Anal. Chem. 2007, 79, 4177-4181
Stereoisomeric Identification of Norephedrine Derived from Methamphetamine or Amphetamine: Urinalysis Results of 33 Methamphetamine Abusers and 1 Amphetamine Abuser in Japan Toshiaki Nagai,*,† Masahito Kido,† Junko Maeda,† Kazumi Matsushima,† Toshio Okazaki,‡ Akira Kurosu,† Masahito Hitosugi,† and Shougo Tokudome†
Department of Legal Medicine, Dokkyo University School of Medicine, Mibu, Tochigi 321-0293, Japan, Department of Forensic Science, School of Allied Health Sciences, Kitasato University, Sagamihara-shi, Kanagawa 228-8555, Japan
Stereoisomeric identification of norephedrine (NE) derived from methamphetamine (MA) or amphetamine (AM) was investigated by SIM-GC/MS assay using the urine of 33 MA abusers and 1 AM abuser. The assay simultaneously identified TFA-derivatized MA and AM metabolites, including AM, p-hydroxyl-MA (p-HMA), and p-hydroxyl-AM (p-HAM). The analysis lasted ∼43 min, with a signal-to-noise ratio of g3 and a detection limit of 50 ng/ mL. Among 12 urine samples from different subjects, only the S (+) form of MA and its metabolites (AM, p-HMA, p-HAM) was detected, however, a (1R,2S)-(-)-NE stereoisomer was also identified. Among the urine samples of two subjects, only the R (-) form of MA and its metabolites (AM, p-HMA, p-HAM) was detected, while NE was not detected. Following urinalysis of urine obtained from 19 MA abusers and 1 AM abuser, only the (1R,2S)-(-)NE stereoisomer was identified, while unmetabolized MA, AM, and their metabolites (p-HMA, p-HAM), showed stereoselective metabolism. Although (1R,2S)-(-)-ephedrine (EP) alone was found in the urine of 1 (S)-(+)-MA user and 1 (S)-(+)- and (R)-(-)-MA user among 33 MA users, it was not present in the urine of the remaining 31 subjects. Therefore, (1R,2S)-(-)-NE was likely not of (1R,2S)-(-)-EP origin and was most likely from (S)-(+)AM of the MA metabolite. The production ratio of (1R,2S)(-)-NE to (S)-(+)-AM ranged from 0.01 to 0.25 in MA abusers and was 0.12 in AM abusers. Methamphetamine (MA) is the most abused illegal drug in Japan.1 A method to prove illegal use of MA has been established through detection and identification of unmetabolized MA and its amphetamine (AM) metabolite in urine. At the present time, individual MA stereoisomers ((S)-(+)-MA and (R)-(-)-MA), as well as mixtures of the two stereoisomers, are abused in Japan.2 * To whom correspondence should be addressed. E-mail: tnagai@ dokkyomed.ac.jp. † Dokkyo University School of Medicine. ‡ Kitasato University. (1) White Paper on Police 2002 (Excerpt); National Police Agency Government of Japan. 2002; pp 51-52. (2) Nagai, T.; Matsushima, K.; Nagai, T.; Yanagisawa, Y.; Fujita, A.; Kurosu, A.; Tokudome, S. J. Anal. Toxicol. 2000, 24, 140-145. 10.1021/ac062229o CCC: $37.00 Published on Web 04/24/2007
© 2007 American Chemical Society
Specific stereoisomer identification is required to prove MA use in forensic chemistry. Furthermore, stereoisomer analysis is essential to distinguish use of illegal MAs2 from ingestion of MA with medication3 and is done through analysis of various metabolites. A number of analytical methods have been used for separation and analysis of MA and AM stereoisomers.4-6 MA is primarily converted into AM, as well as p-hydroxyl-MA (p-HMA) and p-hydroxyl-AM (p-HAM), while norephedrine (NE) is a minor metabolite of MA and AM, in humans.7,8 Among the MA metabolites, stereoselective metabolism of MA and AM has been characterized in human urine after ingestion of racemic MA,9 as well as in human urine and plasma in toxicological