Assessing in vitro stability of remdesivir (GS-5734) and conversion to GS-441524 in feline plasma and whole blood

Feline infectious peritonitis (FIP) is a potentially fatal coronavirus-driven disease of cats. Treatment with nucleoside analogue GS-441524 and or prodrug remdesivir (RDV) have produced remission in both experimentally induced and naturally occurring FIP, yet information regarding metabolism of RDV into GS-441524 in cats is scarce. This study assessed possible phase I metabolism of RDV in cats, utilising an in vitro feline microsome model with in vitro t1/2 and in vitro Clint calculated using the substrate depletion method. A previously validated high-performance liquid chromatography (HPLC) fluorescence method was utilised for detection and analysis of RDV and GS-441524. Qualitative yield of RDV and intermediate metabolite GS-441524 were determined following microsome incubation, then compared to whole blood and plasma incubations. In vitro microsome incubation resulted in rapid depletion of RDV, though it did not appear to resemble a conventional phase I-dependent reaction in cats, as it is in humans and dogs. Depletion of RDV into GS-441524 was demonstrated in whole blood in vitro, suggesting cats convert RDV to GS-441524, likely via blood esterases, as observed in mice and rats. RDV metabolism is unlikely to be impacted by impaired liver function in cats. Furthermore, as RDV depletes within minutes, whereas GS-441524 is very stable, whole blood or plasma GS-441524 concentrations, rather than plasma RDV concentrations, are more appropriate for therapeutic drug monitoring (TDM) in cats receiving RDV.

Impurity assessment, development and validation of an RP-HPLC method for the determination of eleven potential impurities of eltrombopag precursor

Eltrombopag is an oral non-peptide thrombopoietin receptor (TPO-R) agonist indicated for the treatment of thrombocytopenia in patients with persistent or chronic immune thrombocytopenia (idiopathic thrombocytopenic purpura, ITP) or chronic hepatitis C infection and the treatment of severe aplastic anemia. The purpose of this research was to assess the possible impurities that may carry over to eltrombopag from its precursor Eltro-1 (3'-amino-2'-hydroxy-[1,1'-biphenyl]-3-carboxylic acid) and to develop a specific analytical method for the determination of these impurities. Eltro-1 samples synthesized by two different synthesis routes were investigated during the evaluation and method development studies. Besides the expected process-related impurities (Eltro-1A - Eltro-1J), e.g., starting materials, intermediates, and/or compounds formed from their further reactions, an unknown impurity detected above 0.10% was identified by LC-MS, synthesized and fully characterized by NMR, MS and FTIR (Eltro-1K). Accordingly, an HPLC-RP method for the determination of eleven impurities (Eltro-1A - Eltro-1K) in Eltro-1 was developed and validated according to ICH Q2. The control limits for impurities in Eltro-1 were set at ≤ 0.15% for Eltro-1A - Eltro-1J and ≤ 1.0% for Eltro-1K based on fate, spike-purge and carryover studies and in accordance with the ICH M7 classification for impurities in drug substance. Eltro-1 and eleven impurities at the specification limit were separated from each other and the diluent peaks with sufficient resolution without interference. Separation was performed on a Waters XBridge C18 column (150 × 4.6 mm, 3.5 μm) at 40 °C with a 10 µL injection volume at a detection wavelength of 220 nm and 15 °C sample temperature. The gradient elution is performed at a flow rate of 1.0 mL/min for 40 min with mobile phase A (0.1% orthophosphoric acid in water) and B (acetonitrile) according to the following program: Time (min) / Acetonitrile (%): 0/0, 35/70, 36/0, 40/0. Test and standard solutions were prepared at a concentration of 1.0 mg/mL and 1.0 µg/mL, respectively, using a mixture of mobile phase A and acetonitrile (75/25) as diluent. This is the first specific, selective, sensitive, linear, precise, accurate, and robust HPLC method for the determination of Eltro-1A - Eltro-1K in Eltro-1, which showed no significant degradation under thermal stress, photostability (UV and VIS), and standard accelerated and long-term stability conditions.

Thermal degradation of red cabbage (Brassica oleracea L. var. Capitata f. rubra) anthocyanins in a water model extract under accelerated shelf-life testing

Red cabbage (RC) represents a source of anthocyanins acylated with hydroxycinnamic acids (HCA) that are described to enhance their stability. Nevertheless, data about their thermal degradation are still controversial. Our aim was to comprehensively analyse the degradation kinetics of individual RC anthocyanins in a model aqueous extract treated at 40 °C × 30 days to simulate severe but realistic storage conditions. Free anthocyanins and radical-scavenging capacity showed different kinetics. The results confirm the high stability of RC anthocyanins (t1/2: 16.4-18.4 days), although HPLC analyses of each molecule displayed distinct kinetics with t1/2 from 12.6 to 35.1 days. In particular, the sinapoyl acylation negatively affected the stability of the anthocyanins, while the forms monoacylated with glycosyl p-coumaric and ferulic acids exhibited higher stability. In conclusion, our results indicate that acylation is not a prerogative of stability, as this is instead more dependent on specific acylation patterns and the glycosylation of HCA.

A specific chiral HPLC method for lifitegrast and determination of enantiomeric impurity in drug substance, ophthalmic product and stressed samples

Lifitegrast is a lymphocyte function-associated antigen-1 (LFA-1) antagonist used to treat the indications and symptoms associated with dry eye disease (DED), one of the most common ocular surface diseases. Lifitegrast has a chiral center, and the S-enantiomer (S-Lif) is responsible for the therapeutic effects, while the R-enantiomer (R-Lif) lacks efficacy in the treatment of DED. Lifitegrast ophthalmic solution containing 5% lifitegrast was approved by the United States Food and Drug Administration (FDA) in July 2016 for the treatment of DED in patients 17 years of age and older. The objective of this study was to develop a chiral HPLC method for the determination of the enantiomeric impurity of lifitegrast in the drug substance and in the ophthalmic product. In addition, we aimed to investigate the effect of stress and stability conditions on the enantiomeric purity of lifitegrast in both drug substance and ophthalmic solution. During the method development studies, four known lifitegrast impurities (Lif. Imp. A-D) and stressed lifitegrast samples were injected to ensure the specificity of the developed method. The enantiomers of lifitegrast are well separated with a resolution of higher than 4.0. They are also well separated from the peaks of the diluent, impurities, and the placebo used to prepare the ophthalmic solution without interference in 20 min. Chiral separation was achieved using a Chiralpak AD-H column (250 × 4.6 mm, 5.0 μm) at 40 °C with a mobile phase consisting of a mixture of n-hexane, 2-propanol, and formic acid (500:500:2, v/v/v) at a flow rate of 1.0 mL/min and a detection wavelength of 260 nm. Methanol was used as the diluent, and the drug substance solution was found to be stable for 48 h at 15 °C. The optimized chiral HPLC method for lifitegrast was validated according to ICH Q2, and the calibration curves showed excellent linearity for R-Lif (0.0369 - 1.816 µg/mL). This is the first stability-indicating, specific / selective, sensitive, linear, precise, accurate, and robust chiral HPLC method for the determination of R-Lif in S-Lif. The amount of enantiomeric impurity R-Lif in S-Lif increased under all stress and photostability test conditions without exceeding the acceptable impurity limit, with the most significant increase observed at elevated temperatures (105 °C) for both the drug substance in powder form and the ophthalmic drug solution.

Quantification of oxaliplatin- and ioversol-related compounds in pharmaceutical formulations using novel HPLC-ICP-MS methods

PURPOSE

Accurate quantifying of drug-related compounds in medicines is vital for safety. Commonly used structure-dependent methods rely on analytical standards. High-performance liquid chromatography coupled with inductively coupled plasma-mass spectrometry (HPLC-ICP-MS) offers a promising solution, being structure-independent and not requiring standards. In this study, we aim to develop HPLC-ICP-MS methods for the determination of related compounds in oxaliplatin and ioversol injections.

RESULTS

The target analytes were eluted on an XSelect HSS T3 column (2.1 ×50 mm, 5 µm). Specifically, oxaliplatin injection was eluted isocracially for 3.5 min, and ioversol injection was eluted gradient with a total chromatographic run time of 12 min. The measurements to determine dihydroxy oxaliplatin-Pt(IV) and two related compounds of ioversol were performed by monitoring at m/z for 195Pt and 127I, respectively. The calibration curves were established over the range of 0.05-1 μM for Pt and 0.3-15 μM for I with the correlation coefficients greater than 0.999. The limits of quantification were 0.004 μM for dihydroxy oxaliplatin-Pt(IV), 0.022 μM for ioversol related compound A and 0.026 μM for ioversol related compound B. The accuracy (recovery between 93-105%) and precision (repeatability ≤ 6.1% RSD) were fit-for-purpose for dihydroxy oxaliplatin-Pt(IV), and the accuracy (recovery between 95-107%) and precision (repeatability ≤ 3.9% RSD) were also fit-for-purpose for both ioversol related compound A and ioversol related compound B.

CONCLUSION

The quantitation accuracy of HPLC-ICP-MS closely matched that of the standard HPLC-UV approach. HPLC-ICP-MS can be used as a complementary analytical technique for quantitative determination of drug-related compounds.

