18 research outputs found
Stockpiling by pups and self-sacrifice by their fasting mothers observed in birth to weaning serum metabolomes of Atlantic grey seals
The work was funded from core support given to the Sea Mammal Research Unit, Scottish Oceans Institute, from the National Environmental Research Council (UK), and separately by the Universities of Glasgow and Strathclyde. The funding of mass spectrometry equipment for metabolomics was provided by the Scottish Life Sciences Alliance.During the uniquely short lactations of true seals, pups acquire a greater proportion of maternal body resources, at a greater rate, than in any other group of mammals. Mothers in many species enter a period of anorexia but must preserve sufficient reserves to fuel hunting and thermoregulation for return to cold seas. Moreover, pups may undergo a period of development after weaning during which they have no maternal care or nutrition. This nutritionally closed system presents a potentially extreme case of conflict between maternal survival and adequate provisioning of offspring, likely presenting strains on their metabolisms. We examined the serum metabolomes of five mother and pup pairs of Atlantic grey seals, Halichoerus grypus, from birth to weaning. Changes with time were particularly evident in pups, with indications of strain in the fat and energy metabolisms of both. Crucially, pups accumulate certain compounds to levels that are dramatically greater than in mothers. These include compounds that pups cannot synthesise themselves, such as pyridoxine/vitamin B6, taurine, some essential amino acids, and a conditionally essential amino acid and its precursor. Fasting mothers therefore appear to mediate stockpiling of critical metabolites in their pups, potentially depleting their own reserves and prompting cessation of lactation.Publisher PDFPeer reviewe
A new isoflavone from Lomariopsis guineensis (Underw.) Alston
Aim/background: Lomariopsis guineensis (Underw.) Alston is an epiphytic climbing fern. It is widely distributed in Africa where it is also used in traditional medicine and as food. There are no previous reports of any constituents of the plant, hence this study to isolate any phytoconstituents. Method: The ethyl acetate extract of the leaves was subjected to column chromatography and isolated constituents were characterized using nuclear magnetic resonance and mass spectrometry. Results: Three compounds were isolated and identified as cycloartenol, pheophytin A and a new isoflavone (5, 7-dihydroxy-4′ methoxy-6,8-dimethylisoflavone). Conclusion: Three phytochemicals including a new isoflavone are reported from the plant for the first time
Plasma free fatty acids metabolic profile with LC-MS and appetite-related hormones in South Asian and White European men in relation to adiposity, physical activity and cardiorespiratory fitness : a cross-sectional study
South Asians have a greater cardiovascular disease (CVD) and type 2 diabetes (T2D) risk than white Europeans, but the mechanisms are poorly understood. This study examined ethnic differences in free fatty acids (FFAs) metabolic profile (assessed using liquid chromatography-mass spectrometry), appetite-related hormones and traditional CVD and T2D risk markers in blood samples collected from 16 South Asian and 16 white European men and explored associations with body composition, objectively-measured physical activity and cardiorespiratory fitness. South Asians exhibited higher concentrations of five FFAs (laurate, myristate, palmitate, linolenic, linoleate; p ≤ 0.040), lower acylated ghrelin (ES = 1.00, p = 0.008) and higher leptin (ES = 1.11, p = 0.004) than white Europeans; total peptide YY was similar between groups (p = 0.381). South Asians exhibited elevated fasting insulin, C-reactive protein, interleukin-6, triacylglycerol and ratio of total cholesterol to high-density lipoprotein cholesterol (HDL-C) and lower fasting HDL-C (all ES ≥ 0.74, p ≤ 0.053). Controlling for body fat percentage (assessed using air displacement plethysmography) attenuated these differences. Despite similar habitual moderate-to-vigorous physical activity (ES = 0.18, p = 0.675), V ˙ O2max was lower in South Asians (ES = 1.36, p = 0.001). Circulating FFAs in South Asians were positively correlated with body fat percentage (r2 = 0.92), body mass (r2 = 0.86) and AUC glucose (r2 = 0.89) whereas in white Europeans FFAs were negatively correlated with total step counts (r2 = 0.96). In conclusion, South Asians exhibited a different FFA profile, lower ghrelin, higher leptin, impaired CVD and T2D risk markers and lower cardiorespiratory fitness than white Europeans
Mitochondrial hyperfusion via metabolic sensing of regulatory amino acids
The relationship between nutrient starvation and mitochondrial dynamics is poorly understood. We find that cells facing amino acid starvation display clear mitochondrial fusion as a means to evade mitophagy. Surprisingly, further supplementation of glutamine (Q), leucine (L), and arginine (R)Â did not reverse, but produced stronger mitochondrial hyperfusion. Interestingly, the hyperfusion response to QÂ + LÂ + R was dependent upon mitochondrial fusion proteins Mfn1 and Opa1 but was independent of MTORC1. Metabolite profiling indicates that QÂ + LÂ + R addback replenishes amino acid and nucleotide pools. Inhibition of fumarate hydratase, glutaminolysis, or inosine monophosphate dehydrogenase all block QÂ + LÂ + R-dependent mitochondrial hyperfusion, which suggests critical roles for the tricarboxylic acid (TCA) cycle and purine biosynthesis in this response. Metabolic tracer analyses further support the idea that supplemented Q promotes purine biosynthesis by serving as a donor of amine groups. We thus describe a metabolic mechanism for direct sensing of cellular amino acids to control mitochondrial fusion and cell fate
