Nomenclature and Symbolism for Amino Acids and Peptides

3AA-18.1 Tables 2-4

This version of Tables 2-4 does not use the HTML table format.

Table 2. Nitrogen substituents (protecting groups) of the urethane type Note i

 Benzyloxycarbonyl-                                       Z- or Cbz- 
 2-(p-Biphenylyl)isopropyloxycarbonyl- [strictly          Bpoc-
 p-Bromobenzyloxycarbonyl-                                Z(Br)-  
 t-Butoxycarbonyl-                                        Boc- or Bu[t]OCO-
                                                          or t-BuOCO- or Me3C-OCO-  

 [alpha],[alpha]-Dimethyl-3,5-dimethoxybenzyloxycarbonyl- Ddz-  
 Fluoren-9-ylmethoxycarbonyl-                             Fmoc-  
 p-Methoxybenzyloxycarbonyl-                              Z(OMe)-  
 p-Nitrobenzyloxycarbonyl-                                Z(NO2)- 
 p-Phenylazobenzyloxycarbonyl-                            Pz-  
Note (i) In the name column the locant "p-" should be in italics and in the symbol column the numbers should be subscript and the [t] should be a superscript "t".

Table 3. Non-urethane substituents for nitrogen, oxygen or sulfur Note iv

 Acetamidomethyl-                                 Acm-  
 Acetyl-                                          Ac-  
 Benzoyl- (C6H5-CO-)                              PhCO- (or Bz-; see note in 3AA-18.1)  
 Benzyl- (C6H5-CH2-)                              PhCH2- (or Bzl; see note in 3AA-18.1)  
 Carbamoyl-                                       NH2CO- (preferred to Cbm-) 
 (3-Carboxy-4-nitrophenyl)thio-                   Nbs- (see 3AA-18.2)  
 3-Carboxypropanoyl- (HOOC-CH2-CH2-CO-)           Suc- (see Note i)  
 Dansyl-, 5-(dimethylamino)naphth-l-ylsulfonyl-   Dns-  
 2,4-Dinitrophenyl-                               Dnp- or N2ph (see Note ii)  
 Formyl-                                          HCO- or For- (see Note iii)  
 4-Iodophenylsulfonyl- (pipsyl-)                  Ips-  
 Maleoyl- (-OC-CH=CH-CO-)                         -Mal- or Mal< (C-404.1 of ref 14)  
 Maleyl- (HOOC-CH=CH-CO-)                         Mal-  
 2-Nitrophenylthio-                               NpS (Nps- often used)  
 Phenyl(thiocarbamoyl)-                           PhNHCS- or Ptc-  
 Phthaloyl-                                       -Pht- or Pht<  
 Phthalyl- (o-carboxybenzoyl-)                    Pht-  
 Succinyl- (-OC-CH2-CH2-CO-)                      -Suc- or Suc< (see Note i)  
 Tosyl-                                           Tos-  
 Trifluoroacetyl-                                 CF3CO-  
 Trityl- (triphenylmethyl-)                       Ph3C- or Trt-  

(i) In organic nomenclature (C-404.1 of [14]), 'succinyl' signifies the bivalent group formed from succinic acid by removal of both hydroxyl groups, but in biochemical usage it usually signifies the 3-carboxypropanoyl group, e.g. succinyl-CoA.

(ii) The use of D for 'di' and T for 'tri' and 'tetra' is discouraged if these apply to atoms or groups for which simple symbols exist, e.g. in CF3 CO-, Me3Si and H4 folate. We feel less strongly when their avoidance involves giving unusual meanings to symbols, e.g. N for nitro, so Dnp and N2ph are offered as alternative symbols for dinitrophenyl. See also Note ii of 3AA-15.2.5.

(iii) The symbol HCO- is preferred to CHO- for the formyl group, because CHO- has sometimes been used to indicate the attachment of carbohydrate.

(iv) In the name column the locant "o-" should be in italics and in the symbol column and molecular formulae in the name column numbers should be subscript.

Table 4. Substituents at the carboxyl group Note i

 Group                    Symbol                     Name of glycine derivative (see note ii)
 Benzotriazol-1-yloxy     -OBt                       1-(Glycyloxy)benzotriazole  
 Benzyloxy                -OCH2Ph                    Glycine benzyl ester  
                     (or-OBzl, see note in 3AA-18.1)

 tert-Butoxy              -OCMe3 or -OBu[t]          Glycine t-butyl ester  
 Diphenylmethoxy          -OCHPh2 or -OBzh           Glycine diphenylmethyl ester
                                                     (or benzhydryl ester)  
 Ethoxy                   -OEt                       Glycine ethyl ester  
 Methoxy                  -OMe                       Glycine methyl ester  
 4-Nitrobenzyloxy         -ONb                       Glycine 4-nitrobenzyl ester  
 4-Nitrophenoxy           -ONp                       Glycine 4-nitrophenyl ester  
 4-Nitrophenylthio        -SNp                       Thioglycine S-(4-nitrophenyl ester) 
 Pentachlorophenoxy       -OPcp                      Glycine pentachlorophenyl ester  
 Phenylthio               -SPh                       Thioglycine S-(phenyl ester)  
 Quinolin-8-yloxy         -OQu                       Glycine quinolin-8-yl ester  
 Succinimido-oxy          -ONSu or -OSu              N-(Glycyloxy)succinimide  
 2,4,5-Trichlorophenyloxy -OTcp                      Glycine 2,4,5-trichlorophenyl ester 
Note. (i) In the name Group column the prefix "tert-" should be in italics; in the Symbol column numbers should be subscript; and in the Name column "t-", "S-" and "N-" should be in italics.

(ii) Carboxyl substituents will not normally appear as prefixes in the names of derivatives of amino acids or peptides, so the name of the group, its prefix name, given in column 1, is little used in naming compounds. Column 3 is therefore given to show how derivatives containing the group are named (by one of the alternative methods of 3AA-9.1).

Return to 3AA-18.1.