Table 3. Effect of quenching with methanol-water mixture (method 2A) and addition of NH4OH during phase separation (method 2B) on a representative set of targeted metabolites that are typically used in 13C-metabolic flux analysis.
| Metabolite Listc | m/z | RTb | Synechococcus elongatus PCC 11801 | Synechococcus elongatus PCC 7942 | Synechococcus sp. PCC 7002 | |||
|---|---|---|---|---|---|---|---|---|
| aObserved changes in the intensity with respective fold change | ||||||||
| Method 2A compared to method 1 | Method 2B 0.2M compared to method 2A | Method 2A compared to method 1 | Method 2B 0.4 M compared to method 2A | Method 2A compared to method 1 | Method 2B 0.4 M compared to method 2A | |||
| Metabolites Confirmed Using Standards | ||||||||
| Malate | 133.05 | 9.6 | UP(9.4) | N | N | N | N | N |
| Glutamate | 146.04 | 6.2 | N | N | N | N | N | DN (3.1) |
| PEP | 166.97 | 14.6 | N | UP (1.5) | N | N | N | N |
| 3PGA | 184.98 | 14.1 | UP(4.1) | UP (2.6) | UP(8.4) | UP (3.5) | N | UP (5.3) |
| Citrate | 191.02 | 14.8 | UP(1.73) | N | UP(2.5) | UP (1.8) | N | UP (6.5) |
| L-Cystine | 239.06 | 17.3 | N | UP (1.6) | N | N | N | N |
| G6P | 259.02 | 9.6 | N | N | UP(2.2) | DN (1.6) | N | N |
| S7P | 289.03 | 10.0 | UP(1.72) | N | N | N | N | N |
| RuBP | 308.98 | 14.9 | N | UP (87.9) | N | UP(58.4) | N | UP (62.0) |
| UMP | 323.03 | 11.3 | UP(3.4) | N | N | N | N | DN (1.7) |
| Sucrose | 341.11 | 1.7 | N | N | N | N | N | DN(1.9) |
| IMP | 347.06 | 11.5 | N | N | N | N | N | N |
| ADP | 426.02 | 14.6 | UP(1.84) | UP (3.3) | N | UP(1.7) | N | UP (4.5) |
| ATP | 505.99 | 15.0 | UP (2.7) | N | N | UP (5.1) | N | UP (7.7) |
| UDP-glucose | 565.05 | 12.2 | UP (1.9) | N | N | DN (1.6) | DN (4.5) | N |
| ADP-glucose | 588.08 | 13.4 | UP (2.6) | N | N | DN (1.5) | N | N |
| Acetyl-CoA | 808.09 | 15.5 | UP (2.1) | DN(3.6) | N | N | N | N |
| Multimer Adducts | ||||||||
| PEP Dimer | 334.91 | 14.7 | N | UP (1.6) | N | N | N | N |
| 3PGA dimer | 370.92 | 14.2 | UP (4.5) | UP (3.9) | UP (17.4) | UP (6.6) | N | N |
| 3PGA trimer | 556.97 | 14.2 | UP (5.3) | UP (4.7) | N | UP (16.4) | N | N |
| RuBP dimer | 618.96 | 14.9 | N | UP (77.4) | N | N | N | N |
| ADP dimer | 853.06 | 14.6 | N | UP (11.7) | N | N | N | N |
| Putative Fatty Acids | ||||||||
| Dodecanoic | 199.17 | 17.8 | N | UP (2.0) | N | UP(2.5) | N | DN (1.8) |
| Myristic | 227.21 | 18.3 | DN(2.0) | UP (13.2) | DN (2.6) | UP(23.3) | N | UP(3.7) |
| Linoleic | 279.23 | 18.7 | DN(2.1) | UP (1.9) | DN (2.1) | UP(2.0) | N | N |
| Pentadecanoic | 241.21 | 18.6 | DN(4.4) | UP (1.9) | N | UP(3.6) | N | N |
aUP (Fold Change) = Increased intensity with the respective fold change; DN (Fold Change): Decreased intensity with the respective fold change; N = No significant Change observed or peak not detected.
bRetention time shown in the table is specifically for the strain PCC 11801.
cMetabolites list: Malate (Mal); Glutamate (Glu); Phopshoenolpyruvate (PEP); 3-Phosphoglyceric acid (3 PGA); Citrate (Cit); L-Cystine; Glucose-6-phosphate (G6P); Sedoheptulose 7-phosphate (S7P); Ribulose Bisphosphate (RuBP); Uridine Monophosphate (UMP); Inosine monophosphate (IMP); Adenosine diphosphate (ADP); Adenosine triphosphate (ATP), Uridine diphosphate-Glucose (UDP-Glucose); Adenosine diphosphate-Glucose (ADP-Glucose); Acetyl Coenzyme A (Acetyl-CoA); Dodecanoic Acid, Myristic Acid, Linoleic Acid, Pentadecanoic Acid.