Elemental fingerprinting of Hypericum perforatum (St John's Wort) herb and preparations using ICP-OES and chemometrics

This is a pre-copyedited, author-produced PDF of an article accepted for publication in Journal of Pharmaceutical and Biomedical Analysis following peer review. The version of record [Journal of Pharmaceutical and Biomedical Analysis (June 2016) Vol 125 pp 15-21, first published online March 4, 2016] is available online at doi: http://dx.doi.org/10.1016/j.jpba.2016.02.054 © 2016 Elsevier. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/St. John's wort (SJW) (Hypericum perforatum) is a herbal remedy commonly used to treat mild depression. The elemental profiles of 54 samples (i.e., dry herbs, tablets and capsules) were evaluated by monitoring 25 elements using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). The major elemental constituents in the SJW samples were Ca (300-199,000 μg/g), Mg (410-3,530 μg/g), Al (4.4-900 μg/g), Fe (1.154-760 μg/g), Mn (2.4-261 μg/g), Sr (0.88-83.6 μg/g), and Zn (7-64 μg/g). For the sixteen elements that could be reliably quantified, principal component analysis (PCA) was used to investigate underlying patterns in the data. PCA models identified 7 key elements (i.e., Ba, Ca, Cd, Mg, Mo, Ni and Y), which described 85% of the variance in the dataset in the first three principal components. The PCA approach resulted in a general delineation between the three different formulations and provides a basis for monitoring product quality in this manner.Peer reviewe

Flipped detection of psychoactive substances in complex mixtures using handheld Raman spectroscopy coupled to chemometrics

© 2022 The Authors. Journal of Raman Spectroscopy published by John Wiley & Sons Ltd. This is an open access article under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives. https://creativecommons.org/licenses/by-nc-nd/4.0/New psychoactive substance (NPS) misuse represents a critical social and health problem. Herein, a novel flipped approach is presented for the detection of psychoactive substances in complex mixtures using portable Raman spectroscopy. This consists firstly of evaluating the spectral dissimilarities of an NPS product to its constituent adulterants followed by detection of the NPS by means of key spectral signatures. To demonstrate it, three structurally diverse NPS and four commonly used adulterants were selected. A Design‐of‐Experiments guided approach was employed to determine the composition of simulate street samples, ranging from binary to quinary mixtures of varying concentrations. Spectra were acquired for all mixtures using a portable Raman spectrometer and examined using projection analysis on model systems, developed via principal component analysis using reference materials. For all 21 mixtures investigated, the innovative ‘flipped’ methodology resulted in isolated and unequivocal detection of the NPS. Interestingly, the NPS signatures were consistent across all mixtures investigated and were 1712, 1000, and 777/1022 cm−1 for 5F‐PB‐22, phenibut, and N‐Me‐2‐AI containing samples, respectively. Thus indicating that the developed model systems could be applicable to structural analogs. NPS were detected to concentrations as low as 6.0% w/w. This flipped methodology was benchmarked to the instrument's output algorithms and outperformed these in terms of NPS detection, particularly for low concentration ternary and quinary mixtures. As a result, this study represents a critical change in the conceptualization of novel approaches for the detection of psychoactive substances and further denotes a blueprint for the development of detection methodologies of target analytes in complex mixtures.Peer reviewedFinal Published versio

Small molecule recognition of mephedrone using an anthracene molecular clip

This document is the Accepted Manuscript version of the following article: Kathryn Kellett, J. Hugh Broome, Mire Zloh, Stewart B. Kirton, Suzanne Fergus, Ute Gerhard, Jacqueline Stair, and Kar J. Wallace, ‘Small molecule recognition of mephedrone using an anthracene molecular clip’, Chemical Communications, Vol. 52(47): 7474-7477, 2016. The version of record is available online at DOI: http://dx.doi.org/10.1039/C6CC03404G. Published by the Royal Society of Chemistry.An anthracene molecular probe has been synthesised and shown to target mephedrone, a stimulant drug from the cathinone class of new psychoactive substances (NPS). A protocol has been developed to detect mephedrone via the probe using NMR spectroscopy in a simulated street sample containing two of the most common cutting agents, benzocaine and caffeine.Peer reviewedFinal Accepted Versio

