Ultra-fast Liquid Chromatography Research Articles

Chemometrics-based analysis of the phytochemical profile and antioxidant activity of Salvia species from Iran

In recent years, the exploration of the therapeutic potential of Salvia has gained considerable attention, leading to a growing number of scientific studies emphasizing its pharmacological properties. Despite this, therapeutic applications of Salvia remain underexploited, requiring further investigation. Iran is a major center for sage diversity in Asia, boasting 60 Salvia species, 17 of which are unique to the area. This study aimed to comprehensively explore and compare the extracts of 102 Salvia samples belonging to 20 distinct Salvia species from Iran, providing a deeper understanding of their specific polyphenol content and, consequently, their antioxidant capabilities and potential therapeutic uses. All samples were analyzed to determine the contents of total phenolics, total flavonoids, total tannin, photosynthetic pigments, and ascorbic acid, along with their antioxidant activity. These data were then combined with the forty distinct chemical fingerprints identified by ultrafast high-pressure liquid chromatography coupled with high-resolution mass spectrometry. Multivariate data analysis was employed to find correlations and differences among the huge number of data obtained and to identify Salvia species with similar phytochemical and/or antioxidant properties. The results show that each Salvia species is characterized by a distinct class of polyphenols recognized for their antidiabetic, anti-inflammatory, cardioprotective and neuroprotective properties. Overall, our findings reveal the potential of some Salvia species for targeted therapeutic applications and provide a rational basis for the development of Salvia-derived nutraceuticals, ultimately improving the prospects for the use of Salvia in medicine.

Alterations in tryptophan metabolism and de novo NAD+ biosynthesis within the microbiota-gut-brain axis in chronic intestinal inflammation.

Inflammatory bowel disease is an incurable and idiopathic disease characterized by recurrent gastrointestinal tract inflammation. Tryptophan metabolism in mammalian cells and some gut microbes comprise intricate chemical networks facilitated by catalytic enzymes that affect the downstream metabolic pathways of de novo nicotinamide adenine dinucleotide (NAD+) synthesis. It is hypothesized that a correlation exists between tryptophan de novo NAD+ synthesis and chronic intestinal inflammation. Transcriptome analysis was performed using high-throughput sequencing of mRNA extracted from the distal colon and brain tissue of Winnie mice with spontaneous chronic colitis and C57BL/6 littermates. Metabolites were assessed using ultra-fast liquid chromatography to determine differences in concentrations of tryptophan metabolites. To evaluate the relative abundance of gut microbial genera involved in tryptophan and nicotinamide metabolism, we performed 16S rRNA gene amplicon sequencing of fecal samples from C57BL/6 and Winnie mice. Tryptophan and nicotinamide metabolism-associated gene expression was altered in distal colons and brains of Winnie mice with chronic intestinal inflammation. Changes in these metabolic pathways were reflected by increases in colon tryptophan metabolites and decreases in brain tryptophan metabolites in Winnie mice. Furthermore, dysbiosis of gut microbiota involved in tryptophan and nicotinamide metabolism was evident in fecal samples from Winnie mice. Our findings shed light on the physiological alterations in tryptophan metabolism, specifically, its diversion from the serotonergic pathway toward the kynurenine pathway and consequential effects on de novo NAD+ synthesis in chronic intestinal inflammation. The results of this study reveal differential expression of tryptophan and nicotinamide metabolism-associated genes in the distal colon and brain in Winnie mice with chronic intestinal inflammation. These data provide evidence supporting the role of tryptophan metabolism and de novo NAD+ synthesis in IBD pathophysiology.

Analysis of omarigliptin forced degradation products by ultra-fast liquid chromatography, mass spectrometry, and in vitro toxicity assay.

