Table 1. Analytical Data for the Peptides Synthesized in This Study.
| Peptide | Sequence | HPLC k′ (System 1) | HPLC k′ (System 2) | Calculated (M+1) | Mass Spectral Analysis (M+1) | Purity (%) |
|---|---|---|---|---|---|---|
| α-MSH | Ac-Ser-Tyr-Ser-Met-Glu-His-Phe-Arg-Trp-Gly-Lys-Pro-Val-NH2 | 4.8 | 10.0 | 1664.8 | 1665.0 | >98 |
| [Ala1]α-MSH | Ac-Ala-Tyr-Ser-Met-Glu-His-Phe-Arg-Trp-Gly-Lys-Pro-Val-NH2 | 5.0 | 9.8 | 1648.8 | 1649.0 | >99 |
| [Ala2]α-MSH | Ac-Ser-Ala-Ser-Met-Glu-His-Phe-Arg-Trp-Gly-Lys-Pro-Val-NH2 | 4.5 | 9.6 | 1572.8 | 1572.5 | >97 |
| [Ala3]α-MSH | Ac-Ser-Tyr-Ala-Met-Glu-His-Phe-Arg-Trp-Gly-Lys-Pro-Val-NH2 | 5.1 | 10.4 | 1648.8 | 1648.7 | >98 |
| [Ala4]α-MSH | Ac-Ser-Tyr-Ser-Ala-Glu-His-Phe-Arg-Trp-Gly-Lys-Pro-Val-NH2 | 4.4 | 9.2 | 1604.8 | 1604.9 | >98 |
| [Ala5]α-MSH | Ac-Ser-Tyr-Ser-Met-Ala-His-Phe-Arg-Trp-Gly-Lys-Pro-Val-NH2 | 4.9 | 10.2 | 1606.8 | 1608.0 | >99 |
| [Ala6]α-MSH | Ac-Ser-Tyr-Ser-Met-Glu-Ala-Phe-Arg-Trp-Gly-Lys-Pro-Val-NH2 | 5.2 | 10.7 | 1598.8 | 1599.0 | >99 |
| [Ala7]α-MSH | Ac-Ser-Tyr-Ser-Met-Glu-His-Ala-Arg-Trp-Gly-Lys-Pro-Val-NH2 | 3.9 | 8.4 | 1588.8 | 1588.9 | >97 |
| [Ala8]α-MSH | Ac-Ser-Tyr-Ser-Met-Glu-His-Phe-Ala-Trp-Gly-Lys-Pro-Val-NH2 | 5.1 | 10.5 | 1579.7 | 1580.5 | >99 |
| [Ala9]α-MSH | Ac-Ser-Tyr-Ser-Met-Glu-His-Phe-Arg-Ala-Gly-Lys-Pro-Val-NH2 | 3.8 | 8.3 | 1549.8 | 1549.8 | >99 |
| [Ala10]α-MSH | Ac-Ser-Tyr-Ser-Met-Glu-His-Phe-Arg-Trp-Ala-Lys-Pro-Val-NH2 | 4.8 | 10.0 | 1678.8 | 1678.4 | >98 |
| [Ala11]α-MSH | Ac-Ser-Tyr-Ser-Met-Glu-His-Phe-Arg-Trp-Gly-Ala-Pro-Val-NH2 | 5.2 | 10.7 | 1607.7 | 1608.0 | >99 |
| [Ala12]α-MSH | Ac-Ser-Tyr-Ser-Met-Glu-His-Phe-Arg-Trp-Gly-Lys-Ala-Val-NH2 | 4.8 | 9.9 | 1638.8 | 1638.6 | >98 |
| [Ala13]α-MSH | Ac-Ser-Tyr-Ser-Met-Glu-His-Phe-Arg-Trp-Gly-Lys-Pro-Ala-NH2 | 4.6 | 9.5 | 1636.8 | 1636.7 | >98 |
| NDP-MSH | Ac-Ser-Tyr-Ser-Nle-Glu-His-DPhe-Arg-Trp-Gly-Lys-Pro-Val-NH2 | 5.1 | 11.0 | 1646.8 | 1647.6 | >99 |
| [Ala1]NDP-MSH | Ac-Ala-Tyr-Ser-Nle-Glu-His-DPhe-Arg-Trp-Gly-Lys-Pro-Val-NH2 | 5.2 | 10.1 | 1630.8 | 1632.5 | >95 |
