Continued from 2-Carb-23
2-Carb-24.1. Acyl (alkyl) names
Substituents replacing the hydrogen atom of an alcoholic hydroxy group of a saccharide or saccharide derivative are denoted as O-substituents. The 'O-' locant is not repeated for multiple replacements by the same atom or group. Number locants are used as necessary to specify the positions of substituents; they are not required for compounds fully substituted by identical groups. Alternative periphrase names for esters, ethers, etc. may be useful for indexing purposes. For cyclic acetals see 2-Carb-28.
or D-galactopyranose 6-methanesulfonate
Note. Acyl substituents on anomeric OH are designated (as above) by O-acyl prefixes. However, anomeric O-alkyl derivatives are named as glycosides (see 2-Carb-33).
2-Carb-24.2. Phosphorus oxoacid esters
Of special biochemical importance are the esters of monosaccharides with phosphoric acid. They are generally termed phosphates (e.g. glucose 6-phosphate). In biochemical use, the term 'phosphate' indicates the phosphate residue regardless of the state of ionization or the counter ions.
The prefix terms used for phosphate esters in organic nomenclature (, p.65) are 'O-phosphono-' and 'O-phosphonato-' for the groups (HO)2P(O)- and (O-)2P(O)- respectively, bonded to oxygen.
The term 'phospho-' is used for (HO)2P(O)- or ionized forms in a biochemical context (see recommendations for the nomenclature of phosphorus-containing compounds ).
If a sugar is esterified with two or more phosphate groups, the compound is termed bisphosphate, trisphosphate etc. (e.g. fructofuranose 1,6-bisphosphate). The term diphosphate denotes an ester with diphosphoric acid, e.g. adenosine 5'-diphosphate.
Note. In abbreviations, a capital P is used to indicate a terminal -PO3H2 group or a non-terminal -PO2H- group (or dehydronated forms).
(biochemical usage: glucose 1-phosphate) (Glc1P)
D-Glucopyranose 6-phosphate (often shortened to glucose 6-phosphate)
or 6-phospho-D-glucose (Glc6P) (in a biochemical context)
(often shortened to fructose 1,6-bisphosphate)
or 3-phospho-D-glyceroyl phosphate
or 1,3-bisphospho-D-glycerate (for biochemical usage)
(biochemical usage: glucuronate 1-phosphate) (GlcA1P)
Adenosine 5'-diphosphate (ADP) or 5'-diphosphoadenosine
Uridine 5'-(α-D-glucopyranosyl diphosphate)
(trivial name uridinediphosphoglucose) (UDP-Glc)
Cytidine 5'-(5-acetamido-3,5-dideoxy-D-glycero-β-D-galacto-non-2-ulopyranosylonic acid monophosphate) (CMP-β-Neu5Ac)
The following examples illustrate the use of phosphonate terminology for esters of phosphonic acid, HP(O)(OH)2. For formation of the alternative (substitutive) names, see 2-Carb-31.2.
Derivatives substituted on phosphorus are named by standard procedures [13, 14]; e.g. P-methyl derivatives are named as methylphosphonates.
Compounds with a phosphonate group linked by a P-C bond to a carbohydrate residue may be named as glycos-n-ylphosphonates (cf. 2-Carb-31.2) or as C-substituted carbohydrates (cf. amino sugars, 2-Carb-14).
Esters of phosphinic acid, H2P(O)(OH), are named by the same methods as used for phosphonates. For examples with two P-C bonds see 2-Carb-31.3.
The prefix terms used for sulfuric esters are 'O-sulfo-' and 'O-sulfonato-', for the groups (HO)S(O)2- and (O-)S(O)2- respectively, bonded to oxygen. Sulfates may also be named by citing the word 'sulfate', preceded by the appropriate locant, after the carbohydrate name.
The mixed sulfuric phosphoric anhydride (PAdoPS or PAPS) of 3'-phospho-5'-adenylic acid is named as an acyl sulfate:
13. IUPAC Nomenclature of Organic Chemistry, Sections A, B, C, D, E, F and H, 1979 Edition, Pergamon Press, Oxford, U.K. Sections E and F are reprinted in ref. 2, pp. 1-18 and 19-26, respectively.
14. Guide to IUPAC Nomenclature of Organic Compounds, Recommendations 1993, Blackwell Scientific Publications, Oxford (1993).
24. IUPAC-IUB Commission on Biochemical Nomenclature (CBN), Nomenclature of phosphorus-containing compounds of biochemical importance (Recommendations 1976), Hoppe-Seylers Z. Physiol. Chem., 358, 599-616 (1977); Eur. J. Biochem., 79, 1-9 (1977); Proc. Natl. Acad. Sci. USA, 74, 2222-2230 (1977); Biochem. J., 171, 1-19 (1978); ref. 2. pp. 256-265.
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