1-Nitropyrene is a widely distributed environmental contaminant, but its fate in the environment remains unknown. 1-Nitropyrene in benzene exposed to sunlight was found to degrade rapidly, whereas 1-nitropyrene adsorbed on soot was stable and degraded at a rate of 42% in 40 d. The major degraded compound was identified as 9-hydroxy-1-nitropyrene, using nuclear magnetic resonance and gas chromatography/mass spectrometry. Concentrations of 9-hydroxy-1-nitropyrene were found to be between 15 and 23 pg/m3 in urban airborne samples. The mutagenic potency of 9-hydroxy-1-nitropyrene was much lower than that of 1-nitropyrene. We concluded that 1-nitropyrene in the environment is photodegraded into 9-hydroxy-1-nitropyrene to become a less mutagenic compound.

Adsorption↗

PubMedDate not supplied

Simultaneous HPLC analysis of optical isomers of methamphetamine and its metabolites, and stereoselective metabolism of racemic methamphetamine in rat urine.

Simultaneous identification of optical isomers (D and L) of methamphetamine (MAMP), amphetamine (AMP), para(p)-hydroxy(OH)-MAMP, and para(p)-hydroxy(OH)-AMP in rat urine was attempted by high-performance liquid chromatography (HPLC). They were determined as benzoyl derivatives. After administration of D- or L-isomer (15 mg/kg), only D- or L-isomers of the above mentioned metabolites were found in rat urine. In rats administered racemic MAMP (15 mg/kg), each percent dose of L-isomers of MAMP or AMP excreted at four collection times up to 24 h was less than that of the D-isomer (L/D less than 1.00), but the doses of L-isomers of p-OH-MAMP and p-OH-AMP excreted were higher than those of D-isomers (L/D greater than 1.00). Simultaneous analysis within 36 minutes showed good peak resolution. The L/D ratio for each metabolite decreased with time. The total percent doses of D- or L-isomer excreted by 24 hours were about 50% of the administered dose, 23.70 +/- 1.45% for the D-isomer, 25.70 +/- 1.54% for the L-isomers. The total L/D ratio was 1.08 +/- 0.03. These results indicated that Wistar rats have no chiral isomerization enzyme of MAMP, and show stereoselective metabolism of DL-MAMP. In the optical isomer analysis of 11 MAMP powder samples and 28 human urine specimens obtained from Japanese abusers, only D-MAMP was detected in the powder, and D-MAMP and D-AMP were detected in urine, respectively. This suggested that humans have no chiral isomerization enzyme of D-MAMP.

Adolescent↗

PubMedDate not supplied

Analysis of time-lapse changes of d- and l-enantiomers of racemic ethylamphetamine and stereoselective metabolism in rat urine by HPLC determination.

The analysis of time-lapse changes of d- and l-enantiomers after administration of racemic dl-ethylamphetamine (EAMP) to rats was performed by a high-performance liquid chromatograph equipped with a chiral activity column. After oral administration of dl-EAMP to five rats (dose, 15 mg/kg), the rat urine specimens were collected at four time intervals, 0-4, 4-12, 12-20, and 20-24 h. The two enantiomers of nonmetabolized EAMP and the two enantiomers of metabolized amphetamine (AMP) in urine were simultaneously detected within 20 min. The rate of urinary excretion during 24 h was 3.67% for d-EAMP, 1.03% for l-EAMP, 2.14% for d-AMP, and 1.92% for l-AMP. The total percent of the excreted doses of EAMP and AMP was approximately 8.8% of the administered dosage of dl-EAMP (5.81% for the d-enantiomers and 2.95% for the l-enantiomers). The l/d ratio was 0.51, which was significantly smaller than that (1.01) of the original dl-EAMP powder used (p < .01). The percentages of the doses of l-EAMP in each collection time were significantly less than those of d-EAMP (p < .01), and the l/d ratios of nonmetabolized EAMP decreased to 0.17 within 24 h. For the AMP metabolites, there was a somewhat greater percentage of l-AMP in urine collected up to 4 h than d-AMP (p < .05). Thereafter, it decreased more slowly than d-AMP with time. The l/d ratios of AMP changed from 1.57 to 0.76 within 24 h. The greater decrease of l-EAMP as compared with d-EAMP suggested the stereoselective metabolism of dl-EAMP in rats.

Administration, Oral↗

PubMedDate not supplied

Time-lapse changes of d- and l-enantiomers of racemic (dl)-ethylamphetamine in human urine.

