High-pressure Liquid Chromatography Research Articles

Association of rs8670 Polymorphism in the MSX1 Gene With Non-Syndromic Cleft Lip With or Without Cleft Palate in Malay Population.

This study aimed to investigate the association between variants present in the MSX1 gene and the risk of developing non-syndromic cleft lip with or without cleft palate (NSCL±P) among individuals of Malay ethnicity in Malaysia. This case-control study involved 89 patients with NSCL±P and 100 healthy control subjects. Polymerase chain reaction (PCR) was performed on both exon 1 and exon 2 of the MSX1 gene using four pairs of primers. The amplification products were then subjected to denaturing high-pressure liquid chromatography for initial screening, and the presence of a heteroduplex peak was validated using direct sequencing analysis to detect the single-nucleotide polymorphism. Five previously known variations (c.-36G>A, p.Ala30Ala, p.Ala34Gly, p.Gly110Gly, and rs8670: C>T) were detected within the MSX1 gene in both NSCL±P patients and controls.A significant association was found between the rs8670: C>T variant and NSCL±P (p = 0.017; OR: 0.368; 95% CI: 0.152 - 0.893), with this particular single-nucleotide polymorphism present in 20% (20) among controls and 7.9% (7) of the NSCL±P cases. Our data showed a lower incidence of thers8670: C>Tpolymorphism among NSCL±P cases compared to control in this Malay population. However, since this variant is located in the 3'UTR, it could potentially impact the stability ofMSX1mRNA.

Introducing macrocyclic glycopeptide columns as unique achiral stationary phases: Insights from hydrophobic subtraction model and in-silico modeling

BackgroundThe need for stationary phases with unique selectivity in reversed-phase liquid chromatography has been of utmost importance to chromatographers for advancing the analysis of complex samples. Macrocyclic glycopeptide based stationary phases have been widely used for chiral separations with different chromatographic modes such as normal phase, reversed phase, and supercritical fluid chromatography. Given the multimodal retention mechanisms namely π-π complex interaction, hydrogen bonding, dipole-dipole interaction, and strong Coulombic interactions by which analytes are separated using the macrocyclic glycopeptides, these stationary phases are expected to provide novel selectivity when used under the reversed phase for achiral separations. ResultsHerein, for the first time we have conducted a systematic study using the improved hydrophobic subtraction model (HSM) which incoporates dipole-dipole interactions to demonstrate the novel selectivity offered by four different macrocyclic glycopeptide based stationary phases, namely NicoShell, TeicoShell, TagShell, and VancoShell. A comparison of the HSM parameters for these columns has been made with 551 commercially available reversed phase stationary phases and the differences in the values point to the importance of adding these columns to the already existing arsenal. These stationary phases offer separations over a wide range of pH and show variability in selectivity depending on the pH of the mobile phase which make them versatile for method development in the reversed phase mode. Additionally, we have provided an actual example of a separation from an Amgen discovery project using the VancoShell column aided by computer-assisted modelling. SignificanceThis is the first report characterizing macrocyclic glycopeptides for achiral RPLC applications. The selectivity of these stationary phases were found to be unique when compared to other commercially available stationary phases thereby acting as their own class of columns. The unusual selectivity of the columns enabled separation of complex pharmaceutical samples.

Μagnet integrated fabric phase sorptive extraction (MI-FPSE) for the selective isolation of seven sulfonamides from human urine prior to HPLC-DAD analysis

In the present study magnet integrated fabric phase sorptive extraction (MI-FPSE) was employed for the selective extraction of seven sulfonamides (i.e., sulfamerazine, sulfamethazine, sulfamethoxypyridazine, sulfamonomethoxine, sulfamethoxazole, sulfisoxazole and sulfadimethoxine) from human urine prior to their determination by high pressure liquid chromatography – diode array detection (HPLC-DAD). The MI-FPSE protocol was optimized after studying the critical parameters that affect extraction, namely: type of sol–gel sorbent, extraction time, desorption time, stirring rate, type and volume of elution solvent, the ionic strength and the pH of the sample matrix using the one-factor-at-a-time method. The developed MI-FPSE-HPLC-DAD method was validated in terms of linearity, sensitivity, selectivity, accuracy, and precision and presented satisfactory results. The limits of detection (LODs) and quantification (LOQs) ranged between 0.02–0.04 ng/μL and 0.06–0.15 ng/μL, respectively. The RSD% values of the intra-day and inter-day assays were found lower than 6.7 % and 9.4 %, respectively, showing good precision. Accuracy was assessed using percentage of relative recovery and varied from 86.3–112.9 % (intra-day study) and 85.5–106.9 % (inter-day study) for all examined analytes. The green character and practicality of the proposed method were investigated using the ComplexGAPI index and Blue Applicability Grade Index (BAGI).

