Phytoconstituents from the rhizomes of Curcuma aromatica Salisb.

Phytochemical investigation of the chloroform extract of the rhizomes of Curcuma aromatica Salisb. (Zingiberaceae) yielded three new phytoconstituents characterized as n-heneitriacontan-14-one; n-pentatriacontan-5-one; 11α-cyclopentyl-n-decan-1-ol (curcumapentadecanol) along with the known compounds stigmasterol and n-nonacosan-1-ol. The structures of these phytoconstituents have been elucidated on the basis of structural data analysis and chemical reactions.     

A green and regioselective acetylation of thioglycoside with ethyl acetate

Treatment of saccharidic polyols in ethyl acetate with catalytic sulfuric acid leads to the corresponding primary monoacetate derivatives in good yields. The transesterification was realized by simple stirring without rigorous exclusion of moisture or oxygen. Our protocol is applicable to the regioselective monoacetylation of amino sugars having different substituents at the 2-positions.     

Lipase-mediated selective acetylation of primary alcohols in ethyl acetate

An environmental friendly process to selectively acetylate primary alcohols was demonstrated. The esterification process consists of treatment of a primary alcohol in the presence of immobilized C. antarctica lipase (Novozyme-435) in ethyl acetate at room temperature. Primary alcohols were acetylated in the presence of secondary alcohols and phenols.     

Phytochemical investigation,physicochemical characterization,and antimicrobial activities of Ethiopian propolis

Propolis is a natural resin substance produced by honeybees by collecting from parts of plants, buds, and exudates that are used for several biological activities such as antimicrobial, and fungicide functions. This study aimed to analyze the phytochemical, physicochemical, and antimicrobial activity of propolis collected from Boji Dirmaji and Fincha’a districts of western Ethiopia. The physicochemical characteristics, phytochemical screening, and antimicrobial activity of Ethiopian propolis against Aspergillus niger, Escherichia coli, and Staphylococcus aureus were evaluated using the disk diffusion method from its essential oils and crude ethanol extract were evaluated based on standard procedures. The results indicated that propolis was rich in saponins, tannins, flavonoids, steroids, triterpenes, and glycosides. Physicochemically, n-hexane extractable substances ranged between 8.6 and 33.9%, resins soluble 14.8–16.8%, insoluble residues 70.8–85.5%, moisture 1.7–4.6%, and ash content 2.8–9.7%, and 4.8 pH. The antimicrobial activities of essential oils propolis were active against Escherichia coli with an average inhibition zone of 18.3 ± 0.52 mm and 18.9 ± 0.06 mm at concentrations of 10 and 20 μl in Dirmaji districts. Moreover, the crude ethanol extracted propolis had nearly the same effect of inhibition to Escherichia coli. However, both crude extract and its essential oils didn’t show any activity on Staphylococcus aureus and Aspergillus niger. The analyzed propolis is promising antimicrobial activity from Gram-negative which is very notorious for people of the world.     

Characteristics of thin cellulose ester films spin-coated from acetone and ethyl acetate solutions

Spin-coated films of cellulose acetate (CA), cellulose acetate propionate (CAP), cellulose acetate butyrate (CAB) and carboxymethylcellulose acetate butyrate (CMCAB) have been characterized by ellipsometry, atomic force microscopy (AFM) and contact angle measurements. The films were spin-coated onto silicon wafers, a polar surface. Mean thickness values were determined by means of ellipsometry and AFM as a function of polymer concentration in solutions prepared either in acetone or in ethyl acetate (EA), both are good solvents for the cellulose esters. The results were discussed in the light of solvent evaporation rate and interaction energy between substrate and solvent. The effects of annealing and type of cellulose ester on film thickness, film morphology, surface roughness and surface wettability were also investigated. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Correlation and prediction of partition coefficient between the gas phase and water, and the solvents dry methyl acetate, dry and wet ethyl acetate, and dry and wet butyl acetate

Experimental partition coefficient data have been compiled from the published literature for the water/methyl acetate, water/ethyl acetate and water/butyl acetate partition systems, log P data, and for the gas/methyl acetate, gas/ethyl acetate and gas/butyl acetate partition systems, log K data. Application of the Abraham solvation parameter model to the sets of partition coefficients leads to equations that correlate the log P data and log K data to 0.18 log units for the three dry alkyl acetate solvents. Slightly larger deviations were noted for solute partition into both wet ethyl acetate and wet butyl acetate. The derived correlations were validated using training set and test set analyses.     