cases of MA or AM ingestion.10 However, stereoselective metabolism of NE, p-HMA, and p-HAM has not been examined in human urine or plasma. NE is produced by hydroxylation of the β carbon of AM7 such that, unlike MA and AM, a new stereoisomer is produced as it is metabolized. However, selective stereoisomeric metabolism of NE derived from MA7 and AM8,11 has not been demonstrated in humans to date. Among drugs3 producing MA and AM, only an anti-inflammatory drug called famprofazone is also known to produce NE12,13 as a byproduct of MA and AM metabolism. Four stereoisomers of NE are known to exist [(1S,2R)-(+), (1R,2S)(-), (1S,2S)-(+), and (1R,2R)-(-)].12 These NE stereoisomers are derived from ephedrine (EP) and AM during the metabolism of famprofazone.12 In addition to simultaneous identification of p-HMA and p-HAM stereoisomers, stereoisomeric identification of NE derived from (3) Kraemer, T.; Maurer, H. H. J. Chromatogr., B 1998, 713, 163-187. (4) Jin, H. L.; Beesley, T. E. Chromatographia 1994, 38, 595-598. (5) Armstrong, D. W.; Rundlett, G. L.; Reid, G. L., lll; Nair, U. B. Curr. Sep. 1996, 15, 57-61. (6) Hasegawa, M.; Matsubara, K.; Fukushima, S.; Maseda, C.; Uezono, T.; Kimura, K. Forens. Sci. Int. 1999, 101, 95-106. (7) Caldwell, J.; Dring, L. G.; Williams, R. T. Biochem. J. 1972, 129, 11-22. (8) Hayakawa, K.; Miyoshi, Y.; Kurimoto, H.; Matsushima, Y.; Takayama, N.; Tanaka, S.; Miyazaki, M. Biol. Pharm. Bull. 1993, 16, 817-821. (9) Cody, J. T.; Schwarzhoff, R. J. Anal. Toxicol. 1993, 17, 321-326. (10) Frank, T. P.; Kraemer, T.; Maurer, H. H. Clin. Chem. 2002, 48, 14721485. (11) Dring, L. G.; Smith, R. L.; Williams, R. T. Biochem. J. 1970, 116, 425-435. (12) Shin, H. S. Chirality 1997, 9, 52-58. (13) Shin, H. S.; Park, B. B.; Chol, S. N.; Oh, J. J.; Hong, C. P.; Ryu, H. J. Anal. Toxicol. 1998, 22, 55-60.
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Figure 1. Structures of analytes and internal standard. A star shows a position of asymmetric carbon.
Figure 2. Typical SIM chromatograms of 16 TFA stereoisomers of EP, NE, AM, MA, p-HMA, and p-HAM. Sixteen pure stereoisomers of EP, NE, AM, MA, p-HMA, and p-HAM were added to human control urine and analyzed by SIM-GC/MS. The fragment ion peak of each stereoisomer corresponds to 250 ng mL-1 (500 ng mL-1 racemate). EP, ephedrine; NE, norephedrine; AM, amphetamine; MA, methamphetamine; p-HMA, p-hydroxylmethamphetamine; p-HAM, p-hydroxylamphetamine; IS, internal standard (β-phenethylamine).
MA or AM was performed by gas chromatography/mass spectrometry (GC/MS) with selected-ion monitoring (SIM) using the urine of 33 MA abusers and one AM abuser arrested in Japan. EXPERIMENTAL PROCEDURES Reagents and Materials. Hydrochlorides of (S)-(+)-MA and (R)-(-)-MA were obtained from Dainippon Pharmaceutical Co. (Osaka, Japan). Sulfates of (S)-(+)-AM and (R)-(-)-AM, as well as racemates of AM sulfate and MA hydrochloride, were prepared as previously described.14 Hydrochlorides of racemic p-HAM and p-HMA were supplied by Dr. Terada (Toho University School of Medicine, Tokyo, Japan). (S)-(+)-forms of p-HAM and p-HMA were obtained from urine samples collected after oral administration (30 mg/kg) of (S)-(+)-AM or (S)-(+)-MA in five male Wistar rats, while (R)-(-)-forms were obtained from urine samples collected after oral administration (30 mg/kg) of (R)-(-)-AM or (R)-(-)-MA. Ephedrine hydrochlorides of the (1R, 2S)-(-)-form and (1S,2R)-(+)-form, as well as pseudoephedrine (PEP) hydro(14) Nagai, T.; Kamiyama, S.; Nagai, T. Z. Rechtsmedizin 1988, 101, 151-59.
