A consortium of microorganisms was established that was able to grow with the beta-tripeptide H-beta-HVal-beta-HAla-beta-HLeu-OH, with the beta-dipeptide H-beta-HAla-beta-HLeu-OH, and with the beta-amino acids H-beta-HAla-OH, H-beta-HVal-OH, and H-beta-HLeu-OH as the sole carbon and energy sources. This growth was achieved after several incubation-transfer cycles with the beta-tripeptide as the substrate. During degradation of the beta-tripeptide H-beta-HVal-beta-HAla-beta-HLeu-OH, the temporary formation of a metabolite was observed. The metabolite was identified as the beta-dipeptide H-beta-HAla-beta-HLeu-OH by nuclear magnetic resonance spectroscopy and mass spectrometry. This result indicates that in the course of the degradation of the beta-tripeptide, the N-terminal beta-HVal residue was cleaved off by a not yet known mechanism. During the subsequent degradation of the beta-dipeptide, formation of additional metabolites could not be detected. The growth-yield coefficients Y(x/s) for growth on the beta-di- and beta-tripeptide both had a value of 0.45. When a 1:1 mixture of the beta-tripeptide and the corresponding alpha-tripeptide H-Val-Ala-Leu-OH was added to the enrichment culture, the alpha-peptide was completely utilized in six days and thereafter growth of the culture stopped. This result indicates that even in beta-peptide enrichment cultures, alpha-peptides are the preferred substrates. Our experiments clearly show for the first time that beta-peptides and beta-amino acids are amenable to biodegradation and that a microbial consortium was able to utilize these compounds as sole carbon and energy sources. Furthermore, the preparation of beta-amino acids, of derivatives thereof, and of beta-di- and beta-tripeptides is described.

Excessive fluid intake can substantially dilute urinary drug concentrations and result in false-negative reports for drug users. Methods for correction ("normalization") of drug/metabolite concentrations in urine have been utilized by anti-doping laboratories, pain monitoring programs, and in environmental monitoring programs to compensate for excessive hydration, but such procedures have not been used routinely in workplace, legal, and treatment settings. We evaluated two drug normalization procedures based on specific gravity and creatinine. These corrections were applied to urine specimens collected from three distinct groups (pain patients, heroin users, and marijuana/ cocaine users). Each group was unique in characteristics, study design, and dosing conditions. The results of the two normalization procedures were highly correlated (r=0.94; range, 0.78-0.99). Increases in percent positives by specific gravity and creatinine normalization were small (0.3% and -1.0%, respectively) for heroin users (normally hydrated subjects), modest (4.2-9.8%) for pain patients (unknown hydration state), and substantial (2- to 38-fold increases) for marijuana/cocaine users (excessively hydrated subjects). Despite some limitations, these normalization procedures provide alternative means of dealing with highly dilute, dilute, and concentrated urine specimens. Drug/metabolite concentration normalization by these procedures is recommended for urine testing programs, especially as a means of coping with dilute specimens.

Examines the properties of phthalocyanine, the nomenclature of phthalocyanine compounds, and phthalocyanine polymers.

Chronic pain patients are frequently maintained on one or more powerful opioid medications in combination with other psychoactive medications. Urine tests provide objective information regarding patient compliance status. Little information is available on testing this unique population. The goal of this study was to characterize drug disposition patterns in urine specimens collected from a large population of pain patients. Confirmation data for 10,922 positive specimens were collated into 11 drug Classes. The number of drug/metabolites tested (#) and number of confirmed positive specimens were as follows: amphetamines (7), 160; barbiturates (5), 308; benzodiazepines (6), 2397; cannabinoids (1), 967; carisoprodol (2), 611; cocaine (1), 310; fentanyl (1), 458; meperidine (2), 58; methadone (2), 1209; opiates (7), 8996; and propoxyphene (2), 385. Subdivision into 19 distinct drug Groups allowed characterization of drug use patterns. Of the 10,922 positive specimens, 15,859 results were reported as positive in various drug Classes, and 27,197 drug/metabolites were measured by gas chromatography-mass spectrometry. The frequency of illicit drug use (cannabis, cocaine, ecstasy) was 10.8%. Being the first study of this type, these data present a large array of information on licit and illicit drug use, drug detection frequencies, drug/metabolite patterns, and multi-drug use combinations in pain patients.

No abstract