Table 2.
Tentative identification of significant metabolites in patients undergoing ketamine treatment
| Compound | RT (min) | Measured mass (Da) | Mass error (p.p.m.) | Molecular formula | FC (%) in NRs | P value | CV (%) for QCs | Biochemical category | Subcategory | |
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | Phenyllactic acid§ | 13.58 | 166.0624 | −3.5 | C9H10O3 | 62.7 | 0.049 | 5.58 | Phenolic, benzoyl, and phenyl derivatives | – |
| 2 | Phenylvaleric acid | 10.78 | 178.0988 | −3.3 | C11H14O2 | 70.6 | 0.015 | 3.53 | Phenolic, benzoyl, and phenyl derivatives | – |
| 3 | LPC (16:1)§ | 16.93 | 493.3162 | −1.3 | C24H48NO7P | −21.2 | 0.048 | 5.51 | Glycerophos-pholipids | Monoacyl-glycerophos-phocholines |
| 4 | Deoxytetradecasphingenine | 21.81 | 227.2240 | −4.0 | C14H29NO | −38.0 | 0.022 | 1.53 | Sphingolipids | Sphingoid base |
| 5 | Deoxytetradecasphinganine | 11.27 | 229.2394 | −5.1 | C14H31NO | 17.4 | 0.029 | 7.99 | Sphingolipids | Sphingoid base |
| 6 | Decanamide | 9.23 | 171.1613 | −5.9 | C10H21NO | −46.3 | 0.045 | 2.20 | Fatty acyls | Primary amides |
| 7 | Pentadecatetraenal | 5.65 | 218.1663 | −3.5 | C15H22O | −42.1 | 0.021 | 14.80 | Fatty acyls | Fatty aldehydes |
| 8 | Dimethyldioxododecatrienal | 24.45 | 234.1269 | 5.6 | C14H18O3 | 33.8 | 0.058 | 9.12 | Fatty acyls | Fatty aldehydes |
| 9 | Hexadienoic acid | 8.82 | 112.0523 | −1.1 | C6H8O2 | 143.4 | 0.030 | 8.37 | Fatty acyls | Unsaturated FAs |
| Hexenedial | C6H8O2 | Fatty acyls | Fatty aldehydes | |||||||
| Oxohexenal | C6H8O2 | Fatty acyls | Fatty aldehydes | |||||||
| Hydroxy-hexadienal | C6H8O2 | Fatty acyls | Fatty aldehydes | |||||||
| Dihydrobenzenediol | C6H8O2 | Phenolic, benzoyl, and phenyl derivatives | ||||||||
| 10 | Hexadienoic acid | 9.22 | 112.0523 | −1.1 | C6H8O2 | 145.1 | 0.029 | 7.69 | Fatty acyls | Unsaturated FAs |
| Hexenedial | C6H8O2 | Fatty acyls | Fatty aldehydes | |||||||
| Oxohexenal | C6H8O2 | Fatty acyls | Fatty aldehydes | |||||||
| Hydroxy-hexadienal | C6H8O2 | Fatty acyls | Fatty aldehydes | |||||||
| Dihydrobenzenediol | C6H8O2 | Phenolic, benzoyl, and phenyl derivatives | – | |||||||
| 11 | Unknown§ | 7.35 | 162.1038 | C11H14O | 53.9 | 0.024 | 4.47 | – |
Tentative identification of metabolites significantly associated with response to ketamine treatment in 22 BD patients taking either lithium or VPA.
Note: For putative identification, all the compounds with a score >80% were first formula matched with the experimental isotopic pattern distribution on Mass Hunter software.
Found in the comparison of Rs and NRs for lithium-subgroup in the same direction.
FC, fold change; FC was calculated as follows: (Average [NRs] – Average [Rs])/Average [Rs] × 100).
+/–, increase/decrease in NRs when compared with Rs.
LPC, lysophosphatidylcholine; this entity has been named with the number of carbon of the fatty acid attached to the backbone and the number of unsaturation, for example, LPC (16:1).
BD, bipolar depression; KET, ketamine; Li, lithium; NR, non-responders; R, responders; VPA, valproate.