Analytical Characterization, Antioxidant, Antiviral and Antimicrobial Potential of Selected Medicinal Plants

Objectives/background: The infectious consequences of microorganisms are varied due to resistance to existing antimicrobial drugs or new types of microbes causing lethal consequences for humans. Investigation are being performed to control different viral diseases; therefore; medicinal and herbal plants which have a variety of biological properties, can be evaluated for their anti-viral potential. Methods: The antiviral potential of NADES and water extracts of Senna alexandrina ( S. alexandrina), Peganum harmala ( P. harmala) and Citrullus colocynthis ( C. colocynthis) on Nicotiana benthamiana infected with Cotton Leaf Curl Multan virus were investigated. Results: The results of the antiviral assay revealed that both water and NADES extracts of P. harmala could not exhibit antiviral activity. However, water extracts of S. alexandrina and C. colocynthis successfully inhibited the Cotton Leaf Curl Multan virus , allowing the plant to survive compared to their NADES extracts. High-pressure liquid chromatography (HPLC) and Fourier transform infrared spectroscopy (FTIR) analyses showed higher phenolic and flavonoid content in the water extracts of S. alexandrina, C. colocynthis and P. harmala compared to the NADES extracts. Additionally, both water and NADES extracts of P. harmala showed greater antioxidant and antimicrobial activity against S.aureus in comparison to other extracts, while the NADES extract of C. colocynthis demonstrated higher antimicrobial activity against E.coli strains. Conclusions: Therefore, these results demonstrated that Senna Alexandrina and Citrullus Colocynthis exhibited potent antiviral activity, suggesting that these plants could be therapeutic agent for treating viral infections.

Bioactive secondary metabolites from an endophytic fungus Aspergillus sp. CCH-1E from Catharanthus roseus

This study focused on the bioactive secondary metabolites of an endophytic fungus Aspergillus sp. CCH-1E from Catharanthus roseus. The secondary metabolites from Aspergillus sp. CCH-1E were isolated by using various chromatographic methods [such as normal-phase and reversed-phase chromatography and high-performance liquid chromatography(HPLC)], and their structures were identified by various spectroscopic methods [e.g., ultraviolet(UV) spectroscopy, infrared(IR) spectroscopy, nuclear magnetic resonance(NMR) spectroscopy, and high-resolution electrospray ionization mass spectrometry(HR-ESI-MS)]. Twelve compounds were yielded and identified from Aspergillus sp. CCH-1E, which are chermesinone H(1), chermesinone I(2), chermesinone B(3), 8,11-didehydrochermesinone B(4), chermesinone C(5), chermesinone A(6), chevalone B(7), barbacenic acid(8), 3,6,8-trihydroxy-3,5,7-trimethyl-3,4-dihydroisocoumarin(9), 5-hydroxy-2-methoxy-7-methyl-1,4-naphthoquinone(10), 1-hydroxy-6,8-dimethoxy-3-methylanthracene-9,10-dione(11), and 7-drimen-9α,11,12-triol(12). Among them, compounds 1 and 2 are new compounds. The growth inhibition effects of all compounds were evaluated against non-small cell lung cancer cell lines A549 and NCI-H1650, as well as human cervical cancer cell line HeLa by using methylthiazolyldiphenyl-tetrazolium bromide(MTT). Compound 7 significantly inhibited the growth of three tumor cells with the IC_(50) values of 1.22-2.43 μmol·L~(-1), respectively. Compounds 1-6 showed moderate cell growth inhibition with the IC_(50) values of 16.24-35.28 μmol·L~(-1).