Omarigliptin (OMG) is an antidiabetic drug indicated for the treatment of type 2 diabetes mellitus. Forced degradation studies are practical experiments to evaluate the stability of drugs and to establish degradation profiles. Herein, we present the investigation of the degradation products (DPs) of OMG formed under various stress conditions. OMG was subjected to hydrolytic (alkaline and acidic), oxidative, thermal, and photolytic forced degradation. A stability-indicating ultra-fast liquid chromatography method was applied to separate and quantify OMG and its DPs. Five DPs were adequately separated and detected in less than 6 min, while other published methods detected four DPs. MS was applied to identify and obtain information on the structural elucidation of the DPs. Three m/z DPs confirmed previously published research, and two novel DPs were described in this paper. The toxicity of OMG and its DPs were investigated for the first time using in vitro cytotoxicity assays, and the sample under oxidative conditions presented significant cytotoxicity. Based on the results from forced degradation studies, OMG was found to be labile to hydrolysis, oxidation, photolytic, and thermal stress conditions. The results of this study contribute to the quality control and stability profile of OMG.

A polyphasic characterisation of Aspergillus section Flavi isolated from Malaysian and Nigerian food grains and poultry feeds by phenotypic, chemotypic, and molecular methods

The taxonomy and toxigenicity of Aspergillus section Flavi (ASF) in various regions are still under-reported, as many potentially toxic species are continuously discovered. This study aims to determine the aflatoxigenicity and identify 74 isolates of ASF from Malaysian and Nigerian food grains and feeds using phenotypic, chemotypic, and molecular methods. Isolates were screened for sclerotium morphotype and aspergillic acid production phenotypically, while an ultra-fast reverse-phase high-performance liquid chromatography (HPLC) was optimised to quantify the cyclopiazonic acid and aflatoxins produced by the isolated ASF, based on which, they were characterised into phenotypes L-strains, S-strains, and NS-strains, and chemotypes I to VI. Chemotypic data and nucleotide sequences of β-tubulin and internal transcribed spacer (ITS) genes were utilised to identify the isolates’ species and determine their phylogenetic relationships. Aflatoxigenesis on solid media and multiplex polymerase chain reactions of four essential genes (aflR, aflM, aflD, and aflP) of aflatoxin biosynthesis were used to confirm the aflatoxigenicity of each isolate. All the six chemotypes of ASF were present among the isolated strains, with the aflatoxigenic chemotypes (55.41%) and CPA-positive isolates (68.92%) being significantly higher (p < 0.05) than the non-aflatoxigenic and CPA negative chemotypes. Aflatoxins and CPA were produced in the 0.25–19.58 ng/g range and 29.89–46.55 ng/g, respectively. Chemotypic data accurately differentiate toxigenic from atoxigenic species but only identify 90% of species names. Molecular data accurately resolved species but not toxigenicity. The results highlight the need for robust regulatory measures in the concerned regions to mitigate the risk of aflatoxicosis.

Plasma catalysis. A study of the influence of oxysulfur, SOx• species through the degradation of sulfonated dyes by non-thermal plasma

This work studied the degradation reaction of sulfonated dyes, indigo carmine, phenol red, and their mixtures by non-thermal plasma (NTP). Interestingly, the degradation rate constant showed a faster process and lower activation energy (Ea) for the dye mixtures than for the degradation reaction of the individual dyes. This unexpected result opened up new opportunities for understanding plasma chemistry and the interaction between reactive species formed by the plasma and the target molecule. As no catalyst or chemical additive was added to the reactor, the decrease in Ea came from a self-synergistic effect (SSE), through the dye molecules fragmentation, which resulted in plasma catalysis. The hypothesis proposed in this work is that oxysulfur (SOx) species are formed by the desulfonation reaction of dyes. The sulfonic groups (SO3) present in the chemical structures of dyes can function as precursors for forming several SOx•– species. Studies based on oxygenated sulfonated species such as SO3•–, SO4•– and SO5•– have been widely applied in advanced oxidative and reductive processes due to their satisfactory efficiency and low cost. Among them, SO4•– is the key reactive species with the best performance in the degradation of pollutants due to its high oxidation potential (E° = 2.60 V). In addition, it is an alternative source of HO• in aqueous media, improving the oxidation reaction. In order to elucidate the SSE, the kinetic process was followed by UV–Vis analysis, and the reactive species, such as alkyl, hydroxyl, and oxy-sulfur radicals were identified by Electron Paramagnetic Resonance. The by-products of the NTP degradation reaction were analyzed by ultrafast liquid chromatography coupled with a mass spectrometer, and a fragmentation route was proposed.

