Simultaneous Analysis of Lipid-Soluble Constituents of Erxian Decoction by GC–MS

Erxian Decoction (EXD), a traditional Chinese medicine formula mainly composed of six Chinese herbs, was originally developed for menopausal syndromes and had been practiced since the 1950s in China. Previous studies only focused on the water-soluble compounds involved in EXD by LC or TLC. This study analyzed the whole profile of the volatile constituents contained in EXD to supplement its quality evaluation method. Several EXD samples were extracted with chloroform and ethyl acetate, respectively, to get the lipid-soluble chloroform and ethyl acetate fractions and compared their gas chromatographic profiles by GC–MS. The EXD samples were hydrolyzed with hydrochloric acid in a water-bath at 100 °C, neutralized with 40% NaOH, and finally extracted with ethyl acetate and chloroform for the quantification of the total sarsasapogenins contained in EXD. A total of 56 compounds belonging to a variety of natural product categories such as aromatic phenols, terpenes, fatty acids, ketones, esters, and aldehydes, etc. were identified from the chloroform and ethyl acetate extracts by using the online EI–MS characterization. The GC–MS method showed a linear response for sarsasapogenin quantification with r = 0.994. The intra-day and inter-day variations of precision and accuracy of the assay were less than 5%. This developed GC–MS method could thus be successfully applied for the identification of lipid-soluble constituents derived from EXD, and also for the accurate quantification of the total sarsasapogenins contained in the acid hydrolyzed EXD samples.     

Inclusion compounds based on 16(S)-dihydro- and 15-ene-steviols

XRD is used to study the structures of inclusion compounds of diterpenoid 15-ene-steviol with chloroform and 16-S-dihydrosteviol with chloroform and ethyl acetate. In all three cases, the guest-host ratio is 1:2; by means of a branched system of hydrogen bonds, diterpenoid molecules form a three-dimensional associate with helical voids, in which solvent molecules are located. Crystals of all three complexes are isostructural, the ethyl acetate molecule being localized in the corresponding inclusion compound, while solvent molecules are disordered in complexes with chloroform.     

A new selective reagent for the spectrofluorometric determination of beryllium

The fluorescence properties of the beryllium and aluminum complexes with 2, 4-dioxo-4-(4-hydroxy-6-methyl-2-pyrone-3-yl) butyric acid ethyl ester (Ligand) were studied and optimal conditions for their fluorometric determination were established. Beryllium can be determined in the linearity range of 0.5–2.0 μg/ml and aluminum 0.5–1.5 μg/ml. The effect of diverse ions on the determination of beryllium is discussed.A simple procedure for the fluorometric determination of beryllium in human blood plasma in the concentration range of 5–50 μg Be/ml is described.     

Leaves of Chenopodium album as source of natural fungicides against Sclertium rolfsii

Series of experiments were conducted to identify the possible antifungal components of Chenopodium album leaves for the management of a highly destructive soil-borne fungal pathogen Sclerotium rolfsii. A 4% methanolic extract caused up to 82% reduction in biomass of the target organism. This extract was partitioned using solvents of variable polarities, and the obtained subfractions were evaluated for their activity against S. rolfsii. The best antifungal activity was detected for the ethyl acetate subfraction (60–74%) followed by n-hexane (51–69%), n-butanol (50–60%), chloroform (20–40%) while the aqueous sub-fraction had the lowest activity (9–35%) as detected by the decrease in biomass of the pathogen. Ethyl acetate and n-hexane sub-fractions were analyzed for their chemical constituents by GC–MS technique. Literature survey showed that among the identified compounds kitazin P, imidazole-4-carboxylic acid, 2-fluoro-1-methoxymethyl-, ethyl ester and 9,12,15-octadecatrienoic acid, 2,3-dihydroxypropyl ester, (Z,Z,Z)- had antifungal activities against other fungal species and could be responsible for control of S. rolfsii by methanolic extract in the present study.     