Lipophilic arsenic compounds in the cultured green alga Chlamydomonas reinhardtii

In this study, arsenic (As) speciation was investigated in the freshwater alga Chlamydomonas reinhardtii treated with 20 μg/L arsenate using fractionation as well as ICP-MS/ESI-MS analyses and was compared with the known As metabolite profile of wild-grown Saccharina latissima. While the total As accumulation in C. reinhardtii was about 85% lower than in S. latissima, the relative percentage of arsenolipids was significantly higher in C. reinhardtii (57.0% vs. 5.01%). As-containing hydrocarbons and phospholipids dominated the hydrophobic As profile in S. latissima, but no As-containing hydrocarbons were detectable in C. reinhardtii. Instead for the first time, an arsenoriboside-containing phytol (AsSugPhytol) was found to dominate the hydrophobic arsenicals of C. reinhardtii. Interestingly, this compound and its relatives had so far been only found in green marine microalgae, open sea plankton (mixed assemblage), and sediments but not in brown or red macroalgae. This compound family might therefore relate to differences in the arsenic metabolism between the algae phyla.

Evaluation of gamma irradiation effects on antioxidant capacity of propolis

The irradiation effects on antioxidant potential and on content of phenolic compounds of propolis ethanoic extracts were studied. It was found out that gamma treatment of samples with 2 and 10 kGy had a weak decreasing effect on the total phenolic content (TPC), while no change was observed in the propolis irradiated with 5 kGy. The antiradical activity of extracts was assessed by the DPPH free radical scavenging activity evaluated by Electron Paramagnetic Resonance (EPR) spectroscopy. The EPR results were in agreement with TPC. Some main phenolic compounds of the studied non-irradiated and irradiated samples were identified and compared by ultra-high performance liquid chromatography (UHPLC).

Effects of omitting titanium dioxide from the film coating of a pharmaceutical tablet - An industrial case study of attempting to comply with EU regulation 2022/63

Recently, concerns have been raised about the safety of titanium dioxide (TiO2), a commonly used component of pharmaceutical film coatings. The European Union has recently prohibited the application of this material in the food industry, and it is anticipated that the same will happen in the pharmaceutical industry. For this reason, pharmaceutical manufacturers have to consider the possible impact of removing TiO2 from the film coating of tablets. In this paper, we present a case study of a commercially produced tablet where the film coating containing TiO2 was replaced with a coating using calcium carbonate (CaCO3) or with a transparent coating. The performance of the coatings was compared by measuring the moisture absorption rate and the dissolution profile of the tablets. In these regards, there were negligible differences between the coating types. The tablets contained a highly photosensitive drug, the ability of the coatings to protect the drug was evaluated through environmental stability and photostability measurements. The HPLC results showed that the inclusion of TiO2 does not provide additional benefits, when humidity and thermal stress is applied, however its role was vital in protecting the drug from external light. There were several decomposition products which appeared in large quantities when TiO2 was missing from the coating. These results imply that photosensitivity is an issue, replacing TiO2 will be challenging, though its absence can be tolerated when the drug does not need to be protected from light.

Uptake of vanadium and its intracellular metabolism by Coprinellus truncorum mycelial biomass

BACKGROUND

Fungi absorb and solubilize a broad spectrum of heavy metals such as vanadium (V), which makes them a main route of its entry into the biosphere. V as vanadate (V5+) is a potential medical agent due to its many metabolic actions such as interaction with phosphates in the cell, and especially its insulin-mimetic activity. Antidiabetic activity of V-enriched fungi has been studied in recent years, but the biological and chemical bases of vanadium action and status in fungi in general are poorly understood, with almost no information on edible fungi.

METHODS

This manuscript gives a deeper insight into the interaction of V5+ with Coprinellus truncorum, an edible autochthonous species widely distributed in Europe and North America. Vanadium uptake and accumulation as V5+ was studied by 51V NMR, while the reducing abilities of the mycelium were determined by EPR. 31P NMR was used to determine its effects on the metabolism of phosphate compounds, with particular focus on phosphate sugars identified using HPLC.

RESULTS

Vanadate enters the mycelium in monomeric form and shows no immediate detrimental effects on intracellular pH or polyphosphate (PPc) levels, even when applied at physiologically high concentrations (20 mM Na3VO4). Once absorbed, it is partially reduced to less toxic vanadyl (V4+) with notable unreduced portion, which leads to a large increase in phosphorylated sugar levels, especially glucose-1-phosphate (G1P) and fructose-6-phosphate (F6P).

CONCLUSIONS

Preservation of pH and especially PPc reflects maintenance of the energy status of the mycelium, i.e., its tolerance to high V5+ concentrations. Rise in G1P and F6P levels implies that the main targets of V5+ are most likely phosphoglucomutase and phosphoglucokinase(s), enzymes involved in early stages of G6P transformation in glycolysis and glycogen metabolism. This study recommends C. truncorum for further investigation as a potential antidiabetic agent.

Selective hydrophobic interaction chromatography for high purity of supercoiled DNA plasmids

High purity of plasmid DNA (pDNA), particularly in supercoiled isoform (SC), is used for various biopharmaceutical applications, such as a transfecting agent for production of gene therapy viral vectors, for pDNA vaccines, or as a precursor for linearized form that serves as a template for mRNA synthesis. In clinical manufacturing, pDNA is commonly extracted from Escherichia coli cells with alkaline lysis followed by anion exchange chromatography or tangential flow filtration as a capture step for pDNA. Both methods remove a high degree of host cell contaminants but are unable to generically discriminate between SC and open-circular (OC) pDNA isoforms, as well as other DNA impurities, such as genomic DNA (gDNA). Hydrophobic interaction chromatography (HIC) is commonly used as polishing purification for pDNA. We developed HIC-based polishing purification methodology that is highly selective for enrichment of SC pDNA. It is generic with respect to plasmid size, scalable, and GMP compatible. The technique uses ammonium sulfate, a kosmotropic salt, at a concentration selective for SC pDNA binding to a butyl monolith column, while OC pDNA and gDNA are removed in flow-through. The approach is validated on multiple adeno-associated virus- and mRNA-encoding plasmids ranging from 3 to 12 kbp. We show good scalability to at least 300 mg of >95% SC pDNA, thus paving the way to increase the quality of genomic medicines that utilize pDNA as a key raw material.

New ring-A modified cycloartane triterpenoids from Dysoxylum malabaricum bark: Isolation, structure elucidation and their cytotoxicity

The Genus Dysoxylum (Meliaceae) consists of approximately 80 species that are abundant in structurally diverse triterpenoids. The present study focused on isolating new triterpenoids from the bark of Dysoxylum malabaricum, one of the predominant species of Dysoxylum present in India. The methanol-dichloromethane bark extract was subjected to LCMS profiling followed by silica gel column chromatography and HPLC analysis to target new compounds. Two new ring A-modified cycloartane-type triterpenoids (1 and 2) were isolated from the bark extract. Spectroscopic methods like NMR, HRESIMS data, and electronic circular dichroism calculations elucidated the structuresandabsolute configurations of the isolated compounds. These compounds were evaluated for their cytotoxic potential against breast cancer cells and displayed notable cytotoxicity. Compound 1 exhibited the highest cytotoxicity against the MDA-MB-231 cells and induced apoptotic cell death. Also, it was able to inhibit glucose uptake and increase nitric oxide production in breast cancer cells.

Sacrificial template synthesis of hollow sulfonate group functionalized microporous organic network for efficient solid phase extraction of sulfonamide antibiotics from milk and honey samples

The highly conjugated and hydrophobic characteristics of microporous organic networks (MONs) have largely impeded their broad applications in sample pretreatment especially for the polar or ionic analytes. In this work, a novel uniform hollow shaped sulfonate group functionalized MON (H-MON-SO3H-2) was synthesized via the sacrificial template method for the efficient solid phase extraction (SPE) of sulfonamides (SAs) from environmental water, milk, and honey samples prior to HPLC analysis. H-MON-SO3H-2 exhibited large specific surface area, penetrable space, good stability, and numerous hydrogen bonding, electrostatic, hydrophobic and π-π interaction sites, allowing sensitive SPE of SAs with wide linear range (0.150-1000 μg L-1), low limit of detection (0.045-0.188 μg L-1), good precisions (intra-day and inter-day RSD < 7.3%, n = 5), large enrichment factors (95.7-98.5), high adsorption capacities (250.4-545.0 mg g-1), and satisfactory reusability (more than 80 times). Moreover, the established method was successfully applied to extract SAs from spiked samples with the recoveries of 86.1-104.3%. This work demonstrated the great potential of H-MON-SO3H-2 in the efficient SPE of trace SAs in complex environmental water and food samples and revealed the prospect of hollow MONs in sample pretreatment.

Food selection and effect of home preparation procedure for antibiotic food mixtures on homogeneity, stability, and dissolution

Amoxicillin, doxycycline, and clindamycin are among the commonly used antibiotics to treat bacterial infections. However, dosage forms of antibiotics for pediatric patients may not be as readily available as the formulations for adult patients. As such, it is anticipated that during a public health emergency, special instruction may need to be provided on home preparation and administration procedures to dose pediatric patients using available stockpiles of oral tablet and capsule dosage forms. Mixing crushed tablets or capsule contents with soft- or liquid- foods is one of the most common home preparation procedures. To gain knowledge for safe and effective use of prepared drug product instead of the intended intact dosage form, the impact of manipulation of the dosage form was studied. Capsule opening, capsule content assay and uniformity, dissolution, homogeneity, and stability studies of drug mixed with various liquid and soft foods were carried out using intact capsules of amoxicillin, doxycycline, and clindamycin. Higher recovery of capsule contents was achieved when using hands or knives to open capsules compared to using scissors. The capsules of all three antibiotic products contained the labeled amount of active pharmaceutical ingredients (API). The peanut butter-drug mixtures failed both United States Pharmacopeia (USP) assay and dissolution criteria because the peanut butter significantly affected the solubility of the drugs, and hence it was omitted from further study. All drug-food mixtures of the three antibiotic products and 15 selected foods exhibited fast dissolution (e.g., >80 % in 60 min) in the tested medium, except for the amoxicillin-chocolate pudding mixture. Three household containers (cups, plates, and bowls) and four mixing times (0.5 min, 1 min, 2 min, and 5 min) were found to be suitable for preparation of homogeneous mixtures of the antibiotics and foods. For practical purposes, 1 to 2 min mixing time is sufficient to produce homogeneous mixtures. The results of this study provided product quality data on the interactions between the antibiotics and the foods and can potentially support future development of home preparation instructions of antibiotics for pediatric patients or patients with swallowing difficulties.

