Biomedical Chromatography最新文献

Nimbolide is a major furanoid compound isolated from Azadirachta indica. The aim of this study was to characterize the metabolites of nimbolide in rats and to propose the metabolic pathways. The metabolites were generated by incubating nimbolide (10 μM) with rat liver microsomes, nicotinamide adenine dinucleotide phosphate (NADPH), and nucleophiles (glutathione [GSH] or N-acetyl-lysine [NAL]) at 37°C for 60 min. For the in vivo study, nimbolide was intravenously administered to rats at a single dose of 10 mg/kg, and the bile and urine were collected. The metabolites were identified by ultra-high-performance liquid chromatography-quadrupole/orbitrap mass spectrometry (UPLC-Q/Orbitrap-MS) using electrospray ionization in positive ion mode. Totally, nine metabolites were detected, and their identities were characterized by accurate MS and MS/MS data. In GSH-supplemented liver microsomes, GSH conjugation was the primary elimination pathway. The furan ring was bioactivated into cis-butene-1,4-dial that can be trapped by GSH. In NAL-supplemented liver microsomes, two NAL conjugates (M4 and M5) derived from cis-butene-1,4-dial were observed. In rat bile and urine, N-acetyl-cysteine, cysteine-glycine, and GSH conjugate were also found. The current study provides an overview of the metabolism and the bioactivation profiles of nimbolide in rats, which aids in understanding its safety and activity.

Glutathione (GSH), a tripeptide that consists of cysteine, glutamate and glycine, is present in all mammalian tissues in the millimolar range. Besides having numerous cellular functions, GSH is an important antioxidant and is considered a valuable biomarker in evaluating oxidative stress. This paper provides a sensitive analytical method using HPLC-ECD to quantify GSH in erythrocytes, validated using the ICH guidelines for Bioanalytical Method Validation. The sample preparation was optimised using centrifugal filtration and a hypotonic phosphate buffer for extracting GSH from erythrocytes. HPLC-ECD parameters were adjusted to allow a fast, reversed phase, isocratic separation in 10 min. The detector response was linear between 0.3 and 9.5 μg/mL with a satisfactory regression coefficient and a LOQ of 0.11 μg/mL. Intra- and inter-day repeatability ranged between 1.10% and 8.57% with recoveries ranging from 94.3% to 106.0%. Dilution integrity, benchtop, freeze-thaw and long-term stability were investigated. Samples were stable for up to 6 months at -80°C. This method has a good linear response and is repeatable, precise and accurate. It minimises GSH auto-oxidation using a centrifugal filter during sample preparation, instead of acidification. Therefore, this analytical method is suitable for quantifying GSH in erythrocytes as a marker of oxidative stress.

A sensitive and simple method using ultra-liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed and validated to determine the concentration of curcumin in rat plasma and tissue samples. Emodin was selected as the internal standard (IS), and biological samples were pretreated with simple one-step acetonitrile precipitation. The calibration curves exhibited linearity within the range of 1-1000 ng/ml for both rat plasma and tissue samples. The accuracy and precision of intra-day as well as inter-day determinations ranged from 99.3% to 117.3% and from 98.2% to 105.1%, respectively. This method demonstrated excellent recovery rates ranging from 76.4% to 96.4% along with minimal matrix effect ranging from 86.5% to 99.6%. The effectiveness of this method was successfully demonstrated through its application in an in vivo pharmacokinetic and tissue distribution study after single administration via inhalation (100 mg/kg), oral gavage (100 mg/kg) and intravenous injection (2.5 mg/kg) of curcumin in rats. The results revealed that inhalation significantly improved the bioavailability of curcumin, with most of the drug being deposited in the lung. These findings highlight inhalation as an effective route for targeted delivery of drugs directly into lung tissues, thus suggesting potential future applications for treating pulmonary diseases utilizing inhaled curcumin.