Isolation of the mixed ligand complex of beryllium(II) with acetylacetone and thenoyltrifluoroacetone by gel permeation chromatography

Summary The mixed ligand, metal complex (acetylacetonato) (thenoryltrifluoroacetonato) beryllium(II) has been isolated from a reaction mixture of bis(acetylacetonato) beryllium(II) and bis(thenoyltrifluoroacetonato)beryllium(II) in ethyl acetate by gel permeation chromatography using Shodex 801 gel column and ethyl acetate as the solvent.     

Chelatbildene Austaoscherharze XI — Abtrennung des Be(II) vom Al(III) am Chelataustauscher auf der Basis von o-(2-Hydroxyphenylazo)benzoesäure

A chelate-exchanger based on o-(2-hydroxyphenylazo)-benzoic acid is used for the rapid and quantitative separation of beryllium from aluminium. Aluminium is eluted with 4M ammonium acetate, and beryllium with 2M hydrochloric acid.     

Synthesis and investigation of the solution behavior of graft block copolymers of polyimide and poly(methyl methacrylate)

Graft copolymers with a polyimide backbone and poly(methyl methacrylate) side chains are investigated in dilute chloroform and ethyl acetate solutions via the methods of molecular hydrodynamics and optics. Copolymer samples are prepared through the “grafting from” method via atom-transfer radical polymerization with a multicenter polyimide macroinitiator. In solutions of copolymers with low degrees of functionalization Z (40%), supermolecular structures are formed as a result of interactions between the polyimide backbones. In samples with Z → 100%, the backbone is well screened by side chains; therefore, molecular solutions are formed in both solvents. The hydrodynamic and conformational behavior of samples with high functionalization degrees changes after the transition from ethyl acetate to chloroform owing to the different thermodynamic qualities of the solvents with respect to the copolymer components. In both solvents, the backbone tends to avoid contact with a poor solvent. This effect is more pronounced in the case of ethyl acetate. Macromolecules of the studied graft copolymers are characterized by high equilibrium rigidities (>40 nm) that are 10 times higher than the corresponding characteristics of aromatic polyimides.     

Atomic-absorption determination of beryllium in liquid environmental samples

A method is described for the atomic-absorption determination of beryllium in liquid environmental samples after separation by solvent extraction and cation-exchange. The beryllium is first isolated from natural waters and beverages by chloroform extraction of its acetylacetonate from a solution at pH 7 and containing EDTA. The chloroform extract is then mixed in the ratio of 3:6:1 with tetrahydrofuran and methanol containing nitric acid, and passed through a column of Dowex 50 x 8 (H(+)-form). After removal of acetylacetone, chloroform and tetrahydrofuran by washing the resin bed with methanol-HNO(3), beryllium is eluted with 6M hydrochloric acid and determined by atomic-absorption spectroscopy. The method was successfully applied to determine beryllium in tap-, river- and sea-water samples, mineral waters and wines. Beryllium contents in the range from < 0.01 to 2.3 microg/l were found in these materials.     

Synthesis of 1,2,4,5-tetrasubstituted imidazoles using silica-bonded propylpiperazine N-sulfamic acid as a recyclable solid acid catalyst

A simple and efficient procedure for the preparation of silica-bonded propylpiperazine-N-sulfamic acid (SBPPSA) by the reaction of 3-piperazine-N-propylsilica (3-PNPS) and chlorosulfonic acid in chloroform is described. Silica-bonded propylpiperazine-N-sulfamic acid is employed as a recyclable catalyst for the synthesis of highly substituted imidazoles from the reaction of benzil, aromatic aldehydes, ammonium acetate and amines under solvent-free conditions. The heterogeneous catalyst was recycled for five runs upon the reaction of benzil, 4-methylbenzaldehyde, benzylamine, and ammonium acetate without losing its catalytic activity.     

