Evaluation of Agonistic Activity of Fluorinated and Nonfluorinated Fentanyl Analogs on µ-Opioid Receptor Using a Cell-Based Assay System.

The agonistic activity of fluorinated and nonfluorinated fentanyl analogs on µ-opioid receptor was investigated using a cell-based assay system. Based on the activity, fentanyl analogs were ranked as follows: fentanyl > isobutyrylfentanyl ≈ butyrylfentanyl ≈ methoxyacetylfentanyl > acetylfentanyl. However, among the fentanyl analogs fluorinated on the N-phenyl ring, 2-fluoro analogs and 3-fluoro analogs showed the strongest and weakest activities, respectively. These results suggest that the 2-fluorinated isomers of fentanyl analogs are more likely to cause poisoning.

Rapid detection of synthetic cannabinoids in herbal highs using surface-enhanced Raman scattering produced by gold nanoparticle co-aggregation in a wet system.

Synthetic cannabinoids (SCs) are a major category of new psychoactive substances that are frequently distributed after addition to plants. To date, various SCs with small differences in their chemical structures have prevailed in the illegal drug market. Thus, the development of a method for rapid detection with high discrimination capability is critically important for the forensic field. Vibrational spectroscopy is a possible analytical technique for this purpose because it can sensitively reflect differences among chemical structures. In this study, we applied surface-enhanced Raman scattering (SERS) with gold nanoparticle co-aggregation in a wet system to plant samples containing SCs. The experimental protocol used was simple and involved only mixing of the sample with several other solutions. It was possible to detect SERS spectra from various stock solutions of SCs by this method. The method was then applied to street samples containing SCs. Some of the plant samples containing SCs did not produce significant SERS signals even though stock solutions of the same SCs did produce SERS spectra. We investigated the reason for this discrepancy and speculated that the solubility in aqueous solutions was a factor determining whether a significant SERS signal could be detected or not. According to this hypothesis, minimal sample pre-treatment methods were applied. This allowed for the detection of SERS spectra from the examined plant samples. The developed approach is a powerful method for screening analysis of SCs in plant fragments.

Development of simple and accurate detection systems for Cannabis sativa using DNA chromatography.

In recent years, the need for analyzing cannabis DNA has increased in order to accommodate the various types of cannabis samples encountered in forensic investigation. This study was aimed to establish a simple and accurate cannabis DNA detection system using DNA chromatography. Two chromatography chip systems with different features were successfully developed. One system (the "four-line version") involves tetraplex PCR amplification, which could be used to detect cannabis DNA and distinguish between drug-type and fiber-type cannabis using the tetrahydrocannabinolic acid synthase gene sequence. The other system was the "three-line version" with triplex amplification, which was specialized to distinguish cannabis from other plants, and had a sensitivity (10fg DNA/reaction) that was 100 times greater than the four-line version. In both versions, no false positives were observed for 60 medicinal plants, and accurate detection could be performed for several simulated forensic samples such as cannabis leaves, buds, stems, roots, seeds, resin, and cannabis leaves blended 1/100 in tobacco. Detection could be performed by the naked eye and only a thermal cycler was required for operation. Thus, DNA chromatography systems for cannabis detection are expected to contribute to the analysis of cannabis DNA in forensic chemistry laboratories without extensive equipment.

Development of a novel immunoassay for herbal cannabis using a new fluorescent antibody probe, "Ultra Quenchbody".

We developed a novel immunoassay for herbal cannabis based on a new immunoassay principle that uses Ultra Quenchbody ("UQ-body"), a recombinant antibody Fab fragment fluorolabeled at the N-terminal regions. When the antigen binds to anti-Δ(9)-tetrahydrocannabinol (THC) UQ-body, the fluorescence intensity (FI) decreases. The analytical conditions of the immunoassay were optimized based on the FI reduction rate (FIRR). Following are the steps in the final analytical procedure: (1) 10mg of samples were extracted with 1ml of a 60:40 mixture of methanol and phosphate-buffered saline (PBS); (2) the extract was filtered through a centrifugal 0.2-µm polytetrafluoroethylene membrane filter; (3) the filtrate was diluted 100 times with extraction solvent; (4) 6-µl diluted solution was mixed with 19-µl PBS and 75-µl UQ-body solution; and (5) FIRR was measured under 275-mV excitation light. Herbal cannabis samples containing ≥4.0-mg/g THC gave FIRRs of ≥5.2%. FIRRs of negative samples (cigarette, tea, spice, and so-called "synthetic marijuana") were ≤3.1%. When setting the FIRR threshold to 5.0%, cannabis samples containing ≥4.0-mg/g THC were correctly judged as positive without being affected by false positives caused by the negative samples. This detection limit was lower than total THC level (10-200mg/g) in most herbal cannabis samples seized in Japan. In seven of the 10 cannabis samples, the results of the UQ-body test were comparable with those of the Duquenois-Levine test. Thus, the UQ-body-based immunoassay is presumed to be an effective and objective drug screening method for herbal cannabis; however, to show the true usefulness, it is necessary to test a number of real case samples in the field situation.