Exploring the potential applications of amphiphilic carbon dots based nanocomposite hydrogel in liquid chromatographic separations

BACKGROUND

Due to their excellent stability, low toxicity, flexible modification and adjustable functionality, carbon dots (CDs) have a promising application prospect in the field of chromatographic stationary phases. Hydrogels are new functional polymer materials with three-dimensional network structure that have excellent hydrophilicity, high porosity and unique mechanical properties, which are also good candidate materials for liquid chromatography. Nevertheless, a review of the literature reveals that CDs based nanocomposite hydrogels have not yet been reported as HPLC stationary phases.

RESULTS

In this work, amphiphilic CDs with multiple functional groups and polyacrylic acid hydrogel were grafted to the surface of silica gel by an in-situ polymerization method, and a CDs/polyacrylic acid nanocomposite hydrogel stationary phase (CDs/hydrogel@SiO2) was prepared. CDs act as the macroscopic cross-linking agents to form a cross-linked network with polyacrylic acid chains through physical cross-linking by hydrogen bonding and chemical cross-linking by amidation and esterification reactions, which not only improve the swelling property of the hydrogel but also increase its stability. Additionally, the introduction of CDs with multifunctional groups modulates the hydrophilic-hydrophobic balance of the hydrogel that also imparts good hydrophobicity to the composite hydrogel. Through the study of retention mechanism and influencing factors, it is certificate that the CDs/hydrogel@SiO2 has mixed-mode chromatographic performance. Furthermore, the CDs/hydrogel@SiO2 column shows great potential for the determination of organic contaminants in environmental water samples.

SIGNIFICANCE

This work confirms the potential application of CDs/hydrogel composite for the separation of various samples and provides the possibility of developing CDs based nanocomposite hydrogel in the field of liquid chromatography. Introducing CDs into hydrogel can open up a new way for nanocomposite hydrogels to be used in HPLC, which expands the advance of hydrogel and CDs in separation field.

Growing value of data standardization: Allotrope Foundation Connect Workshop Proceedings

Recent Allotrope Foundation (AF) Connect Workshops (2021-2023) showcased some of the latest advancements in data standardization for analytical data in the pharmaceutical industry. These workshops demonstrated the adaption of two key technologies, the Allotrope Data Format (ADF) and the Allotrope Simple Model (ASM), which streamline instrument data representation and terminology to enhance interoperability across systems. Notably, ASM has facilitated broader adoption of the standard. The increasing significance of data-driven decision-making in the life sciences is underscored by the evolving landscape of open-source solutions and commercial implementations, as demonstrated by industry leaders adopting these standards. Here, we highlight selected examples that illustrate the collective efforts of the community in advancing data standards and data management in the life sciences.

A New α1-Globin Variant, Hb Ormylia [HBA1:c.63C > G; p.His21Gln]. Report of Eleven Cases in Northern Greece

The first identification of a novel α1-Globin variant, Hb Ormylia in 11 Greeks originating from a small village, Ormylia, Chalkidiki, Greece is reported. The new genetic variant leads to the production of a hemoglobin variant that can be identified and quantified by High-Performance Liquid Chromatography. Capillary and classic electrophoresis were not informative. Direct DNA sequencing revealed a new mutation C > G mutation at codon 21 of α1 gene (His > Gln). The new variant has been named Hb Ormylia and this is the first description of this genetic variant of α1 gene in the literature.

The Michael addition of thiols to 13-oxo-octadecadienoate (13-oxo-ODE) with implications for LC-MS analysis of glutathione conjugation

Unsaturated fatty acid ketones with αβ,γδ conjugation are susceptible to Michael addition of thiols, with unresolved issues on the site of adduction and precise structures of the conjugates. Herein we reacted 13-keto-octadecadienoic acid (13-oxo-ODE or 13-KODE) with glutathione (GSH), N-acetyl-cysteine, and β-mercaptoethanol and identified the adducts. HPLC-UV analyses indicated none of the products exhibit a conjugated enone UV chromophore, a result that conflicts with the literature and relevant to mass spectral interpretation of 1,4 versus 1,6 thiol adduction. Aided by development of an HPLC solvent system that separates the GSH diastereomers and thus avoids overlap of signals in proton NMR experiments, we established the two major conjugates are formed by 1,6 addition of GSH at the 9-carbon of 13-oxo-ODE with the remaining double bond α to the thiol in the 10,11 position. N-acetyl cysteine reacts similarly, while β-mercaptoethanol gives equal amounts of 1,4 and 1,6 addition products. Equine glutathione transferase catalyzed 1,6 addition of GSH to the two major diastereomers in 44:56 proportions. LC-MS in positive ion mode gives a product ion interpreted before as evidence of 1,4-thiol adduction, whereas here we find this ion using the authentic 1,6 adduct. LC-MS with negative ion APCI gave a fragment selective for 1,4 adduction. These results clarify the structures of thiol conjugates of a prototypical unsaturated keto fatty acid and have relevance to the application of LC-MS for the structural analysis of keto-fatty acid glutathione conjugation.

Improved preconcentration workflow for organic explosive traces in aqueous samples using solvent-assisted dispersive solid-phase extraction

The present study deals with the development of a solvent-assisted dispersive solid phase extraction method for the extraction of HMX, RDX, and TNT from aqueous samples. Benzophenone and methanol were selected as explosives sorbent and dispersive solvent respectively. Extraction parameters like pH, extraction time, amount of sorbent, volume and type of the disperser solvent and centrifuge time were optimized. Dispersion of 0.5 mL dispersive solution (4% (w/v) benzophenone in methanol) was performed by injection into the 5 mL aqueous sample (pH=7) using a 1.0 mL syringe. After centrifuge, the extracted explosives were analyzed by high performance liquid chromatography with ultraviolet detection (HPLC-Uv). The results indicated that the linear ranges with the correlation coefficients of 0.99 ≤ R2 were 1.6-204.6 μg L-1, 1.4-213.7 μg L-1 and 1.3-225.9 μg L-1 for HMX, RDX and TNT respectively. The limit of detection and limit of quantification obtained for each explosive were: 0.3 μg L-1 and 0.8 μg L-1 for HMX, 0.3 μg L-1 and 0.9 μg L-1 for RDX and 0.2 μg L-1 and 0.7 μg L-1 for TNT. Finally, the practical applicability of the developed method was evaluated for the extraction of some organic explosives in water samples followed their determination by HPLC-Uv.

Metabolomics distinguishes different grades of Scrophularia ningpoensis hemsl: Towards a biomarker discovery and quality evaluation

In managing unique complexities associated with Chinese medicinal quality assessment, metabolomics serves as an innovative tool. This study proposes an analytical approach to assess differing qualities of Scrophularia ningpoensis （S. ningpoensis）Hemsl by identifying potential biomarker metabolites and their activity with the corresponding secondary metabolites. The methodology includes four steps; first, a GC-MS based metabolomics exploration of the Scrophularia ningpoensis Hemsl. Second, a multivariate statistical analysis (PCA, PLS-DA, OPLS-DA) for quality assessment and biomarker identification. Third, the application of ROC analysis and pathway analysis based on identified biomarkers. Finally, validation of the associated active ingredients by HPLC. The analysis showed distinct metabolite profiles across varying grades of S. ningpoensis Hemsl, establishing a grading dependency relationship. Select biomarkers (gluconic Acid, d-xylulose, sucrose, etc.) demonstrated robust grading performances. Further, the Pentose Phosphate Pathway, deemed as most influential in grading, was tied to the synthesis of key constituents (iridoids, phenylpropanoids). HPLC validation tests affirm a decreasing trend in harpagoside and cinnamic acid levels between first and third-grade samples. In conclusion, this GC-MS based metabolomics combined HPLC method offers a sound approach to assess and distinguish quality variations in S. ningpoensis Hemsl samples.

Synthesis of Rupestonic Acid L-Ephedrine Derivatives with Preliminary In vitro Anti-influenza Viral Activity

BACKGROUND

Influenza virus is a kind of RNA virus. Nowadays, the high incidence of influenza and the morbidity and mortality of epidemic influenza are substantial. It has been reported that one hundred million people in the world are infected with influenza viruses, and two hundred and fifty thousand to five hundred thousand people die from the flu per year. In 2021, the number of infected persons in China was reported to be 654,700, and 0.07% of the infected persons died. The flu has caused a serious threat to human survival. Although several drugs, such as Zanamivir, Oseltamivir, Peramivir, and Laninamivir, have been used in clinics for the treatment of the influenza virus, there are some shortcomings of these drugs. The strain of influenza H5N1 (avian influenza) has been found to resist the effective drug Oseltamivir. Thus, there is an urgent demand to discover new anti-influenza virus inhibitors to overcome the emergence of influenza antigens.