UHPLC-UV Method for Simultaneous Determination of Perindopril Arginine and Indapamide Hemihydrate in Combined Dosage Form: A Stability-Indicating Assay Method
Perindopril arginine and Indapamide hemihydrate in combination were proven to have a synergistic antihypertensive impact when compared with the use of each component alone. Therefore, a new Ultra-High Performance Liquid Chromatography coupled with Ultraviolet detector (UHPLC-UV) method has been developed and subsequently validated for simultaneous determination of the anti-hypertensive combination of Perindopril arginine and Indapamide hemihydrate. The separation of Perindopril arginine and Indapamide hemihydrate was achieved using a BEH C18 (1.7 μm, 2.1 × 50 mm) analytical column (Waters® Acquity UPLC) and a mobile phase composed of 0.01% v/v formic acid in water adjusted to pH 4 with acetic acid and acetonitrile (40:60 v/v). The method was able to separate Perindopril arginine and Indapamide hemihydrate within less than 4.5 min with high accuracy, precision, resolution, and sensitivity. The content of Perindopril arginine and Indapamide hemihydrate present in the dosage form Coversyl Plus® (5000 µg of Perindopril arginine/1250 µg of Indapamide hemihydrate) was determined in triplicate to give a concentration of 4991 µg and 1247 µg, respectively, from the manufacturer’s stated amounts with Relative Standard Deviation (%RSD) of ±0.63% for Perindopril arginine and ±0.84% for Indapamide hemihydrate. Moreover, the degradation products of the combination were elucidated by UHPLC-Quadrupole Time of Flight-Mass spectrometry (UHPLC-QToF-MS) under acidic, basic, and thermal conditions. In conclusion, the developed UHPLC-UV method was sensitive, rapid, and precise. Furthermore, forced degradation studies were performed and the degradants were identified by UHPLC-Electro-Spray Ionization-QToF (UHPLC-ESI-QToF)
Eco-Friendly Separation of Antihyperlipidemic Combination Using UHPLC Particle-Packed and Monolithic Columns by Applying Green Analytical Chemistry Principles
Efficient separation of pharmaceuticals and metabolites with the adequate resolution is a key factor in choosing the most suitable chromatographic method. For quality control, the analysis time is a key factor, especially in pharmacokinetic studies. High back pressure is considered as one of the most important factors in chromatography’s flow control, especially in UHPLC. The separation of the anti-hyperlipidemic mixtures was carried out using two columns: a column silica-based particle packed UHPLC and a monolithic column. The systematic suitability of the two columns was compared for the separation of Fenofibrate, its active metabolite, Fenofibric acid and Pravastatin using Atorvastatin as an internal standard. Separation on both columns was obtained using ethanol: buffer potassium dihydrogen orthophosphate pH = 3 (adjusted with orthophosphoric acid) (75:25 v/v) as mobile phase and flow rate 0.8 mL/min. The analytes’ peak detection was achieved by using a PDA detector at 287 nm, 214 nm, 236 nm, and 250 nm for Fenofibrate, Fenofibric acid, Pravastatin, and Atorvastatin, respectively. Reduction of back-pressure was achieved with the monolithic column, where the analytes could be completely separated in less than 1.5 min at a flow rate of 5 mL/min. The principles of Green Analytical Chemistry (GAC) were followed throughout the developed method using environmentally safe solvents
Antimycobacterial Activities of N-Substituted-Glycinyl 1H-1,2,3-Triazolyl Oxazolidinones and Analytical Method Development and Validation for a Representative Compound
Twelve N-substituted-glycinyl triazolyl oxazolidinone derivatives were screened for antimycobacterial activity against susceptible (Mycobacterium tuberculosis (Mtb) H37Rv) and resistant (isoniazid (INH)-resistant Mtb (SRI 1369), rifampin (RMP)-resistant Mtb (SRI 1367), and ofloxacin (OFX)-resistant Mtb (SRI 4000)) Mtb strains. Most of the compounds showed moderate to strong antimycobacterial activity against all strains tested, with minimum inhibitory concentration (MIC) value ranges of 0.5–11.5, 0.056–11.6, 0.11–5.8, and 0.03–11.6 μM, and percent inhibition ranges of 41–79%, 51–72%, 50–75%, and 52–71% against Mtb H37Rv, INH-R, RMP-R, and OFX-R M. tuberculosis, respectively. The 3,5-dinitrobenzoyl and 5-nitrofuroyl derivatives demonstrated strong antimycobacterial activities with the N-(5-nitrofuroyl) derivatives (PH-145 and PH-189) being the most potent, with MIC value range of 0.3–0.6 μM against all strains tested. Compounds were not bactericidal, but showed intracellular (macrophage) antimycobacterial activity. A reliable validated analytical method was developed for a representative compound PH-189 using Waters Acquity ultra High-Performance Liquid Chromatography (UHPLC) system with quaternary Solvent Manager (H-Class). A simple extraction method indicated that PH-189 was stable in human plasma after 90 min at 37 °C with more than 90% successfully recovered. Moreover, stress stability studies were performed and degradants were identified by using UHPLC-ESI-QToF under acidic, basic, and oxidative simulated conditions
