Mounting concern among forensic examiners regarding the emergence of positional isomers as technically legal alternatives to scheduled benzodiazepines has encouraged the preemptive synthesis of analogues as standards. Recently, flubromazepam was identified by the Drug Enforcement Administration for future scheduling, and subsequently, 9 of the 12 possible flubromazepam isomers were synthesized. However, the three (6,X')-isomers proved inaccessible via that approach. Herein, through a redesigned synthetic approach, the remaining three isomers were obtained, thus completing the set and enabling future forensic analysis.
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http://dx.doi.org/10.1021/acs.joc.1c02492 | DOI Listing |
Antioxidants (Basel)
December 2024
Dipartimento di Chimica e Tecnologie Chimiche, Università Della Calabria, Via Pietro Bucci Cubo 12/D, I-87030 Rende, CS, Italy.
A novel and efficient analytical protocol based on paper spray tandem mass spectrometry was developed for the determination of isomeric -glycoside flavanones in citrus juices and beverages. This approach significantly reduces sample preparation time and solvent consumption compared to traditional chromatographic techniques. By exploiting the unique fragmentation patterns of these compounds, accurate quantification of both diglycosides and their individual isomers (neohesperidoside and rutinose derivatives) was achieved.
View Article and Find Full Text PDFChemistry
January 2025
Osaka Metropolitan University: Osaka Koritsu Daigaku, Chemistry, 3-3-138 Sugimoto, Sumiyoshi-ku, 558-8585, Osaka, JAPAN.
Gold(I)-catalyzed intramolecular hydroarylation of dialkynyl(biaryl)phosphine oxides provided versatile benzo-fused phosphepine oxides. O-exo adducts were obtained as the major product, and O-endo adducts were the minor product. O-exo and O-endo indicate the position of an oxygen atom with respect to the central phosphepine framework.
View Article and Find Full Text PDFAnal Bioanal Chem
January 2025
Department of Pathology, Immunology and Laboratory Medicine, University of Florida College of Medicine, Gainesville, FL, USA.
An increasing number of cannabis-related products have become available and entered the market, particularly those containing cannabidiol (CBD) and Δ-tetrahydrocannabinol (Δ-THC). Analytical methods for cannabinoids in urine have been described extensively in the literature. However, methods providing good resolution for distinguishing interferences from THC positional isomers are needed.
View Article and Find Full Text PDFActa Crystallogr C Struct Chem
February 2025
Institute of Applied Chemistry, Shanxi University, Wucheng, Taiyuan, Shanxi 030006, People's Republic of China.
Three bisferrocene-based bis(acylthiourea) positional isomers, namely, 1,2-bis(ferrocenylcarbonylthioureido)benzene (1), 1,3-bis(ferrocenylcarbonylthioureido)benzene (2) and 1,4-bis(ferrocenylcarbonylthioureido)benzene (3), all [Fe(CH)(CHNOS)], have been synthesized via facile nucleophilic addition reactions of 2.3 equivalents of ferrocenoyl isothiocyanate with o-, m- and p-phenylenediamine, respectively. The structures of the three new synthesized isomers were fully characterized by H NMR, C NMR, IR and UV-Vis spectroscopy, elemental analyses and cyclic voltammetry.
View Article and Find Full Text PDFAnal Chem
January 2025
Analytical Chemistry Group, ‡VI-NEXT Group, Regeneron Pharmaceuticals, Inc., Tarrytown, New York 10591-6706, United States.
Phosphorothioate (PS) modifications in single-guided RNA (sgRNA) are crucial for genome editing applications using the CRISPR/Cas9 system. These modifications may enhance sgRNA stability, pharmacokinetics, and binding to targets, thereby facilitating the desired genetic alterations. Incorporating multiple PS groups at varying positions may introduce chiral centers into the sgRNA backbone, resulting in a complex mixture of constitutional- and stereoisomers that challenges current analytical capabilities for reliable identification and quantification.
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