Phenolic-rich extract from Bryophyllum pinnatum leaf cultivated under drought stress conditions modulates the antioxidant and anti-inflammatory response

Bryophyllum pinnatum (Lam) Pers (Crassulaceae) is used in traditional medicine to treat inflammatory diseases. There is preclinical and clinical evidence that proves its anti-inflammatory effect. This species is a good source of phenolic compounds such as flavonoids, being quercetin 3-O-L-arabinopyranosyl-(1→2)-O-L-rhamnopyranoside (Bp1), the main compound. However, to ensure the reproducibility of raw material as an active pharmaceutical ingredient, it is necessary to standardize the production chain from cultivation to the final product. The aim of this study was to understand whether water stress increases the phenolic content in B. pinnatum leaves and its effect on the modulation of anti-inflammatory and antioxidant responses. B. pinnatum was submitted to drought stress, with daily watering suspended for specified periods: 0, 5, 10, 20, and 30 days, along with a cyclic regimen involving 10 days of water deprivation followed by 10 days of regular watering for recovery (denoted as T0, T5t, T10t, T20t, T30t, and T10tcyc, respectively). For each water stress treatment (n = 10), there were control plants (n = 10) that received daily watering. After treatment, dry leaf extracts from each sample were prepared. Subsequently, the total flavonoids (TFC) and total phenolics (TPC) content were performed using spectrophotometric tests. Ultrafast liquid chromatography was used to quantify the main compound (Bp1) in the extracts. Extracts under different stress conditions showed no signs of cytotoxicity (RAW 264.7 cells) and were able to donate electrons in in vitro assays (CAT, reducing power, and DPPH). Extracts with high TPC (T20t and T30t) in the ear edema model induced by croton oil at a dose of 200 mg/kg orally showed an anti-inflammatory effect when compared to positive control, dexamethasone (1 mg/kg, orally). Regarding the Bp1 content, no major differences between the groups were observed. The results demonstrate that water stress is a promising and sustainable strategy for cultivating B. pinnatum to increase the phenolic content and positively modulate its pharmacological effects. Therefore, phenolic-rich extract of B. pinnatum can be obtained with low water resource consumption and it is a good source to use as an active ingredient in herbal medicines or supplements.

Chemical profile and difference analysis of four parts of Strobilanthes sarcorrhiza by ultrafast flow liquid chromatography coupled with quadrupole‐time‐of‐flight mass spectrometry and multivariate statistical analysis

AbstractStrobilanthes sarcorrhiza (CTS) is a medicinal plant with various pharmacological effects such as tonifying kidney and anti‐inflammatory. However, the chemical composition and difference of its four parts (leaves, stems, rhizomes, and root tubers) have been rarely reported. In this study, ultrafast flow liquid chromatography coupled with quadrupole‐time‐of‐flight MS was applied to analyze the chemical profile of CTS and identify 55 compounds, including terpenoids, phenylethanol glycosides, fatty acid derivatives, chain glycosides, flavonoid glycosides, and others. Among these compounds, 34 compounds were first identified in CTS. They were mainly terpenoids, phenylethanol glycosides, fatty acid derivatives, and so forth. Multivariate statistical analysis, such as principal component analysis and orthogonal partial least squares‐discriminant analysis were also used to evaluate the difference in chemical compounds from the four parts of CTS. The results showed that phenylethanol glycosides were the main compounds of the underground parts, while terpenoids were the main compounds of the aboveground parts. This study revealed the chemical diversity and similarity of CTS and suggested that the rhizomes could be used as an alternative medicinal part to improve the resource utilization of CTS.

