Nomenclature Arabic numerals

The pneumococci all belong to different types of the same species, namely, Streptococcus pneumoniae. This was earlier called Diplococcus pneumoniae, but has been renamed.5 6 7 There are some 80 different types of pneumococcus, and two systems of nomenclature, the Danish, used in Europe, and Eddy s, used in the United States.8 Tables correlating the Danish and American designations have been published.8 The Danish system, with Arabic numerals and common abbreviations, such as Phi for Type 1 and SI for its type-specific, capsular polysaccharide, will be used in this article. 

Arabic numerals are crucially important in nomenclature their placement in a formula or name is especially significant. 

Metal-metal bonding is indicated by the italicized element symbols of the appropriate metal atoms, separated by an em dash and enclosed in parentheses, placed after the list of central atom names and before the ionic charge. The element symbols are placed in the same order as the central atoms appear in the name, i.e. with the element met last in the sequence of Table VI given first. The number of such metal-metal bonds is indicated by an arabic numeral placed before the first element symbol and separated from it by a space. For the purpose of nomenclature, no distinction is made between different metal-metal bond orders. 

A widely recognized nomenclature has been adopted that classifies these enzymes into families and subfamilies based on their amino acid sequence homology [4]. Families are defined as having > 40% homology in their amino acid sequence and are coded with the letters CYP and an Arabic numeral (e.g., CYPl). Subfamilies have a >55% homology in amino acid sequence and have an additional letter (e.g., CYPl A). Where more than one subfamily has been identified, an additional Arabic numeral is added to identify the first, second, third gene found (e.g., CYPlAl, CYP1A2). 

The name of a borane denotes the number of boron atoms, the number of hydrogen atoms, and the overall charge. The number of boron atoms is given by a Greek prefix (di-, tri-, tetra-, penta-, hexa- etc.), the exception being for nine and eleven, where the Latin nona- and undeca- are used. The number of hydrogen atoms is shown as an Arabic numeral in parentheses at the end of the name (see below). The charge for an ion is shown at the end of the name the nomenclature... 

The nomenclature for the prostaglandins (PGs) involves the assignment of a capital letter (PGE), an Arabic numeral subscript (PGEi), and, for the PGF family, a Greek letter subscript (e.g., PGF2C,). The capital letter, in this case F, refers to the ring substituents shown in figure 35.5. 

The cytochrome P-450 family is the most important class of enzymes involved in drug metabolism. The nomenclature uses an Arabic numeral to denote the family, followed by a capital letter to designate a subfamily, followed by another Arabic numeral to denote an individual gene/enzyme. In humans five CYP450 isoforms are commonly involved in hepatic drug metabolism lA, 2C, 2D, 2E, and 3A. Table 3.3 presents a summary of substrate specificities and inhibitors for the common isoforms. 

The nomenclature is that of Svennerholm (J. Neurochem. 10 (1963) 613-623) in which G = ganglioside, M = monosialo-, D - disialo-, T = trisialo-, and the arabic numerals indicate the sequence of migration on thin layer chromatograms. 

Even in the crystalline state, crotonase catalyzes different types of reactions (see Fig. 1-24). The discussion of these properties is simpler if some basic concepts in organic chemistry are reviewed. Many carboxylic acids have at least two different names—one is based on molecular structure and has been assigned by the International Union of Chemists (lUC) another, referred to as the trivial name, usually is derived from the name of the source in which the carboxylic acid was first discovered (butyric, oleic, etc.). The position of the substitutes on the carbon chain is denoted by either Greek letters or Arabic numerals. The numerals should be used with the lUC nomenclature, and the Greek letters correspond in numerical order with the trivial name. It is important to remember that the letter or number does not refer to the first carbon but to that carbon immediately adjacent to the carboxyl. 

It appeared useful in the text to designate compounds by arabic numerals or in a somewhat abbreviated fashion, for example as 1,3,5,7-tetrasilaadamantane, in referring to a particular basic structure, still in accordance with lUPAC nomenclature. 

There is no universally recognized system for the nomenclature of polymorphs. They are often labeled with Arabic (1, 2, 3,. . . ) or Roman (I, II, III, IV,. . . ) numerals, lowercase or uppercase Roman letters (a, b, c,. .. or A, B, C,. . . ) or lowercase Greek letters (a, (3, y,. . . ), or by names descriptive of properties (red form, low-temperature polymorph, metastable modification, etc.). If polymorphs are described by Roman numerals, it is a common convention to label the polymorph with the highest melting point with I, the one with the second highest with II, and so on. This notation vdll be used in this chapter. 

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