Reflux In Ethanol Research Articles

Extraction, Partial Identification and Bioactivities of Total Flavonoids from Carex meyeriana Kunth

To date, knowledge associated with extraction, chemical constituents and bioactivities of Total Flavonoids from Carex meyeriana Kunth (TFCMK) that remains unclear. Therefore, this paper was designed to optimize the ethanol reflux extraction method by response surface methodology and determine the chemical constituents by Liquid Phase-Mass Spectrometry (HPLC-MS); additionally, the bioactivities including antioxidant, antibacterial and hemolysis test were also explored. The maximum TFCMK extraction yield of 6.248%±0.016% was obtained under the optimal conditions as follows: Ethanol concentration 50%, ratio of liquid-to-solid 31 mL/g, extraction time 91 min and extraction temperature 71°C. Meanwhile, 9 compounds of TFCMK were identified by using LP-MS for the first time. In addition, TFCMK showed higher antioxidant activity compared with vitamin C, as evidenced by the lower EC50 or IC50 of TFCMK (reducing power assay: 0.125±0.025 mg/mL, DPPH radicals: 0.28±0.031, ABTS+ radicals:0.012±0.005, hydroxyl radicals: 0.028±0.008 mg/mL; The EC50 or IC50 of VC 0.156±0.012, 0.059±0.019, 0.068±0.024 and 0.032±0.007 mg/mL, respectively.). Broth microdilution assays had demonstrated that the minimal inhibitory concentrations (MICs) of TFCMK on Bacillus pumilus, Bacillus subtilis and Escherichia coli were 0.625±0.0032, 1.250±0.0216 and 5.000±0.0205 mg/mL, respectively. Besides, the hemolysis rate (less than 5%) in vitro implied that TFCMK possessed a good blood compatibility. In summary, this paper provides evidences that TFCMK might be applied as an antioxidant and antibacterial agent in the pharmaceutical and chemical industries.

Enhancement of gaharu oleoresin quality by process optimization using response surface methodology

Abstract Gaharu is the most expensive resinous wood fragrance making it a very highly valuable product. Its oleoresin was produced using ethanol reflux extraction method. In optimization study, the influence of process parameters on the extraction of oleoresin from dried gaharu particles was investigated. The parameters include particle sizes, raw material to solvent ratio and extraction duration. With the aid of regression analysis using response surface methodology (RSM), the results suggested that the optimal set of extraction condition to be consists of particle size of 0.5–1.0 mm (S3), raw material to ethanol ratio of 1:29.9 g/ml and extraction time of 4.97 h. Under this condition, the highest gaharu oleoresin yield was obtained, i.e. 7.63% (w/w) with total resin content of 6.90% (w/w). In brief, higher yield of oleoresin can be extracted from smaller particle size of dried gaharu in shorter extraction time and lower raw material to solvent ratio. In the comparison study, the optimized reflux extraction produced higher quality of gaharu oleoresin compared to reflux using WHO protocol, nevertherless just as comparable to the conventional Soxhlet extraction. Further investigation on the quality of extracts resulted to six chemical compounds determined in gaharu oleoresin using GC-MS. The outcomes of this study indicated an improvement of 62.97% of overall chemical compositions in gaharu oleoresin extract which includes 4-phenyl-2-butanone, β-guaiene, agarospirol, α-bisabolene epoxide, alloaromadendrene oxide and aromadenderence oxide compared to the conventional Soxhlet method.

Subcritical water extraction of bioactive compounds from Radix Puerariae and optimization study using response surface methodology

Subcritical water extraction (SWE) of bioactive extracts from Radix Puerariae (RP) was firstly optimized by response surface methodology (RSM) and its extraction efficiency was compared with two traditional volatile isolation methods including hot water extraction (HWE) and ethanol reflux extraction (ERE). The optimal SWE parameters were as follows: extraction temperature of 141 °C, extraction time of 58 min, and liquid-solid ratio l of 23:1 mL/g. Under these conditions, yield of bioactive extracts was 28.9 ± 0.2%, which was slightly higher than that obtained by ERE, and more than two-fold the value obtained by HWE respectively. Isoflavones and polysaccharide content in SWE was significantly higher than that of HWE and slight lower than that of ERE. The results indicated that SWE could be a productive and environmental friendly technique for extracting bioactive extracts from RP.