Utilization of matrix-assisted laser desorption/ionization imaging mass spectrometry to search for cannabis in herb mixtures.

Herb mixtures including cannabis among the other herbs have recently appeared. When cannabinoids from herb extracts are detected by chemical examinations such as gas chromatography/mass spectrometry, forensic analysts have to determine whether cannabis is actually in the mixture or the cannabinoids are spiked. Morphological examinations are time-consuming, since it is difficult to find several pieces of cannabis among a large number of herb pieces using a microscope. Here, we propose a procedure for efficiently searching for cannabis in herb mixtures using matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI/IMS). Pieces of herb mixtures were spread on double-sided adhesive tape attached to a stainless steel plate. The pieces were then covered with a conductive sheet and pressed. After a solution containing a matrix reagent was sprayed, the distribution of cannabinoids in the sample was visualized by MALDI/IMS. Then, just the pieces with cannabinoids could be picked up selectively with tweezers and decolorized. Cystolith hairs and trichomes, which are characteristic of cannabis, were observed in most of these pieces using a biological microscope. This MALDI/IMS procedure enables cannabis to be found in herb mixtures without inefficient random sampling and microscopic morphological examination.

Time-course measurements of caffeine and its metabolites extracted from fingertips after coffee intake: a preliminary study for the detection of drugs from fingerprints.

The aim of this study was to determine whether an ingested drug and its metabolites could be detected in the subject's fingerprints. Caffeine (CF) was chosen as the model drug. Three healthy subjects were asked to consume a cup of coffee (ca. 100 mL) containing 80 micro micro mg CF as the total dose, which is the normal amount in one cup of coffee. After washing hands with water to remove external contaminants, each subject pressed the index fingertip to a collecting matrix just before consuming the test cup of coffee, and then again pressed the index fingertip to the collecting matrix after 1, 3, 5, and 7 h. The time curve of the amounts of CF and its metabolites-theobromine (TB), paraxanthine (PX), and theophylline (TP)-in fingerprints and blood was determined using liquid chromatography/tandem mass spectrometry (LC/MS). A filter paper wetted with water (50 µL) was an efficient collecting matrix for extracting the analytes from the fingertip. With optimized sample preparation and LC/MS conditions, the total operating time, from taking the fingerprints to obtaining the analytical result, was approximately 10 min. The lower limits of quantification for CF, TB, PX, and TP were 0.5, 5, 0.5, and 5 ng/fingerprint, respectively. The amount of CF or PX determined in fingerprints obtained over 7 h after coffee intake was significantly greater than the amount determined in fingerprints taken before drinking coffee. Fingerprints were a more efficient source for drug testing than other biological samples, such as blood and sweat, because the procedures for sampling and extracting the drugs were simpler and took less time. The method could be used to prove drug intake in criminal investigations.

Determination of salvinorin A and salvinorin B in Salvia divinorum-related products circulated in Japan.

Two major salvinorins, salvinorin A (SalA) and salvinorin B (SalB), in three Salvia divinorum dried leaf products and nine of its "concentrated extract" products circulated in Japan were determined. These ingredients were extracted twice with acetonitrile and decolored with graphite carbon powder. SalA and SalB were confirmed by liquid chromatography-tandem mass spectrometry in product ion scan mode, and quantified by high-performance liquid chromatography with UV detection (for SalA) and by mass spectrometry in single ion monitoring mode (for SalB). The SalA/SalB contents (mug/mg) were in the range of 3.2-5.0/0.10-0.17 in the dried leaf products and 4.1-38.9/0.26-2.42 in the "concentrated extract" products. These findings would be useful for analysis of S. divinorum-related products circulated in the drug market.

Development of an on-site screening system for amphetamine-type stimulant tablets with a portable attenuated total reflection Fourier transform infrared spectrometer.

We tried to develop a library search system using a portable, attenuated total reflection Fourier transform infrared (ATR-FT-IR) spectrometer for on-site identification of 3,4-methylenedioxymethamphetamine (MDMA) and 3,4-methylenedioxyamphetamine (MDA) tablets. The library consisted of the spectra from mixtures of controlled drugs (e.g. MDMA and ketamine), adulterants (e.g. caffeine), and diluents (e.g. lactose). In the seven library search algorithms, the derivative correlation coefficient showed the best discriminant capability. This was enhanced by segmentation of the search area. The optimized search algorithm was validated by the positive (n=154, e.g. the standard mixtures containing the controlled drug, and the MDMA/MDA tablets confiscated) and negative samples (n=56, e.g. medicinal tablets). All validation samples except for four were judged truly. Final criteria for positive identification were decided on the basis of the results of the validation. In conclusion, a portable ATR-FT-IR spectrometer with our library search system would be a useful tool for on-site identification of amphetamine-type stimulant tablets.