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chlorides of the (1S,2S)-(+)-form and (1R,2R)-(-)-form, were supplied by Dr. Yasuda (Tokyo Metropolitan Institute of Public Health, Tokyo, Japan). Racemic EP was purchased from Iwaki Pharmaceutical., Co (Tokyo, Japan). Norephedrine of the (1R,2S)(-)-form was purchased from Aldrich Chemical Co (Milwaukee, WI). NE of the (1S,2R)-(+)-form and racemic NE were obtained from Tokyo Kasei Ind., Co. (Tokyo, Japan). A pseudo-NE (PNE) hydrochloride of the (1S,2S)-(+)-form was from Sigma (Tokyo, Japan). A PNE hydrochloride of the (1R,2R)-(-)-form was supplied by Dr. Yasuda. Trifluoroacetic anhydride (TFA) and β-phenylethylamine hydrochloride were purchased from Tokyo Kasei Ind., Co. The structures of these substances are shown in Figure 1. β-Glucuronidase/arylsulfatase (EC 3.2.1.31) was purchased from Merck (Tokyo, Japan). All other chemicals were obtained from commercial sources. Urine samples from 33 MA abusers and 1 AM abuser arrested following implementation of strict controls against psychostimulant drug use in Japan were obtained. Extraction and TFA Derivatization. Urine (500 µL) was hydrolyzed for 16 h at 37 °C with 1 M acetate buffer (pH 5.5, 500 µL) and β-glucuronidase/arylsulfatase (15 µL). The hydrolysate (10-70 µL) was further diluted to a volume of 0.9 mL with distillated water after adding 25 µL of β-phenylethylamine (1000 ng/mL) as an internal standard (IS). The pH of this solution was adjusted between 9.0 and 9.3 with saturated NaHCO3 aqueous solution and loaded onto an Extrelut NT 1 column (Merck). EP, PEP, NE, PNE, and four AM analogues (MA, AM, p-HMA, p-HAM) were then eluted from the column after 15 min with dichloromethane/2-propanol (88:12 v/v, 6 mL). Following this, they were re-extracted with 0.01 M HCl (0.7 mL). The extracts (0.6 mL) were then dried with nitrogen gas at 55 °C. The residue was dissolved in acetonitrile/ethyl acetate (1:1 v/v, 200 µL) and TFA (75 µL). The solution was then reacted for 45 min at 100 °C. The reacted solution was then dissolved in ethyl acetate (1.0 mL) after drying under nitrogen gas, and a 1-µL aliquot was used for analysis. Instrumentation. Sixteen TFA stereoisomers of EP, PEP, NE, PNE, and four AM analogues (MA, AM, p-HMA, p-HAM), were analyzed using a JEOL Automass II 150 GC/MS system (Tokyo, Japan) equipped with a Beta Dex 225 capillary column (30 m × 0.25 mm, 0.25-µm film thickness, Supelco/Sigma-Aldrich Co.), with a chiral stationary phase consisting of a β-cyclodextrin derivative. The stereoisomers were then identified using four mass fragment ions of 91, 118, 154, and 230 m/z, using electron impact mode. The mass fragment ion of 91 m/z was used to detect the IS, the mass fragment ion of 118 m/z was used to detect AM, the mass fragment ion of 154 m/z was used to detect EP, PEP, MA, and p-HMA, and the mass fragment ion of 230 m/z was used to detect p-HAM, PNE, and NE. Each sample for analysis was injected into the GC in splitless mode. The following operating temperatures were used: the column temperature was raised from 50 to 150 °C by 3 °C/min, and then held at 150 °C for 4 min, after which the temperature was further increased to 220 °C by 12 °C/min. The temperature was then held at 220 °C for 7 min for simultaneous analysis of EP, PEP, NE, PNE, and four AM analogues, for which the injection port, ion source, and interface temperatures were maintained at 220, 180, and 230 °C, respectively. The ionization voltage was set at 75 eV. The flow rate of helium gas was maintained at 1.0 mL/min.