Pharmacokinetic analysis of febuxostat in human serum by UFLC based on fluorimetric derivatization

An ultra fast liquid chromatographic (UFLC) method using fluorimetric detection for the quantitation of Febuxostat (FEB) in human serum was developed by precolumn derivatization with 4-bromomethyl-7-methoxy coumarin (BrMmC). The derivatization was catalyzed with dibenzo-18-crown-6-ether to produce a fluorescent derivative which was determined through fluorescence measurement with excitation at 320 nm and emission at 395 nm wavelengths. A C18 column with 100 cm x 4.6 mm, 3 µm particule size was used for the UFLC separation procedure. A mixture of acetonitrile: methanol: 0.05 M aqueous ammonium acetate (pH 5.0) (40:40:20, v/v/v) was used as mobile phase. During the procedure, the flow rate was maintained at 0.5 mL/min. A calibration curve was then plotted as 0.005–3.0 µg/mL with a detection limit of 0.0022 µg/mL and quantification limit of 0.0073 µg/mL. The mean recovery to reveal the accuracy and relative standard deviation (RSD) that indicates the precision of the method were found out to be 85.20 % and less than 3.52 %, respectively. The utility of the new method has been demonstrated by measuring the pharmacokinetics of FEB by administration of 80 mg tablets to a healthy female volunteer, aged 42.

Optimization of ultrasound-assisted extraction using response surface methodology and quantification of polyphenol compounds in Avicennia officinalis L. from Vietnam

Response surface methodology was used to estimate the optimum extraction parameters, for which the total phenolic content and total flavonoid content of Avicennia officinalis L. extract were the highest. Based on the 3D surface plots and regression analysis of the independent variables, the optimal conditions for the ultrasound-assisted extraction were as follows: methanol content, 55.27%; liquid-to-solid ratio, 14:1 (mL/g, v/w); temperature, 48.8 °C, and time, 9.66 min. Optimal extraction conditions were applied to validate the quantification. The bioactive compounds from the Avicennia officinalis L. extract were identified through ultra-fast liquid chromatography coupled to diode array detector for the first time. These methods were applied to quantify phenolic acids and flavonoids from A. officinalis extracts collected at six different locations in Vietnam. The results showed that the concentrations of these compounds varied from 0.319 ± 0.022 to 3.524 ± 0.125 mg/g in the methanol extract. The result showed that cinnamic acid is the major compound in A. officinalis collected in Vietnam. In the present study, an optimized ultrasound-assisted extraction was first designed to improve the content of phenolic acids and flavonoid compounds from A. officinalis. Additionally, the bioactive compounds from the A. officinalis extract were identified through UFLC-DAD for the first time.

The compatibility rationality of Sijunzi decoction based on integrated analysis of tissue distribution and excretion characteristics in spleen deficiency syndrome rats

Ethnopharmacological relevanceAs a classical prescription for treating spleen deficiency syndrome (SDS), Sijunzi decoction (SJZD) is composed of Ginseng Radix et Rhizoma (RG, Panax ginseng C.A.Mey.), Atractylodes Macrocephalae Rhizoma (AM, Atractylodes macrocephala Koidz.), Poria (Poria cocos (Schw.) Wolf) and Glycyrrhizae Radix et Rhizoma Praeparata Cum Melle (GRP, processed from Glycyrrhiza uralensis Fisch., Glycyrrhiza inflata Bat. or Glycyrrhiza glabra L.). The non-polysaccharides (NPSs) are the pharmacodynamic substance basis of SJZD, whose pharmacokinetics in SDS rats were elaborated previously. Further study on their tissue distribution and excretion properties is of significance for understanding the compatibility laws of SJZD. Aim of the studyThe aim was to unravel the tissue distribution and excretion characteristics of NPSs of SJZD in SDS rats, and explore the scientific connotation of SJZD compatibility. Materials and methodsA validated ultrafast liquid chromatography tandem mass spectrometry method was developed for monitoring the accurate dynamics of sixteen components in the tissues, feces and urine of SDS rats. The four incomplete formulae of SJZD were prepared by randomly deleting one herb to uncover the herb-herb interactions. ResultsAll components of NPSs in SJZD were distributed in the tissues, except for ononin in the heart. Among them, glycyrrhetinic acid and atractylenolide III were more abundant in the liver and lung, respectively, while other components were enriched in the ileum, especially saponins. The evaluation of fecal excretion and urinary excretion revealed the low cumulative excretion of all components. The comparative analysis of incomplete formulae indicated that the tissue distribution and excretion became faster after removing Poria from SJZD, while a lack of RG led to slower tissue distribution. The tissue distribution at most time points was reduced when AM was absent. Further comprehensive visualization implied that SJZD compatibility can improve tissue distribution of the NPSs, especially ginsenosides and atractylenolide, at the specific time periods. ConclusionThe tissue distribution and excretion characteristics of NPSs of SJZD were elucidated in current research. Meanwhile, this study proposed new insights into the mechanism of SJZD compatibility rationality.