The determination of beryllium in geological and industrial materials by atomic-absorption spectrometry after cation-exchange separation

A method is described for the determination of beryllium in geological and industrial samples. After dissolution of the sample in mineral acids, beryllium is separated from the matrix elements by chloroform extraction of its acetylacetonate from a solution of pH 7 containing ascorbic acid and EDTA. Beryllium is separated from the organic extract and from co-extracted aluminium by means of a column of the strongly acidic cation-exchanger Dowex 50; beryllium is adsorbed from a medium consisting of 60 % (v/v) tetrahydrofuran, 30 % (v/v) chloroform and 10 % (v/v) methanol containing hydrochloric acid, aluminium is removed with 0.4 M oxalic acid and after elution with 6 M hydrochloric acid, beryllium is determined by atomic-absorption spectrometry with a nitrous oxide-acetylene flame. The method was used to determine p.p.m. and sub-p.p.m. quantities of beryllium in geochemical reference materials, U₃O₃ and yellow cake samples, and manganese nodules.     

Isolation of quercetin and mandelic acid from <Emphasis Type="Italic">Aesculus indica</Emphasis> fruit and their biological activities

Background

In this study Aesculus indica fruit was subjected to isolation of phytochemicals. Two antioxidants quercetin and Mandelic acid were isolated in pure state. The free radical scavenging and acetyl choline esterase inhibitory potential of the crude extract and sub fractions were also determined.

Results

The antioxidant capacity of crude extract, fractions and isolated compounds were determined by DPPH and ABTS methods. Folin-Ciocalteu reagent method was used to estimate the total phenolic contents and were found to be 78.34?±?0.96, 44.16?±?1.05, 65.45?±?1.29, 37.85?±?1.44 and 50.23?±?2.431 (mg/g of gallic acid) in crude extract, ethyl acetate, chloroform, n-hexane and aqueous fractions respectively. The flavonoid concentration in crude extract, ethyl acetate, chloroform, n-hexane and aqueous fraction were; 85.30?±?1.20, 53.80?±?1.07, 77.50?±?1.12, 26.30?±?1.35 and 37.78?±?1.25 (mg/g of quercetin) respectively. The chloroform fraction was more potent against enzymes, acetyl choline esterase and butyryl choline esterase (IC₅₀?=?85 and 160 μg/ml respectively). The phenolic compounds in the crude extract and fractions were determined using HPLC standard method. Chlorogenic acid, quercetin, phloroglucinol, rutin, mandelic acid and hydroxy benzoic acid were detected at retention times 6.005, 10.062, 22.623, 30.597, 35.490 and 36.211 in crude extract and different fractions. The ethyl acetate fraction was rich in the targeted compounds and was therefore subjected to column isolation. The HPLC chromatogram of isolated compounds showed single peak at specified retention times which confirms their isolation in pure state. The isolated compounds were then characterized by FTIR and NMR spectrophotometric techniques.

Conclusion

The Aesculus indica fruit extracts showed antioxidant and anticholine esterase inhibitory potentials. Two bioactive compounds were isolated in the pure form ethyl acetate fraction. From results it was concluded that the fruit of this plant could be used to minimize oxidative stress caused by reactive oxygen species.

     

Extraction of cations as salts of fatty acids : Analytical and chromatographic separation of beryllium from iron and aluminium

Quantitative extractions of aluminium and ferric ions are carried out in presence of butyric acid. A method has been given for quantitative extraction of beryllium from aluminium and ferric ion in presence of ethylenediaminetetra-acetic acid. Interference has been studied and interference due to phosphate has been avoided by addition of zirconium salt. The method has been applied to thc analysis of beryl.     

Determination of melatonin and its precursors and metabolites using capillary electrophoresis with UV and fluorometric detection

A micellar electrokinetic chromatography method has been developed for simultaneous determination of melatonin and its precursors and metabolites. A 20 mM borate buffer pH 9.5 with 50 mM SDS served as the electrolyte. Tryptophan, 5-methoxyindoleacetic acid, 6-hydroxymelatonin, melatonin, serotonin, and 5-methoxytryptamine were baseline separated in less than 13 min. The limits of detection for UV detection and fluorometric detection based on native fluorescence of analytes were at the sub-ppm level. The proposed method with UV detection was applied to melatonin content control in pharmaceutical tablets with a precision expressed as RSD (n = 7) = 1.6%. For biological samples extraction with chloroform and ethyl acetate was examined. With ethyl acetate and chloroform recoveries of 87.2% and 82.1% melatonin, respectively, were obtained from plasma samples. The recovery of melatonin from spiked urine samples was 80.0% for ethyl acetate and 82.5% for chloroform. Fluorometric detection provides about two-fold improvement over UV in the detection of melatonin and minor improvements for three other analytes, but is much poorer than UV for tryptophan and 6-hydroxymelatonin in applied conditions.     

