scholarly journals Is it possible to substitute hexane with green solvents for extraction of carotenoids? A theoretical versus experimental solubility study

RSC Advances ◽  
2016 ◽  
Vol 6 (33) ◽  
pp. 27750-27759 ◽  
Author(s):  
E. Yara-Varón ◽  
A. S. Fabiano-Tixier ◽  
M. Balcells ◽  
R. Canela-Garayoa ◽  
Antoine Bily ◽  
...  
Keyword(s):  
Ethyl Acetate ◽  
Methyl Ether ◽  
Isopropyl Alcohol ◽  
Dimethyl Carbonate ◽  
Green Solvents ◽  
Solubility Study ◽  
Experimental Solubility

Evaluation of five green solventsi.e.2-methyltetrahydrofuran (2-MeTHF), dimethyl carbonate (DMC), cyclopentyl methyl ether (CPME), isopropyl alcohol (IPA) and ethyl acetate, for replacing of hexane in extraction of carotenoids from carrots.

IN VITRO AND IN SILICO ALPHA-AMYLASE INHIBITION POTENTIAL (ANTI-DIABETIC ACTIVITY) OF PSEUDERANTHEMUM BICOLOR (SIMS) RADIK

2020 ◽  
pp. 157-161
Author(s):  
RAMESH BS ◽  
LOKESH RAVI
Keyword(s):  
Binding Energy ◽  
Hydrogen Bonds ◽  
Ethyl Acetate ◽  
Bioactive Compounds ◽  
Methyl Ether ◽  
Docking Study ◽  
Alpha Amylase ◽  
Ligand Docking ◽  
Standard Drug ◽  
Reference Drug

Objective: Aim of this study is to evaluate theanti-diabetic activity of Pseuderanthemum bicolor commonly called limang-sugat by inhibiting alpha-amylase protein. Methods: Leaves of P. bicolor were extracted with methanol, chloroform, and ethyl acetate. The extracts were subjected for alpha-amylase inhibition assay and gas chromatography–mass spectrometry (GC–MS) analysis. Phytochemical compounds identified by GC-MS were subjected for protein-ligand docking study against alpha-amylase protein. Acarbose was used as a positive standard drug. Results: The major bioactive compounds obtained from methanol, chloroform, and ethyl acetate extracts were 1,6;2,3-Dianhydro-4-Deoxy-Beta-D-Ribo-Hexopyranose, Pseduosarsasapogenin-5,20-Dien, methyl ether/Hexatriacontane, Di-N-decylsulfone/Octadecanal, and squalene, respectively. A total of 19 secondary metabolites were subjected for protein–ligand docking study against the alpha-amylase protein. The reference drug acarbose demonstrated binding energy of −7.8 Kcal/mol and formed 20 hydrogen bonds with the enzyme. Acarbose signified high polar interaction with the amylase enzyme. Among the 19 test ligands, “2,2-Dibromocholestanone” from ethyl acetate extract exemplified the highest binding energy of −9.3 Kcal/mol. The next highest remarkable inhibition was showed by “Pseduosarsasapogenin-5,20-Dien Methyl Ether” present in the methanol extract, with a binding energy of -9.3 Kcal/mol with the formation of 2 hydrogen bonds. Conclusion: From the result, it could be concluded that the P. bicolor leaves contain various bioactive compounds which are considered as a good anti-diabetic drug.

scholarly journals Liquid-Phase Exfoliation of Biochars in Green Solvents and Correlation with Solvent Parameters

2021 ◽  
Author(s):  
Juliana Vidal ◽  
Stephanie Gallant ◽  
Evan Connors ◽  
Douglas Richards ◽  
Stephanie MacQuarrie ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Dimethyl Carbonate ◽  
Layered Materials ◽  
Polyethylene Glycols ◽  
Green Solvents ◽  
Biomass Waste ◽  
Solvent Parameters ◽  
Benign Solvents ◽  
Liquid Phase Exfoliation ◽  
Concentrated Dispersions

<div> <div> <div> <div> <p>Liquid-phase exfoliation (LPE) is a process frequently used to overcome the interactions between layers in layered materials to produce small sheets of material, with remarkable properties and high value applications. Materials are prepared via direct or indirect sonication in a solvent that must be able to effectively disperse and stabilize the sheets produced. Unfortunately, the preferred solvents for exfoliation processes are often toxic and possess several health risks. In this work, we show that LPE in greener solvents can be used to access nanostructures of biochar and further improve the applications of this renewable and bio-based material. Herein, pristine and oxidized biochars prepared from hardwood and softwood biomass waste (e.g. sludge, bark, and sawdust) are exfoliated in a range of solvents to allow the identification of benign alternatives that could afford highly concentrated dispersions. The majority of biochar nanostructures produced after exfoliation are stacked nanosheets containing between 2-8 layers (average 15 nm thickness). Correlations between effective LPE of biochar in solvents and different solvent parameters, including Kamlet-Taft, were established and allowed greener solvents to be used. Surface modification of biochars (e.g. via oxidation) has potential to increase their dispersibility in more benign solvents. LPE of oxidized biochars is more efficient in hydrogen-bond accepting solvents due to the increased concentration of carboxylic acid and alcohol functional groups on the surface of particles, when compared to non- functionalized biochars. Dispersions containing 0.20-0.75 mg/mL exfoliated oxidized biochar were obtained in solvents such as polyethylene glycols, glycerol formal and e-caprolactone. Moreover, LPE of pristine biochars in dimethyl carbonate, ethyl acetate, and solketal gave similar yields to more commonly used solvent for this process, N-methyl-2-pyrrolidone (NMP) a known reprotoxic molecule. </p> </div> </div> </div><br></div>

scholarly journals Orthoamide und Iminiumsalze, LXXVI [1]. Ein weiterer Beitrag zur Chemie der Trialkoxyacetonitrile/ Orthoamides and Iminium Salts LXXVI [1]. A Further Contribution to the Chemistry of Trialkoxyacetonitriles