Novel Ultra-Fast Liquid Chromatography Method for Simultaneous Quantification of Metformin Hydrochloride and Remogliflozin Etabonate

An advanced formulation having remogliflozin etabonate (REM) and metformin hydrochloride (MET) for the treatment of diabetes was recently approved. However, there hasn't been any information reported on a UFLC technique for simultaneously quantifying both active substances. Therefore, aim of the study was the development of an ultra-fast isocratic liquid chromatography method for quantification of MET and REM in API and dosage form. The reversed phase-UFLC method was developed with a very short run time of only 3 min with no interference due to blank. The compounds were separated using Shimadzu Sim-pack XR ODS (75 mm × 3 mm, 2.2 μ) column with mobile phase consisting of buffer (0.1% phosphoric acid):acetonitrile (30:70). The developed method was validated as per ICH-Q2(R1). The linearity was established in the range of 0.01-125 ppm and 0.01-25 ppm for MET and REM, respectively. The average assay was found 99.4% for MET and 99.1% for REM. The accuracy was observed 98.29-99.49% for MET and 98.39-99.73% for REM. The proposed method is very fast and simple however precise and accurate. This method is very useful for regular quality control laboratory to quantify MET and REM in API and dosages forms.

Development and Validation of a New UFLC-MS/MS Method for the Detection of Organophosphate Pesticide Metabolites in Urine.

To monitor human exposure to pesticides, experts commonly measure their metabolites in urine, particularly dialkyl phosphates (DAPs), which include diethyl phosphate (DEP), Diethyl thiophosphate (DETP), diethyl dithiophosphate (DEDTP), dimethyl phosphate (DMP), dimethyl thiophosphate (DMTP) and dimethyl dithiophosphate (DMDTP)to monitor the metabolites of organophosphates. These DAP metabolites are a urinary biomarker for assessing pesticide exposure and potential health risks. This study presented a new screening method combining ultrafast liquid chromatography with tandem mass spectrometry (UFLC-MS/MS) to detect six DAP metabolites in human urine. The study also compared standard sample extraction methods, namely, liquid-liquid extraction (LLE); quick, easy, cheap, effective, ruggedand safe (QuEChERS); and lyophilization. After a comprehensive analysis of the methods used to extract the analytes, including recovery rate, repeatability and reproducibility, the liquid-liquid extraction (LLE) method was found to be the best. It had a high recovery rate, was easy to handle, required less sample volume and had a short extraction time. Therefore, the LLE method was chosen for further analysis. The results showed excellent performance with high recoveries between 93% and 102%, precise repeatability (RSD) between 0.62% and 5.46% and acceptable reproducibility values (RSD) between 0.80% and 11.33%. The method also had limits of detection (LOD) ranging from 0.0201 ng/mL to 0.0697 ng/mL and limits of quantification (LOQ) ranging from 0.0609 ng/mL to 0.2112 ng/mL. Furthermore, the UFLC-MS/MS method was validated based on the SANTE guidance and successfully analyzed 150 urine samples from farmers and non-farmers. This validated method proved useful for biomonitoring studies focusing on OP pesticide exposure. It offers several advantages, such as a reduced need for samples, chemicals and materials, and a shorter analysis time. The method is sensitive and selective in detecting metabolites in human urine, making it a valuable approach for the practical and efficient assessment of pesticide exposure.