Tuberculosis (TB) is a persistent global health issue, evidenced by an increasing number of cases. Although anti-TB drugs have proven efficacy, they are often associated with severe liver injury (ATB-DILI). The objective of this research was to uncover the mechanisms through which Shaoyao Gancao Decoction (SGD) mitigates ATB-DILI, emphasizing the role of the Nrf-2/HO-1/NF-κB signaling pathway. We prepared SGD granules and subjected them to HPLC-MS/MS for analysis. An ATB-DILI rat model was then developed and administered SGD. We evaluated liver injury markers, the extent of oxidative stress, inflammation, and the principal proteins involved in the Nrf-2/HO-1/NF-κB pathway. Additionally, network pharmacology techniques were utilized to discern potential SGD targets and their associated pathways. Administering SGD had a notable effect in counteracting the elevation of liver injury markers and pathological alterations induced by ATB-DILI. Moreover, there was a marked reduction in oxidative stress and inflammation in the treated rats. We identified 12 active compounds in SGD, with 88 shared targets between SGD and ATB-DILI. Subsequent KEGG analysis brought attention to pathways like MAPK, NF-κB, and IL-17 signaling. Our findings pave the way for more in-depth studies into the application of SGD in treating drug-induced liver injuries.

Six polysaccharide-based chiral stationary phases were screened to separate the enantiomers of six chloro-containing derivatives and one derivative bearing electron donating mesomeric substituents, chosen for comparison. These compounds are expected to be P2X7 receptor antagonists with potential anti-inflammatory activity. The study was carried out with four different mobile phases composed of n-heptane and ethanol or isopropanol. Thus, a total of 168 experiments were implemented to find the best conditions aimed at scaling-up the separation of these anti-inflammatory compounds. Chiralpak AD-H separated half of them, i.e., 1, 2, and 6; Chiralpak AS separated also three out of the six compounds, i.e., 1, 2, and 3; Lux Cellulose-5 separated 2, 4, and 6; Lux Cellulose-2 separated 1, 2, and 4; Chiralcel OD-H separated compounds 2 and 5; and finally Chiralcel OJ separated only 3, thus having the lowest rate of success. Additionally, the influence of (i) the stationary and mobile phases and (ii) the chemical structure of the analytes on retention and resolution was investigated.

Trichosanthes kirilowii-Allium macrostemon (Chinese name Gualou and Xiebai, GLXB), a classical herb pair, has significant clinical efficacy in the treatment of myocardial ischemia (MI). In this study, network pharmacology combined with RNA-seq strategy was employed to predict the targets and pathways of GLXB for MI. GLXB significantly modulated signaling pathways related to the pathology of MI, such as anti-inflammatory and anti-apoptotic signaling pathways such as WNT, PI3K/AKT, and AMPK. GSEA showed that GLXB administration downregulated these key pathways. In addition, Metabolomic analysis demonstrated that GLXB treatment reversed metabolic disorder. Integrative analysis demonstrated three key metabolites (pyruvate, lactate, and palmitate) and three differential genes (Pck1, Cdo1, and Cth) that affected glycolysis or gluconeogenesis and cysteine and methionine metabolism. The results of molecular docking showed that chrysin-7-O-glucuronide and diosmetin-7-O-rutinoside may be the crucial components that exert myocardial protective activity. Western blot showed that GLXB administration reversed the expression levels of Pck1, Cdo1, Cth, Alb, Bcl2, and Ccnd1. This study has elucidated that GLXB could alleviate MI in rats by modulating WNT and PI3K/AKT signaling pathways, thereby reducing inflammation and apoptosis as well as improving energy metabolism.

