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1.
Anal Bioanal Chem ; 416(3): 827-837, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37999721

RESUMEN

The opium poppy (Papaver somniferum) is a global commercial crop that has been historically valued for both medicinal and culinary purposes. Naturally occurring opium alkaloids including morphine, codeine, thebaine, noscapine, and papaverine are found primarily in the latex produced by the plant. If the plant is allowed to fully mature, poppy seeds that do not contain the opium alkaloids will form within the pods and may be used in the food industry. It is possible for the seeds to become contaminated with alkaloids by the latex during harvesting, posing a potential health risk for consumers. In the USA, there have been more than 600 reported adverse events including 19 fatalities that may be linked to the consumption of a contaminated poppy-containing product such as home-brewed poppy seed tea. Unwashed poppy seeds and pods may be purchased over the Internet and shipped worldwide. The Forensic Chemistry Center, US Food and Drug Administration (FDA) has evaluated several mass spectrometers (MS) capable of rapid screening to be used for high-throughput analysis of samples such as poppy seeds. These include a direct analysis in real-time (DART) ambient ionization source coupled to a single-quadrupole MS, an atmospheric solids analysis probe (ASAP) ionization source coupled to the same MS, and ion mobility spectrometers (IMS). These instruments have been used to analyze 17 poppy seed samples for the presence of alkaloids, and the results were compared to data obtained using liquid chromatography with mass spectral detection (LC-MS/MS). Results from the 17 poppy seed samples indicate that the DART-MS, ASAP-MS, and IMS devices detect many of the same alkaloids confirmed during the LC-MS/MS analyses, although both the false-positive and false-negative rates are higher, possibly due to the non-homogeneity of the samples and the lack of chromatographic separation.


Asunto(s)
Alcaloides , Papaver , Papaver/química , Opio/análisis , Cromatografía Liquida , Espectrometría de Movilidad Iónica , Látex/análisis , Espectrometría de Masas en Tándem , Morfina , Alcaloides/análisis , Semillas/química
2.
J Am Chem Soc ; 142(17): 8019-8028, 2020 04 29.
Artículo en Inglés | MEDLINE | ID: mdl-32250115

RESUMEN

Tris[N,N-bis(trimethylsilyl)amide]lanthanum (LaNTMS) is an efficient and selective homogeneous catalyst for the deoxygenative reduction of tertiary and secondary amides with pinacolborane (HBpin) at mild temperatures (25-60 °C). The reaction, which yields amines and O(Bpin)2, tolerates nitro, halide, and amino functional groups well, and this amide reduction is completely selective, with the exclusion of both competing inter- and intramolecular alkene/alkyne hydroboration. Kinetic studies indicate that amide reduction obeys an unusual mixed-order rate law which is proposed to originate from saturation of the catalyst complex with HBpin. Kinetic and thermodynamic studies, isotopic labeling, and DFT calculations using energetic span analysis suggest the role of a [(Me3Si)2N]2La-OCHR(NR'2)[HBpin] active catalyst, and hydride transfer is proposed to be ligand-centered. These results add to the growing list of transformations that commercially available LaNTMS is competent to catalyze, further underscoring the value and versatility of lanthanide complexes in homogeneous catalysis.

3.
J Chem Health Saf ; 27(4): 209-213, 2020 Jul 27.
Artículo en Inglés | MEDLINE | ID: mdl-34191962

RESUMEN

The COVID-19 pandemic has led to an acute shortage of hand sanitizer, which is crucial to keeping people safe and to preventing the spread of the SARS-CoV-2 virus. However, universities across the world have used their expertise to help to meet urgent demand from public bodies and the emergency services for supplies of safe and effective sanitizer. We explore here the experience of the University of Bristol, UK, in negotiating the regulatory demands and logistical challenges facing its own sanitizer production efforts. We also reflect on the different regulatory situation for US colleagues pursuing similar activities, and we share our advice for other universities wishing to follow a similar path.

4.
J Med Chem ; 61(16): 7034-7042, 2018 08 23.
Artículo en Inglés | MEDLINE | ID: mdl-29870665

RESUMEN

After the inhibition of acetylcholinesterase (AChE) by organophosphorus (OP) nerve agents, a dealkylation reaction of the phosphylated serine, referred to as aging, can occur. When aged, known reactivators of OP-inhibited AChE are no longer effective. Realkylation of aged AChE may provide a route to reversing aging. We designed and synthesized a library of quinone methide precursors (QMPs) as proposed realkylators of aged AChE. Our lead compound (C8) from an in vitro screen successfully resurrected 32.7 and 20.4% of the activity of methylphosphonate-aged and isopropyl phosphate-aged electric-eel AChE, respectively, after 4 days. C8 displays properties of both resurrection (recovery from the aged to the native state) and reactivation (recovery from the inhibited to the native state). Resurrection of methylphosphonate-aged AChE by C8 was significantly pH-dependent, recovering 21% of activity at 4 mM and pH 9 after only 1 day. C8 is also effective against isopropyl phosphate-aged human AChE.


Asunto(s)
Acetilcolinesterasa/química , Acetilcolinesterasa/metabolismo , Inhibidores de la Colinesterasa/farmacología , Agentes Nerviosos/farmacología , Organofosfatos/farmacología , Inhibidores de la Colinesterasa/química , Humanos , Simulación de Dinámica Molecular , Estructura Molecular , Agentes Nerviosos/química , Organofosfatos/química
5.
Chem Sci ; 9(6): 1634-1639, 2018 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-29675209

RESUMEN

The direct enantioselective chiral calcium(ii)·phosphate complex (Ca[CPA]2)-catalyzed conjugate addition of unprotected alkyl amines to maleimides was developed. This mild catalytic system represents a significant advance towards the general convergent asymmetric amination of α,ß-unsaturated electrophiles, providing medicinally relevant chiral aminosuccinimide products in high yields and enantioselectivities. Furthermore, the catalyst can be reused directly from a previously chromatographed reaction and still maintain both high yield and selectivity.

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