Extraction and quantification of melatonin in cornelian cherry (Cornus mas L.) by ultra-fast liquid chromatography coupled to fluorescence detector (UFLC-FD)

AbstractWild edible plants (WEPs) can be widely found in the world and defined as native species that grow naturally in their natural habitat. They have become part of the traditional food as human diet and used in folk medicine to treat diseases. They are very rich in terms of nutraceuticals. Melatonin is a natural hormone providing several benefits for human health. It has functions such as regulating growth and development and increasing tolerance to environmental stress factors in plants. It is stated that the serum melatonin level in humans increases after intake of foods containing melatonin. This study examined the presence of melatonin in wild grown cornelian cherry fruits by UFLC-FD and determined suitable extraction and chromatographic conditions. The optimum mobile phase, excitation/emission wavelength, and extraction solvent were determined as methanol: water: acetic acid, 275/345 nm, and methanol: water: HCl, respectively. Melatonin content in fruits ranged from 130.82 to 201.84 ng g−1 in fresh fruit.

Analysis and evaluation of bioactive constituents from different parts of Epimedium brevicornum

A comprehensive analytical method based on ultra-fast liquid chromatography coupled with triple quadrupole/linear ion trap tandem mass spectrometry(UFLC-QTRAP-MS/MS) was established for simultaneous determination of the content of 45 bioactive constituents including flavonoids, alkaloids, amino acids, phenolic acids, and nucleosides in Epimedium brevicornum. The multiple bioactive constituents in leaves, petioles, stems and rhizomes of E. brevicornum were analyzed. The gradient elution was performed at 30 ℃ in an XBridge~® C_(18) column(4.6 mm×100 mm, 3.5 μm) with 0.4% formic acid aqueous solution-acetonitrile as the mobile phase at a flow rate of 0.8 mL·min~(-1). Single factor experiment and response surface methodology were employed to optimize the extraction conditions. Multivariate statistical analyses including systematic cluster analysis(SCA), principal component analysis(PCA), partial least squares discriminant analysis(PLS-DA), and one-way analysis of variance(One-way ANOVA) were carried out to classify the samples from different parts and identify different constituents. Grey relation analysis(GRA) and entropy weight-TOPSIS analysis were performed to build a multi-index comprehensive evaluation model for different parts of E. brevicornum. The results showed that there was a good relationship between the mass concentrations of 45 constituents and the corresponding peak areas, with the correlation coefficients(r) not less than 0.999 0. The precision, repeatability, and stability of the established method were good for all the target constituents in this study, with the relative standard deviations(RSDs) less than 5.0%(0.62%-4.9%) and the average recovery of 94.51%-105.7%. The above results indicated that the bioactive constituents varied in different parts of E. brevicornum, and the overall quality followed the trend of leaves &gt; petioles &gt; rhizomes &gt; stems. This study verified the rationality of the Chinese Pharmacopoeia(2020 edition) stipulating that the medicinal part of E. brevicornum is the leaf. Moreover, our study indicated that the rhizome had the potential for medicinal development. The established method was accurate and reliable, which can be used to comprehensive evaluate and control the quality of E. brevicornum. This study provides data reference for clarifying the medicinal parts and rationally utilizing the resources of E. brevicornum.

Evaluation of herb-drug interactions between compound Danshen dripping pills and clopidogrel based on the pharmacokinetics and pharmacodynamics in rats.