Inhibitory effects of ethyl acetate and butanol fractions from Morinda lucida benth on benzene-induced leukemia in mice

IntroductionMorinda lucida Benth has been traditionally reported as a remedy for the treatment of cancer as well as Leukemia in Africa. Therefore, this study was aimed at screening fractions of M. lucida for potential anti-leukemia constituents and activities in mice.Methodsleukemia was induced with intra-peritoneal administration of benzene. Fractions of M. lucida were administered by oral gavaging in mice and screened for anti-leukemia and anti-clastogenic activities. The liver sections were assessed for hepatoprotective activity and possible anti-leukemia compounds in fractions were analysed using GC-MS. Docking analysis was done to understand the mechanism of anti-leukemic activity.ResultsSignificant (p < 0.05) anti-leukemic activity was observed in the ethyl acetate and n-butanol fractions while prevention of chromosomal and liver damage was exhibited by all the fractions. GC-MS analysis of the fractions revealed anti-leukemic constituents. The identified constituents showed promising pharmacokinetic properties and inhibitory potential against certain proteins involved in cancer development.ConclusionOverall, the anti-leukemic activity observed in this study might be attributed to the antioxidant, apoptotic induction, cell cycle control, and anti-inflammatory properties of M. lucida fractions.     

Aza-Morita-Baylis-Hillman reaction of ethyl (arylimino)acetate with methyl vinyl ketone and ethyl vinyl ketone

Aza-Morita-Baylis-Hillman (aza-MBH) reaction of ethyl (arylimino)acetate with methyl vinyl ketone and ethyl vinyl ketone has been investigated. We found that aza-MBH adducts 1 could be formed in the presence of DABCO (30 mol %) and the corresponding adducts 2 could be obtained in the presence of PPh₃ (30 mol %) in moderate to good yields in acetonitrile under mild conditions, respectively.     

Phytochemical investigation and antioxidant activities of methanol extract,methanol fractions and essential oil of Dillenia suffruticosa leaves

Oxidative stress has been known as a key factor of many disorders affecting human beings. Reactive oxygen species (ROS) attack vital biomolecules, weakening their functioning, thus exacerbating diseases. To attenuate oxidative stress-associated diseases a novel approaches of antioxidant therapies have been anticipated. Antioxidants have the potential to inhibit the propagation and formation of ROS. Dillenia suffruticosa is a medicinal plant, used by the local people for the treatment of various ailments. The study aimed to evaluate the phytochemical screening, antioxidative activity, total phenolic and flavonoid contents of methanol extract, fractions and essential oil of D. suffruticosa. Furthermore, the analysis of phytochemicals was done using gas chromatography and mass spectrometry (GCMS). The result showed the existence of alkaloids, anthraquinones, flavonoids, phytosterol, saponins, tannins, triterpenoids and steroids in the methanol extract and fractions of D. suffruticosa. The butanol fraction and methanol extract showed high phenolic (379.00 ± 9.25 and 277.00 ± 3.50 mg/g) and flavonoid values (74.44 ± 2.18 and 34.83 ± 0.71 mg/g) as compared to ethyl acetate, n-hexane and chloroform fractions. The scavenging capacity of butanol fraction and methanol extract was also higher than other fractions. GCMS analysis indicated the presences of various compounds in methanol extract, fractions and essential oil including methyl glycolate, lauryl acetate, phenol, 2,4-bis (1,1-dimethylethyl), 9,12-octadecadienoic acid, hexadecanoic acid, methyl ester, methyl stearate, phenol, benzyl alcohol, 3-hexen-1-ol, acetate and phytol. Thus, methanol extract, fractions and essential oil of D. suffruticosa leaves mainly contain vital phytochemical and shows good antioxidant activity.     

Catalytic combustion of ethyl acetate over ceria-promoted platinum supported on Al2O3 and ZrO2 catalysts

Platinum-supported catalysts prepared by impregnation of mixed CeO₂/Al₂O₃ and CeO₂/ZrO₂ oxides using the sol-gel method were characterized and used in the combustion of ethyl acetate. In each series, the effect of CeO₂ loading (3 and 5 wt%) was studied. Characterization data from the studied catalysts (specific area measurements, hydrogen chemisorption, programmed temperature reduction (TPR), X-ray diffraction (XRD), photoelectron spectra (XPS) and transmission electron microscopy (TEM)) revealed significant changes in porosity and metal dispersion in each series. The catalytic activity of the solids, evaluated in the total combustion of ethyl acetate, exhibited a positive effect with the addition of Ce in the zirconia series whereas no significant changes was observed in the alumina series.     