Table 1. MA Stereoisomers in Human Urine and Concentrations of MA Metabolitesa sample group
I
II
III
IV V AM a
MA (µg/mL)
AM (µg/mL)
p-HMA (µg/mL)
p-HAM (µg/mL)
NE (µg/mL)b
EP (µg/mL)c
case
age
(S )-(+)
(R )-(-)
(S )-(+)
(R )-(-)
(S )-(+)
(R )-(-)
(S )-(+)
(R )-(-)
(1R,2S)-(-)
(1R,2S)-(-)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34
28 (M) 44 (M) 35 (M) 19 (F) 22 (M) 44 (M) 23 (M) 19 (M) 25 (M) 38 (M) 29 (m) 20 (f) 41 (M) 33 (M) 32 (M) 20 (F) 42 (M) 21 (M) 33 (F) 27 (M) 36 (M) 29 (M) 44 (M) 31 (M) 39 (M) 23 (F) 52 (M) 32 (M) 37 (M) 42 (M) 26 (M) 25 (M) 41 (M) 18 (M)
108.70 305.60 194.60 11.10 12.70 120.60 27.50 26.00 22.30 10.70 102.40 44.90 213.50 26.50 107.60 15.80 136.60 66.20 120.80 98.80 43.70 269.50 20.80 4.30 43.00 11.40 33.10 1.40 10.80 13.80 28.00 -
2.30 0.68 10.90 23.80 18.10 1.20 6.10 1.30 2.00 2.50 3.30 70.20 4.00 0.90 23.80 2.70 87.90 14.10 46.60 56.30 35.80 -
9.80 8.30 7.70 1.90 1.70 6.60 3.10 9.60 4.70 1.30 1.70 9.10 8.60 3.00 5.40 3.10 26.30 13.50 15.00 12.50 16.20 56.50 2.34 2.03 5.97 1.10 1.94 1.26 1.68 3.08 4.08 2.03
0.50 0.11 0.24 0.80 0.33 0.16 0.43 0.11 0.18 0.21 0.63 2.72 0.14 0.09 1.11 0.10 1.97 1.61 1.16 2.94 2.33 2.17
0.18 6.46 0.14 3.91 0.36 0.35 2.65 9.31 3.08 6.63 1.13 1.62 0.16 6.20 8.15 1.95 0.22 3.61 1.12 0.35 0.34 0.30 0.75 0.45 1.64 2.67 -
0.50 0.19 0.40 0.74 0.30 0.20 0.35 0.30 0.10 0.20 0.90 1.00 1.80 1.80 -
0.24 0.18 0.18 0.33 0.22 0.26 0.16 0.25 0.28 0.17 0.30 0.14 0.13 0.13 0.17 0.21 0.13
0.14 0.13 0.14 0.14 0.14 0.18 0.20 0.14
0.34 0.24 0.30 0.25 0.25 0.32 0.28 0.35 0.28 0.23 0.30 0.30 0.39 0.26 0.44 0.34 0.33 0.28 0.36 0.46 0.58 0.83 0.25 0.23 0.40 0.22 0.27 0.32 0.30 0.27 0.25 0.24
0.90 0.51 -
Minus, not detected. b No data for (1S,2R)-(+)-, (1S,2S)-(+)-, or (1R,2R)-(-)-NE. c No data for (1S,2R)-(+)-, (1S,2S)-(+)-, or (1R,2R)-(-)-EP.
Quantitation. The stereoisomer concentrations of EP, PEP, NE, PNE, and four AM analogues (MA, AM, p-HMA, p-HAM) in urine were computed using calibration curves. These were prepared by plotting the peak area ratio of each mass fragment ion versus the IS for each concentration range from 50 to 2000 ng/mL (100 to 4000 ng/mL racemate) for EP, PEP, NE, PNE, and each of the four AM analogues. RESULTS AND DISCUSSION Stereoisomer Analysis of EP, NE, and four AM Analogues (AM, MA, p-HAM, p-HMA). TFA derivatization of the amino and hydroxyl groups of EP, PEP, NE, PNE, and the four AM analogues (MA, AM, p-HMA, p-HAM), was easily performed in a single step. No byproducts were generated by the reaction. Figure 2 shows typical SIM-GC/MS chromatograms of 16 TFA stereoisomers (using 250 ng/mL of each stereoisomer) by SIM-GC/ MS using human urine spiked with individual stereoisomers (including stereoisomers of EP, PEP, NE, PNE, MA, AM, p-HMA, p-HAM). SIM chromatograms of the 16 stereoisomers were similar to those produced from 8 pure racemate mixtures. All of the stereoisomers were separated, and simultaneous identification of EP, NE, and the four AM analogues was performed using a SIMGC/MS assay with fragment ions of 91, 118, 154, and 230 m/z. Linear increases in the calibration curves of all 16 stereoisomers
were observed as concentrations increased from 50 to 2000 ng/ mL (100 to 4000 ng/mL racemate), producing R2 values of 0.99690.9998. In particular, the detection limits of NE and EP were 50 ng/mL (100 ng/mL of racemate) for each stereoisomer, with a signal-to-noise ratio of g3. Inter-assay variation for the 16 stereoisomers was e11.7%, while intra-assay variation was e8.9%. The assay was able to detect the stereoisomers of EP, PEP, NE, PNE, and the four AM analogues, with high sensitivity, compared with the CE-MS15,16 and LC-MS methods.17 Moreover, the five mass fragment ions did not detect