Total flavonoids content and biochemical screening of the leaves of tropical endemic medicinal plant Merremia borneensis

The developing and under developed countries mostly rely on traditional medicines. This herbal or traditional medicine involves the use of different types of organic extracts or the bioactive chemical constituents. This type of biochemical investigation provides health care at an affordable cost. This survey such as ethnomedicine keenly represents one of the best avenues in searching new economic plants for medicines. Keeping this view in mind, the present study is carried out in Merremia borneensis leaves of University Malaysia Sabah, Sabah, Malaysia. The plant has several beneficial properties, such as antioxidant activity. The dry powder of the leaves of M. borneensis was extracted with hexane, ethyl acetate, chloroform, butanol and aqueous ethanol. The flavonoids content of the extracts was determined by Willet method. The flavonoids content of the extracts as quercetin equivalents was found to be highest in aqueous ethanol (53.28%) followed by chloroform (38.83%), ethyl acetate (24.51%), butanol (12.54%) and hexane extract (3.44%). The results suggest the presence of phytochemical properties in the leaves, which are used in curing the ailments.     

Phytochemical Analysis,Antispasmodic, Myorelaxant,and Antioxidant Effect of Dysphania ambrosioides (L.) Mosyakin and Clemants Flower Hydroethanolic Extracts and Its Chloroform and Ethyl Acetate Fractions

Dysphania ambrosioides (L.) Mosyakin and Clemants is an annual or ephemeral perennial herb used traditionally in the Mediterranean region in folk medicine to treat various illnesses, including those related to the digestive system. This study aims to assess the antispasmodic, myorelaxant, and antioxidant effects of D. ambrosioides flower hydroethanolic extract and its chloroform and ethyl acetate fractions in a comparative study to evaluate the result of the extraction type on the potential activity of the extract. Both rat and rabbit jejunum were used to evaluate the antispasmodic and myorelaxant effect, while the antioxidant effect was evaluated using DPPH, a ferric reducing power assay, and a beta-carotene bleaching test. LC/MS-MS analysis was carried out to reveal the composition of the different types of extract. Following the results, the hydroethanolic extract showed a significant myorelaxant effect (IC₅₀ = 0.39 ± 0.01 mg/mL). Moreover, it was shown that the hydroethanolic extract demonstrated the best antispasmodic activity (IC₅₀ = 0.51 ± 0.05 mg/mL), followed by the ethyl acetate (IC₅₀ = 4.05 ± 0.32 mg/mL) and chloroform (IC₅₀ = 4.34 ± 0.45 mg/mL) fractions. The antioxidant tests showed that the hydroethanolic extract demonstrated high antioxidant activity, followed by the ethyl acetate and chloroform fractions. The LC/MS-MS analysis indicates that the plant extract was rich in flavonoids, to which the extract activity has been attributed. This study supports the traditional use of this plant to treat digestive problems, especially those with spasms.     

Effect of solute hydrophobicity on phase behaviour in solutions of thermoseparating polymers