Rapid phenol mineralisation in a low-pressure dead-end light transmitting photocatalytic membrane reactor (LT-PMR)

Photocatalytic membrane reactors (PMRs) are widely studied for wastewater decontamination but reactions are too slow for scaled up application. This PMR study proposes a novel operation involving rapid decontamination in just one pass through the confined space within the membrane. This approach was demonstrated for the first time by light transmitting PMR (LT-PMR), conveniently receiving UV LED light (λpeak = 365 nm) via the permeate side to the photocatalyst P25 TiO2 microfiltration membrane coated on porous glass. A 93 % reduction in model contaminant phenol concentration from a 10 mg/L feed occurred at a flux of 4.7 L/m2/h. The phenol degradation occurred without any additional residence time from external vessels or recirculation. Phenol was almost entirely mineralised, confirmed by total organic carbon (TOC) measurements, with trace by-products identified by high pressure liquid chromatography (HPLC) analysis. Mass transfer and reaction rate constants from Langmuir-Hinshelwood modelling were comparable to literature. Highest reaction rates occurred at lowest permeate phenol concentrations, highlighting potential to destroy recalcitrant pollutants persisting through established treatments. LT-PMR is therefore an effective and practical process that very rapidly destroys phenol. Further work to explore improved flux by enhanced light transmission, tailored catalytic materials and demonstration on other pollutants and water matrices is warranted.

Untargeted Blood Lipidomics Analysis in Critically Ill Pediatric Patients with Ventilator-Associated Pneumonia: A Pilot Study.

This study aims to explore the diagnostic potential of blood lipid profiles in suspected ventilator-associated pneumonia (VAP). Early detection of VAP remains challenging for clinicians due to subjective clinical criteria and the limited effectiveness of current diagnostic tests. Blood samples from 20 patients, with ages between 6 months and 15 years, were collected at days 1, 3, 6, and 12, and an untargeted lipidomics analysis was performed using a Ultra high Pressure Liquid Chromatography hyphenated with High Resolution Mass Spectrometry UPLC-HRMS (TIMS-TOF/MS) platform. Patients were stratified based on modified pediatric clinical pulmonary index score (mCPIS) into high (mCPIS ≥ 6, n = 12) and low (mCPIS < 6, n = 8) VAP suspicion groups. With the untargeted lipid profiling, we were able to identify 144 lipid species from different lipid groups such as glycerophospholipids, glycerolipids, and sphingolipids, in the blood of children with VAP. Multivariate and univariate statistical analyses revealed a distinct distribution of blood lipid profiles between the studied groups, indicating the potential utility of lipid biomarkers in discriminating VAP presence. Additionally, specific lipids were associated with pharyngeal culture results, notably the presence of Klebsiella pneumoniae and Staphylococcus aureus, underscoring the importance of lipid profiling in identifying the microbial etiology of VAP.

Microbial diversity, aflatoxin M1 contamination and potential lactic acid starters for commercially produced traditional fermented dairy beverages, a case of Bongo from Uganda

This was a cross sectional study that examined the microbial ecology and aflatoxin M1 contamination in commercially produced Bongo, a traditionally fermented dairy beverage from Uganda. It also involved isolation and preliminary evaluation of defined starter cultures for Bongo. Microbial analyses were done by agar plating. Microbial identification was initially done by biochemical testing and microscopy. Followed by 16S rRNA and Internal Transcribed Spacer (ITS) region sequencing for bacteria and yeasts, respectively. Community DNA was studied using Next Generation Sequencing (NGS). Aflatoxin M1 was determined using Ultra High Pressure Liquid Chromatography - Triple Quadrupole Mass Spectrometry. (GTG)5 Rep PCR fingerprinting was used to cluster candidates for starter culture evaluation. The rates of acidification of cow milk by candidate LAB coupled with sensory acceptability of the milk they fermented were the criteria for the selection of the starter cultures. Results indicated that lactic acid bacteria (LAB) and yeasts were the dominant groups. Molds, coliforms, enterococci and staphylococci were also detected. Aflatoxin M1 were insignificant. Based on agar plating technique, lactococci and lactobacilli were dominant, however, NGS showed Streptococci. Agar plating also showed Saccharomyces as dominant, but NGS showed Dipodascus. Cluster analysis identified 18 LAB, which were evaluated for starter culture properties. Three showed promise suggesting that they could be used for commercial production of cultured milks like Bongo.