AIMS

This study aimed to develop new anti-influenza virus inhibitors based on the rupestonic acid parent core.

OBJECTIVE

The rupestonic acid L-ephedrine ester (A) and rupestonic acid L-ephedrine complex (B) were synthesized in this work for the development of anti-influenza virus inhibitors.

METHODS

The target compounds were synthesized using rupestonic acid and L-ephedrine as starting materials. Their structures were characterized by 1H NMR and 13C NMR, and the purity was determined by HPLC. Then, their preliminary in vitro anti-influenza activity was evaluated using Oseltamivir as a reference drug.

RESULTS

The results showed that the synthesized rupestonic acid L-ephedrine derivatives A and B were more potent anti-influenza virus agents against the strains of A/PR/8/34 (H1N1) and A/FM/1/47 (H1N1) with the IC50 values of 51.0, 51.0 μM and 441.0, 441.0 μM, respectively, than that of rupestonic acid. By comparing the IC50 of compounds A and B, compound A can be regarded as a very promising lead compound for the development of anti-influenza inhibitors.

CONCLUSION

The rupestonic acid L-ephedrine ester (A) and rupestonic acid L-ephedrine complex (B) were synthesized and characterized using 1H NMR and 13C NMR. Moreover, their purity was determined by HPLC. Both compounds A and B exhibited more potent activities against the strains of A/PR/8/34 (H1N1) and A/FM/1/47 (H1N1) than rupestonic acid. Compound A can be regarded as a very promising lead compound for the development of anti-influenza inhibitors. Based on these results, more rupestonic acid derivatives will be designed and synthesized in the future for the development of anti-influenza inhibitors.

Sensitive, reliable and simultaneous determination of Fingolimod and Citalopram drug molecules used in multiple sclerosis treatment based on magnetic solid phase extraction and HPLC-PDA

An analytical methodology has been developed for trace amounts of Fingolimod (FIN) and Citalopram (CIT) drug molecules based on magnetic solid phase extraction (MSPE) and high performance liquid chromatographic determination with photodiode array detector (HPLC-DAD). Fingolimod is used in treatment of Multiple sclerosis (MS) disease and sometimes antidepressant drugs such as citalopram accompany to treatment. Both simultaneous analysis of these molecules and application of MSPE with a new adsorbent has been performed for first times. Fe3O4@L-Tyrosine magnetic particles has been synthetized and characterized as a new magnetic adsorbent. Experimental variables of MPSE were examined and optimized step by step such as pH, adsorption and desorption conditions, time effect, etc. Analytical parameters of the proposed method were studied and determined under optimized conditions according to international guidelines. HPLC analysis of FIN and CIT molecules was performed by isocratic elution of a mixture of 50 % Acetonitrile, 40 % pH:3 phosphate buffer and 10 % methanol with flow rate 1.0 mL min-1. The chosen wavelengths in PDA was determined as 238 nm for FIN and 213 nm for CIT. The limits of detection (LOD) for proposed method were 6.32 ng mL-1 for FIN and 6.85 ng mL-1 for CIT molecules. RSD % values were lower than 5.5 % in analysis of model solutions including 250 and 500 ng mL-1 of target molecules. Recovery values by means of synthetic urine and saliva samples were in the range of 95.7-105.4 % for both molecules.

Mechanism of Xing 9 ling tablet candy for alcoholic liver disease based on network pharmacology

Xing 9 Ling tablet candy (X9LTC) effectively treats alcoholic liver disease (ALD), but its potential mechanism and molecular targets remain unstudied. We aimed to address this gap using network pharmacology. Furthermore, high-performance liquid chromatography (HPLC) and database analysis revealed a total of 35 active ingredients and 311 corresponding potential targets of X9LTC. Protein interaction analysis revealed PTGS2, JUN, and FOS as its core targets. Enrichment analysis indicated that chemical carcinogenesis-receptor activation, IL-17 and TNF signaling pathway were enriched by multiple core targets, which might be the main pathway of action. Further molecular docking validation showed that the core targets had good binding activities with the identified compounds. Animal experiments showed that X9LTC could reduce the high expression of ALT, AST and TG in the serum of ALD mice, alleviate the lesions in liver tissues, and reverse the high expression of PTGS2, JUN, and FOS proteins in the liver tissues. In this study, we established a method for the determination of X9LTC content for the first time, and predicted its active ingredient and mechanism of action in treating ALD, providing theoretical basis for further research.

Development of 3β,4α-dihydroxy-5α-androstan-17-one standard solution for doping analyses

Doping analyses are essential for sporting events because some athletes might use prohibited substances to win games. To obtain reliable results from doping analyses, it is important to use both reliable standard solutions and validated analytical methods at accredited laboratories. Among the focused compounds related to prohibited substances listed by the World Anti-Doping Agency, we developed a certified reference material (CRM) for 3β,4α-dihydroxy-5α-androstan-17-one (DHAS), a metabolite of formestane that is used to conceal prohibited anabolic steroids, in methanol solution (NMIJ CRM 6212-a). To develop a CRM traceable to the International System of Units (SI), we newly applied different analytical methods with an SI-traceable internal standard for quantitative NMR (qNMR) instead of mass balance approach because this CRM solution was required to develop rapidly using a limited amount of high-purity DHAS. One method was gravimetric blending using the purity of DHAS powder evaluated by both qNMR and a combination of qNMR and high-performance liquid chromatography (HPLC), and the other was direct quantification of the DHAS mass fraction in the candidate solution CRM by both qNMR and qNMR/HPLC. Because the values obtained by gravimetric blending and direct quantification of the mass fraction were comparable, the arithmetic mean was applied to obtain the certified value. Considering homogeneity and stability according to ISO Guide 35: 2017, the certified values with expanded uncertainties (coverage factor k = 2, approximate 95% confidence interval) were (135.2 ± 9.5) μg/g for the mass fraction and (107.0 ± 7.5) μg/ml for the mass concentration.

Chemical Interactions between Dissolved Polysulfides and Potential Catalytic Host Materials for Li-S Batteries

Given that both elemental sulfur (S8) and lithium sulfide (Li2S) exhibit insulating properties, the involvement of conductive host materials becomes crucial for facilitating charge transfer in sulfur cathodes within lithium-sulfur (Li-S) batteries. Furthermore, there has been a recent surge in the exploration of host materials for sulfur cathodes to address the "polysulfide shuttle" effect. This effect arises from the formation of polysulfide species during the charge-discharge cycles of the Li-S batteries and can be mitigated through physical or chemical interactions with specific materials. To qualitatively and accurately assess the interactions between polysulfides and the potential host materials, this study utilized a well-established high-performance liquid chromatography method for polysulfide analysis. The objective was to monitor the changes in polysulfide solutions after contact with 44 different carbon and inorganic materials. Based on both qualitative and quantitative chromatographic results, it was determined that 20 out of the 44 materials exhibit significant interactions with polysulfides. The primary form of interaction observed is the irreversible disproportionation reaction with elemental sulfur being one of the resulting products.

Species selective concentration and determination of nano-selenium and inorganic selenium species in environmental waters by micropore membrane filtration and ICP-MS

Accurate quantification of nano-selenium (nSe) and other ionic Se species in aquatic environments is a prerequisite for reliable estimation of their potential hazards. In this study, a micropore membrane filtration-based method followed by ICP-MS analysis was proposed for the selective concentration and determination of nSe in the water column. Polyvinylidene fluoride (PVDF) and nylon micropore filtration membranes were proven to efficiently capture nSe under optimal conditions (retention > 91.0 ± 0.87%). At the same time, ionic selenite and selenate could escape from the membranes, realizing the isolation of nSe and ionic Se species. The interference of dissolved organic matter (DOM) during separation can be resolved by adding Ca(II) ions, which can induce the formation of DOM aggregates by cation bridging effects. nSe retained on PVDF membranes could be effectively eluted with FL-70 (a powerful alkaline surfactant) aqueous solutions (0.5%, m/v) while maintaining the original size and morphology. Although nSe trapped on nylon membranes could not be easily eluted, quantification can also be achieved after membrane digestion. Speciation of ionic selenite and selenate in the filtrate was further conducted with an anion exchange column by using HPLC coupled with ICP-MS. The developed method was used to analyze Se species in six real water samples. Spiking experiments showed that the recoveries of nSe ranged from 70.2 ± 2.7% to 85.8 ± 1.3% at a spike level of 0.2 µg/L, and the recoveries of Se(IV) and Se(VI) ranged from 83.6 ± 0.5% to 101 ± 1% at a spike level of 0.55 µg/L, verifying the feasibility for the analysis of environmental water samples. This work provides possibilities to investigate the transformation and potential risks of nSe in the environment.

