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Biomedical subjects

R D Budd

Publications and source records attributed to R D Budd.

At least 37 records · Page 2Linked to original sources
PubMed1981

Amphetamine EMIT--structure versus reactivity.

Over 60 different amphetamine-related amines were analyzed by EMIT (Enzyme Multiplied Immunoassay Technique) at several different concentrations. An attempt is made to relate structural differences to the affinity of the compounds for the EMIT amphetamine antibody. The effects of substituent placement on the amphetamine molecule are studied. Addition of a single alkyl group to the nitrogen of amphetamine increased reactivity, whereas all other structural changes had the reverse effect, decreasing reactivity.

Amphetamines↗
PubMed1981

Amphetamine radioimmunoassay--structure versus reactivity.

Over 60 different amphetamine-related amines were analyzed by radioimmunoassay (RIA) at several concentrations. An attempt is made to relate structural differences to the affinity of the compounds with The RIA amphetamine antibody. The effects of substituent placement in the amphetamine molecule are studied. Addition of groups to the para position of amphetamine increased reactivity whereas changes in all positions reduced reactivity.

Amphetamines↗
PubMed1981

Barbiturates--structure versus RIA reactivity.

Over 90 different compounds having structural similarities to barbituric acid were analyzed by radioimmunoassay (RIA) using 125I-secobarbital reagents (Roche). Affinities were compared with molecular structures and a number of observations are made. It was found that all definitive components of the 5,5-dialkyl barbituric acid ring structure were essential for reactivity with the Roche RIA reagents; structural changes at any position of the ring reduced reactivity. No compounds studied were found to be more reactive than secobarbital [5-allyl-3-(1-methylbutyl) barbituric acid] and RO-2-1126[5-allyl-5-(1-carbamoylisopropyl) barbituric acid (the hapten used to prepare the RIA antibody)]. Changes in the 5-allyl and/or the 5-(1-methylbutyl) groups of secobarbital resulted in decreased reactivity.

Barbiturates↗
PubMed1981

Cocaine radioimmunoassay--structure versus reactivity.

Twenty-seven different cocaine-related substances were analyzed by radioimmunoassay (RIA) at several concentrations. An attempt was made to relate structural differences to the affinity of the compounds with the RIA benzoylecgonine (cocaine metabolite) antibody. The effects of substituent placement in the cocaine molecule were studied. Adding an alkyl group to the 2-carboxylic acid (conversion to an alkyl ester) increased reactivity, whereas changes in all other positions reduced reactivity.

Cocaine↗
PubMed1981

Phencyclidine (PCP)-structure versus reactivity.

Seventeen different compounds having structural similarities o PCP (phencyclidine) were analyzed by radioimmunoassay (RIA) using 125I-phencyclidine reagents (Roche). Affinities were compared with molecular structures and several observations were made. It was found that the three-ring structure (1-phenylcyclo-hexylpiperidine) is essential for reactivity. Changes in and to the cyclohexyl ring and/or the piperidine ring reduced reactivity, while changes in the phenyl ring increased reactivity.

Phencyclidine↗
PubMed1980

Mass screening and confirmation of methaqualone and its metabolites in urine by radioimmunoassay-thin-layer chromatography.

A sensitive, rapid, and specific procedure is described for the mass screening and confirmation of methaqualone (Quaalude) in urine specimens. The method is sensitive to 1.0 microgram/ml levels of total methaqualone excretion products (free methaqualone, free hydroxylated methaqualone metabolites, and conjugated hydroxylated methaqualone metabolites). The raw urine is screened directly by radioimmunoassay, which is reactive to all the methaqualone excretion products. Specimens that are screened positive are confirmed by thin-layer chromatography using a solvent system of ethyl acetate-1,2-dichloroethane-chloroform (75:15:10) which separates methaqualone and its four major metabolites without interference from other drugs or urinary substances. The distinctive spot pattern produced by the methaqualone metabolites makes false positive results nearly impossible.

Chromatography, Thin Layer↗
PubMed1980

Drug use trends among Los Angeles County probationers over the last five years.

The frequency of use of various drugs including certain opiates, diazepam, barbiturates, amphetamines, methadone, cocaine, propoxyphene, methaqualone, and phencyclidine has been determined in Los Angeles County probationers during January and February of each of the last 5 years. The results indicate that while the overall amount of drug use has decreased slightly, the frequency of use of some drugs, such as phencyclidine and cocaine, has increased greatly while the frequency of use of most other drugs, such as phenobarbital and amphetamine, has considerably decreased.

California↗
PubMed1980

TLC analysis of urine for benzoylecgonine and norpropoxyphene.

A thin-layer chromatography (TLC) procedure has been developed for the analysis of urine samples for benzoylecgonine and norpropoxyphene, the major metabolites of cocaine and propoxyphene, respectively. Urine is made slightly acidic and methylated with dimethyl sulfate to convert the difficult-to-extract benzoylecgonine back into the much more readily extractable cocaine. The urine is then chilled, made basic, and extracted with chloroform/isopropanol. The organic layer containing the cocaine and norpropoxyphene is separated and evaporated to dryness. The residue is reconstituted and spotted on a TLC plate which is developed in hexane:chloroform:diethylamine (80:10:10) which separates the two substances without interference from other drugs, metabolites, and urinary substances. The two substances are visualized with acidified iodoplatinate spray and can be detected down to levels of 2.0 microgram/mL for benzoylecgonine and 1.0 microgram/mL for norpropoxyphene.