Spectrothermal investigation of the decomposition course of lanthanum acetate hydrate

Thermogravimetry, differential thermal, X-ray diffraction and infrared spectroscopy analyses showed La(CH₃COO)₃·1.5H₂O to decompose completely at 700°C yielding La₂O₃. The results revealed that the compound dehydrates in two steps at 130 and 180°C, and recrystallizes at 210°C. Water thus produced hydrolyzes surface acetates (at 310°C), releasing acetic acid into the gas phase. At 334°C, the anhydrous acetate releases gas phase CH₃COCH₃ to give La₂(CO₃)₃ residue, which decomposes to La₂O₂(CO₃) via the intermediate La₂O(CO₃)₂. On further heating up to 700°C, La₂O₃ is formed. IR spectroscopy of the gaseous products indicated a chemical reactivity at gas/solid interfaces formed throughout the decomposition course. As a result, CH₃COCH₃ was involved in a surface-mediated, bimolecular reaction, releasing CH₄ and C₄H₈ (isobutene) into the gas phase. Non-isothermal kinetic parameters, the rate constantk, frequency factorA, and activation energy ΔE, were calculated on the basis of temperature shifts experienced in the thermal processes encountered, at various heating rates (2–20 deg·min^?1).     

Determination of inorganic anions in ethyl acetate by in-line hollow fiber membrane extraction with ion chromatography

In this work,a novel hollow fiber membrane extractor was set up to extract inorganic anions from ethyl acetate using deionized water.Inorganic anions in slightly soluble organic solvents can be determined by the in-line hollow fiber membrane extractor coupled with ion chromatography at first time.Different aspects of the extraction procedure such as magnetic stirring speed, extraction flow rate and extraction time were optimized to achieve high extraction efficiency and good separation results. Satisfact...     

DABCO catalyzed facile synthesis of highly functionalized pyrazolines from Baylis-Hillman acetates and ethyl diazoacetate

A convenient synthesis of pyrazolines is reported via DABCO mediated reaction of ethyl diazoacetate (EDA) with Baylis-Hillman acetates. The products were obtained in good to excellent yields (70-95%).     

First isolation of a flavonoid from Juniperus procera using ethyl acetate extract

Phytochemical investigation of the ethyl acetate extract of the leaves of Juniperus procera growing in south Saudi Arabia Enemas region led to the isolation of a new flavonoid using different chromatographic methods (i.e. paper, thin layer and column chromatography). The isolated flavonoid was identified and established by m.p., ¹H-NMR, ¹³C-NMR, UV and MS spectral analysis. The isolated compound was identified as 3′,4′,3,7-tetrahydroxyflavone.     

Silphos [PCl3−n(SiO2)n]: a heterogeneous phosphine reagent for formylation and acetylation of alcohols and amines with ethyl formate and acetate

Alcohols and amines are formylated and acetylated in the presence of Silphos [PCl_3−n(SiO₂)_n] in ethyl formate and ethyl acetate in high to excellent yields. This procedure provides a method to separate the product by a simple filtration.     

Bisabocurcumin, a new skeleton curcuminoid from the rhizomes of Curcuma longa L.

A new skeleton bisabolane-type sesquiterpene curcuminoid,bisabocurcumin(1),along with 5 known compounds,curcumin(2), demethoxycurcumin(3),bidemethoxycurcumin(4),(1E,4E)-1,5-bis(4-hydroxy-3-methoxyphenyl)-penta-1,4-dien-3-one(5),and (1E,4E)-1-(4-hydroxy-3-methoxyphenyl)-5-(4-hydroxy phenyl-)-penta-1,4-dien-3-one(6)were isolated from the rhizomes of Curcuma longa L.Their structures were determined on the basis of spectroscopic analysis.Bisabocurcumin(1) is firstly obtained from nature with a new skeleton combined by a bisabolane-type sesquiterpene and a 1,7-diphenylheptanoid through a C-C bond.     

