Petroleum Ether Ethyl Acetate Research Articles

Attenuation of reactive nitrogen species by different flavonoids enriched fractions of Schima Wallichii

ObjectiveTo investigate Schima wallichii (S. wallichii) Choisy (Ternstroemiaceae) which is a well known plant of Sikkim in the Himalayan region, India. MethodsTherefore three major flavonoid enriched fractions (FPet.Ether, FChloroform and FEthylacetate) were isolated by petroleum ether chloroform and ethyl acetate successively. The reactive nitrogen species scavenging activity of the flavonoid fractions was established using biochemical assay to measure scavenging of 2, 2 diphenyl picrylhydrazyl (DPPH), nitric oxide (NO) and peroxinitrite. ResultsFEthylacetate showed maximum scavenging activity: their IC50 being (7.33 ± 3.32), (7.11 ± 2.21), and (6.67 ± 2.23) μg/mL in DPPH, NO, peroxinitrite radical respectively. Presence of (57.32 ± 2.31) and (163.4 ± 2.22) μg of flavonoids and phenolic compound in 1 mg of extract is assumed to be responsible for free radical scavenging activity. ConclusionTaken together S. wallichii has potent free radical scavenging property indicating its importance in food supplement as a rich source of active flavonoid and phenolic compounds in ethyl acetate fraction which is responsible for its free radical scavenging as well as antioxidant activity.

菹草提取物对3种赤潮微藻生长的抑制作用<br>Growth Inhibition of the Three Species of Red Tide Microalgae by Extracts from Potamogeton crispus

以甲醇浸泡菹草干粉4 d，过滤、减压蒸干后，制备到菹草甲醇浸膏。此浸膏用90%甲醇水溶液(V/V)溶解后，依次以石油醚、乙酸乙酯和正丁醇为溶剂，采用液液萃取法进一步分离。经过滤、减压蒸干，获得4种液液分离提取物-石油醚、乙酸乙酯、正丁醇和蒸馏水提取物，得率分别为38.5%、21.9%、9.37%和26.6%。在此基础上，通过测定藻细胞数量，观察藻细胞形态，分析藻细胞内叶绿素、蛋白质和多糖含量等生理指标的变化，研究了此4种液液分离提取物对米氏凯伦藻(Karenia mikimitoi)、中肋骨条藻(Skeletonema costatum)和塔玛亚历山大藻(Alexandrium tamarense)生长的影响。结果表明，石油醚和乙酸乙酯提取物能明显降低3种赤潮微藻的细胞数量。当提取物浓度为16 mg/L时，此2种提取物对3种赤潮微藻的生长抑制率超过66%(第12 d)。同时，此2种提取物显著改变了3种赤潮微藻的细胞形态，致使藻细胞出现空洞、破碎和色素明显减褪现象。并且，它们还能显著影响藻细胞内叶绿素、蛋白质和多糖等生理指标的合成。在实验设定浓度范围内，正丁醇和蒸馏水提取物未对3种赤潮微藻的生长产生明显的影响。 To study effects of solvent-partitioned fractions of methanol extracts from Potamogeton crispus on the growth of the three species of microalgae (Karenia mikimitoi, Skeletonema costatum and Alexandrium tamarense), the extracts were extracted with petroleum ether, ethyl acetate, n-butanol and distilled water by liquid-liquid fractionaction, respectively. And yields of solvent-partitioned fractions were 38.5% petroleum ether extracts, 21.9% ethyl acetate extracts, 9.37% n-butanol extracts and 26.6% distilled water extracts, respectively. Based on the observation of algal morphology and the measurement of algal number, and the contents of physiological indicators (protein, polysaccharide and chlorophyll), the results showed the petro- leum ether extracts and ethyl acetate extracts from methanol extracts of Potamogeton crispus had the stron- gest action. The inhibitory effect of the tested microalgae by these two extracts was above 66% in day 12 at the concentration of 16 mg/L. And the petroleum ether extracts and ethyl acetate extracts caused cavities, pieces and chlorophyll decreased in cells. The further investigation found that these two extracts significantly decreased the contents of protein, polysaccharide and chlorophyll in the cells of those microalgae. But n- butanol extracts and distilled water extracts had not significant affect the growth of the all test microalgae.