Proanthocyanidins and Phenolic Compounds from the Twigs of Salix chaenomeloides and Their Anti-Lipogenic Effects on 3T3-L1 Preadipocytes

The present study investigated potential bioactive natural products from the EtOH extract of Salix chaenomeloides twigs using column chromatography, leading to the isolation of six compounds (1-6), which were characterized as two proanthocyanidins, procyanidin B2 (1) and procyanidin B1 (2), and four phenolic compounds, 4-hydroxybenzoic acid β-D-glucosyl ester (3), di-O-methylcrenatin (4), p-coumaric acid glucoside (5), and syringin (6) by the comparison of their NMR spectra with the reported data and high-resolution (HR)-electrospray ionization mass spectroscopy (ESI-MS) analysis. We investigated the potential of six compounds (1-6) to inhibit adipogenesis in 3T3-L1 preadipocytes, which showed that the compounds (1-6) significantly reduced lipid accumulation in 3T3-L1 adipocytes without affecting cell proliferation. Notably, compound 1 demonstrated a remarkable 60% and 90% reduction in lipid levels with 50 and 100 µM treatments, respectively. Oil Red O staining results indicated that compound 1 significantly inhibits the formation of lipid droplets, comparable to the effect of T863, an inhibitor of triglyceride used as a positive control, in adipocytes. Compound 1 had no effect on the regulators PPARγ, C/EBPα, and SREBF1 of adipocyte differentiation in 3T3-L1 preadipocytes, but compound 1 activated the fatty acid oxidation regulator, PPARα, compared to the lipogenic-induced control. It also suppressed fatty acid synthesis by downregulating the expression of fatty acid synthase (FAS). Finally, compound 1 induced the mRNA and protein levels of CPT1A, an initial marker of mitochondrial fatty acid oxidation in 3T3-L1. This finding substantiates the anti-lipogenic and lipolytic effects of procyanidin B2 (1) in 3T3-L1 preadipocytes, emphasizing its pivotal role in modulating obesity-related markers.

Development of a green high-performance liquid chromatography method for tofacitinib quantification in pharmaceutical formulations and degradation studies

A new high-performance liquid chromatography (HPLC) method was applied for the quantification of the active substance of tofacitinib. Analysis was performed on a Chromasil 100 C18 (100.0 × 4.0 mm, 3.5 μm) stationary phase. The mobile phase consisted of acetonitrile:0.2% phosphoric acid in water (12:88, v/v). The prepared sample (20.0 μL) was injected into the system. A detection wavelength of 285.0 nm was chosen for the compound, and the flow rate was 0.8 mL/min. The experiment was completed in 5.0 min. The analysis temperature was set to 40.0°C. The method was evaluated using green chemistry. The method was validated according to the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use guidelines. For linearity studies calibration curves were constructed in the range of 10.0-200.0 μg/mL. The recovery values were calculated at 97.66% and 105.68%. The method developed for the analysis of the active substance had a short analysis time and was cost-effective. It is an environmentally friendly method due to the mobile phase content used. The technique can be used in laboratory analysis and bioequivalence experiments.

Mycotoxin detection in selected medicinal plants using chromatographic techniques

Mycotoxins are toxic mycological products that when consumed, absorbed or inhaled cause sickness or even the death of humans. Therefore, the present study aimed to evaluate the contamination levels of mycotoxins (aflatoxins, AFB1 , AFB2 , AFG1 , AFG2 , and ochratoxin A, OTA) in selected medicinal herbs and shrubs using thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC). A total of 15 samples of medicinal herbs and shrubs were selected. Among them, four samples were aflatoxin contaminated while two samples were ochratoxin A contaminated. The highest level of aflatoxin was detected in Justicia adhathoda (4,704.94 ppb) through HPLC (153.4 ppb) and through TLC, while the lowest level of aflatoxin was detected in Pegnum harmala (205.1 ppb) through HPLC. Similarly, the highest level of OTA was detected in Dodonia viscosa (0.53 ppb) through HPLC (0.5 ppb) and through TLC, while the lowest level was detected in J. adhathoda (O.11 ppb) through HPLC (0.4 ppb) and through TLC. The OTA concentration was very low, being negligible and below permissible limits. The present study concludes that there is a potential risk for the consumption of herbal decoctions. Therefore, regular monitoring and proper management of mycotoxins, including aflatoxins and OTA, in herbal medicines are needed to ensure the safety of herbal drugs to protect consumers.

Glutamate Chemical Exchange Saturation Transfer (GluCEST) MRI to Evaluate the Rapid Antidepressant Effects of Ketamine in the Hippocampus of Rat Depression Model

BACKGROUND

Ketamine is a quick acting antidepressant drug, and an accurate detection method is lacking. Ketamine's effects in a rat depression model have not previously been well explored using glutamate chemical exchange saturation transfer (GluCEST).

PURPOSE

To investigate the GluCEST changes of chronic unpredictable mild stress (CUMS) rats after receiving either ketamine or saline injection.

STUDY TYPE

Randomized animal model trial.

ANIMAL MODEL

12 CUMS and 6 Sprague-Dawley rats. Divided into three groups: ketamine (N = 6), saline (N = 6), and control (N = 6).

FIELD STRENGTH/SEQUENCE

7.0 T/the sequence is GluCEST and 1 H MR spectroscopy (MRS).

ASSESSMENT

The CUMS rats were exposed to different stress factors for 8 weeks. The glutamate concentration in the hippocampus was assessed by the GluCEST,1 H MRS, and the high-performance liquid chromatography (HPLC).

STATISTICAL TESTS

The t-test, Mann-Whitney U test, and Pearson's correlation.

RESULTS

In depression conditions, GluCEST signals were lower in the bilateral hippocampus than in control group. Thirty minutes after ketamine injection, the GluCEST signals in the bilateral hippocampus were higher compared with the saline group (left: 2.99 ± 0.34 [Control] vs. 2.44 ± 0.20 [Saline] vs. 2.85 ± 0.11 [Ketamine]; right: 2.97 ± 0.28 [Control] vs. 2.49 ± 0.25 [Saline] vs. 2.86 ± 0.19 [Ketamine]). In 1 H MRS, significant changes were only observed in the left hippocampus (2.00 ± 0.16 [Control] vs. 1.81 ± 0.09 [Saline] vs. 2.04 ± 0.14 [Ketamine]). Furthermore, HPLC results showed similar trends to those observed in the GluCEST results (left: 2.32 ± 0.22 [Control] vs. 1.96 ± 0.11 [Saline] vs. 2.18 ± 0.11 [Ketamine]; right: 2.35 ± 0.18 [Control] vs. 1.87 ± 0.16 [Saline] vs. 2.09 ± 0.08 [Ketamine]).

DATA CONCLUSION

GluCEST can sensitively evaluate the ketamine's antidepressant effects by detecting the fast increase in glutamate concentration.

LEVEL OF EVIDENCE

1 TECHNICAL EFFICACY STAGE: 1.

Encapsulation of quercetin fraction from Musa balbisiana banana blossom in chitosan alginate solution, its optimization and characterizations

This study comprises the isolation of quercetin from the bhimkol banana (Musa balbisiana) blossom, encapsulation, and its characterizations. An isolated quercetin rich fraction was obtained from HPLC followed by column chromatography and subsequently encapsulated with chitosan-alginate polyelectrolyte complex at optimum encapsulation conditions obtained by ant colony optimization. Quercetin fraction and encapsulated quercetin were characterized for their physicochemical properties (by HPLC, FTIR, NMR, XRD, Dynamic Light Scattering, and release study). The yield and purity of isolated quercetin rich fractions were 2.35 ± 0.08 μg/ml and 83.12 ± 0.31 %, respectively. After the optimization of encapsulation, quercetin 0.2 %, sodium alginate 4 %, chitosan 0.5 %, and agitation at 300 rpm were found to be the optimal conditions resulting in higher encapsulation efficiency (EE, 84.54 %). EE was significantly improved by a slight increase in sodium alginate, and agitation. Encapsulated quercetin revealed good pH resistance by releasing 68.27 mg QE/g quercetin in simulated gastric fluid at 60 min. Microbeads of encapsulated quercetin showed the structural bond stretching of encapsulating materials and quercetin in FTIR spectra (stretching at 1511 cm-1, 1380 cm-1, and 1241 cm-1 are attributed to the stretching vibration of CO in aromatic rings, and bending vibration of OH bond in phenols). An average particle size of 2.71 μm exhibited the microgel behavior of microbeads (by XRD). The present study on the underutilized variety of banana blossoms has diverse applications in the food and pharmaceutical industries that will productively exhibit effective drug delivery properties.

Dye stability of black cherry plum anthocyanins in the interaction with co-pigments and sucrose sweetener

In this research, the co-pigmentation reactions between black cherry plum (Prunus cerasifera Ehrh. cv. Pissardii Nigra) anthocyanins and caffeic, gallic, 4-hydroxybenzoic, malic, and tannic acids with different concentrations (0, 120, 240, 480, and 960 mg L-1) at various temperatures (20, 40, 60, 80, and 100°C) were investigated at pH 3.5. The strongest immediate co-pigmentations resulted at 960 mg L-1, being significantly highest using tannic acid at all temperatures. In addition, the anthocyanin stability and the brown polymeric color formation were investigated in the presence of different concentrations of sucrose sweetener (0, 30, and 60%) and different pHs (2 and 3) in the range of 0-60 h. Also, the amount of furfural was measured in the presence of 0% and 30% sucrose concentrations at pH 2 after 20 h at 90°C by HPLC (high-performance liquid chromatography), and the most polymeric color formation was observed in the concentration of 60% sucrose at pH 2 after 60 h.

Identification, validation and quantification of thymoquinone in conjunction with assessment of bioactive possessions and GC-MS profiling of pharmaceutically valuable crop Nigella (Nigella sativa L.) varieties

Background

Plants have been pivotal in traditional and modern medicine globally, with historical evidence supporting their therapeutic applications. Nigella (Nigella sativa L.) is an annual herbaceous plant of the Ranunculaceae family and is cultivated in the Middle East, Eastern Europe, and Western and Central Asia. The medicinal use of plants dates back thousands of years, documented in ancient writings from various civilizations. Alkaloids, phenolics, saponins, flavonoids, terpenoids, anthraquinones, and tannins found in plants exhibit antioxidant, immunomodulatory, anti-inflammatory, anticancer, antibacterial, and antidiabetic activities.