A study on the photoisomerization of phenylpropanoids and the differences in their radical scavenging activity using in-situ NMR spectroscopy and on-line radical scavenging activity analysis

Phenylpropanoids are naturally occurring secondary metabolites that exhibit various biological activities such as ultra-violet (UV) light protection and reactive-oxygen species (ROS) scavenging. In this study, we utilized a light-emitting diode (LED) based in-situ UV irradiation nuclear magnetic resonance (NMR) technique to monitor the photoisomerization reactions of these phenylpropanoids under UV irradiation in real-time. Through this approach, we measured the photochemical reaction rates and photostationary state (PSS) ratios of these molecules and observed distinct reaction rate and PSS ratio information depending on the variation of substituent groups in each phenylpropanoid molecule. We also evaluated the radical scavenging activity (RSA) for each photochemical product through diphenyl-1-picrylhydrazyl radical (DPPH) assay and 2,2’-azino-bis(3-ethylbenzenthiazoline-6-sulphonic acid) (ABTS) assay. We found that the photoisomerization product of caffeic acid can increase both DPPH and ABTS radical scavenging activities, and confirmed the enhanced ABTS radical scavenging ability of caffeic acid cis-isomer based on the online high-pressure liquid chromatography (HPLC)-ABTS analysis and the PSS ratio information of each isomer.

Novel method for monitoring of carcinogenic impurity of N-nitrosamine in nizatidine pharmaceutical products using ultra high-pressure liquid chromatography triple quadrupole mass spectrometry.

Nitrosamine compounds pose a significant concern as potential carcinogens, prompting heightened scrutiny from regulatory bodies, particularly regarding their presence in pharmaceuticals. The detection of unacceptable levels of N-nitrosodiethylamine (NDMA) in ranitidine has led to widespread recalls, driving interest in alternative medications such as nizatidine, which shares a similar pharmacological class and is used to treat various gastrointestinal conditions. Despite fewer reports on NDMA levels in nizatidine, its structural similarity to ranitidine, characterized by a tertiary amine, underscores the potential for NDMA formation. Addressing the analytical challenges associated with nitrosamine detection, this study focuses on developing and validating an ultra-high pressure liquid chromatography triple quadrupole mass spectrometry (UHPLC-MS/MS) method for quantifying NDMA in both nizatidine active pharmaceutical ingredients and tablet formulations. Method validation adheres to International Council for Harmonisation recommendations, with a demonstrated linear range of 0.25-100 ng/mL for NDMA, exhibiting excellent linearity (regression coefficient >0.999) and efficient recovery rates ranging from 95.98% to 109.57%. The method shows high sensitivity, with limits of detection and quantification of 0.25 and 0.5ng/mL, respectively. The developed UHPLC-MS/MS method offers a simple, precise, accurate, and selective approach for monitoring NDMA levels in nizatidine formulations available in Australia, promising enhanced sensitivity and specificity with limits of quantification in the ppb and sub-ppb ranges.

Comparation of chicoric acid and rosmarinic acid in fresh and dry herbs of sweet and purple basil (Ocimum basilicum L.) populations

Ocimum basilicum is used either as a fresh or dry herb. Most used species are characterized by sweet and purple leaves and are typically used for culinary purposes and in traditional medicine. Therefore, it is important to analyse the content of functional compounds, rosmarinic acid and chicoric acid, in dry and fresh form of the plant. It was determined that rosmarinic acid and chicoric acid content of dry and fresh form of sweet, purple, and purple flower colored of the plant by high pressure liquid chromatography equipped diode array detector (HPLC-DAD). According to obtained results, it was observed that the distribution of rosmarinic acid in fresh samples varied between 128.38 and 4072.20 mg kg-1 DW, and in dry samples between 1792.20 and 8149.45 mg kg-1 DW. It is clearly observed that rosmarinic acid content in dry samples higher than fresh samples. The concentration of chicoric acid in fresh samples varied between 51.53 and 2278.40 mg kg-1 DW and it varied in dry samples between 38.55 and 555.85 mg kg-1 DW. Chicoric acid levels in dry samples were observed to be lower than fresh samples. These changes were found statistically significant (p

Effects of Chemical Modification on the Structure and Biological Activities of Polysaccharides Extracted from Inonotus Obliquus by Microwave.