Yiqi Fumai lyophilized injection (YQFM), a compound traditional Chinese medicine prescription derived from "Sheng Mai Powder," is approved for the treatment of cardiovascular diseases. YQFM is usually prescribed in combination with some Western medicines to treat patients, such as aspirin, nifedipine, and clopidogrel. However, the herb-drug interactions (HDIs) of YQFM are still unclear. We determined the effect of YQFM on drug metabolism-related CYP450 enzymes by in vitro assays. And the effects of YQFM on the pharmacokinetics of aspirin, nifedipine, or clopidogrel were analyzed in rats, as well as the effect of YQFM on the prothrombin time of aspirin or clopidogrel, to evaluate the safety and efficacy of co-administration. Our study indicated that the clinical dose of YQFM did not significantly influence the relevant CYP450 isoenzymes. Besides, YQFM had no effect on the pharmacokinetics of aspirin, nifedipine, or clopidogrel single and multiple administrations in rats. In pharmacodynamics study, YQFM also had no impact on prothrombin time of aspirin or clopidogrel. Based on the results of pharmacogenomics, pharmacokinetics, and pharmacodynamics, the HDIs of YQFM have a good safety profile, and the combination with the above three drugs might have synergistic effects due to the different efficacy of YQFM-quality markers.

The present study discusses the development of simple, rapid, specific, precision, accuracy, stability indicating the HPLC method for the analysis of amlodipine besylate and valsartan tablet dosage form. The chromatographic separation was achieved using phosphate buffer with 1% triethyl amine (pH 3.0) as mobile phase-A and mixed Methanol and buffer in the ratio of (65:35)(v/v) as mobile phase-B. The detection of components was made at 237 nm for amlodipine besylate and valsartan. Analytical techniques should enrich sensitivity and specificity for the estimation of pharmaceutical drug products. Evaluated stress studies under different types of ICH conditions. The optimized HPLC method was validated as per the current ICH guidelines. The validated HPLC method was obtained highly specific with linearity ranging between 25 and 200 μgmL^-1 of amlodipine besylate and 40-320 μgmL^-1 of valsartan and both components correlation coefficient was > 0.999. The method showed high accuracy more than 97%. In stress studies, amlodipine besylate and valsartan were found to be sensitive to acid stress conditions and oxidation stress conditions. The method was found to be suitable for the quality control of amlodipine besylate and valsartan in the tablet as well as in stability-indicating studies. The method was applied to the analysis of stability samples.

TLC is used globally, yet less attention has been paid to TLC (in enantioseparation) despite its advantages. The present paper describes/reviews successfully practiced direct approaches of 'chiral additive in achiral stationary phase' (as an application of in-home thought out, prepared, tested, and modified chiral stationary phase), 'pre-mixing of chiral reagent with the enantiomeric mixture' (an approach using both achiral phases during chromatographic separation) and 'chiral additive in mobile phase', and chiral ligand exchange for enantioseparation of DL-amino acids, their derivatives, and some active pharmaceutical ingredients. It provided efficient enantioseparation, quantitative determination, and isolation of native forms via in-situ formation of non-covalent diastereomeric pair. The mechanism of enantioseparation in these approaches has been discussed along with the isolation and establishment of the structure of diastereomers. This may help chemists gain useful insights into fields outside their specialization and the experts get brief accounts of recent key developments, providing solutions for sustainable development of less expensive methods for control of enantiomeric purity and isolation of native enantiomers.

Chiral recognition and enantioseparation are of paramount importance in various fields, including pharmaceuticals, agrochemicals, and material science. Covalent organic frameworks (COFs) have emerged as promising materials for chiral separation due to their unique structural features and tunable properties. This review provided a comprehensive overview of recent progress in the application of COFs and related innovative materials for chiral separation and recognition. Various strategies were analyzed for the design and synthesis of chiral COFs, including the incorporation of chiral building blocks, post-synthetic modification, and the integration of chiral selectors. The applications of chiral COFs in chromatographic techniques, membrane separations, and other emerging methods were critically evaluated with the emphasis on their advantages and limitations. Additionally, the review summarized the potential of combining COFs with other nanomaterials, such as metal-organic frameworks (MOFs) and nanoparticles, to enhance chiral recognition and separation performance. The fundamental principles and mechanisms of chiral recognition were discussed, highlighting the role of chiral selectors and their interactions with enantiomers. Finally, current challenges and future perspectives in this field were discussed, providing insights into the development of more efficient and versatile chiral separation systems based on COFs and related materials.