Methodology

This study specifically examines the pharmacological potential of Nigella sativa L., emphasizing thymoquinone-a compound with diverse nutraceutical benefits. The extraction, characterization, and quantification of thymoquinone, alongside other physicochemical parameters, were carried out using ethanol through Soxhlet extraction procedures on five nigella varieties. HPLC analysis was performed to determine the maximum accumulation of thymoquinone in the released variety of the plant and the chemical composition of the seed oil isolated from Nigella sativa L., varieties utilized in the study was determined through GC-MS analysis.

Results

The research revealed that the Ajmer nigella-20 variety stands out, exhibiting elevated levels of thymoquinone (0.20 ± 0.07%), antioxidants (76.18 ± 1.78%), and substantial quantities of total phenols (31.85 ± 0.97 mg GAEg-1 seed) and flavonoids (8.150 ± 0.360 mg QE 100 g-1 seed) compared to other varieties. The GC-MS profiling showed the presence of 11 major compounds in the studied varieties, with p-cymene, longifolene, and myristic acid identified as the major chemical compounds present in the oil.

Conclusion

The observed variations among Nigella varieties indicate the Ajmer nigella-20 variety as particularly promising for thymoquinone and bioactive compound extraction. This study underscores Nigella's potential as a source of pharmacologically active compounds, highlighting the need for further exploration in therapeutic applications.

Macauba (Acrocomia aculeata) pulp oil has the potential to enhance the intestinal barrier morphology, goblet cell proliferation and gut microbiota composition in mice fed a high-fat diet

Macauba (Acrocomia aculeata) is a palm tree native from Brazil, whose pulp is rich in oil that has a high content of oleic acid and carotenoids. Macauba pulp oil can bring health benefits due to its bioactive compounds; however, its effects on gut health are unknown. Thus, the objective of this study was to evaluate the effect of macauba pulp oil on the intestinal health in mice fed a high-fat (HF) diet. Male C57BL1/6 mice were randomly divided into three groups (10 animals/group): control diet, HF diet and HF diet with 4 % of macauba pulp oil (HFM). Concentration of short-chain fatty acids (SCFA), faecal pH and histomorphometric analysis of the colon were performed. Content of colon samples was used on microbiome analysis using 16S rRNA amplicon sequencing. Animals from the HFM group had higher butyric acid content and goblet cells number, greater circular and longitudinal muscle layer and higher α-diversity compared with the HF group. Moreover, consumption of MPO reduced Desulfobacterota phylum, Ruminococcaceae, Oscillospiraceae, Prevotellaceae, Bifidobacteriaceae family, Faecalibacterium, Prevotella, Ruminococcus and Enterorhabdus genus. Therefore, macauba pulp oil was able to modulate the gut microbiota and enhance intestinal barrier morphology, showing preventive effects on gut dysbiosis in mice fed a HF diet.

Overproduction of Xanthophyll Pigment in Flavobacterium sp. JSWR-1 under Optimized Culture Conditions

Flavobacterium can synthesize xanthophyll, particularly the pigment zeaxanthin, which has significant economic value in nutrition and pharmaceuticals. Recently, the use of carotenoid biosynthesis by bacteria and yeast fermentation technology has shown to be very efficient and offers significant advantages in large-scale production, cost-effectiveness, and safety. In the present study, JSWR-1 strain capable of producing xanthophyll pigment was isolated from a freshwater reservoir in Wanju-gun, Republic of Korea. Based on the morphological, physiological, and molecular characteristics, JSWR-1 classified as belonging to the Flavobacterium species. The bacterium is strictly aerobic, Gram-negative, rod-shaped, and psychrophilic. The completed genome sequence of the strain Flavobacterium sp. JSWR-1 is predicted to be a single circular 3,425,829-bp chromosome with a G+C content of 35.2% and 2,941 protein-coding genes. The optimization of carotenoid production was achieved by small-scale cultivation, resulting in zeaxanthin being identified as the predominant carotenoid pigment. The enhancement of zeaxanthin biosynthesis by applying different light-irradiation, variations in pH and temperature, and adding carbon and nitrogen supplies to the growth medium. A significant increase in intracellular zeaxanthin concentrations was also recorded during fed-batch fermentation achieving a maximum of 16.69 ± 0.71 mg/l, corresponding to a product yield of 4.05 ± 0.15 mg zeaxanthin per gram cell dry weight. Batch and fed-batch culture extracts exhibit significant antioxidant activity. The results demonstrated that the JSWR-1 strain can potentially serve as a source for zeaxanthin biosynthesis.

Isolation, purification and structure elucidation of eight saponin compounds from Calotropis gigantea

Identifying the active ingredient from plant extracts and establishing its safety and efficacy remains a challenge, so there is need to develop optimised Isolation and purification method to concentrate the natural product from plant resources. In the key content areas of Pharmaceutical, natural product Industry and food application. Asclepiadaceae perennial herb Calotropis gigantea has a long history of usage in folk medicine. The purpose of this study to isolate, purified and structure elucidation of the saponin compounds. As per the Literature study reported that, the saponin compounds remain a huge source for medicinal, are rich sources of chemical compounds having tremendous diversity with respect to structure, function and mechanism of action. In this study we selected Calotropis gigantea for the separation of the saponin. In the present study we successfully isolated, purified, elucidated the structure and identified the saponin compounds using HPLC and HR LC-MS techniques.

Thermodynamic solubility measurement without chemical analysis

In this work, the optical imaging based single particle analysis (SPA) and the gold standard shake-flask (SF) solubility methods are compared. We show that to analyze pharmaceutical compounds spanning 7 log units in solubility and a diverse chemical space with limited resources, several analytical techniques are required (HPLC-UV, LC-MS, refractometry and UV-Vis spectrometry), whereas solely the SPA method is able to analyze all the same compounds. SPA experiments take only minutes, while for SF, it may take days to reach thermodynamic equilibration. This decreases the time span needed for the solubility experiment from initial preparations to obtaining the result from roughly three days to less than three hours. The optimal particle size for SPA ranges from approximately one to hundreds of microns. Challenges include measuring large particles, very fast dissolving compounds and handling small sample sizes. Inherent exclusion of density from the SPA measurement is a potential source of error for compounds with very low or high density values. The average relative difference of 37 % between the two methods is very good in the realm of solubility, where 400 % interlaboratory reproducibility can be expected.

Influence of Thermal Treatment on the Composition of Alpinia officinarum Rhizome

Alpinia officinarum is a representative of the Zingiberaceae family, which is known for its wide use in the food and pharmaceutical industries also due to its precious pharmacological potential. The major aim of the present study was to evaluate the influence of thermal treatment on the composition of the rhizome of Alpinia officinarum and its antioxidant activity. The fresh rhizome was subjected to various thermal treatment processes-boiling, frying and microwave heating during various time intervals-and their composition and antioxidant activity were determined using chromatographic (HPLC - High Performance Liquid Chromatography and HPLC-MS - High Performance Liquid Chromatography Mass Spectrometry) and spectrophotometric (DPPH and TPC - Total Phenolic Content) methods. Pinobanksin was the main compound found in the extract of the fresh rhizome (537.79 mg/kg), followed by galangin (197.7 mg/kg) and zingerone (185.5 mg/kg). The effect of thermal treatment on the rhizome composition was varied. In general, thermal processing significantly decreased the content of active compounds in the rhizome. However, there were some exceptions-boiling for 4 min significantly increased the content of pinobanksin (1162.4 mg/kg) and galangin (280.7 mg/kg), and microwave processing for 4 min increased the content of pinocembrin (213 mg/kg). It was found that boiling and microwave treatment significantly increased the antioxidant activity of the processed rhizomes.

Flower via network pharmacology-HPLC integration

BACKGROUND

Paeonia lactiflora Pall. (PL) is widely used in China as a homologous plant of medicine and food. PL flower is rich in bioactive substances with anti-inflammatory effects, while the pathogenesis of skin inflammation is complex and the specific mechanism is not clear, the current treatment of skin inflammation is mainly hormonal drugs, and hormonal drugs have obvious toxic side effects. The research on the treatment of skin inflammation by PL flowers is relatively small, so this study provides a basis for the development and utilisation of PL resources.

OBJECTIVE

Our study was to investigate the interventional effects of PL flower extracts on skin inflammation and thus to understand its functional role in the treatment of skin inflammation and its molecular mechanisms.

METHODS

The major active substances in PL flower extracts were investigated by the HPLC-DAD method, and the potential targets of action were predicted by network pharmacology, which was combined with in vitro experimental validation to explore the mechanism of PL flower extracts on the regulation of skin inflammation. The HPLC-DAD analysis identified seven major active components in PL flower extracts, and in response to the results, combined with the potential mechanism of network pharmacological prediction with skin inflammation, the PL flower extract is closely related to MAPK and NF-κB signaling pathways. In addition, we also investigated the interventional effects of PL flower extract on skin inflammation by western blot detection of MAPK signaling pathway and NF-κB signaling pathway proteins in cells.

RESULT

Seven active components were identified and quantified from the extract of PL flowers, including Gallic acid, 1,2,3,4,6-O-Pentagalloylglucose, Oxypaeoniflorin, Paeoniflorin, Albiflorin, Benzoyloxypeoniflorin, and Rutin. It was predicted targets for the treatment of skin inflammation, with PPI showing associations with targets such as TNF, MAPK1, and IL-2. KEGG enrichment analysis revealed that the main signaling pathways involved included MAPK and T cell receptor signaling pathways. Cell experiments showed that the peony flower extract could inhibit the release of NO and inflammatory factors, as well as reduce ROS levels and inhibit cell apoptosis. Furthermore, the extract was found to inhibit the activation of the MAPK and NF-κB signaling pathways in cells.