 Two-phase systems consisting of a polymer rich phase and polymer depleted phase, where the polymer is either ethyl(hydroxy ethyl)cellulose (EHEC) or Ucon (a random copolymer of ethylene oxide and propylene oxide), have been studied. Both of these polymers can be separated from an aqueous solution by either temperature increase or addition of cosolutes. The polymers are thermoseparating and phase separate in water solutions at the cloud point temperature. Two types of EHEC have been studied: one with a cloud point at 60 °C and the other at 37 °C. The Ucon polymer used in this study has a cloud point at 50 °C. Ternary phase diagrams of polymer/water/cosolute systems have been investigated. When a strongly hydrophilic or hydrophobic cosolute is added to an EHEC- or Ucon–water solution, a phase separation occurs already at, or below, room temperature. As cosolutes, hydrophobic molecules like phenol, butyric and propionic acid, and hydrophilic molecules like glycine, ammonium acetate, sodium carboxylates (acetate to valerate), were studied. The polymer rich phase formed when mixing polymer, water and cosolute was strongly enriched or depleted with hydrophobic or hydrophilic cosolutes, respectively. The two phase region increased for propionic acid, butyric acid and phenol as a result of increased cosolute hydrophobicity. The opposite occurred in the series sodium acetate, sodium butyrate and sodium valerate. The effect of temperature on the phase behaviour has also been investigated. Model calculations based on Flory–Huggins theory of polymer solutions are presented, in form of a phase diagram, which semiquantitatively reproduce some experimental results. Received: 5 July 1996 Accepted: 4 November 1996     

The solvent extraction of trace antimony(V)

An investigation of the extraction of trace amounts of antimony(V) from aqueous hydrochloric acid solutions into various others and chloroform has been carried out. Before extractions were made, mutual solubility studies of the two-phased systems were conducted. Then extraction experiments were performed using original aqueous acid concentrations from 0 to 12N and non-aqueous phases of ethyl ether, isopropye ether, isoamyl ether, n-hexyl ether, and chloroform. Dielectric constant determinations were made in the equilibrated non-aqueous phases, and spectrophotormetric and salting-out studies were carried out on the ethyl ether system. It was found that the isopropyl ether system presents the most advantageous conditions for the extraction of trace antimony(V)     

Sequential Thin-Layer Chromatography of 2,4-D and Related Compounds

Abstract

Separations and identification of carboxylic herbicidal substances such as 2,4-dichlorophenoxyacetic acid, trichloroacetic acid, 2,4,5-trichlorophenoxyacetic acid and plant growth regulators such as benzoic acid, cinnamic acid, indole-3-acetic acid, β-naphthaleneacetic acid, β-naphthoxyacetic acid, phenoxyacetic acid have been made by sequential thin-layer chromatography on calcium sulphate layer with acetone, benzene, carbon tetrachloride, chloroform, ethyl acetate, dioxan, propanol as solvents and bromophenol blue as detector.     

GC-MS analysis of the bioactive phytoconstituents of various organic crude extracts from the seed kernels of Manilkara bidentata (balata) collected in Trinidad,W.I.

The present study reports the first phytochemical investigation of the seed kernels of Manilkara bidentata (Balata) harvested in Trinidad, W.I. Gas chromatography–mass spectrometry (GC-MS) analysis of the n-hexane, chloroform, ethyl acetate, ethanol and methanol extracts showed a total of 39 components. 2,6,10,14,18-pentamethyl-2,6,10,14,18-eicosapentaene (74.93%), 9-octadecenoic acid, (Z)- 2,3-dihydroxypropyl ester (79.98%), (Z)-ethyl oleate (92.75%), Z,E-2-methyl-3,13-octadecadien-1-ol (80.51%) and 5-(hydroxymethyl)-2-furancarboxyaldehyde (50.32%) were the major constituents identified in the n-hexane, chloroform, ethyl acetate, ethanol and methanol extracts, respectively. The extracts showed the presence of several bioactive components and provides reference data for further research of its active constituents.     

Silica-bonded N-propyl sulfamic acid as an efficient catalyst for the formylation and acetylation of alcohols and amines under heterogeneous conditions

A simple and efficient procedure for the preparation of silica-bonded N-propyl sulfamic acid (SBNPSA) by the reaction of 3-aminopropylsilica (1) and chlorosulfonic acid in chloroform is described. This solid acid is employed as a new catalyst for the formylation of alcohols and amines with ethyl formate under mild and heterogeneous conditions at room temperature with good to excellent yields. Also, SBNPSA catalyzed acetylation of various alcohols and amines with acetic anhydride at room temperature.