Compound Danshen dripping pills (CDDP), a well-known traditional Chinese medicine, is widely used to prevent and treat cardiovascular diseases. CDDP is usually prescribed in combination with clopidogrel (CLP), but the herb-drug interactions are rarely reported. This study evaluated the effects of CDDP on the pharmacokinetics and pharmacodynamics of coadministered CLP, and ensured the safety and efficacy of their usage. The trial design included a single-dose administration and multidose test for 7 consecutive days. Wistar rats received CLP alone or CLP combined with CDDP. After the final dose, plasma samples were collected at various time points, and the active metabolite H4 of CLP was analyzed by ultrafast liquid chromatography coupled with triple quadrupole tandem mass spectrometry. The main pharmacokinetic parameters of Cmax (maximum [or peak] serum concentration), Tmax (peak plasma time), t1/2 (half-time), AUC0-∞ (area under the concentration-time curve from dosing (time 0) to infinite time), and AUC0-t (area under the concentration-time curve from dosing [time 0] to time t) were calculated using the non-compartment model. In addition, prothrombin time, activated partial thromboplastin time, bleeding time, and adenosine diphosphate-induced platelet aggregation were evaluated for anticoagulation and antiplatelet aggregation activity. In this study, we found that CDDP had no significant effect on the metabolism of CLP in rats. In pharmacodynamic studies, the combination group showed significant synergistic antiplatelet activity compared with the CLP or CDDP groups alone. Based on pharmacokinetic and pharmacodynamic results, CDDP and CLP have synergistic effects on antiplatelet aggregation and anticoagulation.

RP-UFLC based Bioanalytical Method Development, Optimization, and Validation for the Estimation of Isradipine in Rabbit Serum

Introduction: The objective of this study is to provide a rapid, sensitive, consistent, and costeffective method for quantifying isradipine using ultra-fast liquid chromatography. Methods: Quality by Design principles will form the basis of this approach, grounded on response surface analysis. Shimadzu liquid chromatographic system equipped with a photodiode array detector and LC solution software was used to conduct the RP-UFLC method development and validation. An ODS C18 (250 x 4.6 mm; 5 μm) UFLC column was used to complete the analysis. The RSM methodology utilized a central composite design to perform the optimization studies. Results: The mobile phase ratio and flow rate were considered crucial method parameters, as well as the peak area, retention time, and USP plate were considered critical analytical attributes. The optimal conditions for chromatographic separation were followed using 80% acetonitrile and water (20% v/v) as mobile phase, a 1 mL/min flow rate, an injection volume of 20 μL, 40°C of column oven temperature, and maximum absorption at λmax 254 nm using graphical optimization technique. When examining concentrations between 5 and 150 ng/mL, linearity was observed with an R2 of 0.999. The method created was validated by employing stability testing per the recommendations provided by ICH Q2 (R1). The analysis of blood serum was modified so that it could be used to examine the pharmacokinetic parameters. Conclusion: As a result, high accuracy, precision, sensitivity, linearity, and robustness were established for predicting the amount of isradipine present in its freeze-dried nano-formulations.

Metabolite Profiling and Transcriptome Analysis Explain the Difference in Accumulation of Bioactive Constituents in Taxilli Herba from Two Hosts.

Taxilli Herba (TH) is a semi-parasitic herb and the host is a key factor affecting its quality. Flavonoids are the main bioactive constituents in TH. However, studies on the difference in accumulation of flavonoids in TH from different hosts are vacant. In this study, integrated transcriptomic and metabolomic analyses were performed on TH from Morus alba L. (SS) and Liquidambar formosana Hance (FXS) to investigate the relationship between the regulation of gene expression and the accumulation of bioactive constituents. The results showed that a total of 3319 differentially expressed genes (DEGs) were screened in transcriptomic analysis, including 1726 up-regulated genes and 1547 down-regulated genes. In addition, 81 compounds were identified using ultra-fast performance liquid chromatography coupled with triple quadrupole-time of flight ion trap tandem mass spectrometry (UFLC-Triple TOF-MS/MS) analysis, and the relative contents of flavonol aglycones and glycosides were higher in TH from SS group than those from the FXS group. A putative biosynthesis network of flavonoids was created, combined with structural genes, and the expression patterns of genes were mostly consistent with the variation of bioactive constituents. It was noteworthy that the UDP-glycosyltransferase genes might participate in downstream flavonoid glycosides synthesis. The findings of this work will provide a new way to understand the quality formation of TH from the aspects of metabolite changes and molecular mechanism.

