalogen Compounds - A Comprehensive Update


Book Description

Despite the long association of organohalogen compounds with human activities, nature is the producer of nearly 5,000 halogen-containing chemicals. Once dismissed as accidents of nature or isolation artifacts, organohalogen compounds represent an important and ever growing class of natural products, in many cases exhibiting exceptional biological activity. Since the last comprehensive review in 1996 (Vol. 68, this series), there have been discovered an additional 2,500 organochlorine, organobromine, and other organohalogen compounds. These natural organohalogens are biosynthesized by bacteria, fungi, lichen, plants, marine organisms of all types, insects, and higher animals including humans. These compounds are also formed abiogenically, as in volcanoes, forest fires, and other geothermal events.In some instances, natural organohalogens are precisely the same chemicals that man synthesizes for industrial use, and some of the quantities of these natural chemicals far exceed the quantities emitted by man.







Fortschritte der Chemie organischer Naturstoffe / Progress in the Chemistry of Organic Natural Products


Book Description

Isocoumarins have been isolated from a wide variety of microbial, plant and insect sources and have been shown to possess an impressive array of biological activities. Since the review by BARRY in 1963 (24), the number of known naturally occurring isocoumarins has increased dramatically. This increase is largely due to improvements in isolation procedures and structural analysis. Previous reviews have concentrated on fungal isocoumarins (293,294) and mycotoxic isocoumarins (301). This review lists over 160 naturally occurring isocoumarins. Leading references on isolation, structure elucidation, biosynthesis and synthesis are given in the accompanying Tables. The known natural isocoumarins are listed in the Tables according to the number and orientation of oxygen atoms on the benzenoid ring and by carbon substituents. For completeness, those isocoumarins bearing additional fused carbocyclic rings and those containing nitro gen substituents are included in separate Tables. It is hoped that by using these Tables in conjunction with the Formula Index, the Trivial Name Index and the Source Index the reader will be able to locate key references in the literature and gain an understanding of the fascin ating chemistry and action of naturally occurring isocoumarins.







Fortschritte der Chemie organischer Naturstoffe / Progress in the Chemistry of Organic Natural Products 88


Book Description

The volumes contain contributions on various topics related to the origin, distribution, chemistry, synthesis, biochemistry, function or use of various classes of naturally occurring substances ranging from small molecules to biopolymers. Each contribution is written by a recognized authority in his field and provides a comprehensive and up-to-date review of the topic in question.
















Fortschritte der Chemie Organischer Naturstoffe / Progress in the Chemistry of Organic Natural Products / Progrès dans la Chimie des Substances Organiques Naturelles


Book Description

The properties of proteins are determined not only by the sequence of amino-acid residues in the polypeptide chains, but also by the con figuration of the chains-the way in which the chains are coiled or folded. It is probable that denaturation, the loss of some of the specific properties of a native protein, may in many cases be the result simply of a change in configuration of the polypeptide chains, without any change whatever in the sequence of amino-acid residues. During the past few years great progress has been made in the attack on the determination of the sequence of amino-acid residues in the poly peptide chains of proteins, through the work of SANGER and his collabora tors (Io9, IIO) and of other investigators. There has also been significant progress in the attack on the problem of the configuration of polypeptide chains, largely through the application of the X-ray diffraction technique.