these products in human control urine, and chiral inversion of NE and EP stereoisomers was not observed in this sample preparation and analysis. Stereoisomers of NE Derived from (S)-(+)-MA or (R)(-)-MA in Human Urine. Next, stereoisomers of NE derived from MA or AM were investigated by SIM-GC/MS assay using MA or AM abusers’ urine, with simultaneous identification of MA or AM metabolite stereoisomers. Concentrations of MA and MA metabo-lites (AM, NE, p-HMA, p-HAM) in urine are shown in Table 1. (15) Iio. R.; Chinaka, S.; Tanaka, N.; Takayama, N.; Hayakawa, K. Analyst 2003, 128, 646-650. (16) Iio. R.; Chinaka, S.; Takayama, N.; Hayakawa, K. Anal. Sci. 2005, 21, 1519. (17) Katagi, M.; Nishioka, H.; Nakajima, K.; Tsuchihashi, H.; Fujima, H.; Wada, H.; Nakamura, K.; Makino, K. J. Chromatogr., B 1996, 676, 35-43.
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Figure 4. Stereoisomeric form of norephedrine derived from (S)(+)-amphetamine produced from (S)-(+)-methamphetamine in human urine.
Figure 3. Typical SIM chromatograms of stereoisomers of NE and AM analogues (MA, AM, p-HMA, p-HAM) obtained from the urine of a (S)-(+)-methamphetamine abuser (A) and a (R)-(-)-methamphetamine abuser (B). The SIM chromatogram (A) shows the SIM-GC/MS analysis of urine obtained from case 6 of methamphetamine abuse in this study (See Table 1.). The SIM chromatogram (B) shows the SIM-GC/MS analysis of urine obtained from case 13 of methamphetamine abuse in this study (See Table 1.).
From these, five urinary excretion patterns of MA and MA metabolites (AM, p-HAM, p-HMA) were identified (I-V). Among the urine of 12 (S)-(+)-MA abusers (I) and 2 (R)-(-)-MA abusers (II), the same stereoisomeric forms of AM, p-HAM, and p-HMA were observed as for unmetabolized MA (Figure 3A and B). In addition, chiral inversions were not observed; however, the NE stereoisomer resulting from metabolism of (S)-(+)-MA was identified as the (1R,2S)-(-)-form (NE) (Table 1). The remaining three stereoisomers of NE, (1S,2R)-(+), (1S,2S)-(+), and (1R,2R)(-), were not detected (detection limit, >50 ng/mL), and thus, their presence could not be confirmed. NE was detected at concentrations ranging from 224.7 to 353.8 ng/mL. The production ratio of (1R,2S)-(-)-NE to (S)-(+)-AM ranged from 0.02 to 0.18. All four NE stereoisomers were not detected in the urine of 2 (R)-(-)-MA abusers (Table 1). Similar results were noted with larger quantities of urine (10-fold) among (R)-(-)-MA users. Based on these results, it appears that NE is produced through hydroxylation of the β carbon of AM.7,11 Moreover, the observed stereoisomer of NE results from the (1R,2S)-(-)-form of (S)-(+)4180 Analytical Chemistry, Vol. 79, No. 11, June 1, 2007
AM following metabolism of (S)-(+)-MA (Figure 4), which may be the result of stereoselective β-hydroxylation of AM. Stereoselective Metabolism of MA and AM in Humans and Stereoisomeric Identification of NE. In urine from 19 subjects, (S)-(+)-MA and (R)-(-)-MA were detected simultaneously. Stereoselective metabolism of each of the MA metabolites (MA, AM, p-HAM, p-HMA) was observed, and the results were classified into three groups (III-V), as shown in Table 1. Among these, the urinary excretion of MA and AM stereoisomers within the classification scheme of the fifth group resembled that of MA and AM in urine after ingestion of racemic MA in humans,9,10 specifically, presence of the (S)-(+)-form < (R)-(-)-form for MA, and (S)-(+)-form > (R)-(-)-form for AM. On the other hand, only two types of urinary excretion patterns were observed for p-HMA and p-HAM stereoisomers: (S)-(+)-form < (R)-(-)-form or (S)(+)-form > (R)-(-)-form. Thus, it is not possible to determine the composition of MA