Separation and Purification of Three High-Purity Isoflavonoids from Belamcanda chinensis (L.) DC. by Supercritical Fluid Extraction and High-Speed Counter-Current Chromatography

Supercritical fluid extraction (SFE) was used to extract three isoflavonoids including irigenin, irisfloretin and dichtomitin from Belamcanda chinensis (L.) DC. The parameters including pressure, temperature, sample particle size, and flow rate of CO2 were optimized with an orthogonal test. Under the optimized conditions of 15 MPa, 55°C, a sample particle size of 20–40 mesh and CO2 flow rate of 40 L h−1. The process was then scaled up by 10 times using a preparative SFE system. The yield of the crude extract from SFE was 4.1%, which contained irigenin, irisfloretin, and dichtomitin 0.71%, 0.49%, and 0.05%, respectively. To compare the extraction methods, Soxhlet Extraction (SE) was performed. The results indicated that SFE was better than SE. Irigenin, irisfloretin, and dichtomitin in the SFE extract were then separated and purified by high-speed counter-current chromatography (HSCCC) with a two-phase solvent system composed of petroleum ether–ethyl acetate–methanol–water (2:4:3:3, v/v). From 5.0 g of dry crude extract, 27.8 mg irigenin, 16.4 mg irisfloretin, and 2.1 mg dichtomitin were obtained at purities of 97.1%, 96.4%, and 98.0%, respectively, as determined by HPLC-PDA. These results well indicate that SFE and HSCCC are very powerful techniques for the extraction and purification of irigenin, irisfloretin, and dichtomitin from B. chinensis.

Isolation and purification of seven lignans from Magnolia sprengeri by high-speed counter-current chromatography

Seven lignans including (−)-maglifloenone, futoenone, magnoline, cylohexadienone, fargesone C, fargesone A and fargesone B were isolated and purified from Magnolia sprengeri Pamp. using high-speed counter-current chromatography (HSCCC) with two-step separation. In the first step, a stepwise elution mode with the two-phase solvent system composed of petroleum ether–ethyl acetate–methanol–water (1:0.8:0.6:1.2, 1:0.8:0.8:1, v/v) was used and 15.6 mg of (−)-maglifloenone, 19.2 mg of futoenone, 10.8 mg of magnoline, 14.7 mg of cylohexadienone and 217 mg residues were obtained from 370 mg crude extract. In the second step, the residues were successfully separated by HSCCC with the solvent system composed of petroleum ether–ethyl acetate–methanol–water (1:0.8:1.2:0.6, v/v), yielding 33.2 mg of fargesone C, 47.5 mg of fargesone A and 17.7 mg of fargesone B. The purities of the separated compounds were all over 95% determined by HPLC. The chemical structures of these compounds were confirmed by 1H NMR, 13C NMR and ESI-MS.

Preparative isolation of alkaloids from Dactylicapnos scandens using pH-zone-refining counter-current chromatography by changing the length of the separation column

pH-Zone-refining counter-current chromatography was successfully applied for the preparative separation of alkaloids from Dactylicapnos scandens. The two-phase solvent system was composed of petroleum ether–ethyl acetate–methanol–water (3:7:1:9, v/v), where 20 mM of triethylamine (TEA) was added to the upper phase as a retainer and 5 mM of hydrochloric acid (HCl) to the aqueous phase as an eluter. In this experiment, the apparatus with an adjustable length of the separation column was used for the separation of alkaloids from D. scandens and the resolution of the compounds can be remarkably improved by increasing the length of the separation column. As a result, 70 mg protopin, 30 mg (+) corydine, 120 mg (+) isocorydine and 40 mg (+) glaucine were obtained from 1.0 g of the crude extracts and each with 99.2%, 96.5%, 99.3%, 99.5% purity as determined by HPLC. The chemical structures of these compounds were confirmed by positive ESI-MS and 1H NMR.