Remdesivir—Bringing Hope for COVID-19 Treatment
At the beginning of 2020, the world was swept with a wave of a new coronavirus disease, named COVID-19 by the World Health Organization (WHO 2). The causative agent of this infection is the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The data available on one of the promising therapeutic agents—nucleotide analog remdesivir (Gilead Sciences number GS-5734)—were evaluated. These data were concerned with remdesivir activation from the prodrug to the active molecule—triphosphate containing 1′-cyano group and modified nucleobase. This triphosphate competes with the natural substrate adenosine triphosphate. Additionally, its mechanisms of action based on RNA and proofreading exonuclease inhibition, leading to the delayed RNA chain termination of infected cells, and basic pharmacological data were assessed. Additionally, the analytical determination of remdesivir and its metabolites in cells and body liquids and also some data from remdesivir use in other RNA infections—such as Ebola, Nipah virus infection, and Middle East Respiratory Syndrome (MERS)—were summarized. More recent and more detailed data on the clinical use of remdesivir in COVID-19 were reported, showing the intensive efforts of clinicians and scientists to develop a cure for this new disease. Remdesivir as such represents one of the more promising alternatives for COVID-19 therapy, however the current understanding of this disease and the possible ways of dealing with it requires further investigation
Development of a Robust UPLC Method for Simultaneous Determination of a Novel Combination of Sofosbuvir and Daclatasvir in Human Plasma: Clinical Application to Therapeutic Drug Monitoring
A rapid and selective UPLC-DAD method was developed and validated for simultaneous analysis of the novel two-drug combination Darvoni® for the treatment of HCV: Sofosbuvir (SF)/Daclatasvir (DC) in human plasma using Ledipasvir as internal standard (IS) where the extraction process was conducted using automated SPE. Although the analysis of the combination after concomitant oral intake of two tablets of SF and DC individually was reported in literature, yet simultaneous analysis of this new combination in human plasma after a single oral dose was not previously reported. The adopted chromatographic separation was achieved on Waters® Acquity UPLC BEH C18 column (2.1 × 50 mm, 1.7 µm) as a stationary phase using isocratic elution using a mobile phase system of ammonium formate (pH 3.5; 5 mM) and acetonitrile (60:40 v/v) pumped at a flow rate of 0.2 mL.min−1. The UV detection was carried out at 261 nm for SF and 318 nm for DC and IS. SF was eluted at 1.123 min while DC was eluted at 3.179 min. The proposed chromatographic method was validated in accordance with guidelines of FDA for bioanalytical method validation. A linear range was achieved in the range of 25-6400 and 50-12800 ng.mL−1 for SF and DC, respectively. The proposed UPLC-DAD method was found to be accurate with % bias ranging between -10.0-7.2 for SF and -6.9-8.0 for DC. Also it was proved to be precise with % CV for intraday precision ranging between 3.8-9.6 for SF and 2.8-9.2 for DC whereas interday precision ranged between 5.1-9.3 for SF and 3.7-9.1 for DC. Moreover, % extraction recovery ranged between 90.0-107.2 for SF and 93.1-108.0 for DC using the suggested method. The adopted chromatographic method was successfully applied to the therapeutic drug monitoring of SF and DC in healthy volunteers after the oral intake of one Darvoni® tablet
Green Chemistry and its Implementation in Pharmaceutical Analysis : Green Pharmaceutical Analysis
The expanding progression of industrial development was a pioneer for world economic growth. Green chemistry has been defined as ‘the employment of techniques and methodologies that reduce or eliminate the use or production of feedstocks, products, by-products, solvents, and reagents that are harmful to human health or the environment’. The quality-by-design approach is well known in the pharmaceutical industry, and it has a great influence on analytical methods and procedures. In the green method of chemistry, the core consideration is directed towards the design of a material or the chemical procedure; four of twelve principles are associated with design, e.g., designing fewer hazardous chemical syntheses, designing harmless chemicals and products, designing for energy effectiveness, and designing for degradation. One of the most active fields of research and development in green chemistry is the establishment of analytical methodologies, leading to the beginning of so-called green analytical chemistry. The influences of green chemistry on pharmaceutical analysis, the environment, the population, the analyst, and companies are discussed in this review, and they are multidimensional. Every selection and analytical attitude have effects both in the end-product and everything that surrounds it