racemate based on the excretion patterns of MA and AM stereoisomers because stereoselective metabolism of the two para-hydroxylation metabolites (p-HMA, p-HAM) has not been determined in human urine after ingestion of racemic MA. With regard to the third and fourth categories of stereoselective metabolism, urinary excretion of AM, p-HAM, and p-HMA was similar to that of MA: (S)-(+)-form > (R)-(-)-form in the third category, and (S)-(+)-form < (R)-(-)-form in the fourth category of urinary excretion. These results (I-V) indicate that the main metabolites of MA are AM and p-HMA, while p-HAM is a minor metabolite, compared with NE, which is further supported by a report by Hayakawa et al.8 Production of NE was related to the metabolite (S)-(+)-AM, rather than (R)-(-)-AM. The concentration of NE ranged from 221.3 to 834.4 ng/mL. The production ratio of (1R,2S)-(-)-NE to (S)-(+)-AM ranged from 0.01 to 0.25. In addition, an AM abuser had similar urinary excretion patterns of unmetabolized AM and p-HAM (Table 1): (S)-(+)form < (R)-(-)-form for unmetabolized AM and p-HAM. NE resulted from unmetabolized (S)-(+)-AM, as well as two MA stereoisomers, among MA abusers. NE was detected at a concentration of 242.6 ng/mL. The production ratio of (1R,2S)(-)-NE to (S)-(+)-AM was 0.12. Interpretation of Ephedrine Detected in MA Abusers’ Urine. Among 12 (S)-(+)-MA users and 19 (S)-(+)-MA and (R)(-)-MA users, (1R,2S)-(-)-EP was found in the urine samples of two subjects (Table 1, groups I and III). The remaining three EP stereoisomers, (1S,2R)-(+), (1S,2S)-(+), and (1R,2R)-(-), were
not detected (detection limit, >50 ng/mL). None of the four EP stereoisomers were detected in the remaining 29 subjects’ urine (Table 1, groups I and III-V). On the other hand, EP production from metabolism of MA has not been observed in humans.7 Therefore, (1R,2S)-(-)-EP was likely not a metabolite of MA, but rather derived from ingestion of a cough remedy, such as (1R,2S)(-)-EP, or an impure sample of (S)-(+)-MA.18 Most of the (1R,2S)(-)-NE detected was likely derived from (S)-(+)-MA. CONCLUSION The urinalysis results of MA and AM abusers showed that production of (1R,2S)-(-)-NE results from (S)-(+)-AM rather than (R)-(-)-AM. This was determined using SIM-GC/MS equipped with a chiral capillary column. This indicates a role of NE stereoisomers in distinguishing between (S)-(+)-MA and (R)(-)-MA use. The mechanism of metabolism of (S)-(+)-AM, specifically hydroxylation of the β carbon of AM, is thought to be responsible for NE production. Furthermore, NE production does not seem to depend on the amount of (S)-(+)-AM available. (18) Makino, Y.; Urano, Y.; Nagano, T. J. Chromatogr., A 2002, 947, 151-154.
Moreover, (1R,2S)-(-)-EP was found in the urine of only two subjects among 33 MA users examined. In addition, none of the four EP stereoisomers were found in the urine of 31 other MA users or 1 AM user. Therefore, most NE production is not the result of EP, but rather AM. This clearly differs from the mechanism of NE production following ingestion of the antiinflammatory agent famprofazone.12,13 With famprofazone, NE production results from both EP and AM metabolites. In addition, famprofazone metabolism results in additional NE stereoisomers, including (1S,2R)-(+), (1R,2S)-(-), (1S,2S)-(+), and (1R,2R)-(-) stereoisomers.12 The production of these NE stereoisomers is thought to depend on EP, rather than AM, based on the results presented here. Accordingly, (1R,2S)-(-)-NE may be an important metabolite in distinguishing between illegal MA use and ingestion of MA with famprofazone.
Received for review November 24, 2006. Accepted March 26, 2007. AC062229O
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