A novel polysaccharide, Inonotus obliquus polysaccharide (IOP), was extracted using a microwave extraction method and subsequently subjected to modifications through sulfation, carboxymethylation, phosphorylation, and acetylation. Its physical and chemical properties were analyzed using various chemical techniques, including high-pressure liquid chromatography, ultraviolet light, Fourier-transform infrared spectroscopy, X-ray diffraction, Congo red test, and scanning electron microscopy. The antioxidant capacity was assessed using DPPH, ABTS, and hydroxyl radical assays, as well as by measuring the reducing power. Additionally, hypoglycemic activity was evaluated through α-glucosidase and α-amylase assays. The results indicated that the chemical modifications effectively altered the physical and chemical properties, as well as the biological activities of IOP. Compared to the unmodified IOP, the derivatives exhibited reduced sugar content, uronic acid content, and molecular weight, while demonstrating varying levels of antioxidant and hypoglycemic capabilities. Notably, the carboxymethylated IOP (IOP-C) displayed lower molecular weight, higher ABTS free radical scavenging rate, greater reducing ability, and increased α-amylase inhibition rate. Therefore, IOP-C shows promise as a potential edible antioxidant and hypoglycemic agent.

Biochemical analysis of catecholamine and cortisol for the evaluation of the fetal distress in third trimester stillbirths

BackgroundStress hormones like catecholamine and cortisol are thought to reflect the magnitude of physical stress in adults and were studied in relationship to the cause of death and agony time. Intrauterine distress, intrapartum events, and modes of delivery can affect the fetal endocrine stress response, as reflected by biochemical analyses. The aim of the present study was to evaluate the role of catecholamines and cortisol as markers of ante-mortem fetal distress. The role of cortisol as a marker of circadian timing of delivery was also assessed.MethodsA 2-year prospective cohort-comparison inclusion of stillbirths and newborns took place with collection of antemortem data, labor parameters, neonatal outcome, post-mortem data and blood samples. Stillbirths were classified as acute or chronic on the basis of a multidisciplinary evaluation. Heart blood of stillbirths and cord blood of newborns were analyzed by high pressure liquid chromatography (HPLC) for adrenaline and noradrenaline and by immunoassay for cortisol determination.ResultsFifteen stillbirths and 46 newborns, as a comparison group, delivered by spontaneous vaginal birth, elective, and emergency cesarean sections were included. Stillbirths’ main cause of death was cord thrombosis. Levels of adrenaline and noradrenaline (median: 14,188 pg/ml and 230.5 pg/ml, respectively) were significantly higher (p < 0.001) in stillbirths than in newborns and were also higher in acute compared to chronic distress. Cortisol levels were significantly higher (p < 0.05) in spontaneous vaginal delivery (median: 18.2 μg/dl) compared to elective cesarean sections (median: 3.8 μg/dl). No difference in cortisol concentrations was detected between newborns delivered at morning and at afternoon/evening.ConclusionOur results suggest that the biochemical measurement of adrenaline and noradrenaline levels might reflect a marked physical stress response during the process of death in stillbirths. On the contrary, the elevation of cortisol levels could mirror the elevation in maternal cortisol level during vaginal delivery. For the post-mortem evaluation of stillbirths, the analysis of CA levels could provide additional data on the duration of distress, useful to integrate the forensic diagnosis.

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.

Determination of in-vitro bioaccessibility of vitamin B1 in baby biscuits prepared with or without UHT cow's milk

Since thiamine is a vitamin that is not stored in the body, it must be taken daily. Especially in infants, its intake is essential for infant development, and it is a crucial factor in ensuring infants receive adequate nutrition to calculate the bioavailability of thiamine, especially when switching to follow-up milk. For this purpose, this study investigates the bioaccessibility of thiamine in baby biscuits and follow-on milk. Thiamine levels were analyzed using High-Pressure Liquid Chromatography. At gastric pH 1.5, baby biscuits exhibited an average thiamine bioaccessibility of 43 % without Ultra-high temperature (UHT) milk and 107 % with added UHT milk. At pH 4, thiamine bioaccessibility for biscuits was 96 % without UHT milk and 104 % with UHT milk. Follow-on milk bioaccessibility was 47 % at pH 1.5 and increased to 80 % at pH 4. The study results that bioaccessibility can vary due to factors like dietary fiber content, manufacturing temperature, polysaccharides, peptides, and gastric pH. Notably, the addition of UHT milk to baby biscuits enhanced thiamin bioaccessibility. Understanding these nuances is crucial for formulating infant nutrition that meets thiamine requirements. The findings emphasize the need for tailored nutritional strategies, considering diverse factors influencing thiamine bioavailability in infant products.