Chromatography, Thin Layer↗
PubMed1980

Thin-layer chromatographic screening and confirmation of methadone and its primary metabolite in urine.

A thin-layer chromatographic method for the simultaneous screening and confirmation of methadone and its primary metabolite (2-ethylidene-1,5-diemthyl-3,3-diphenylpyrrolidine) in urine specimens is presented. Urine is made basic and extracted with organic solvent. After separation and concentration, the residue is spotted, half on each of two thin-layer chromatography plates. One plate is developed in an ethyl acetate:methanol:diethylamine (90:10:1.6) solvent system and the second in an ethyl acetate:methylene chloride:propylamine (85:17:1.0) solvent system. Methadone and its primary metabolite can be detected in concentration as low as 0.5 micrograms/mL without interference from other drugs and urinary substances.

Biotransformation↗
PubMed1980

Screening and confirmation of opiates by thin-layer chromatography.

A thin-layer chromatography (TLC) procedure for the screening and confirmation of urinary codeine and morphine has been developed. Urine samples are hydrolyzed to liberate free codeine and morphine, extracted into an organic solvent, and concentrated. For screening, the extraction residues are spotted on TLC plates which are developed in chloroform:ethyl acetate:methanol:propylamine (35:45:5:5). For confirmation, the extraction residues are acetylated and then spotted on TLC plates which are developed in hexane:chloroform:diethylamine (50:30:7). The spots for the two drugs are visualized with acidified iodoplatinate. Codeine and morphine are well separated from one another and from normal urinary substances on both plates and can be detected at a concentration of 0.4 micrograms/mL.

Acetylation↗
PubMed1980

GLC/TLC analysis of codeine and morphine in urine via derivatization techniques.

A procedure has been developed for the TLC and GLC analysis of codeine and morphine derivatives in urine in cases where there is too much interference for TLC analysis as free drugs. Urine is hydrolyzed, then split into two fractions. One fraction is extracted with a polar solvent, concentrated, and acetylated. An aliquot is injected in a 3% OV-17 column and the rest is spotted on a plate developed in hexane:chloroform:diethylamine (50:30:6). The other fraction is ethylated (converting morphine to ethylmorphine), extracted with a nonpolar solvent, concentrated, acetylated, concentrated, and then spotted on a plate developed in hexane:n-butanol:acetonitrile:diethylamine (80:5:5:10). Codeine and morphine can be detected without interference at concentrations as low as 0.3 micrograms/mL.

Chromatography, Gas↗
PubMed1980

On-column gas chromatographic synthesis of 1,3-dialkyl (c = 1-10), benzyl, and cyclohexyl barbiturate derivatives.

Procedures are described for the on-column gas chromatographic synthesis of various N-alkyl-N-alkyl barbiturates where groups added to the nitrogens are benzyl, cyclohexyl, or straight chains with 1 to 10 carbons. The 1,3-dialkyl barbiturates having methyl, ethyl, n-propyl, n-butyl, cyclohexyl, isopropyl, or t-butyl groups can be prepared on-column by injecting an aliquot of a chloroform solution of the barbiturate with the appropriate N,N-dimethylformamide dialkyl acetal. The 1,3-dialkyl barbiturates where benzyl or butyl through decyl groups are added can be similarly prepared with N,N-dimethylformamide dineopentyl acetal and the appropriate alcohol to yield the desired compound. The 1-alkyl (I)-3-alkyl-(II) barbiturates where the alkyl groups differ are prepared by on-column reaction reaction of a barbiturate with aliquots of each of the respective reagents giving the desired groups.

Alkylation↗
PubMed1980

Mass screening and confirmation of diazepam in urine by EMIT-thin-layer chromatography.

A rapid, sensitive, and specific procedure is described for the mass screening and confirmation of diazepam (Valium) in urine at levels as low as 0.5 micrograms/mL. Raw urine specimens are screened directly by the enzyme multiplied immunoassay technique, and those screened positive are confirmed by thin-layer chromatography. Diazepam and its metabolites are converted to benzophenones; diazepam, 3-hydroxydiazepam, and its glucuronide yield 2-methylamino-5-chlorobenzophenone (MACB); whereas N-desmethyldiazepam, oxazepam, and oxazepam glucuronide yield 2-amino-5-chlorobenzophenone (ACB). The two benzophenones are well separated by a solvent system of petroleum ether:glacial acetic acid (90:10) and can be detected under ultraviolet light. A specimen reported positive for diazepam must produce spots for both ACB and MACB. No other benzodiazepines used in the United States or other urinary substances have been found to interfere; thus the procedure described is specific for for diazepam.

Chromatography, Thin Layer↗