Facile Catalyst-Free Synthesis of New Functionalized 1H-Pyrazolo[1,2-b]phthalazines

Some new derivatives of 3-amino-1-aryl-N-butyl-5,10-dioxo-5,10-dihydro-1H-pyrazolo[1,2-b]- phthalazine-2-carboxamide are synthesized via in situ Knoevenagel condensation of aromatic aldehydes with N-butyl-2-cyanoacetamide, which leads to 3-aryl-N-butyl-2-cyanoacrylamides. This is followed by the reaction with phthalhydrazide upon refluxing in ethanol under catalyst-free conditions. The products are characterized on the basis of IR, 1H and 13C NMR spectral data.

Comparison of Index Compounds Content and Antioxidative Activity of Wild Ginseng Pharmacopuncture by Extraction Methods

Objectives Wild ginseng pharmacopuncture is widely used in oriental medicine. However, there is no standard method for efficiently extracting the active ingredient. In this study, in order to determine an efficient extraction method, wild ginseng was extracted by the distillation and 70% ethanol reflux methods, respectively. In comparing each extract, the index compounds were analyzed, and antioxidant activity was measured. Methods The index compounds, ginsenoside Rg1 and ginsenoside Rb1, were detected using high performance liquid chromatography (HPLC). Antioxidative activities of total phenolic compounds, DPPH (α, α-diphenyl-β-picrylhydrazyl), ABTS (2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)) and FRAP (ferric reducing antioxidant power) were measured to compare their bioactivities. Since saponin is known to be hemolytic, the hemolytic activity of each extract was compared. Results The index compounds were analyzed. Nothing was detected in the wild ginseng distilled extracts (WGDE). In the wild ginseng 70% ethanol reflux extracts (WGEE), ginsenoside Rg1 was 3.66 mg/g, and ginsenoside Rb1 was 16.70 mg/g. WGEE showed higher levels than WGDE in all antioxidative activities. In the hemolytic test, the extracts showed almost no toxicity, but WGEE showed lower toxicity than WGDE. Conclusions In this study, it was concluded that WGEE is more advantageous than WGDE in the detection of index compounds and bioactivity. However, additional studies of additional extraction methods and other bioactivity tests are needed. Keywords: wild ginseng pharmacopuncture, distilled extraction, reflux extraction, ginsenoside, antioxidative activity

Porous MnO as efficient catalyst towards the decomposition of Li2CO3 in ambient Li-air batteries

The undesirable formation and low-efficient decomposition of Li2CO3 on cathode of Li-air battery, is an insurmountable obstacle for its practical applications. High efficient cathode catalysts toward Li2CO3 decomposition still have not been thoroughly studied. Here, we report a porous MnO prepared by heating precursor using a facile ethanol refluxing method and employed as high efficient cathode catalyst in ambient Li-air battery for Li2CO3 decomposition. Compared with the pure carbon electrode, it demonstrated an improved electrochemical performance of more than 100 cycles in ambient air and low charging overpotential. At the 100th cycle, the discharge/charge terminal voltage of MnO cathode remains 2.65/4.00 V, which is much higher/lower than that of pure carbon electrode (2.36/4.44 V). These results reveal that the superior catalytic performance of MnO towards the Li2CO3 decomposition during charging. Additionally, we carefully examined the time- and depth-dependent discharge products distributions in the carbon-containing cathode, especially for the formation of Li2CO3, by X-ray photoelectron spectroscopy. The Li2CO3 was initially formed on the surface of Li2O2, and then gradually into the inner part of the Li2O2, which reveals that the Li2O2 is inclined to react with CO2 rather than the carbon based electrode materials. These results present essential information for the development of high efficient cathode catalysts toward the high-efficient decomposition of Li2CO3 for practical Li-air batteries in ambient air.

