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Molecules ◽  
2022 ◽  
Vol 27 (2) ◽  
pp. 399
Author(s):  
Carla Monteiro Leal ◽  
Suzana Guimarães Leitão ◽  
Leonardo Luiz Oliveira de Mello ◽  
Isabel de Castro Rangel ◽  
Carlos Vinicius Azevedo da Silva ◽  
...  

Siparuna glycycarpa occurs in the Amazon region, and some species of this genus are used in Brazilian folk medicine. A recent study showed the inhibitory effect of this species against influenza A(H1N1)pdm09 virus, and in order to acquire active fractions, a polar solvent system n-butanol-methanol-water (9:1:10, v/v) was selected and used for bioassay-guided fractionation of n-butanol extract by centrifugal partition chromatography (CPC). The upper phase was used as stationary phase and the lower phase as mobile (descending mode). Among the collected fractions, the ones coded SGA, SGC, SGD, and SGO showed the highest antiviral inhibition levels (above 74%) at 100 µg·mL−1 after 24 h of infection. The bioactive fractions chemical profiles were investigated by LC-HRMS/MS data in positive and negative ionization modes exploring the Global Natural Products Social Molecular Networking (GNPS) platform to build a molecular network. Benzylisoquinoline alkaloids were annotated in the fractions coded SGA, SGC, and SGD collected during elution step. Aporphine alkaloids, O-glycosylated flavonoids, and dihydrochalcones in SGO were acquired with the change of mobile phase from lower aqueous to upper organic. Benzylisoquinolinic and aporphine alkaloids as well as glycosylated flavonoids were annotated in the most bioactive fractions suggesting this group of compounds as responsible for antiviral activity.


Author(s):  
Sebnem Duzyer Gebizli ◽  
Saban Cunayev ◽  
Serpil Koral Koc ◽  
Serkan Tezel ◽  
Ahmet Peksoz

Metabolomics ◽  
2022 ◽  
Vol 18 (1) ◽  
Author(s):  
Julia M. Malinowska ◽  
Taina Palosaari ◽  
Jukka Sund ◽  
Donatella Carpi ◽  
Mounir Bouhifd ◽  
...  

Abstract Introduction High-throughput screening (HTS) is emerging as an approach to support decision-making in chemical safety assessments. In parallel, in vitro metabolomics is a promising approach that can help accelerate the transition from animal models to high-throughput cell-based models in toxicity testing. Objective In this study we establish and evaluate a high-throughput metabolomics workflow that is compatible with a 96-well HTS platform employing 50,000 hepatocytes of HepaRG per well. Methods Low biomass cell samples were extracted for metabolomics analyses using a newly established semi-automated protocol, and the intracellular metabolites were analysed using a high-resolution spectral-stitching nanoelectrospray direct infusion mass spectrometry (nESI-DIMS) method that was modified for low sample biomass. Results The method was assessed with respect to sensitivity and repeatability of the entire workflow from cell culturing and sampling to measurement of the metabolic phenotype, demonstrating sufficient sensitivity (> 3000 features in hepatocyte extracts) and intra- and inter-plate repeatability for polar nESI-DIMS assays (median relative standard deviation < 30%). The assays were employed for a proof-of-principle toxicological study with a model toxicant, cadmium chloride, revealing changes in the metabolome across five sampling times in the 48-h exposure period. To allow the option for lipidomics analyses, the solvent system was extended by establishing separate extraction methods for polar metabolites and lipids. Conclusions Experimental, analytical and informatics workflows reported here met pre-defined criteria in terms of sensitivity, repeatability and ability to detect metabolome changes induced by a toxicant and are ready for application in metabolomics-driven toxicity testing to complement HTS assays.