CONCLUSIONS

In this study, we found that PL flower extract can inhibit the production of cell inflammatory substances, suppress the release of inflammatory factors, and deactivate inflammatory signaling pathways, further inhibiting the production of cell inflammation. This indicates that PL flower extract has a therapeutic effect on skin inflammation.

In vitro dissolution equivalence of Jordanian sildenafil generics via validated, stability-indicating HPLC method

This study was conducted to compare dissolution profiles of four Jordanian registered sildenafil (SDF) products to the originator. Dissolution samples were analyzed utilizing a validated and stability-indicating HPLC method in human plasma. Validation was performed for specificity, linearity, limit of detection, lower limit of quantification, precision, trueness and stability. SDF was extracted from plasma samples using liquid-liquid extraction. The analysis was performed utilizing isocratic elution on C18 column with 1.0 ml/min flow rate. The regression value was ∼0.999 over 3 days with drug recovery between 86.6 to 89.8%with 10 ng/ml lower limit of quantitation. This method displayed a good selectivity of SDF with improved stability under various conditions. The method was used for SDF quantification in dissolution medium. Similarity factors for local products varied according to the used mediums, but all SDF local products passed the dissolution in vitro test since all of them showed a released of >85% after 60 min at the dissolution mediums.

A new approach for analysing biogenic amines in meat samples: Microwave-assisted derivatisation using 2-chloro-3-nitropyridine

Biogenic amines are compounds whose occurrence in meat is linked to the presence of undesirable microorganisms. They can be utilised as a means to assess the quality and purity of the raw material. Therefore, the methods used to determine their levels are crucial in ensuring meat safety. We propose 2-chloro-3-nitropyridine as a new reagent for microwave-assisted synthesis of biogenic amine derivatives. The obtained products were synthesised with high purity and yield and characterised using 1H and 13C NMR as well as high-resolution mass spectrometry. The proposed derivatisation procedure, coupled with the HPLC method, was applied to determine the levels of biogenic amines in sirloin, ham, and chicken breast samples. Furthermore, differences in the content of the aforementioned compounds in the meat samples were analysed after storage for 24 and 72 h. The results suggest that cadaverine can be considered the primary indicator of meat changes, regardless of its type.

HPLC-based cytotoxicity profiling and LC-ESIQTOF-MS/MS analysis of Helichrysum leucocephalum

Introduction

Helichrysum leucocephalum Boiss. (Asteraceae) is an endemic plant to Iran. No reports have studied the cytotoxicity of the plant. The current study aimed to evaluate the cytotoxicity of H. leucocephalum collected from Fars province (Iran) against MCF-7 and HDF cell lines using HPLC-based activity profiling and to annotate the active constituents by LC-ESIQTOF-MS/MS.

Methods

H. leucocephalum was collected from three locations in Fars province. The dried flowers and leaves were separately extracted by percolation using methanol. The crude extracts were fractionated by liquid-liquid partitioning with dichloromethane (DCM) and aqueous methanol. The cytotoxicity of the fractions was evaluated against MCF-7 and HDF cells by Alamarblue assay. HPLC-based activity profiling was used to track the active constituents. LC-MS dereplication strategy was used for the annotation of the compounds in the active time window. LC-MS data were preprocessed by MZmine 3.3.0 and submitted to multivariate analysis to compare the differences and similarities in the metabolites of the samples.

Results

The DCM fractions showed a dose-dependent cytotoxicity against the cancerous cells (IC50s, 9.8-105.1 μg/ml). In general, the metabolites of the flowers and their cytotoxicity were higher than the leaves. LCESIMS/MS analyses revealed that prenylated and geranylated α,β-unsaturated spiroketal phloroglucinols were among the active constituents.

Conclusion

It can be concluded that H. leucocephalum is a rich source of phloroglucinol derivatives with cytotoxic activities. Further phytochemical analysis is needed to characterize the bioactive components.

The first LC-MS/MS stereoselective bioanalytical methods to quantitatively detect 9R- and 9S-hexahydrocannabinols and their metabolites in human blood, oral fluid and urine

A sensitive LC-MS/MS method for the simultaneous quantification of the (9 R)- and (9 S)- hexahydrocannabinols (HHCs), and their metabolites, in human urine, oral fluid (OF) and blood samples were developed, validated and used to the biological samples of volunteers. The analytes were extracted from 100 μL human samples. An isocratic elution mode with methanol was used for chromatographic separation of (9 R)- and (9 S)-HHC on an immobilized amylose tris(3-chloro-5-methylphenylcarbamate)-based chiral column Lux i-Amylose-3. The flow-rate of the mobile phase was 0.5 mL/min. An isocratic elution mode of methanol and water (80/20, v/v) was used for chromatographic separation of metabolites of (9 R)- and (9 S)-HHC on a Lux AMP chiral column (with a proprietary chiral selector) at a flow rate of 0.5 mL/min. MS/MS analysis was performed in positive ionization mode for HHC epimers, while in negative ionization mode was used for metabolites of HHCs. The calibration curves for HHCs and their metabolites in human samples ranged from 0.25- 240 ng mL-1 and 1 - 100 ng mL-1, respectively, with determination coefficients (r2) of ≥ 0.99. All analytes were stable at room temperature, 4 °C, in the autosampler (+10 °C) and -20 °C for 24 h, after three freeze/thaw cycles, and when stored at -20 °C up to one week after quality control (QC) sample preparation (concentration differences less than 20% with respect to time zero response), in blood, urine and OF.

Ephedra alte extracts' GC-MS profiles and antimicrobial activity against multidrug-resistant pathogens (MRSA)

The extracts of E. alte offer promising potential as renewable resources for various chemical derivative products aimed at addressing antibiotic resistance. These extracts exhibited significant activity against methicillin-resistant Staphylococcus aureus (MRSA), a strain known for its resistance to multiple antibiotics. The extracts were found to be effective against several common antibiotics, including Imipenem, Ampicillin, Penicillin G, Oxacillin, and Amoxicillin-clavulanate. GC-MS analysis revealed that the phytoconstituents of E. alte extracts, obtained using both methanol and ethyl acetate, consist of a diverse range of 83 and 160 phytocompounds, respectively. These organic compounds serve as important biochemical precursors for the synthesis of vitamins E and K1, and exhibit antioxidant, antimicrobial, and anti-inflammatory properties in both plants and microorganisms. Notable compounds identified include fatty acids (such as palmitic acid, dodecanoic acid, sebacic acid, pentadecanoic acid, myristic acid, stearic acid, behenic acid, and linoelaidic acid), phytosterols (Campesterol, β-sitosterol, Stigmast-5-ene), sugars (D-fructose, Fructofuranans), terpenoids (Phytol, citronellol), and phenolic acids (Protocatechoic acid, shikimic acid). The antimicrobial activity of all E. alte extracts was found to be superior to that of mupirocin and ciprofloxacin, as observed in susceptibility testing against MRSA ATCC 43300 and other pathogenic bacteria and fungi. It is likely that the combined action of the antimicrobial components within the E. alte extract bypasses the mechanisms employed by MRSA to protect itself from antibiotics. Further experiments are needed to investigate the individual effects of each pure compound and their potential synergistic interactions, which may enhance their overall performance.

Flavonol profiles of mature leaves allow discriminating Toona sinensis Roem from different north-south geographical origins across China with varied antioxidant activities

Toona sinensis (A. Juss.) Roem, a multipurpose economic tree, is widely cultivated across Asia, but its high-yielding mature leaves are largely overlooked. This study systematically analysed the flavonols in the mature leaves of T. sinensis from 44 different geographic locations across China, using HPLC-DAD and HPLC-ESI-MS2 techniques. In total, 18 flavonols were detected, among which 6 (f1, f3, f7, f14, f15, and f17) were firstly identified in this plant. Significant variations in quality among different T. sinensis varieties were observed (p < 0.01). Through OPLS-DA analysis, all samples could be clearly categorised into two distinct geographical groups. The northern varieties (N1-N20) exhibited concise flavonol fingerprints with higher total flavonol content (TFC) (727.55 ± 22.79 mg/100 g fresh weight, FW), predominantly non-acylated flavonols (705.95 ± 21.65 mg/100 g FW), particularly quercetin glycosides (614.60 ± 22.76 mg/100 g FW). In contrast, the southern varieties (S1-S24) presented more intricate flavonol profiles with lower TFC (622.81 ± 21.82 mg/100 g FW) and balanced amounts of quercetin (344.75 ± 16.41 mg/100 g FW) and kaempferol glycosides (278.06 ± 12.29 mg/100 g FW). Notably, the southern samples possessed higher content of acylated flavonols (184.50 ± 12.87 mg/100 g FW), especially galloylated ones, which contributed to their heightened antioxidant activities. Quercetin 3-O-rhamnoside (f11') and kaempferol 3-O-galloyglucoside (f11) were determined to be the crucial biomarkers for quality discrimination. Considering quality control of mature T. sinensis leaves as potential resources for natural flavonol extraction, this study suggested that their northern/southern geographic origins should be distinguished first. Additionally, the flavonol profiles allow for discriminating the origin and assessing the quality of T. sinensis.

