Introduction
Methods
Patient samples
Extraction and measurement of tamoxifen and metabolites
Method 1
Method 2
Quantification of tamoxifen and metabolites
Trivial name | R1
| R2
| R3
| R4
| R5
| R6
| R7
| Formula | Mol. Mass | Transition (m/z)
| RT1 (min) | RT2 (min) |
---|---|---|---|---|---|---|---|---|---|---|---|---|
Tamoxifen | O–CH2–CH2–N(CH3)2
| CH2–CH3
| H | H | H | H | H | C26H29NO | 371.5 | 372/72 | 8.00 | 2.99 |
N-desmethyltamoxifen | O–CH2–CH2–NH–CH3
| CH2–CH3
| H | H | H | H | H | C25H27NO | 357.5 | 358/58 | 7.91 | 2.96 |
N-desmethyl-α-hydroxytamoxifena
| O–CH2–CH2–NH–CH3
| CH(OH)–CH3
| H | H | H | H | H | C25H27NO2
| 373.5 | 374/58 | 6.65 | 2.81 |
N-desmethyl-4-hydroxytamoxifen (Endoxifen) | O–CH2–CH2–NH–CH3
| CH2–CH3
| H | H | OH | H | H | C25H27NO2
| 373.5 | 374/58 | 5.79 | 2.81 |
N-desmethyl-3-hydroxytamoxifena
| O–CH2–CH2–NH–CH3
| CH2–CH3
| H | OH | H | H | H | C25H27NO2
| 373.5 | 374/58 | 5.85 | 2.81 |
N-desmethyl-4′-hydroxytamoxifen | O–CH2–CH2–NH–CH3
| CH2–CH3
| H | H | H | H | OH | C25H27NO2
| 373.5 | 374/58 | 6.41 | 2.81 |
α-Hydroxytamoxifena
| O–CH2–CH2–N(CH3)2
| CH(OH)–CH3
| H | H | H | H | H | C26H29NO2
| 387.5 | 388/72 | 3.91 | 2.84 |
4-Hydroxytamoxifen | O–CH2–CH2–N(CH3)2
| CH2–CH3
| H | H | OH | H | H | C26H29NO2
| 387.5 | 388/72 | 6.03 | 2.84 |
3-Hydroxytamoxifena
| O–CH2–CH2–N(CH3)2
| CH2–CH3
| H | OH | H | H | H | C26H29NO2
| 387.5 | 388/72 | 6.17 | 2.84 |
4′-Hydroxytamoxifen | O–CH2–CH2–N(CH3)2
| CH2–CH3
| H | H | H | H | OH | C26H29NO2
| 387.5 | 388/72 | 6.66 | 2.84 |
Tamoxifen-N-oxide | O–CH2–CH2–NO(CH3)2
| CH2–CH3
| H | H | H | H | H | C26H29NO2
| 387.5 | 388/72 | 8.32 | 3.06 |
β-Hydroxytamoxifenb
| O–CH2–CH2–N(CH3)2
| CH2–CH2–OH | H | H | H | H | H | C26H29NO2
| 387.5 | 388/72 | – | – |
2-Hydroxytamoxifenb
| O–CH2–CH2–N(CH3)2
| CH2–CH3
| OH | H | H | H | H | C26H29NO2
| 387.5 | 388/72 | – | – |
1,2-Epoxytamoxifenb
| O–CH2–CH2–N(CH3)2
| CH2–CH3
| H | H | H | H | H | C26H29NO2
| 387.5 | 388/72 | – | – |
Results and discussion
Mean concentration (ng/mL) | ||
---|---|---|
Analyte | Method 1 [16] ± s.d. | Method 2 [15] ± s.d. |
Tamoxifen | 99.7 ± 39.3 | 103.3 ± 40.4 |
N-desmethyltamoxifen | 184.0 ± 74.7 | 187.1 ± 77.9 |
Endoxifen | 9.0 ± 4.5 | 18.1 ± 6.4 |
4-Hydroxytamoxifen | 1.7 ± 0.7 | 4.6 ± 1.7 |