One Pot Synthesis of Novel Substituted 2',4'-Dihydrospiro[chroman-2,3'-pyrazol]-4- one Derivatives

Aim and Objective: In the work, we have successfully presented a synthetic route for the synthesis of novel 2',4'-dihydrospiro[chroman-2,3'-pyrazol]-4-one derivatives via one pot multicomponent approach. Materials and Method: Substituted 2',4'-dihydrospiro[chroman-2,3'-pyrazol]-4-one were prepared through cascade three-component condensation of ortho-hydroxyacetophenone, β-ketoester, hydrazine in the presence of pyrrolidine as a catalyst under ethanol reflux conditions. Results: A series of novel 2',4'-dihydrospiro[chroman-2,3'-pyrazol]-4-one have been synthesized through a facile strategy. These structures of newly synthesized derivatives were determined by 1H, 13C NMR, HRMS and CHNS analysis. Conclusion: We have achieved the one-pot, three-component synthesis of highly substituted pyrazole spirochromanones in presence of pyrrolidine as a catalyst under ethanol reflux conditions. Using different types of aliphatic and aromatic β-ketoesters, o-hydroxyacetophenone derivatives and different kinds of hydrazine derivatives as building blocks, we could construct novel libraries of substituted pyrazole spirochromanones that make this method suitable for combinatorial and parallel synthesis in drug discovery.

Synthesis, structural analysis, and absorption properties of disperse benzothiazol-derivative mono-azo dyes

A series of carbocyclic amines was reacted with 3-aminocrotonitrile to give the 2-arylhydrazone-3-ketiminobutyronitriles 1(a–m). Separately, 2-aminobenzothiazole was treated with hydrazine monohydrate to afford 2-hydrazinobenzothiazole. Then, compounds 1(a–m) were reacted with 2-hydrazinobenzimidazole under reflux in ethanol to give the 1-(1,3-benzothiazol-2-yl)-3-methyl-4-arylazo-5-aminopyrazole compounds 2(a–m). The structures of the synthesized compounds were investigated using FT-IR and 1H NMR spectroscopic methods and elemental analysis. Furthermore, the absorption profiles of the dyes in different solvents and in acidic and basic media were investigated.

Solvent extraction of caffeoylquinic acids from Artemisia selengensis Turcz leaves and their in vitro inhibitory activities on xanthine oxidase

In this study, the caffeoylquinic acid (CQA) extract solution of the Artemisia selengensis Turcz (AST) leaves prepared by 70% ethanol reflux method was separated with petroleum ether, ethyl acetate, and water-saturated n-butanol to obtain the proper solvent to purify CQAs. Results showed that the ethyl acetate fraction (EAF) exhibited the highest total chlorogenic acid content (TCC) (241.46 ± 0.00 mg/g dry fraction), followed by the water-saturated n-butanol fraction (nBuF) (TCC = 62.30 ± 0.82 mg/g dry fraction). Ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry and high-performance liquid chromatography photodiode array were used to qualitatively and quantitatively determine the CQAs in these two fractions. In EAF, four CQAs, namely, 3-CQA, 3,5-diCQA, 3,4-diCQA, and 4,5-diCQA, were identified with the contents of 5.69 ± 0.03, 106.65 ± 0.83, 15.65 ± 0.24, and 28.08 ± 0.82 mg/g, respectively. Six CQAs, namely, 3-CQA, 4-CQA, 1,3-diCQA, 3,5-diCQA, 3,4-diCQA, and 4,5-diCQA, with contents of 16.57 ± 0.23, 3.22 ± 0.55, 4.49 ± 0.01, 16.86 ± 0.24, 7.35 ± 0.11, and 6.41 ± 0.13 mg/g, respectively, were identified in nBuF. Quantitative analysis of the six CQAs in AST leaves have not been reported, and 1,3-diCQA has been found in AST leaves for the first time. Moreover, either EAF or nBuF and the six CQA reference compounds showed certain inhibitory activity on xanthine oxidase (XOD) in vitro. EAF demonstrated a stronger XOD inhibitory effect (IC50 = 1.67 mg/mL) than nBuF. Among the six CQA compounds, 3,4-diCQA had the lowest IC50 of 12.80 μM, whereas 1,3-diCQA and 3-CQA had IC50 values of 23.69 and 28.29 μM, respectively. The inhibitory activity of 4-CQA was weak. These findings indicated that CQAs are the major components inhibiting the XOD activity in vitro in AST leaves.