2022 ◽  
Vol 9 (1) ◽  
Author(s):  
Dileep Kumar ◽  
K. M. Sachin ◽  
Naveen Kumari ◽  
Ajaya Bhattarai

In this study, kaempferol (0.2 m/mmol kg −1 ) dispersed cationic surfactant micelles were prepared as a function of alkyltrimethylammonium bromide (C n TAB) hydrophobicity (C = 12 to C = 16). The dispersion study of kaempferol in different C n TAB, i.e. dodecyltrimethylammonium bromide (C = 12), tetradecyltrimethylammonium bromide (C = 14) and hexadecyltrimethylammonium bromide (C = 16), was conducted with the physico-chemical properties of density, sound velocity, viscosity, surface tension, isentropic compressibility, acoustic impedance, surface excess concentration and area occupied per molecule and thermodynamic parameters Gibbs free energy, enthalpy and activation energy measured at 298.15 K. These properties were measured with varying concentration of C n TAB from 0.0260 to 0.0305 mol kg −1 in a 10% (w/w) aqueous dimethyl sulfoxide solvent system. The variations in these measured properties have been used to infer the kaempferol dispersion stability via hydrophobic–hydrophilic, hydrophilic–hydrophilic, van der Waals, hydrogen bonding and other non-covalent interactions.


2021 ◽  
Vol 14 (4) ◽  
pp. 2165-2172
Author(s):  
Deepshi Arora ◽  
Manish Kumar ◽  
Shailendra Bhatt ◽  
Yugam Taneja ◽  
Abhishek Tiwari ◽  
...  

Background: Rivastigmine Tartrate belongs to the class of cholinesterase inhibitors in Anti-alzheimer’s disease with optimum therapeutic efficacy. Till now no validated method of its quantification has been reported in simulated nasal fluid. Objective: The current research investigation aims to develop a rapid, simple, and reliable UV spectrophotometric method for the quantitative determination of the pure form of Rivastigmine Tartrate in SNF. Method: A suitable method was developed by using double beam UV spectrophotometer and selection of a suitable solvent system for estimation of Rivastigmine Tartrate at absorbance maxima 263nm in SNF. The method was validated for various parameters like including accuracy, linearity and precision as per the International Conference on Harmonization guidelines. Results: The method developed by selecting simulated nasal fluid as the solvent system satisfied the optimum condition of the good quality peak at the selected wavelength. The results proposed the developed method for Rivastigmine Tartrate quantification in the simulated nasal fluid to be linear in the working concentration range of 5-60 µg/ml with a co-relation coefficient of 0.998. The % accuracy was found to be 99.8 -100.57. The % RSD values were < 2 while LOD & LOQ values were detected to be 0.316 and 1.053 respectively. Conclusion: The stated method was analyzed to be rapid, accurate, reliable, and precise. Further, it can be used in checking the quality control parameters of the Rivastigmine Tartrate in routine analysis.


2021 ◽  
Vol 13 (2) ◽  
pp. 29-35
Author(s):  
N. D. Nnamani ◽  
I. S. Okafor ◽  
O.N. Ume

Spherical crystallization and crystal agglomeration have been used to optimize compact crystals and functional properties of powders. The aim of this work is to evaluate the effect of spherical crystallization of acetylsalicylic acid crystals and crystal agglomeration of Manihotesculenta starch on direct compression tablet. Typical spherical crystallization using three solvent system of water–ethanol-carbon tetrachloride was used to produce spherical acetylsalicylic acid. Salting-out agglomeration of gelling in water and salting in ethanol was used to produce starch-xerogel from Manihotesculenta starch. The modified products were qualified using FT-IR analysis. The analysis results showed that modification did not alter chemical nature of the products. Acetylsalicylic acid tablets were formulated using spherical-crystallizedacetylsalicylic acid with 5 and 10% w/w starch-xerogel respectively, and using acetylsalicylic acid with 5 and 10% w/w of starch, and microcrystalline cellulose respectively. The physicochemical properties of the tablets were evaluated. Astatistical 23 factorial design of the tablet properties at 5% level of significance showed that the effects of the variables are different. Theacetylsalicylic acid tablets formulated from direct compression of spherical-crystallizedacetylsalicylic acid with 5 % w/w starch-xerogel produced quality tablets comparable to standard tablets from direct compression of acetylsalicylic acid with10 % w/w microcrystalline cellulose. Spherical crystallization and crystal agglomeration optimized the compact crystals of starch and acetylsalicylic acid, and improved direct compression properties of the crystals, and drug release from tablet.