A symmetric chiral aromatic polyamide modified silica material combining rigid-flexible and application in liquid chromatography

The development of new separation materials is an effective way to improve the separation efficiency of chiral and achiral analytes. Here, a C3-symmetric chiral tricarboxylic acid compound was prepared and successfully immobilized onto the surface of porous silica particles by a one-pot synthesis strategy. The resulting material (TPHs-SiO2) was composed of symmetric chiral aromatic polyamide with a combination of rigid-flexibility, which gave it both chiral and hydrophilic interaction/ion exchange (HILIC/IEC) characteristics. TPHs-SiO2 as a new stationary phase for liquid chromatography can separate 1-phenyl-ethanol, 1-phenyl-propanol, 1-phenyl-1,2-ethylene glycol, 4-chloro-a-methylbenzyl alcohol, ofloxacin and mandelic acid in normal phase chromatography (NPLC) with resolutions of 2.69, 5.89, 4.49, 1.04, 1.73 and 5.47, respectively, thus indicating that TPHs-SiO2 has chiral resolution performance. TPHs-SiO2 can also achieve the separation of achiral compounds, such as nucleosides, nucleotides, and aniline compounds in HILIC/IEC mode. Therefore, the prepared stationary phase can be used as an ideal multifunctional separation material with chiral separation capability and mixed-mode separation capability (HILIC/IEC), realizing the separation of chiral compounds and different types of compounds. This work provides a new idea and method for developing multifunctional separation materials with multi-selectivity and high efficiency, that has important theoretical and application value.

Comparison of decarboxylation rates of acidic cannabinoids between secretory cavity contents and air-dried inflorescence extracts in Cannabis sativa cv. ‘Cherry Wine’

Studies with secretory cavity contents and air-dried inflorescence extracts of the CBD-rich hemp strain, Cannabis sativa cv. ‘Cherry Wine’, were conducted to compare the decarboxylation rates of acidic cannabinoids between two groups. The secretory cavity contents acquired from the capitate-stalked glandular trichomes by glass microcapillaries, and inflorescence samples air-dried for 15 days of storage in darkness at room temperature were analysed by high-pressure liquid chromatography. The ratio of acidic cannabinoids to the total cannabinoids was ranging from 0.5% to 2.4% lower in the air-dried inflorescence samples compared to the secretory cavity samples as follows. In the secretory cavity content, the percentage of acidic cannabinoids to the total cannabinoids was measured as 86.4% cannabidiolic acid (CBDA), 6.5% tetrahydrocannabinolic acid (THCA), 4.3% cannabichromenic acid (CBCA), 1.4% cannabigerolic acid (CBGA), and 0.6% cannabidivarinic acid (CBDVA), respectively. In the air-dried inflorescence, however, the acidic cannabinoids were detected with 84% CBDA, 4.8% THCA, 3.3% CBCA, 0.8% CBGA, and 0.3% Δ9-tetrahydrocannabivarinic acid (Δ9-THCVA), respectively. The ratio of cannabidiol (CBD) to cannabidiolic acid (CBDA) was close to 1:99 (w/w) in secretory cavity contents, however, it was roughly 1:20 (w/w) in the air-dried inflorescence. In addition, Δ9-tetrahydrocannabivarin (Δ9-THCV) and Δ9-tetrahydrocannabivarinic acid (Δ9-THCVA) were only detected in the air-dried inflorescence sample, and the ratio of Δ9-THCV to Δ9-THCVA was about 1:20 (w/w). Besides, cannabidivarinic acid (CBDVA) was only observed in the secretory cavity content.

(E)-2-Benzylidenecyclanones: Part XIX. Reaction of (E)-2-(4'-X-Benzylidene)-1-tetralones with Cellular Thiols: Comparison of Thiol Reactivities of Open-Chain Chalcones and Their Six- and Seven-Membered Cyclic Analogs.