Benzodiazepine Boom: Tracking Etizolam, Pyrazolam, and Flubromazepam from Pre-UK Psychoactive Act 2016 to Present Using Analytical and Social Listening Techniques

© 2024 The Author(s). Licensee MDPI, Basel, Switzerland. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY), https://creativecommons.org/licenses/by/4.0/Introduction: The designer benzodiazepine (DBZD) market continues to expand whilst evading regulatory controls. The widespread adoption of social media by pro-drug use communities encourages positive discussions around DBZD use/misuse, driving demand. This research addresses the evolution of three popular DBZDs, etizolam (E), flubromazepam (F), and pyrazolam (P), available on the drug market for over a decade, comparing the quantitative chemical analyses of tablet samples, purchased from the internet prior to the implementation of the Psychoactive Substances Act UK 2016, with the thematic netnographic analyses of social media content. Method: Drug samples were purchased from the internet in early 2016. The characterisation of all drug batches were performed using UHPLC-MS and supported with 1H NMR. In addition, netnographic studies across the platforms X (formerly Twitter) and Reddit, between 2016–2023, were conducted. The latter was supported by both manual and artificial intelligence (AI)-driven thematic analyses, using numerous.ai and ChatGPT, of social media threads and discussions. Results: UHPLC-MS confirmed the expected drug in every sample, showing remarkable inter/intra batch variability across all batches (E = 13.8 ± 0.6 to 24.7 ± 0.9 mg; F = 4.0 ± 0.2 to 23.5 ± 0.8 mg; P = 5.2 ± 0.2 to 11.5 ± 0.4 mg). 1H NMR could not confirm etizolam as a lone compound in any etizolam batch. Thematic analyses showed etizolam dominated social media discussions (59% of all posts), with 24.2% of posts involving sale/purchase and 17.8% detailing new administration trends/poly-drug use scenarios. Artificial intelligence confirmed three of the top five trends identified manually. Conclusions: Purity variability identified across all tested samples emphasises the increased potential health risks associated with DBZD consumption. We propose the global DBZD market is exacerbated by surface web social media discussions, recorded across X and Reddit. Despite the appearance of newer analogues, these three DBZDs remain prevalent and popularised. Reporting themes on harm/effects and new developments in poly-drug use trends, demand for DBZDs continues to grow, despite their potent nature and potential risk to life. It is proposed that greater controls and constant live monitoring of social media user content is warranted to drive active regulation strategies and targeted, effective, harm reduction strategies.Peer reviewe

Sensor materials for the detection of proteases

The concept of generic and tunable sensor materials for the detection of proteases based on the thin film degradation of peptide cross-linked dextran hydrogels was explored. Hydrogel cross-links were formed via simple imine linkages between aldehyde groups in oxidized dextran and a peptide sequence susceptible to protease cleavage. Degradation of the hydrogel films was monitored in this study using a quartz crystal microbalance (QCM). The sensor material was developed using the protease/peptide pair of human neutrophil elastase (FINE) and Ala-Ala-Pro-Val-Ala-Ala-Lys (AAPVAAK). A direct relationship between the hydrogel degradation rate and protease activity was observed; HNE activities from 2.5 to 30 U ml(-1) were detected using 25% cross-linked films. Film degradation was rapid and was complete in less than 10 min for HNE activities >10 U ml(-1). An increase in the rate of degradation by a factor of 3.5 was achieved by increasing the cross-linking density from 25% to 75%. QCM admittance data fitted with a BVD equivalent circuit showed increases in film viscoelasticity upon enzyme addition. A second protease/peptide pair of cathepsin G and Ala-Ala-Pro-Phe-Phe-Lys (AAPFFK) was tested where 25% AAPFFK cross-linked hydrogels demonstrated a rapid response at 100 mU ml(-1). Swapping the protease/peptide pairs to HNE/AAPFFK and cathepsin G/AAPVAAK showed low levels of cross-sensitivity further demonstrating the specificity of film degradation. (C) 2008 Elsevier B.V. All rights reserved.Peer reviewe