Gastric antisecretory and cytoprotective effects of leaf extracts of Amaranthus tricolor Linn. in rats

The present study was aimed to evaluate the antiulcer activity of leaf extracts of Amaranthus tricolor Linn. (Amaranthaceae) in rats. The effects of A. tricolor leaves on gastric secretion and the effect of gastric cytoprotection were evaluated using five different models of gastric ulcers: acetic acid-induced, pylorus ligation-induced, ethanol-induced, indomethacin-induced and ischemia-reperfusion-induced gastric ulcers. The different extracts, namely, ethanolic extract (EAT), petroleum ether extract (PEAT), chloroform extract (CAT) and ethyl acetate extract (EAAT) of A. tricolor leaves were administered at a dose of 200 mg/kg per oral (p.o.). The acute oral toxicity study revealed that all the extracts were safe up to 2 000 mg/kg, p.o; hence one-tenth of this dose was selected for evaluation of antiulcer activity. The EAT and EAAT (200 mg/kg, p.o.) showed gastric ulcer-healing effect in acetic acid-induced chronic gastric ulcers. The EAT and EAAT inhibited gastric secretion in pylorus-ligated rats and showed gastric cytoprotective effect in ethanol-induced and indomethacin-induced gastric ulcers, while PEAT and CAT showed no significant antiulcer effect. The leaf extracts of A. tricolor are found to possess very good antiulcer property in the experimental animal models of gastric ulcers which is consistent with the literature report in folk medicine.

Combined microwave-assisted extraction and high-speed counter-current chromatography for separation and purification of xanthones from Garcinia mangostana

A microwave-assisted extraction (MAE) method is presented for the extraction of xanthones, α-mangostin and γ-mangostin from Garcinia mangostana. The MAE conditions including extraction temperature, liquid/solid ratio, extraction time and concentration of ethanol were optimized with an orthogonal test, and 5 g sample was extracted with the optimized conditions. The crude extraction of MAE was successfully isolated and purified by high-speed counter-current chromatography (HSCCC) with a two-phase solvent system composed of petroleum ether–ethyl acetate–methanol–water (0.8:0.8:1:0.6, v/v) in one-step separation. The separation yielded 75 mg of α-mangostin at 98.5% purity, and 16 mg of γ-mangostin at 98.1% purity from 360 mg crude extract of G. mangostana in less than 7 h. The purity of the two xanthones was determined by HPLC. Their structures were further identified by ESI-MS, 1H NMR and 13C NMR.

Application of high-speed counter-current chromatography for preparative separation of cyclic peptides from Vaccaria segetalis

Following an initial clean-up step on silica gel, high-speed counter-current chromatography (HSCCC) was used to separate cyclic peptides from an extract of the seeds of Vaccaria segetalis. The two-phase solvent system used for HSCCC separation was composed of petroleum ether–ethyl acetate–methanol–water at an optimized volume ratio of 0.5:3.5:1:5. From 190 mg of crude extract, 38.0 mg of segetalin B and 28.5 mg of segetalin A were obtained with purities of 98.1% and 95.6% as determined by HPLC, respectively. The chemical structures of the target compounds were confirmed by high resolution electrospray ionization time of flight MS (HRESI-TOF-MS) and 1H NMR analyses.

Crystal structure of 1-(4-ethylphenyl)-2-nicotinoyl-3-(1Hbenzo[d]-1,2,3-triazol-1-yl)-1-oxopropan, C23H20N4O3

Article Crystal structure of 1-(4-ethylphenyl)-2-nicotinoyl-3-(1Hbenzo[d]-1,2,3-triazol-1-yl)-1-oxopropan, C23H20N4O3 was published on September 1, 2011 in the journal Zeitschrift für Kristallographie - New Crystal Structures (volume 226, issue 3).

Preparative separation of gingerols from Zingiber officinale by high-speed counter-current chromatography using stepwise elution

Following an initial clean-up step on silica column, high-speed counter-current chromatography (HSCCC) was used to purify gingerols from an extract of the dried rhizome of Zingiber officinale. The sample was separated with petroleum ether–ethyl acetate–methanol–water (1:0.2:0.5:0.7, v/v) and petroleum ether–ethyl acetate–methanol–water (1:0.2:0.7:0.5, v/v) in a stepwise elution and yielded 132 mg of 6-gingerol, 31 mg of 8-gingerol and 61 mg of 10-gingerol from 360 mg of pre-purified sample. The purity of each compound was over 98% as determined by HPLC. The structures of the three compounds have been identified by LC-ESI-MS, 1H NMR and 13C NMR.