Synthesis and X-ray diffraction data of N1,N2-di(2-hydroxy)benzylidenbenzene-1,2-di-imine, C20H16N2O2

The Schiff base N1,N2-di(2-hydroxy)benzylidenebenzene-1,2-di-imine was prepared from salicylaldehyde and 1,2-diaminobenzene by reflux in ethanol for 6 h obtaining an orange crystalline solid. The Schiff base solid was separated by filtration and washed with ethanol and ethylic ether, and finally, it was dried in a vacuum system for 2 h. The X-ray powder diffraction pattern for this new compound showed that the crystalline compound belongs to the monoclinic system and space group P21/c (No. 14) with refined unit-cell parameters a = 5.9672 (7) Å, b = 16.561 (1) Å, c = 16.337 (2) Å, β = 91.41° (1). The volume of the unit cell is V = 1614.1 (2) Å3.

Synthesis, properties and structure of copper(II) complexes of quinolyl azo derivatives of pyrazole-5-one(thione)

The interaction of 5-methyl-2-phenyl-4-[(8-quinolylhydrazono)]pyrazol-3-one (2) and 5-methyl-2-phenyl-4-(8-quinolylhydrazono)pyrazole-3-thione (4) with copper(II) acetate monohydrate under reflux in ethanol results in the formation of copper(II) azo chelates incorporating CuN4O2 (5) and CuN3S2 (6) chromophores. All the compounds were characterized with FT-IR, EPR, X-ray absorption spectroscopy and magnetic measurements. The structures of complexes 5 and 6 were determined by X-ray single-crystal diffraction. Complex 5 adopts a pseudo-octahedral geometry with a cis disposition of the oxygen atoms around the copper(II) centre, whilst in 6 the copper(II) ion displays a square-pyramidal geometry with a {N3S2} ligand environment.

Synthesis, FTIR and Electronic Spectra Studies of Metal (II) Complexes of Acethydrazide Derivative

Acethydrazide was modified by addition of benzaldehyde refluxing in ethanol to obtain a new product: N’-Benzylideneacethydrazide. The new product obtained was complexed with Iron (II) and Copper (II) salt. The result of the FT-IR analysis of acethydrazide, N’-Benzylideneacethydrazide and its complexes were compared to ascertain the possible points and mode of coordination to the metal (II) centre. The shift in the absorption band of the N’-Benzylideneacethydrazide (N'-BA) from 3337 cm-1 (N-H) to 3462 cm-1 and 3406 cm-1 (N-H) in the spectra of the Fe(II) and Cu(II) complexes respectively, indicates the coordination of the N’-Benzylideneacethydrazide to the metal ion via O and N atoms of the carbonyl and amide functional groups. The products were further characterized by UV/Visible spectroscopic technique and other physical measurements like melting point and solubility test.

Analysis and identification of chemical constituents of fenugreek by UPLC-IT-MS n and UPLC-Q-TOF-MS

Fenugreek, a traditional Chinese medical plant, has been widely used as food ingredients because of its outstanding medicinal qualities. The hypoglycemic activity of fenugreek is one of its important pharmacological properties. Both of saponin and flavonoid components have the hypoglycemic activity and their contents in fenugreek are 4%—8% and 1%—2%, respectively. This paper focused on these two types of components to carry out purification research and chemical analysis. The heating reflux extraction method and macroporous resin purification method were designed to prepare the saponins and the flavonoids components from defatted fenugreek seeds. Petroleum ether ultrasonic skim and 70% ethanol refluxing were used for the extraction of saponins and flavonoid from fenugreek. The column of DM130 macroporous resin and D101 macroporous resin were respectively used to prepare fenugreek saponin and flavonoid components, and the total contents of them were 78.56% and 62.28%, respectively. The saponin and flavonoids were subsequently analyzed by an ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry(UPLC-Q-TOF-MS) along with an ultra-performance liquid chromatography and ion-trap tandem mass spectrometry(UPLC-IT-MS n ). As a result, 57 saponins and 19 flavonoid compounds were characterized. The obtained results will provide a theory basis for further research on fenugreek, as well as research and development of hypoglycemic new drugs.

