General Aspects and Nomenclature

General Aspects and Nomenclature.—A four-volume work entitled The Enzymes of Biological Membranes deals with physical and chemical techniques used to identify the enzymes, the biosynthesis of cell components, membrane- and electron-transport systems, and receptors.  

The first supplement to Enzyme Nomenclature - Recommendations (1972) of the International Union of Pure and Applied Chemistry and the International Union of Biochemistry contains corrections and additions based on the literature up to 1975. Various -o-glucan hydrolases can be distinguished by determining whether or not they hydrolyse cellulose, reduced Sill pneumococcal polysaccharide, lichenin, and laminarin.  

The spectroscopic behaviour of the homoisoflavanones resembles very closely that of flavonoids 48). The data clearly indicate the presence of sixteen carbon atoms in the basic skeleton and are consistent only with a 3-benzyl(idene)chroman-4-one structure. This has been proven by synthesis of ( )-5,7-dimethoxy-3(4-methoxybenzylidene)chroman-4-one (33) which was identical with the di-O-methyl derivative of ( )-eucomin (3) (9). 

Dewick 19) suggested abandonment of the term homoisoflavanoid in favor of the more systematic name 3-benzylchroman-4-one, because biosynthetic studies revealed that the 2,3-rearrangement of the Ce-Cs-Ce moiety typical of isoflavonoids had not occurred. For practical reasons however we wish to maintain the term homoisoflavanone which allows one to include the structurally more complex scillascillins. 

A third edition of the well-known book Enzymes by Dixon and Webb reflects the changes and developments which have occurred in the area of enzyme chemistry. Enzyme techniques, isolation, kinetics, classification, specificity, mechanisms, inhibition and activation, co-factors, structure, biosynthesis, and biology are all covered. Most of the material has been rewritten but, despite the wealth of new material included, the book retains the general form of the previous editions. 

Three further volumes of the well-known series Methods in Enzymology deal with the following aspects of biomembranes Biological Oxidations — Specialized techniques Bioenergetics — Oxidative phosphorylation and Bioenergetics — Biogenesis of mitochondria, organization, and transport.  

A two part compendium in the Monographs in Human Genetics series deals with inborn errors of metabolism in man and covers carbohydrate, amino-acid, and lipid metabolism and connective tissues and purine metabolism and endocrinology.  

Methods of Assay. — The Technicon basic autoanalyser sampler system has been modified for simultaneous sampling of glycoside hydrolases and substrate-buffer solutions. This inexpensive modification allows performance of automated enzyme analysis and enzyme kinetic studies with minimal consumption of substrate and/or enzyme. 

---

Helmchen G (1996) A. General aspects. 1. Nomenclature and vocabulary of organic stereochemistry. In Helmchen G, Hoffinann RW, Mulzer J, Schaumann E (eds) Stereoselective Synthesis. Methods of Organic Chemistry (Houben-Weyl), Workbench Edition E21, vol 1,4th edn. Georg Thieme, Stuttgart, New York, pp 1-74 Hirschmann H (1983) Trans N Y Acad Sci Ser II 41 61-69 Hirschmann H, Hanson KR (1971a) Eur J Biochem 22 301-309 Hirschmann H, Hanson KR (1971b) J Org Chem 36 3293-3306... 

Currie LA (1995), IUPAC, Analytical Chemistry Division, Commission on General Aspects of Analytical Chemistry. Nomenclature in evaluation of analytical methods including detection and quantification capabilities. Pure Appl Chem 67 1699... 

Another characteristic point is the special attention that in intermetallic science, as in several fields of chemistry, needs to be dedicated to the structural aspects and to the description of the phases. The structure of intermetallic alloys in their different states, liquid, amorphous (glassy), quasi-crystalline and fully, three-dimensionally (3D) periodic crystalline are closely related to the different properties shown by these substances. Two chapters are therefore dedicated to selected aspects of intermetallic structural chemistry. Particular attention is dedicated to the solid state, in which a very large variety of properties and structures can be found. Solid intermetallic phases, generally non-molecular by nature, are characterized by their 3D crystal (or quasicrystal) structure. A great many crystal structures (often complex or very complex) have been elucidated, and intermetallic crystallochemistry is a fundamental topic of reference. A great number of papers have been published containing results obtained by powder and single crystal X-ray diffractometry and by neutron and electron diffraction methods. A characteristic nomenclature and several symbols and representations have been developed for the description, classification and identification of these phases. 

It is anticipated that readers will already be familiar with many of the general principles of nomenclature and will be able to name a range of simple compounds. It is not the object of this section to provide an exhaustive series of instmctions for naming every class of compound. Instead, the examples chosen here (Box 1.1) have been selected to illustrate some of the perhaps less familiar aspects that will be commonly encountered, and to foster a general understanding of the approach to nomenclature. 

General Considerations Introduction. A Note on Classes and Nomenclature. Bonding and Structure in Hypervalent Iodine. Reactivity Patterns. Practical Aspects. General References. 

The most important general characteristics, structures and nomenclature of the biflavonoids have been covered, and biological activities are carefully displayed. The structmal aspects of the biflavonoids are shown in a detailed list of figmes, thus providing an overview of their structmal featmes. The current status and futme prospects of the structure-activity studies of these compounds are also discussed. 

---