Separation of minor coumarins from Peucedanum praeruptorum using HSCCC and preparative HPLC guided by HPLC/MS

Two minor coumarins, including a new compound qianhucoumarin J, were isolated from Peucedanum praeruptorum by a multi-step separation procedure using high-speed counter-current chromatography (HSCCC) and preparative high performance liquid chromatography ( prep-HPLC) monitored by high performance liquid chromatography coupled with mass spectrometry (HPLC/MS) analysis. The crude extract was analyzed first by HPLC/MS to detect unknown compounds. The target compounds were enriched by HSCCC, using a two-phase solvent system of petroleum ether–ethyl acetate–methanol–water (5:5:6:4, v/v) and then isolated and purified by preparative HPLC monitored by HPLC/MS. The structure of the new compound was elucidated mainly by analysis of its 1D and 2D NMR spectral data. Its absolute configuration was determined by chemical degradation followed by chiral HPLC analysis.

Chemical investigation of Ervatamia yunnanensis

The study of Ervatamia yunnanensis Tsiang, growing in Yunnan and Guangxi provinces of China, has focused on the isolation of alkaloids [1–6], which are demonstrated to have significant anti-addictive, anti-malarial, anti-reproductive, and anticancer activities [7, 8]. About 30 indole alkaloids have been isolated from E. yunnanensis Tsiang. Continuing our investigations into the biologically active constituents of nonalkaloid parts of Ervatamia yunnanensis by chromatographic and spectroscopic methods, we have isolated two lignans (1 and 2), five flavonoids (6, 9, 11, 13, and 14), two triterpenoids (7 and 8), three organic or fatty acids and derivatives (3, 4, and 12), vanillin (10), and one aromatic ketone (5). The plant material was collected in May 2003 at Xishuangbanna, Yunnan province and identified as the stems of Ervatamia yunnanensis Tsiang by Senior Engineer Wang Hong, Xishuanbanna Tropical Plant Garden of the Chinese Academy of Sciences. The air-dried and powdered stems and branches (5 kg) were extracted with 95% EtOH (10 L) by reflux. The percolate was evaporated in vacuum to yield the EtOH extract (425 g), which was suspended in 2% HCl solution. The precipitate in the lower layer after centrifugation, which was deplete of alkaloids, was dissolved in distilled water; then the solution was chromatographed over macroporous adsorptive resin AB-8, eluting with a gradient mixture of water and alcohol. The compositions of fractions were analyzed by TLC. Similar fractions were combined to afford fraction A, 60.0 g (30% alcohol); fraction B, 40.0 g (60% alcohol), and fraction C, 15.0 g (90% alcohol). Fractions A, B, and C were subjected to repeated chromatography on silica-gel columns eluting with a gradient mixture of petroleum ether–ethyl acetate or chloroform–methanol, Sephadex LH-20 eluting with chloroform–methanol, methanol, or a gradient mixture of methanol–water, and C-18 reverse silica-gel columns eluting with a gradient mixture of methanol–water. A total of fourteen compounds (1–14) was isolated and identified based on NMR and mass spectrum, and by direct comparison with authentic samples and the literature. All the identified compounds are known compounds and are reported for the first time from Ervatamia yunnanensis. (+)-Isolariciresinol-9-O-D-glucopyranoside (1), white crystalline powder, C26H34O11, ESI-MS: m/z 521 [M – H]–, 545 [M + Na]+. 1H NMR (300 MHz, CD3OH, , ppm, J/Hz): 3.81, 3.80 (each 3H, OCH3 2), 4.10 (1H, d, J = 7.8, H-Glu-1), 6.17 (1H, s, H-5 ), 6.63 (1H, dd, J = 8.1, 1.8, H-6), 6.64 (1H, s, H-2 ), 6.73 (1H, d, J = 8.1, H-5), 6.79 (1H, d, J = 1.8, H-2). 13C NMR (75 MHz, CD3OH, ): 148.9 (C-3), 147.2 (C-3 ), 145.9 (C-4), 145.2 (C-4 ), 38.7 (C-1), 134.4 (C-6 ), 129.2 (C-1 ), 123.2 (C-6), 117.4 (C-5 ), 116.1 (C-5), 114.4 (C-2), 112.4 (C-2 ), 69.5 (C-9), 65.2 (C-9 ), 48.4 (C-7), 45.9 (C-8), 39.6 (C-8 ), 33.9 (C-7 ), 105.2 (Glc-1), 78.2 (Glc-5), 77.9 (Glc-3), 75.2 (Glc-2), 71.7 (Glc-4), 62.8 (Glc-6) [9]. Isolariciresinol (2), white powder, C17H26O10, ESI-MS: m/z 383 [M + Na] +. 1H NMR (600 MHz, CD3OD, , ppm, J/Hz): 1.78 (1H, m, H-2), 2.00 (1H, m, H-3), 2.75 (2H, d, J = 8.0, H-4), 3.39 (1H, dd, J = 4.0, 12.0, H-9b), 3.63–3.84 (10H, m, H-1, 10, H-9a, 2 OCH3), 6.20 (1H, s, H-8), 6.61 (1H, dd, J = 9.0, 2.4, H-6 ), 6.63 (1H, s, H-5), 6.68 (1H, d, J = 2.4, H-2 ), 6.75 (1H, d, J = 9.0, H-5 ). 13C NMR (150 MHz, CD3OD, ): 112.2 (C-5), 128.7 (C-5 ), 115.8 (C-5 ), 148.7 (C-6), 123.1 (C-6 ), 145.7 (C-7), 134.0 (C-1 ), 117.3 (C-8), 138.5 (C-8 ), 113.8 (C-2 ), 147.2 (C-3 ), 145.3 (C-4 ), 65.6 (C-10), 61.8 (C-9), 56.2, 56.2 (2 OCH3), 48.1 (C-2), 47.7 (C-1), 39.7 (C-3), 33.5 (C-4) [10]. Berchemolide (3), white powder, C28H32O16, ESI-MS: m/z 647 [M + Na] +, 1271 [2M + Na]+. 1H NMR (600 MHz, DMSO-d6, , ppm, J/Hz): 3.20–4.50 (H-Glu), 3.78 (6H, s, OCH3 2), 5.29 (2H, d, J = 7.2, H-1 , 1 ), 7.36 (2H, d, J = 8.4, H-5, 5 ), 7.40 (2H, d, J = 1.8, H-2, 2 ), 7.74 (2H, dd, J = 1.8, 8.4, H-6, 6 ).