Synthesis, antibacterial and antitubercular activity of novel Schiff bases of 2-(1-benzofuran-2-yl)quinoline-4-carboxylic acid derivatives

Novel Schiff bases of 2-(1-benzofuran-2-yl)quinoline-4-carboxylic acid derivatives 5a–5e were synthesized by the reaction of 2-(1-benzofuran-2-yl)quinoline-4-carbohydrazide 3 with substituted aromatic aldehydes 4a–4e in presence of catalytic amount of acetic acid. Reaction of methyl 2-(1-benzofuran-2-yl)-quinoline-4-carboxylate 2 with hydrazine hydrate upon refluxing in ethanol for 4 h gave the key intermediate, hydrazide compound 3. All newly synthesized compounds were characterized by IR, NMR and Mass spectra and screened for antibacterial and antitubercular activity. Among the tested compounds carbohydrazide 3 and the compounds 5a and 5e exhibited high activity against S. aureus and E. faecalis respectively with MIC 0.064 mg/mL. Compound 5e demonstrated significant activity against S. aureus and E. faecalis with MIC 0.064 mg/mL. The antibacterial tests revealed hydrazide derivative 3 sensitivity at 25 μg/mL, showing high activity among the synthesized compounds.

Copper(II)-complex functionalized magnetite nanoparticles: a highly efficient heterogeneous nanocatalyst for the synthesis of 5-arylidenthiazolidine-2,4-diones and 5-arylidene-2-thioxothiazolidin-4-one

Magnetite nanoparticles (MNPs) have proved to be a useful support for heterogeneous catalysis. We have synthesized Fe3O4 MNPs functionalized with a copper(II) complex, and tested the resulting material as a heterogeneous nanocatalyst. The catalyst was tested for aldol condensation reactions between aliphatic/aromatic aldehydes and rhodanine or thiazolidine-2,4-dione (TZD) derivatives under reflux in ethanol, giving the target products in high yield. Environmentally benign chemistry, short reaction times, simple work-up, excellent yields, and the reusability of the new nanocatalyst are beneficial features of the present study. The nanocatalyst was characterized by scanning electron microscopy, vibrating sample magnetometery, thermogravimetry, X-ray diffraction, and energy-dispersive X-ray analyses. The data showed that the magnetic nanoparticles are super-paramagnetic with a size range of 10–20 nm.

PVP immobilized SiO2 nanospheres for high-performance shear thickening fluid

We develop a modified method to improve the rheological performance of SiO2-based shear thickening fluid (STF). Directly adding surfactant into STF is the most common method to improve the rheological performance of SiO2-based STF. However, the final viscosity increases quickly with the increase of shear rate, which is against for the practical applications. In this work, SiO2 nanospheres are firstly modified by PVP K30 through an ethanol refluxing method and the modified SiO2 nanospheres are used to prepare PVP@SiO2-STF. Compared with the unmodified SiO2 based STF (SiO2-STF), the PVP@SiO2-STF presents an obvious increase of shear thickening (ST) effects and the maximum viscosity increases by 7 times and the critical shear rates decrease about 10 times approximately. A reasonable explanation is proposed to interpret the influence of the modification methods on the rheological properties of STF. This work provides a new way to control the shear thickening behavior and also contributes to understand the mechanism of ST effect, which has an important significance to develop controllable STF.

Multi-Dimensional Spectrum-Effect Relationship of the Impact of Chinese Herbal Formula Lichong Shengsui Yin on Ovarian Cancer.