| [Ala2]NDP-MSH | Ac-Ser-Ala-Ser-Nle-Glu-His-DPhe-Arg-Trp-Gly-Lys-Pro-Val-NH2 | 5.1 | 9.8 | 1554.8 | 1556.2 | >95 |
| [Ala3]NDP-MSH | Ac-Ser-Tyr-Ala-Nle-Glu-His-DPhe-Arg-Trp-Gly-Lys-Pro-Val-NH2 | 6.0 | 10.2 | 1630.8 | 1630.9 | >97 |
| [Ala4]NDP-MSH | Ac-Ser-Tyr-Ser-Ala-Glu-His-DPhe-Arg-Trp-Gly-Lys-Pro-Val-NH2 | 4.4 | 8.4 | 1604.8 | 1605.6 | >95 |
| [Ala5]NDP-MSH | Ac-Ser-Tyr-Ser-Nle-Ala-His-DPhe-Arg-Trp-Gly-Lys-Pro-Val-NH2 | 5.4 | 9.4 | 1588.8 | 1589.6 | >95 |
| [Ala6]NDP-MSH | Ac-Ser-Tyr-Ser-Nle-Glu-Ala-DPhe-Arg-Trp-Gly-Lys-Pro-Val-NH2 | 5.9 | 12.0 | 1580.8 | 1582.5 | >95 |
| [Ala7]NDP-MSH | Ac-Ser-Tyr-Ser-Nle-Glu-His-Ala-Arg-Trp-Gly-Lys-Pro-Val-NH2 | 4.3 | 8.9 | 1570.8 | 1571.9 | >98 |
| [Ala8]NDP-MSH | Ac-Ser-Tyr-Ser-Nle-Glu-His-DPhe-Ala-Trp-Gly-Lys-Pro-Val-NH2 | 6.0 | 10.9 | 1561.8 | 1562.4 | >95 |
| [Ala9]NDP-MSH | Ac-Ser-Tyr-Ser-Nle-Glu-His-DPhe-Arg-Ala-Gly-Lys-Pro-Val-NH2 | 4.2 | 8.7 | 1531.8 | 1532.5 | >95 |
| [Ala10]NDP-MSH | Ac-Ser-Tyr-Ser-Nle-Glu-His-DPhe-Arg-Trp-Ala-Lys-Pro-Val-NH2 | 5.0 | 9.5 | 1660.9 | 1661.7 | >99 |
| [Ala11]NDP-MSH | Ac-Ser-Tyr-Ser-Nle-Glu-His-DPhe-Arg-Trp-Gly-Ala-Pro-Val-NH2 | 5.5 | 11.8 | 1589.8 | 1590.9 | >96 |
| [Ala12]NDP-MSH | Ac-Ser-Tyr-Ser-Nle-Glu-His-DPhe-Arg-Trp-Gly-Lys-Ala-Val-NH2 | 5.5 | 10.9 | 1620.8 | 1621.6 | >95 |
| [Ala13]NDP-MSH | Ac-Ser-Tyr-Ser-Nle-Glu-His-DPhe-Arg-Trp-Gly-Lys-Pro-Ala-NH2 | 5.0 | 9.6 | 1618.8 | 1619.6 | >95 |
HPLC k′ =[(peptide retention time – solvent retention time)/solvent retention time] in solvent system 1 (10% acetonitrile in 0.1% triflouroacetic acid/water and a gradient to 90% acetonitrile over 35 min) or solvent system 2 (10% methanol in 0.1% triflouroacetic acid/water and a gradient to 90% methanol over 35 min). An analytical Vydac C18 column (Vydac 218TP104) was used for solvent system 1 and a Vydac C4 column (Vydac 214TP104) was used for solvent system 2. For both solvent system used a flow rate of 1.5 mL/min. The peptide purity was determined by HPLC at a wavelength of 214 nm.