TABLE 1.
Additive | Structurea | Mol wt | Retention time (min) | Area (%) |
---|---|---|---|---|
d-Met | PentaMet | 1,140.6 | 2.5 | 0.42 |
d-Phe | PentaPhe | 1,156.6 | 8.7 | 6.75 |
d-Phe | TetraPhe | 1,074.5 | 28.3 | 0.85 |
PentaMet, G–M–l-Ala–d-Gln–l-Lys (d-Asn)–d-Ala–d-Met; PentaPhe, G–M–l-Ala–d-Gln–l-Lys (d-Asn)–d-Ala–d-Phe; TetraPhe, G–M–l-Ala–d-Gln–l-Lys (d-Asp)–d-Phe (d-Asn or d-Asp is the peptide bridge bound to l-Lys, G is N-acetylglucosamine [GlcNAc], and M is N-acetylmuramic acid [MurNAc]).