Non-enzyme-catalyzed thiol addition onto the α,β-unsaturated carbonyl system is associated with several biological effects. Kinetics and diastereoselectivity of non-enzyme catalyzed nucleophilic addition of reduced glutathione (GSH) and N-acetylcysteine (NAC) to the six-membered cyclic chalcone analogs 2a and 2b were investigated at different pH values (pH 3.2, 7.4 and 8.0). The selected compounds displayed in vitro cancer cell cytotoxicity (IC50) of different orders of magnitude. The chalcones intrinsically reacted with both thiols under all incubation conditions. The initial rates and compositions of the final mixtures depended both on the substitution and the pH. The stereochemical outcome of the reactions was evaluated using high-pressure liquid chromatography with UV detection (HPLC-UV). The structures of the formed thiol-conjugates and the retro-Michael products (Z)-2a and (Z)-2b were confirmed by high-pressure liquid chromatography-mass spectrometry (HPLC-MS). Frontier molecular orbitals and the Fukui function calculations were carried out to investigate their effects on the six-membered cyclic analogs. Data were compared with those obtained with the open-chain (1) and the seven-membered (3) analogs. The observed reactivities do not directly relate to the difference in in vitro cancer cell cytotoxicity of the compounds.

APPLICATION OF VALIDATED RP-HPLC METHOD FOR SIMULTANEOUS DETERMINATION OF METAXALONE AND DICLOFENAC POTASSIUM IN PLASMA

Objective: The present investigation demonstrates a simple, sensitive and accurate high-pressure liquid chromatographic (HPLC) method for simultaneous determination of metaxalone (MTX) and Diclofenac potassium (DIC) in plasma by using Valsartan (VSN) as internal standard. Methods: The chromatographic separation was achieved within 10 min by using methanol: potassium dihydrogen phosphate buffer pH 4.5 adjusted with orthophosphoric acid (60:40) as mobile phase on Altima Grace Smart C-18 column (5μ; 250×4.6 mm) at flow rate of 1.0 ml/min with injection volume 25µl. The drug was extracted from plasma by liquid-liquid extraction using methanol as a solvent. The retention times of drugs (MTX and DIC) and internal standard were found to be 5.83, 9.65 and 11.79 min, respectively. This method was validated as per United States Food and Drug Administration (US-FDA) guidelines. Results: The results of the validation parameters were found to be within the acceptance limits. The method was linear in the concentration range from 25-1000 ng/ml (r2= 0.9998) and the extraction recovery was found to be 77.06% for MTX and 78.37% for DIC. The lower limit of quantification was found to be 25ng/ml and the stability of recovered samples at different conditions were found to be more than 95% for both the drugs. Conclusion: The developed method possesses good selectivity specificity, there was no interference found in the plasma blanks at retention times of MTX and DIC. We found good correlation between the peak area and concentration of the drug under prescribed conditions. Furthermore, the method can also be used to estimate the pharmacokinetic parameters of MTX and DIC simultaneously.

Comparative pharmacokinetics of a single oral dose of meloxicam in the California sea lion (Zalophus californianus) and Pacific harbor seal (Phoca vitulina richardii).

Pharmacokinetics studies have investigated meloxicam, a non-steroidal anti-inflammatory drug, dosing strategies in a wide variety of non-domestic animals; however, there is no prior study examining well-founded dosing for pinnipeds. To develop dosing protocols, pharmacokinetic information is needed, with an examination of differences between pinniped species. Apparently, healthy California sea lions (Zalophus californianus: CSL; n = 13) and Pacific harbor seals (Phoca vitulina richardii: PHS; n = 17) that had completed rehabilitation were enrolled into a population-based pharmacokinetic study. Each animal was administered a single oral dose of meloxicam at 0.1 mg/kg, and two blood samples were collected from each animal at varying intervals during a 96-h study period. Plasma concentrations of meloxicam were determined by high-pressure liquid chromatography. Data were analyzed with nonlinear mixed effects modeling (Phoenix® NLME™, Certara, St. Louis, MO 63105, USA). The results indicated that in PHS, peak plasma concentration (Cmax) was 0.33 μg/mL with an elimination half-life (Ke t½) of 31.53 h. In CSL, Cmax was 0.17 μg/mL with Ke t½ of 32.71 h. All animals enrolled completed the study without outward adverse clinical signs. The elimination half-life was longer than previously recommended dosing intervals for pinnipeds; however, we cannot speculate in the optimum clinical dose from these results.