2012 ◽  
Vol 67 (4) ◽  
pp. 373-388
Author(s):  
Willi Kantlehner ◽  
Markus Vettel ◽  
Bernhard Eppinger
Keyword(s):  
Ethyl Acetate ◽  
Acetyl Chloride ◽  
Dimethyl Carbonate ◽  
Dimethyl Sulfate ◽  
Benzyl Bromide ◽  
Sodium Hydride ◽  
Pyridinium Salts ◽  
Dimethylformamide Dimethylacetal ◽  
Butyl Lithium ◽  
Iminium Salts

An improved procedure for the preparation of trimethoxyacetonitrile (3a) starting from trichloroacetonitrile and sodium methanolate is described. Carbanions, obtained by the action of sodium hydride on nitriles, ethyl acetate and methylketones, react with trialkoxyacetonitriles 3 to give α- imino-orthocarboxylic acid trialkylesters 12, 14 and 20, which form an equilibrium with the tautomeric enamines 13, 15 and 21. The enamines 21 react with N,N-dimethylformamide dimethylacetal (24) to give amidines 25 which are cyclized to pyridinium salts 28 and 29 on treatment with benzyl bromide and acetyl chloride, respectively. The reaction of the enaminonitrile 13a with the orthoamide derivative of phenylpropiolic acid 30 affords the pyridine-2-orthocarboxylic acid trimethylester 31. The N,O-protected 4-hydroxy-piperidine 35 can be deprotonated by means of sec-butyl lithium. The carbanions thus formed are trapped with D2O, dimethyl sulfate, phenylisocyanate, CO2, and dimethyl carbonate delivering the piperidine derivatives 37 - 41. The heterocyclic orthoester 43 can be prepared analogously from 35 and 3a. The piperidine derivatives 44, 46 and 47 are prepared from the N,O-protected piperidines 39 and 41.

scholarly journals Determination of residual solvents in paclitaxel by headspace gas chromatography

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Khaleel Noorbasha ◽  
Abdul Rahaman Shaik
Keyword(s):  
Ethyl Acetate ◽  
Chromatographic Method ◽  
Isopropyl Alcohol ◽  
Limit Of Detection ◽  
Good Resolution ◽  
Relative Standard ◽  
Limit Of Quantitation ◽  
Gas Chromatographic Method ◽  
Ethyl Amine

Abstract Background A simple and sensitive gas chromatographic method was developed and validated for the simultaneous determination of methanol, ethanol, acetone, isopropyl alcohol, dichloromethane, N-hexane, ethyl acetate, tetrahydrofuran, and N,N-diisopropyl ethyl amine in Paclitaxel. A chromatographic separation was done on DB-624 column, 30 m length × 0.53 mm ID, and film thickness 3 μm, using a flame ionization detector (FID) with gradient column oven temperature program. The injection was carried out in split mode, with a split ratio of 5:1. A mixture of N-methyl-2-pyrrolidinone (contains 1% piperazine) and water in the ratio of 80:20 (v/v) was selected as a diluent to obtain good sensitivity along with the recovery. Results The developed gas chromatographic method offers symmetric peak shape, good resolution of more than 2.0 between the solvent peaks, and the relative standard deviation for replicate injections of all the solvents were found to be not more than 15.0% with reasonable retention time for all the solvents. The limit of detection for methanol, ethanol, acetone, isopropyl alcohol, dichloromethane, N-hexane, ethyl acetate, tetrahydrofuran, and N,N-diisopropyl ethyl amine was found to be 304.69 ppm, 497.98 ppm, 498.99 ppm, 504.49 ppm, 61.81 ppm, 30.07 ppm, 505 ppm, 73.05 ppm, and 2.09 ppm, respectively. Limit of quantitation of methanol, ethanol, acetone, isopropyl alcohol, dichloromethane, N-hexane, ethyl acetate, tetrahydrofuran, and N,N-diisopropyl ethyl amine was found to be 89.62 ppm, 146.47 ppm, 146.76 ppm, 148.38 ppm, 18.18 ppm, 8.84 ppm, 148.53 ppm, 21.49 ppm, and 0.62 ppm, respectively. Precision was found to be satisfactory. Linear in the range of LOQ to 150% level for all the solvents, and accuracy along with robustness, is performed, and acceptable results were obtained. Conclusion The proposed method was demonstrated to be simple, sensitive, specific, linear, precise, accurate, and robust, hence can be used to determine the residual organic solvents in Paclitaxel drug substance and drug product.

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