Table 2.
ESI-Mass Spectrometric Characterization of Cyclic Products
| Ring Size | Substrate | Cyclic Species | Species (m/z) | Observed Mass (Calculated Mass) |
|---|---|---|---|---|
| 6-membered | GS6 | Cyclo(-d-Phe1- l-Pro2- l-Val3- l-Val4- l-Orn5- l-Leu6-) | [M + H]+ | 670.5 (670.4) |
| 6-membered | GS3 | Cyclo(-d-Phe1- l-Pro2- l-Leu3-)2 | [M + H]+ | 715.5 (715.4) |
| 8-membered | GS4 | Cyclo(-d-Phe1- l-Pro2- l-Orn3- l-Leu4-)2 | [M + H]+ | 943.5 (943.6) |
| 8-membered | GS8 | Cyclo(-d-Phe1- l-Pro2- l-Val3- l-Orn4- l-Pro5- l-Val6-l-Orn7- l-Leu8-) | [M + H]+ | 881.5 (881.6) |
| 9-membered | GS9 | Cyclo(-d-Phe1- l-Pro2- l-Val3- l-Orn4- l-Leu5- l-Pro6-l-Val7- l-Orn8- l-Leu9-) | [M + H]+ | 994.5 (994.6) |
| 10-membered | GS5SNAC, GS5SPh or GS10 | Cyclo(-d-Phe1- l-Pro2- l-Val3- l-Orn4- l-Leu5-)2 | [M + H]+ | 1141.7 (1141.7) |
| 10-membered | GS5Ala2 | Cyclo(-d-Phe1- l-Ala2- l-Val3- l-Orn4- l-Leu5-)2 | [M + H]+ | 1089.8 (1089.7) |
| 10-membered | GS5Ala3 | Cyclo(-d-Phe1 -l-Pro2 -l-Ala3 -l-Orn4 -l-Leu -)2 | [M + H]+ | 1085.5 (1085.6) |
| 10-membered | GS5Ala4 | Cyclo(-d-Phe1- l-Pro2- l-Val3- l-Ala4- l-Leu5-)2 | [M + H]+ | 1055.6 (1055.6) |
| 10-membered | GS10Ala2,7 | Cyclo(-d-Phe1- l-Ala2- l-Val3- l-Orn4- l-Leu5-)2 | [M + H]+ | 1089.7 (1089.7) |
| 10-membered | GS10Ala2,8 | Cyclo(-d-Phe1 -l-Pro2 -l-Ala3 -l-Orn4 -l-Leu -)2 | [M + H]+ | 1085.7 (1085.6) |
| 10-membered | GS10Ala2,9 | Cyclo(-d-Phe1- l-Pro2- l-Val3- l-Ala4- l-Leu5-)2 | [M + H]+ | 1055.7 (1055.6) |
| 10-membered | GS6 and GS4 | Cyclo(-d-Phe1- l-Pro2- l-Val3- l-Val4- l-Orn5- l-Leu6-d-Phe7- l-Pro8- l-Orn9- l-Leu10-) | [M + H]+ | 1141.7 (1141.7) |
| 11-membered | GS4 and GS3 | Cyclo(-d-Phe1- l-Pro2- l-Orn3- l-Leu4- d-Phe5- l-Pro6-l-Orn7- l-Leu8- d-Phe9- l-Pro10- l-Leu11-) | [M + H]+ | 1300.7 (1300.8) |
| 12-membered | GS4 | Cyclo(-d-Phe1- l-Pro2- l-Orn3- l-Leu4-)3 | [M + H]+ | 1414.8 (1414.9) |
| 13-membered | GS4 and GS5SNAC | Cyclo(-d-Phe1- l-Pro2- l-Orn3- l-Leu4- d-Phe5- l-Pro6-l-Orn7- l-Leu8- d-Phe9- l-Pro10- l-Val11- l-Orn12- l-Leu13-) | [M + H]+ | 1513.8 (1513.9) |
| 14-membered | GS7 | Cyclo(-d-Phe1- l-Pro2- l-Val3- l-Pro4- l-Val5- l-Orn6- l-Leu7-)2 | [M + H]+ | 1533.8 (1533.9) |
| 15-membered | GS5SNAC | Cyclo(-d-Phe1- l-Pro2- l-Val3- l-Orn4- l-Leu5-)3 | [M + H]+ | 1712 (1712.1) |
| 15-membered | GS5Ala2,7 | Cyclo(-d-Phe1- l-Ala2- l-Val3- l-Orn4- l-Leu5-)3 | [M + H]+ | 1633.9 (1634) |
| 15-membered | GS5Ala3,8 | Cyclo(-d-Phe1- l-Pro2- l-Ala3- l-Orn4- l-Leu5-)3 | [M + H]+ | 1627.9 (1628) |
| 15-membered | GS5Ala4,9 | Cyclo(-d-Phe1- l-Pro2- l-Val3- l-Ala4- l-Leu5-)3 | [M + H]+ | 1582.9 (1582.9) |