Trivedi M.
PMID:PPR1180320
Free PMC article
Abstract A novel, efficient reverse phase high performance liquid chromatography (RP-HPLC) method was developed and validated for the complete separation of nine impurities related to Bisoprolol fumarate active pharmaceutical ingredient. Since existing pharmacopeial methods have various analytical limitations, addressing only a subset of selected impurities, often require multiple approaches in order to meet regulatory expectations. Method validation was conducted in accordance with USP general chapter and ICH Q2 (R1) guidelines, ensuring satisfactory specificity, linearity, precision, accuracy, robustness and stability across a concentration range extending from the limit of quantification to 120% of the specified impurity level. Optimum chromatographic conditions including the use of appropriate stationary phase selection employing a monolithic silica rod with octyl silane chemically bonded to superficially porous silica particles (3 μm), buffer composition, temperature, flow rate and gradient elution enabled successful baseline resolution of all targeted impurities within a single analytical run. A very successful and efficient impurity separations were carried out by optimising chromatographic conditions by making use of differences in polarities of impurities chosen. Besides that, the procedures showed some robustness, assuring reliable results, despite deliberate minor alterations in experimental parameters. The developed RP-HPLC method’s ease of operation, its cost effectiveness, compliance with regulations and applicability to a wide variety of pharmaceutical products makes it an attractive technique in pharmaceutical analysis to meet the standards of regulatory acceptance that help in producing quality products.
Tsuji M, Imanari M, Shimoda T, Watanabe A.
PMID:PPR1180173
Free PMC article
Abstract The odors of five types of vegetables (potato, cabbage, broccoli, onion, and Welsh onion) exhibiting rot symptoms caused by seven bacterial pathogens ( Pectobacterium carotovorum subsp. carotovorum , Erwinia persicina , Pseudomonas marginalis pv. marginalis , Pseudomonas viridiflava , Xanthomonas campestris pv. campestris , Burkholderia gladioli , and Burkholderia cepacia ) were analyzed using gas chromatography-mass spectrometry (GC-MS). A total of 39 compounds were detected across these samples, with each vegetable-pathogen combination exhibiting a distinct profile of microbial volatile organic compounds (mVOCs). These findings suggest that, in principle, phytopathogens can be discriminated based on olfactory information derived from their metabolites.
Behe M, Gruber S, Li C, Schreckenbach G, Mu L, Schottelius M, Faizova R.
Dalton Trans
PMID:41910737
Free PMC article
Here, we report the synthesis and evaluation of La-[ 18/19 F]fluoride coordination complexes with macrocyclic ligands, expanding the family of metal-[ 18 F]fluoride coordination species for PET imaging applications. Fluorination of a series of La complexes with macrocyclic chelators (L = DOTA, DOTAM, macropa, and DOTpy) was explored, and the resulting products were characterized using 19 F and 1 H NMR, mass spectrometry, and X-ray spectroscopy. The stability of these complexes in water was found to inversely correlate with the electron-donating properties of the chelator. Notably, [LaF(L)] x complexes with macropa and DOTpy exhibited high stability in organic solution, with [LaF(DOTpy)]OTf 2 also demonstrating stability in water. DFT study (PBE-D3(BJ)/TZ2P, COSMO) indicates that the ΔΔ G magnitudes between [LaFL] and [La(H 2 O)L] could explain these results: much higher for DOTpy (21.66 kcal mol -1 ) and DOTAM (15.86 kcal mol -1 ) than for DOTA (6.78 kcal mol -1 ) and Macropa (8.05 kcal mol -1 ) supports the observed stabilities. Radiofluorination of [LaF(DOTpy)]OTf 2 afforded [ 18 F][LaF(DOTpy)] 2+ in high radiochemical purity, representing the first example of a La-[ 18 F]fluoride coordination complex. These findings expand the scope of metal-[ 18 F]fluoride coordination chemistry and lay the groundwork for developing La/Ac-based fluoride complexes as theranostic pairs, with applications in 225 Ac-based radiopharmaceuticals for personalized dosimetry and PET-guided therapy monitoring.
Hamzawy AH, Ghuniem MM.
Food Addit Contam Part B Surveill
PMID:42012645
Free PMC article
This study investigated the occurrence of pesticide residues in tomato paste samples collected from Egyptian markets during 2024-2025 to evaluate their safety and potential health risks. LC-MS/MS and GC-MS/MS analysis revealed detection of 70 and 57 residues in 2024 and 2025, respectively, with a noticeable decline in both diversity and frequency of violations over time. The most frequently detected pesticides were chlorfenapyr, cypermethrin, chlorpyrifos, and propargite, with several samples exceeding their maximum residue limits (MRLs). Notably, chlorpyrifos residues persisted, despite its national ban in 2022, indicating gaps in pesticide regulation and application control. Health risk assessment identified haloxyfop, omethoate, emamectin, and chlorfenapyr as major contributors to chronic or acute hazard quotients, with HQ or aHI values above 100%, suggesting potential long-term health concerns. These findings indicate the occurrence of a potential of both non-carcinogenic and carcinogenic health risks for consumers.
Espinoza Ballesteros M, Solis Rodriguez M, Tolbert TJ, Schöneich C.
Mol Pharm
PMID:42011714
Free PMC article
Near-UV and visible-light photodegradation is a concern for the development of stable and efficacious protein therapeutics, but mechanistic information on the underlying processes is scarce. We previously reported on the photoconversion and photofragmentation of IgG1-Fc, IgG1, and an IgG1-based fusion protein in the CH 2 domain. Here, we report a novel site-specific photodegradation mechanism, converting Thr into Ala catalyzed by Fe(III). Site-directed mutagenesis and spin-trapping in conjunction with high pressure liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) analysis reveal that this novel photoconversion proceeds via the generation of intermediary protein glycyl and methyl ( • CH 3 ) radicals analogous to metal-catalyzed cross-coupling reactions observed in synthetic organic processes.
