locant


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locant

[′lō‚kant]
(chemistry)
The portion of a chemical name, usually a number or a letter, that designates the position of an atom or group of atoms in a formula unit.
References in periodicals archive ?
Locant [[delta].sub.exp] 7LysP 7[LysP.sub.a] 7[LysP.sub.b] A 2.37 2.3 2.29 2.32 B 7.65 7.31 7.32 7.3 NH 13.67 13.16 13.16 13.17 C 7.85 8.26 8.24 8.26 D 7.43 7.49 7.48 7.51 E 4.08 4.32 4.33 4.31 Locant 7[LysP.sub.c] [[delta].sub.7LysP] [[delta].sub.7LysPa] A 2.32 0.08 0.09 B 7.31 0.34 0.33 NH 13.11 0.51 0.51 C 8.28 0.41 0.39 D 7.51 0.05 0.05 E 4.31 0.24 0.26 Locant [[delta].sub.7LysPb] [[delta].sub.7LysPc] A 0.06 0.06 B 0.35 0.34 NH 0.5 0.56 C 0.41 0.42 D 0.08 0.08 E 0.23 0.24 Locant [delta] [DELTA][delta] A 0.07 3 B 0.34 4 NH 0.52 4 C 0.41 5 D 0.07 1 E 0.24 6
The locant 2 may be omitted if no ambiguity can arise, especially in a biochemical context.
Among the improvements are uniformly cited locants, a reduction in the number of stereoparent names, and the elimination of nearly 3,000 obscure stereoparents.