TABLE 4.
Assignments of all fengycin mass peaks obtained by MALDI-TOF mass spectrometry of whole cells of B. subtilis C-1, the culture filtrate, and the lipopeptide fractiona
| Mass peak (m/z) | Assignment | nb | Amino acid at position 6 |
|---|---|---|---|
| 1447.7 | C15 fengycin, [M+H]+ | 1 | Ala |
| 1449.8 | C15 fengycin, [M+H]+ | 0 | Ala |
| 1461.8 | C16 fengycin, [M+H]+ | 1 | Ala |
| 1463.9 | C16 fengycin, [M+H]+ | 0 | Ala |
| 1469.8 | C15 fengycin, [M+Na]+ | 1 | Ala |
| 1471.8 | C15 fengycin, [M+Na]+ | 0 | Ala |
| 1475.8 | C17 fengycin, [M+H]+ | 1 | Ala |
| 1477.8 | C17 fengycin, [M+H]+ | 0 | Ala |
| 1483.8 | C16 fengycin, [M+Na]+ | 1 | Ala |
| 1485.8c | C16 fengycin, [M+Na]+ | 0 | Ala |
| 1489.9 | C16 fengycin, [M+H]+ | 1 | Val |
| 1491.7 | C16 fengycin, [M+H]+ | 0 | Val |
| 1497.8 | C17 fengycin, [M+Na]+ | 1 | Ala |
| 1499.9 | C17 fengycin, [M+Na]+ | 0 | Ala |
| 1501.8c | C16 fengycin, [M+K]+ | 0 | Ala |
| 1503.8 | C17 fengycin, [M+H]+ | 1 | Val |
| 1505.8 | C17 fengycin, [M+H]+ | 0 | Val |
| 1513.9 | C16 fengycin, [M+Na]+ | 0 | Val |
| 1515.9c | C17 fengycin, [M+K]+ | 0 | Ala |
| 1527.9 | C17 fengycin, [M+Na]+ | 0 | Val |
| 1529.9c | C16 fengycin, [M+K]+ | 0 | Val |
a
The mass data represent monoisotopic mass numbers.
b
n is the number of double bonds in the fengycin species.
c
Mass numbers of the main isoforms.