Constituent Analysis and Quality Evaluation of Epimedii Folium from Different Species

Epimedii Folium (EF) is a commonly used traditional Chinese drug that includes many species. In Chinese Pharmacopoeia (2020 edition), EF includes Epimedium brevicornu Maxim, E. Sagittatum (Sieb. et Zucc) Maxim, E. pubescens Maxim, E. koreanum Nakai, and Epimedium Wushanense T.S. Ying. It has been reported that the active constituents in EF are different, resulting in the uneven quality of commercial medicinal materials. To explore the specific differences and make a comprehensive quality evaluation of EF, we established an analytical method to simultaneously detect 45 constituents including 23 flavonoids, 4 phenolic acids, 12 amino acids, 5 nucleosides, and 1 alkaloid in 5 species of EF, based on ultrafast performance liquid chromatography coupled with triple quadrupole-linear ion trap mass spectrometry (UFLC-QTRAP-MS/MS). In addition, orthogonal partial least squares discriminant analysis (OPLS-DA), analysis of variance (ANOVA), and grey correlation analysis (GRA) were used to discriminate and evaluate different species of samples. The results showed that EF could be divided into three categories and EBM was superior to the other four species. This study provides data basis for the comprehensive evaluation and a new perspective on the quality control of EF from different species.

Development and Validation of Single Laboratory Ultra Fast Liquid Chromatography Method for Quantification of Buprofezin in Suspension Concentrate (SC) Formulation

A novel ultra fast liquid chromatography (UFLC) method has been developed and validated for quantification of Buprofezin in Suspension Concentrate (SC) formulation, using Shimadzu, packed with C18 (250 mm × 4.6 mm, 5 μm) column. Mixture of acetonitrile:water (80:20 v/v) was used as mobile phase. The flow rate was kept 1.5 ml/min and detection was carried out at 250 nm. The linearity of proposed method was investigated in the range of 200-1002 PPM (r2=0.999). The percentage recovery found to be 99.87%. The % RSD value for precision study was &lt;0.68 as per modified Horwitz equation as requirements by CIPAC. The developed method was found to be specific, linear, precise and accurate. This method is also useful for quantification of Buprofezin in their single or combination formulated products, environmental samples (soil, water), and agricultural products for pesticide residue analysis.

Screening Of Oxytetracycline And Tetracycline Residues In Pork Marketed In Guwahati City And Its Adjoining Areas And Confirmation By Ultra-Fast Liquid Chromatography-UV/Vis

The antimicrobial residues in the animal-based food products that exceeds the maximum residue limits (MRLs) beyond permissible daily consumption attracted considerable attention due to their public health significance. The present study aimed to detect Oxytetracycline and Tetracycline residues in pork marketed in and around Guwahati City (Kamrup Metropolitan) and its adjoining areas. The preliminary screening of 261 pork samples by microbial inhibition assay using endospores of Bacillus subtilis MTCC 441 as test organism revealed that none of the samples were positive for antimicrobial residues except 3 (three) which were doubtful to have traces of antimicrobial residues. A total of 80 pork samples including the doubtful samples were further screened by Ultra-Fast Liquid Chromatography system (Model: Shimadzu Prominence LC-20AD, Detector- SPD-20A-UV/Vis; RP C18 Column: BDS Premium, 250 mm x 4.6 mm, 5 µm) to detect Oxytetracycline and Tetracycline residues. Oxytetracycline residues were detected in 2.5% of the samples, while none of the samples detected Tetracycline residue. The concentrations of the residues were 0.471 µg/g and 0.610 µg/g, respectively, which is well above the MRL value recommended by Codex Alimentarius. However, considering the detection of 2.5% Oxytetracycline residues and the absence of Tetracycline residue indicates that these antimicrobial compounds are not frequently misused in pig husbandry practices in these areas under study.