Phytochemical screening and metabolomic approach based on Fourier transform infrared (FTIR): Identification of α-amylase inhibitor metabolites in Vernonia amygdalina leaves

ContextVernonia amygdalina has been reported as a potential antidiabetic agent. One of the mechanisms in diabetes mellitus treatment is the inhibition of the α-amylase enzyme’s action.ObjectiveThis study is aimed to identify the presence of secondary metabolites in Vernonia amygdalina leaf extract, which has the potential as α-amylase inhibitors through phytochemical screening combined with metabolomic analysis.Materials and methodsMethanol extract from Vernonia amygdalina leaf was partitioned into n-hexane, dichloromethane (DCM), and ethyl acetate. From this process, methanol, hexane, DCM, and ethyl acetate extracts were obtained. These extracts were then being tested for phytochemical screening, α-amylase inhibition, and FTIR. Then FTIR data were used for metabolomic analysis (PCA and PLS).ResultsThe results of the α-amylase inhibition test showed that the ethyl acetate extract had the smallest IC50 average value, which was 3.00 μg/mL. Based on the phytochemical screening test results, the extract showed positive for the presence of compounds such as flavonoids, phenols, tannins, alkaloids, and saponins. From the PCA analysis (Bi-plot), the wavenumbers that were influential in the ethyl acetate extract were 1436 to 1681 and 3341 to 3348 cm^?1. In theory, functional groups such as CH, CC, CO, NH, and OH appeared on the absorption. From the PLS analysis, these wavenumbers affected the activity.ConclusionThe most potential extract as an α-amylase inhibitor was the ethyl acetate extract. Based on phytochemical screening tests and metabolomic analysis, it was proven that this extract contained compounds as hypoglycemic agents.     

Phytochemical study,an evaluation of the antioxidant potential and the antimicrobial activity of Inga semialata (Vell.) C. Mart. hydroalcohol extract

Abstract

Inga semialata (Vell.) C. Mart. belongs to the family Fabaceae. It is known for its therapeutic properties, highlighting its antimicrobial and antioxidant potential. The objective of the present work was to obtain crude extract leaves of Inga semialata, to identify and quantify active compounds, to evaluate the antioxidant potential of the crude extract in vitro, as well as to determine its antimicrobial activity. The crude extract was obtained by the maceration process. The identified and quantified of compounds present in the crude extract of Inga semialata was performed by high performance liquid chromatography. The evaluation of the antioxidant potential of the extract was realized by in vitro tests (DPPH, diacetate dichlorofluorescein test and nitric oxide test) and the evaluation of the antimicrobial activity was carried out using the minimum inhibitory concentration methodology.     

Density, dynamic viscosity, and derived properties of binary mixtures of methanol or ethanol with water, ethyl acetate, and methyl acetate at T = (293.15, 298.15, and 303.15) K

Densities and dynamic viscosities for methanol or ethanol with water, ethyl acetate, and methyl acetate at several temperatures T = (293.15, 298.15, and 303.15) K have been measured over the whole composition range and 0.1 MPa, along with the properties of the pure components. Excess molar volumes, viscosity deviations, and excess free energy of activation for the binary systems at the above-mentioned temperatures, were calculated and fitted to the Redlich-Kister equation to determine the fitting parameters and the root-mean-square deviations. UNIQUAC equation was used to correlate the experimental viscosity data. The UNIFAC-VISCO method and ASOG-VISCO method, based on contribution groups, were used to predict the dynamic viscosities of the binary mixtures.     

Complexation-mediated crystallization. Crystallization of sodium acetate trihydrate needles from cyclohexane solution

The phenomenon of complexation-mediated crystallization is introduced and proposed as a new means for the preparation of novel forms of materials. Attempted crystallization of complexes of salts with crown ethers often results in the precipitation of the uncomplexed salt rather than the complex. In this study, a solution of the 15-crown-5 complex of sodium acetate in cyclohexane precipitated uncomplexed sodium acetate trihydrate as single crystals. The crystal morphology (long needles) of this crystalline sodium acetate stands in sharp contrast to the hexagonal plates known to form from aqueous solution. X-ray diffraction analysis revealed that sodium acetate as crystallized from cyclohexane solution adopted a crystal lattice identical to that in sodium acetate crystallized from aqueous solution. Possible origins of the change in crystal morphology are discussed.