The use of perfluorinated anhydrides coupled with perfluoroalcohols for the derivatization of cannabinoids has been well documented. Derivatization is used in the detection of cannabinoids using gas chromatography-mass spectrometry (GC-MS) with both electron impact ionization (EI) and negative chemical ionization (NCI). During method development for the analysis of cannabinoids in biological samples using GC-MS in EI and NCI mode, it was observed that when Δ(9)-tetrahydrocannabinol (THC) and cannabidiol (CBD) were derivatized with trifluoroacetic anhydride (TFAA), the resultant derivatives produced the same retention times and mass spectra. This was not observed with the trimethylsilyl (TMS) derivatives of THC and CBD. This complication is due to the conversion of CBD to THC under acidic conditions. The work here highlights the unsuitability of the derivatizing reagent TFAA for the detection of THC and CBD. For the analysis of case samples, even if only THC is of interest, the presence of CBD cannot be excluded, and other derivatization techniques should be used.
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http://dx.doi.org/10.1093/jat/bkr017 | DOI Listing |
Naunyn Schmiedebergs Arch Pharmacol
January 2025
Department of Biochemistry, Faculty of Pharmacy, Badr University in Cairo (BUC), Badr City, 11829, Cairo, Egypt.
Antibody-drug conjugates (ADCs) have emerged as a promising strategy in targeted cancer therapy, enabling the precise delivery of cytotoxic agents to tumor sites while minimizing systemic toxicity. However, traditional ADCs face significant limitations, including restricted drug loading capacity, where an optimal drug-to-antibody ratio (DAR) is crucial; low DARs may lead to insufficient potency, while high DARs can cause rapid clearance and increased toxicity. Additionally, ADCs often suffer from instability in circulation due to the potential for premature release of cytotoxic agents, resulting in off-target effects and reduced therapeutic efficacy.
View Article and Find Full Text PDFHeadache
January 2025
Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.
Objective: Our primary objective was to evaluate the safety and feasibility of transcranial direct current stimulation combined with exercise therapy for the treatment of cervicogenic headache. Our exploratory objectives compared symptoms of headache, mood, pain, and quality of life between active and sham transcranial direct stimulation combined with exercise therapy.
Background: Cervicogenic headache arises from injury to the cervical spine or degenerative diseases impacting cervical spine structure resulting in pain, reduced quality of life, and impaired function.
EJNMMI Radiopharm Chem
January 2025
Department of Medicinal Chemistry, Uppsala University, Uppsala, 751 23, Sweden.
Background: Gastrin releasing peptide receptor (GRPR)-directed radiopharmaceuticals for targeted radionuclide therapy may be a very promising addition in prostate and breast cancer patient management. Aiming to provide a GRPR-targeting theranostic pair, we have utilized the Tc-99m/Re-188 radiometal pair, in combination with two bombesin based antagonists, maSSS-PEG2-RM26 and maSES-PEG2-RM26. The two main aims of the current study were (i) to elucidate the influence of the radiometal-exchange on the biodistribution profile of the two peptides and (ii) to evaluate the feasibility of using the [Tc]Tc labeled counterparts for the dosimetry estimation for the [Re]Re-labeled conjugates.
View Article and Find Full Text PDFSci Rep
January 2025
College of Civil Engineering, Liaoning Technical University, Fuxin, 123000, P. R. China.
Aeolian sandy soil is barren and readily leads to low fertilizer utilization rates and yields. Therefore, it is imperative to improve the water and fertilizer retention capacity of these soils. In this paper, three kinds of biochar (rice husk, corn stalk, and bamboo charcoal) and bentonite were used as amendments in the first year of the experiment.
View Article and Find Full Text PDFSci Rep
January 2025
Pharmaceutical Chemistry Department, Faculty of Pharmacy, Horus University, New Damietta, 34517, Egypt.
RP-HPLC technique was developed and optimized for simultaneous identification and estimation of nirmatrelvir (NIR) and ritonavir (RIT) in their new copackaged tablet. Stability of nirmatrelvir (NIR) was studied after exposure to different five stress conditions; alkali, acid, heat, photo and oxidation degradation. The chromatographic separation was achieved using VDSpher PUR 100 ODS (4.
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