Table 1.
Protonated ion masses of microcystin (MC) variants from Phormidium sp. LP904c and their relative amounts (%) identified from either Phormidium sp. LP904c or DVL1003c by HPLC-ESI-ITMS. Peak areas of the extracted ion chromatograms of the protonated microcystins were used in relative amount calculations. Hty = homotyrosine, Hph = homophenylalanine, [M + H]+ (m/z) = mass per charge value of protonated microcystins, Rt (min) = retention time in minutes, RA = relative amount, Aa = amino acid. Additional information presented in Figure S1.
| No. | Microcystin | Aa in Position | Rt | [M + H]+ (m/z) | Error | RA (%) | |||
|---|---|---|---|---|---|---|---|---|---|
| X | Z | (min) | Calculated | Measured | (ppm) | LP904c | DVL1003c | ||
| 1 | MC-YR | Y | R | 15.4 | 1045.5353 | 1045.5329 | –2.35 | <1 | <1 |
| 2 | MC-HtyR | Hty | R | 15.8 | 1059.5510 | 1059.5510 | –0.01 | 4 | 4 |
| 3 | MC-MR | M | R | 15.8 | 1013.5125 | 1013.5148 | 2.26 | 1 | 1 |
| 4 | [DMAdda5]MC-LR | L | R | 15.8 | 981.5404 | 981.5404 | –0.04 | <1 | <1 |
| 5 | [L-MeSer7]MC-LR | L | R | 16.6 | 1013.5666 | 1013.5649 | –1.73 | <1 | <1 |
| 6 | [D-Asp3]MC-LR | L | R | 17 | 981.5404 | 981.5404 | –0.04 | <1 | <1 |
| 7 | MC-LR | L | R | 17 | 995.5560 | 995.5566 | 0.51 | 55 | 49 |
| 8 | MC-FR | F | R | 17.3 | 1029.5404 | 1029.5401 | –0.33 | 9 | 7 |
| 9 | [Dha7]MC-LR | L | R | 17.5 | 981.5404 | 981.5404 | –0.04 | <1 | <1 |
| 10 | MC-HphR | Hph | R | 18.7 | 1043.5560 | 1043.5561 | 0.01 | 17 | 14 |
| 11 | MC-LY | L | Y | 22.8 | 1002.5183 | 1002.5178 | –0.51 | 1 | 2 |
| 12 | MC-LHty | L | Hty | 23.2 | 1016.5339 | 1016.5347 | 0.73 | 5 | 12 |
| 13 | MC-HphHty | Hph | Hty | 24.3 | 1064.5339 | 1064.5337 | –0.24 | 3 | 8 |
| 14 | MC-LW | L | W | 24.6 | 1025.5342 | 1025.5343 | 0.00 | <1 | <1 |
| 15 | MC-LHph | L | Hph | 26.7 | 1000.5390 | 1000.5369 | –2.15 | <1 | 1 |
| 16 | MC-HphHph | Hph | Hph | 27.7 | 1048.5390 | 1048.5403 | 1.20 | <1 | <1 |