2021 ◽  
pp. 118946
Author(s):  
Junchai Zhao ◽  
Mengwei Deng ◽  
Shuaiyao Li ◽  
Zheng Guan ◽  
Yixuan Xia ◽  
...  

Author(s):  
Rakam Gopi Krishna ◽  
M. Srinivasa Murthy ◽  
V. Kavya

The objective of the study was to develop RP-HPLC method for the determination of purity of sumatriptan in bulk and pharmaceutical dosage form. The development of an analytical method for the determination of drugs by HPLC has received considerable attention in recent years because of their importance in quality control of drugs and drug products. The aim of this current study was to develop a simple, rapid, precise, accurate and sensitive HPLC method for the analysis of sumatriptan in bulk and its pharmaceutical dosage form by using solvent system of TEA : ACN : methanol in the ratio 80:10:10 and C8 ODS Inertsil (250*4.6mm, 5i.d) stationary phase. The chromatographic condition is set at flow rate of 1ml/min with PDA detector at 221 nm. As per ICH requirements validation studies are carried out by using freshly prepared solutions. The linearity was demonstrated over the concentration range of 5-150 µg / ml and value was found to be as 0.99998. The %RSD of precision was found to be 0.260. The LOD and LOQ were found to be 1.967μg/ml and 5.961μg/ml respectively. Forced degradation studies were carried out under various stress conditions to demonstrate the stability-indicating capability of the developed RP-HPLC method. The proposed method was found to be simple, precise, accurate and validated according to the International Council for Harmonisation guidelines.


2021 ◽  
Author(s):  
Thenuka M. Ariyaratna ◽  
Nihal U. Obeyesekere ◽  
Tharindu S. Jayaneththi ◽  
Jonathan J. Wylde

Abstract A need for more economic drilling fluids has been addressed by repurposing heavy brines typically used as completion fluids. Heavy brine corrosion inhibitors have been designed for stagnant systems. Drilling fluids are subjected to both heavy agitation and aeration through recirculation systems and atmospheric exposure during the various stages of the drilling process. This paper documents the development of heavy brine corrosion inhibitors to meet these additional drilling fluid requirements. Multiple system scenarios were presented requiring a methodical evaluation of corrosion inhibitor specifications while still maintaining performance. Due to the high density of heavy brine, traditional methods of controlling foaming were not feasible or effective. Additional product characteristics had to be modified to allow for the open mud pits where employees would be working, higher temperatures, contamination from drill cuttings, and product efficacy reduction due to absorption from solids. The product should not have any odor, should have a high flash point, and mitigate corrosion in the presence of drill cuttings, oxygen, and sour gases. Significant laboratory development and testing were done in order to develop corrosion inhibitors for use in heavy brines based on system conditions associated with completion fluids. The application of heavy brine as a drilling fluid posed new challenges involving foam control, solubility, product stability, odor control, and efficacy when mixed with drill cuttings. The key to heavy brine corrosion inhibitor efficacy is solubility in a supersaturated system. The solvent packages developed to be utilized in such environments were highly sensitive and optimized for stagnant and sealed systems. Laboratory testing was conducted utilizing rotating cylinder electrode tests with drill cuttings added to the test fluid. Product components that were found to have strong odors or low flash points were removed or replaced. Extensive foaming evaluations of multiple components helped identify problematic chemistries. Standard defoamers failed to control foaming but the combination of a unique solvent system helped to minimize foaming. The evaluations were able to minimize foaming and yield a low odor product that was suitable for open mud pits and high temperatures without compromising product efficacy. The methodology developed to transition heavy brine corrosion inhibitors from well completion applications to drilling fluid applications proved to be more complex than initially considered. This paper documents the philosophy of this transitioning and the hurdles that were overcome to ensure the final product met the unique system guidelines. The novel use of heavy brines as drilling fluids has created a need for novel chemistries to inhibit corrosion in a new application.


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