Immobilized peptides/amino acids on solid supports for metal remediation

Recently, a significant amount of work has focused on metal binding by natural systems for various applications. This review will focus on the utility of amino acids, short peptides, and proteins that have been immobilized onto solid supports for use in metal binding, These systems include single amino acids, poly-amino acids, and peptides immobilized onto supports such as silica, polymer resins, and membranes. Also included are the studies involving the use of immobilized amino acids in ion-exchange chromatographyPeer reviewe

Layered Polyelectrolyte Films as Selective, Ultrathin Barriers for Anion Transport

Jeremy J. Harris, Jacqueline L. Stair, and Merlin L. Bruening, 'Layered Polyelectrolyte Films as Selective, Ultrathin Barriers for Anion Transport', Chemistry of Materials, Vol. 12 (7): 1941-1946, June 2000, doi: http://pubs.acs.org/doi/pdf/10.1021/cm0001004.Synthesis of high-flux composite membranes requires methods for deposition of ultrathin, defect-free films on highly permeable supports. Layer-by-layer deposition of polyelectrolytes on porous alumina (0.02 µm pore diameter) produces such membranes. Electron microscopy shows that five bilayers (<25 nm) of poly(allylamine hydrochloride) (PAH)/poly(styrenesulfonate) (PSS) are sufficient to cover porous alumina and that underlying pores are not clogged during the deposition process. The selectivity of anion transport through these membranes increases with the number of bilayers until the substrate is fully covered. Fivebilayer PAH/PSS membranes have Cl-/SO4 2- and Cl-/Fe(CN)6 3- selectivity values of 7 and 310, respectively. PAH/poly(acrylic acid) membranes show selectivity values similar to those of PAH/PSS membranes but with a 3-fold decrease in anion flux. Selectivity in both of these systems likely results from Donnan exclusion.Peer reviewe

Elemental Profile of Hypericum perforatum (St John's Wort) Preparations Using Icp-Oes

Abstract from the UK-PharmSci Conference 1st-3rd Sept 2010Peer reviewe

Quantitative determination of single-bead metal content from a peptide combinatorial library

An electrothermal vaporizer inductively coupled plasma mass spectrometer (ETV-ICPMS) was used to quantitatively screen metals bound to single polystyrene (TentaGel) beads with immobilized oligopeptides. Tests were performed using ETV-ICPMS to screen a series of identical beads as well as a series of combinatorial library beads exposed to a multimetal solution composed of Mg2+, Mn2+, Ni2+, Cu2+, Cd2+, Eu2+, and Pb2+. The residual metal content remaining bound to the beads after acid extractions was also analyzed by solid sampling of the entire bead using oxygen ashing in the ETV. Nine beads (80 mesh, 0.25 mmol g(-1) nominal capacity) containing covalently attached polyaspartic acid (PLAsp; n = 20) showed metal extract concentrations in the range of 4-130 ng mL(-1). After normalizing by bead volume, the precision of capacity measurements in a single bead (7-14%) was primarily dictated by analysis error and contributions from bead diameter measurement with negligible contributions, surprisingly, from variations in site density from bead to bead. A sample combinatorial library of the sequence GXXGXXGXXGXX (X = cysteine, aspartic acid, or glutamic acid and G = glycine) (60 mesh, 0.25 mmol g(-1) nominal capacity) was also used to demonstrate the utility of this method. Metal extract concentrations ranged from 1 to 1300 ng mL(-1) with significant concentration variation between beads, indicating the individual selectivity on each bead. For these larger beads, analysis precision (i.e., capacity precision) was further improved to 3-10% due to the overall increase in bead metal content. Through metal extract determinations, ETV-ICPMS was shown to be a viable nondestructive tool for full metal characterization of "hit" sequences belonging to a combinatorial library.Peer reviewe