A design of experiment based RP-HPLC method for the simultaneous estimation of antihypertensive drugs with greenness assessment

The correlation between blood pressure (BP) and cardiovascular risk has a continuous, positive, and linear pattern. Lowering high BP decreases the risk associated with cardiovascular disease. Chlorthalidone (CHD) and Losartan potassium (LOS) combination is used to treat hypertension. The analytical community was concerned with minimizing or reducing the use of toxic chemicals and solvents. Therefore, the current study aimed to develop a rapid, sensitive, and cost-effective green RP-HPLC method to determine CHD and LOS simultaneously in a short analysis of time. Method optimization was performed by Central composite design (CCD), the flow rate and the change of time were chosen as factors. Effective separation was conducted on Zorbax SB-C18 (4.6 mm × 150 mm, 5 μm) column by gradient mobile phase comprising phosphate buffer and ethanol flowing at 0.859 ml/min, and the wavelength detected at 230 nm. As per ICH criteria, the technique was proven to be precise, accurate, and linear over the concentration range of 4.3-8.1 μg/ml for CHD and 35-65 μg/ml for LOS. Furthermore, the method's greenness was examined by three different metrics, confirming that less toxic effect on the environment. Hence, the optimized approach proves to be eco-friendly, simple, and robust for the concurrent evaluation of CHD and LOS in pharmaceutical formulations.

Advances and Challenges in the Analysis of Boswellic Acids by Separation Methods

Boswellia resin is an exudate from the cut bark of Boswellia trees. The main constituents of pharmacological interest are boswellic acids (pentacyclic triterpenoids), namely α-boswellic acid, β-boswellic acid, 3-O-acetyl-α-boswellic acid, 3-O-acetyl-β-boswellic acid, 11-keto-β-boswellic acid, and 3-O-acetyl-11-keto-β-boswellic acid. Nowadays, dietary supplements with Boswellia serrata extract are used in the treatment of inflammatory joint diseases. Additionally, the constituents of Boswellia resin have shown potential for the treatment of other chronic inflammatory diseases and various types of cancer. Separation methods including ultra/high-performance liquid chromatography, gas chromatography, thin layer chromatography, supercritical fluid chromatography, and capillary electrochromatography coupled with UV or MS detection have been used for the determination of boswellic acids in various matrices (mostly plant material and biological samples). This review aims to provide a comprehensive summary of these separation methods, offering a critical discussion of their strengths and limitations in the analysis of boswellic acids. The knowledge of various separation methods plays a pivotal role in the quality control of herbal dietary supplements and the monitoring of the metabolism and pharmacokinetics of their constituents. The approaches based on metabolomics and network pharmacology represent new ways of fingerprinting secondary metabolites in Boswellia resin increasing the comprehensiveness of the output of these methods resulting in safer dietary supplements.

OCCURRENCE OF AFLATOXIN M1 AND ESTIMATE OF DIETARY EXPOSURE IN CHEESES FROM ORGANIC AND CONVENTIONAL PRODUCTION SYSTEMS

This study aimed to compare AFM1 occurrence in different cheese types produced by organic and conventional systems; and to evaluate the risk of food exposure to AFM1. A total of 176 commercial cheeses of 17 types were analyzed, 84 of organic and 92 of conventional production. Determination of AFM1 was performed by high performance liquid chromatography (HPLC), being detected in 30.5% of samples, with 4.8% of organic cheese samples presenting quantifiable AFM1 values between 0.88 and 1.50 μg/kg. On the other hand, 4.3% of conventional cheeses samples with values between 0.79 and 6.70 μg/kg. Two conventional cheese samples were above the limit of AFM1 allowed for cheeses by the Brazilian legislation. No statistical difference were found between organic and conventional cheeses regarding the occurrence (p=0.1780) and concentration of AFM1 (p=0.1810), according the Chi-square and the T test, respectively. Estimated daily intake (EDI) and hazard index (HI) of dietary exposure to AFM1 were 0.26 ng/kg/day and 1.28 ng/kg/day, respectively, for conventional cheese samples, and 0.09 ng/kg/day and 0.47 ng/kg/day for organic samples, with no statistical difference for EDI (p=0.1729) and HI (p=0.1802) between the two production systems. Comparison between several cheese types from conventional and organic systems indicated that AFM1 is an obstacle to dairy production. Control and prevention of AFM1 contamination, as well as detoxification methods in the final products, are necessary. In the case of organic products, additional research is needed in order to determine which control and detoxification methods should be allowed in this production system.

Comparison of the sugar and organic acid components of seventeen table grape varieties produced in Ankara (Türkiye): a study over two consecutive seasons

Sugars and organic acids not only have a significant impact on taste balance and sensory acceptance by consumers but also play a crucial role in the chemical equilibrium of grape juices and wines. Therefore, this study aimed to quantify the content and composition of sugars and organic acids in 17 grape varieties over two consecutive years using high-performance liquid chromatography. The variability in all the parameters studied was strongly influenced by both the grape cultivars and specific years (p ≤ 0.05). In grape berries, the primary sugars identified were fructose and glucose, which ranged from 6.50 to 11.10 g/L and from 5.83 to 12.12 g/L, respectively, over the two years. However, sucrose was not detected in any of the grape varieties examined. For the two respective years, the highest titratable acidity (TA) was found in Tekirdağ Çekirdeksizi (TeCe) (0.89 and 0.90 g/L), while the lowest was detected in Victoria (Vi) (0.48 and 0.51 g/L). Total soluble solids (TSS) peaked in Horoz Karası (HoKA) (21.90 °Brix), whereas it reached its lowest point in Big Perlon (BiPe) (14.1 °Brix). The tartaric acid content in the grape berries, ranging from 1.48 to 10.33 g/L for the two years, exhibited similar characteristics to malic acid, which ranged from 1.09 to 9.62 g/L and from 1.03 to 9.68 g/L for the two respective years. The succinic, malic, tartaric, citric, and oxalic acid contents were notably higher in the Kyoho (Ky) variety than in the other varieties. When examining the dendrogram of the contents of organic acid and sugar for similarities, it was evident that 16 out of the 17 grape varieties had a high degree of similarity, except for Alphonse Lavallée (AlLa) and HoKa. The similarity levels among the varieties ranged from 99.49% to 72.36%. The highest similarity (99.49%) was observed between the AlLa and Barış (Ba) varieties. The lowest similarity was observed among the AlLa, HoKa, and Ky varieties. In summary, this study underscores that certain table grape varieties grown in Ankara exhibit significant variations in valuable organic acids and sugars, which are associated with potential health benefits when considering human consumption.

Development and validation of a simple and efficient method for the analysis of commercial formulations containing clopyralid, picloram and aminopyralid as active ingredients

Liquid chromatography plays a pivotal role in evaluating pesticide formulations as it enables the determination of multiple active substances in plant protection products. An adaptable separation technique has been developed, enabling the qualitative and quantitative analysis of clopyralid, picloram, and aminopyralid within pesticide formulations in line with SANCO/3030/99 rev. 5 guidelines. This article offers an insight into the validation procedure encompassing key aspects such as selectivity, linearity, accuracy, precision, and recovery. It places emphasis on critical stages, including sample preparation, chromatographic separation, detection, quantification, and data analysis. The active ingredients are separated using chromatography with isocratic elution, utilizing a mobile phase consisting of a mixture of water, acetonitrile, and acetic acid in a specific ratio (83:15:2 v/v/v). This separation is carried out on a YMC-Pack ODS-AQ column (250 mm x 4.6 mm, 5 μm) at a flow rate of 1.5 mL/min. The method's validation parameters have produced satisfactory outcomes. The recovery rates for each individual compound were found to be in the range of 98.6% to 101.0%. Precision, as indicated by the relative standard deviation (%RSD), was lower than the values predicted by the modified Horwitz equation. Furthermore, the correlation coefficients assessing the linearity of the response exceeded 0.99.

Investigation of dissipation kinetics and half-lives of fipronil and thiamethoxam in soil under various conditions using experimental modeling design by Minitab software

To determine the extent of pesticide buildup and their environmental contamination, the environmental half-lives of pesticides are examined. The influence of the factors affecting the half-lives of fipronil and thiamethoxam including soil type, sterilization, temperature, and time and their interactions was studied using experimental modeling design by Minitab software. Based on the dissipation kinetics data, fipronil concentrations reduced gradually over 60 days while thiamethoxam concentrations decreased strongly. Also, fipronil and thiamethoxam dissipated more rapidly in calcareous soil than in alluvial soil. Thiamethoxam, however, disappeared more rapidly than fipronil in all treatments. Incubation at 50 °C leads to rapid the pesticide degradation. For prediction of the dissipation rate, model 5 was found to be the best fit, Residue of insecticide (%) = 15.466 - 11.793 Pesticide - 1.579 Soil type + 0.566 Sterilization - 3.120 Temperature, R2 = 0.94 and s = 3.80. Also, the predicted DT50 values were calculated by a model, DT50 (day) = 20.20 - 0.30 Pesticide - 7.97 Soil Type + 0.07 Sterilization - 2.04 Temperature. The shortest experimental and predicted DT50 values were obtained from treatment of thiamethoxam at 50 °C in calcareous soil either sterilized (7.36 and 9.96 days) or non-sterilized (5.92 and 9.82 days), respectively. The experimental DT50 values of fipronil and thiamethoxam ranged from 5.92 to 59.95 days while, the modeled values ranged from 9.82 to 30.58 days. According to the contour plot and response surface plot, temperature and sterilization were the main factors affecting the half-lives of fipronil and thiamethoxam. The DT50 values of fipronil and thiamethoxam increased in alluvial soil and soil with low temperature. In general, there is a high agreement between the experimental results and the modeled results.