Lichong Shengsui Yin (LCSSY) is an effective and classic compound prescription of Traditional Chinese Medicines (TCMs) used for the treatment of ovarian cancer. To investigate its pharmacodynamic basis for treating ovarian cancer, the multi-dimensional spectrum-effect relationship was determined. Four compositions (I to IV) were obtained by extracting LCSSY successively with supercritical CO2 fluid extraction, 75% ethanol reflux extraction, and the water extraction-ethanol precipitation method. Nine samples for pharmacological evaluation and fingerprint analysis were prepared by changing the content of the four compositions. The specific proportions of the four compositions were designed according to a four-factor, three-level L9(34) orthogonal test. The pharmacological evaluation included in vitro tumor inhibition experiments and the survival extension rate in tumor-bearing nude mice. The fingerprint analyzed by chromatographic condition I (high-performance liquid chromatography-photodiode array detec tor，HPLC-PDA) identified 19 common peaks. High-performance liquid chromatography-photodiode array detector-Evaporative Light-scattering Detector (HPLC-PDA-ELSD )hyphenated techniques were used to compensate for the use of a single detector, and the fingerprint analyzed by chromatographic condition II identified 28 common peaks in PDA and 23 common peaks in ELSD. Furthermore, multiple statistical analyses were utilized to calculate the relationships between the peaks and the pharmacological results. The union of the regression and the correlation analysis results were the peaks of X5, X9, X11, X12, X16, X18, Y5, Y8, Y12, Y14, Y20, Z4, Z5, Z6, and Z8. The intersection of the regression and the correlation analysis results were the peaks of X11, X12, X16, X18, Y5, Y12, and Z5. The correlated peaks were assigned by comparing the fingerprints with the negative control samples and reference standard samples, and identifying the structure using high-performance liquid chromatography-mass spectrometry detector(HPLC-MS). The results suggested that the pharmacodynamic basis of LCSSY on anti-ovarian cancer activities were germacrone, furandiene, β-elemene, calycosin-7-glucoside, ononin, epimedin B, icariin, ginsenoside Rc, astragaloside, ginsenoside Rd, astragaloside II, and some unknown components.

Synthesis of chromenoimidazocarbolines by a reaction of quaternary iminium salts with o-hydroxybenzaldehydes

It was shown that the interaction of N 2-(cyanomethyl)-β-carbolinium bromide with o-hydroxybenzaldehydes in the presence of ammonium acetate upon refluxing in ethanol proceeded as a domino reaction and led to the formation of chromenoimidazocarbolines.

One-pot cascade synthesis and in vitro evaluation of anti-inflammatory and antidiabetic activities of S-methylphenyl substituted acridine-1,8-diones.

Various S-methylphenyl substituted acridine-1,8-dione series (4a-i) were synthesized through a one-pot cascade synthetic approach involving the reaction of 4-(methylthio)benzaldehyde and dimedone with a variety of amines as nitrogen source under reflux in ethanol. All the synthesized derivatives were characterized by using spectroscopic methods. In vitro evaluations of anti-inflammatory and antidiabetic efficacies of all the synthesized compounds were investigated. The anti-inflammatory results infer that the compounds 4c and 4d are showing excellent activity with an inhibition percentage of 80.58±0.42, 81.72±1.72 by membrane stabilization and 77.72±0.76, 78.76±0.81 by albumin denaturation methods, which is comparable with the standard diclofenac at a concentration of 100μg/ml. Further, the antidiabetic assay revealed the moderate activity for the synthesized compounds at a concentration of 100μg/ml with respect to their standard drug, acarbose.

Optimization of ethanol reflux extraction process of red ginseng using a design space approach based on hazard and operability analysis

Quality by design principle was used as a guideline in this study to optimize ethanol reflux extraction of red ginseng. Firstly, hazard and operability analysis(HAZOP) was used as a risk assessment tool to evaluate the hazard degree of process parameters.Ethanol concentration, the ratio of alcohol and herbal material (A/M ratio), and extraction time were identified as the critical process parameters(CPPs) according to HAZOP method.Secondly, Box-Behnken experimental design was applied to establish theregression models between CPPs and the process indices. Finally, the design space was calculated. The recommended operation space of parametersis as follows：alcohol concentration of 90.3%-90.7%, A/M ratio of 2.5-3.1 mL•g ⁻¹ and extraction time of 124-130 min. The study shows that the design space approach combined with the risk assessment using HAZOP has the potential to reduce the risk of red ginseng extraction process, which might ultimately improve the process control..