The time-lapse changes of d- and i-forms in urine specimens collected in the 24 h after the oral dosing of two adult male subjects with 20 mg of racemic (dl)-ethylamphetamine (EAMP)-HCl were examined by high-performance liquid chromatography. The percentage of the excreted dose of nonmetabolized l-EAMP was larger than that of d-EAMP, and the percentage of the excreted dose of metabolized l-amphetamine (AMP) was smaller than that of d-AMP in both subjects, A and B. These differences were observed 4.5-24 h after administration of the drug. The changes in the l/d ratio of EAMP and AMP were not similar between subjects A and B, but the change in the total l/d ratio was nearly the same. The regression line for subject A was as follows: y = 0.021323x + 0.98399. The regression line for subject B was as follows: y = 0.020947x + 0.94893. These two regression lines suggested that the time lapsed after the administration to humans could be predicted. The total percent of the excreted doses of EAMP and AMP was 47.46% (the d-forms, 20.73%; the l-forms, 26.73%) for subject A and was 31.43% (the d-forms, 14.14%; the l-forms, 17.29%) for subject B. The l/d ratio was 1.29 for subject A and 1.22 for subject B, which was somewhat higher than that (1.01) of the dl-EAMP-HCl used.

Amphetamines↗

PubMedDate not supplied

Optical isomer analysis of 3,4-methylene-dioxyamphetamine analogues and their stereoselective disposition in rats.

Identification of the optical activity and simultaneous analysis of racemates (+/-) of three hallucinogens, 3,4-methylenedioxy-amphetamine (MDA), 3,4-methylenedioxymethamphetamine (MDMA), and 3,4-methylenedioxyethylamphetamine (MDEA), and the urinary excretion of their optical isomers in rats was performed by high-performance liquid chromatographic analysis. Analysis of optical enantiomers of three N-alkyl MDA derivatives was performed within 50 min using two different detectors, polarimetry (OR) and ultraviolet spectroscopy (UV). The OR detector proved suitable for identification of the optically active forms, whereas the UV detector was suitable for simultaneous analysis of the enantiomers in urine. After the administration of each of the three N-alkylated derivatives, rat urine specimens were collected over four intervals, 0-4, 4-12, 12-20, and 20-24 h. After the administration of 30 mg/kg of racemic MDA and MDMA, somewhat less of the S(+)-forms of unchanged MDA and MDMA than of the R(-)-forms in each urine specimen were detected, which gave R/S ratios greater than 1.00 (p < 0.01). Conversely, after the administration of 30 mg/kg of racemic MDEA, more of the S(+)-form than the R(-)-form was found in the urine, thus giving R/S ratios less than 1.00 (p < 0.01). The percentage of the dose excreted up to 24 h was approximately 29.4% of the administered dose for MDA [S(+) 13.40% and R(-) 15.98%], 5.8% for MDMA [S(+) 1.96% and R(-) 3.79%], and 7.3% for MDEA [S(+) 3.89% and R(-) 3.43%]. Urinary excretion of optical isomers of N-dealkylated MDA from MDMA and MDEA origin were the opposite of those of the unchanged forms, and their R/S ratios up to 24 h were 0.48 to 0.72 (p < 0.01) and 1.31 to 1.50 (p < 0.01), respectively. The urinary excretion rates up to 24 h were approximately 4.3% for N-dealkylated MDA from MDMA origin [S(+) 2.72% and R(-) 1.63%] and 0.8% for N-dealkylated MDA from MDEA origin [S(+) 0.36% and R(-) 0.47%]. The total percent of unchanged forms and N-dealkylated MDA was approximately 10.1% for MDMA [S(+) 4.68% and R(-) 5.42%] and 8.2% for MDEA [S(+) 4.25% and R(-) 3.91%]. The total R/S ratio of MDMA was found to be 1.95 (p < 0.01), whereas that of MDEA was 0.88 (p < 0.01). The total R/S ratio of MDA was 1.20 (p < 0.01 ), which was comparable with that of MDMA. These three R/S ratios did not conform to the theoretical values for three N-alkyl derivatives used and neither did the R/S ratios of urine specimens collected at the four interval. These results suggested the stereoselective disposition of three N-alkyl MDA analogues in rat. The method would be suitable for the forensic chemistry and toxicology analysis of specimens obtained from hallucinogen abusers.

3,4-Methylenedioxyamphetamine↗