Predictable and linear scale-up of four phenolic alkaloids separation from the roots of Menispermum dauricum using high-performance counter-current chromatography

This paper describes how distribution ratios were used for prediction of peak elution in analytical high-performance counter-current chromatography (HPCCC) to explore the method for separation and purification of bioactive compounds from the roots of Menispermum dauricum. Then important parameters related to HPCCC separations including solvent systems, sample concentration, sample loading volume and flow rate were optimized on an analytical Mini-DE HPCCC and finally linearly scaled up to a preparative Midi-DE HPCCC with nearly the same resolutions and separation time. Four phenolic alkaloids were for the first time obtained by HPCCC separation with a two-phase solvent system composed of petroleum ether–ethyl acetate–ethanol–water (1:2:1:2, v/v). This process produced 131.3 mg daurisolin, 197.1 mg dauricine, 32.4 mg daurinoline and 14.7 mg dauricicoline with the purity of 97.6%, 96.4%, 97.2% and 98.3%, respectively from 500 mg crude extract of the roots of M. dauricum in a one-step separation. The purities of compounds were determined by high-performance liquid chromatography (HPLC). Their structures were identified by electrospray ionization mass spectrometer (ESI-MS) and nuclear magnetic resonance (NMR).

Antipyretic, analgesic, anti-inflammatory and antioxidant activities of two major chromenes from Melicope lunu-ankenda

Aim of the study Melicope lunu-ankenda (Gaertn.) T.G. Hartley is used in Indian traditional medicine for fever, improving complexion and as a tonic. Previous studies have isolated fungicidal, antifeedant, anti-inflammatory and immunomodulatory compounds from Melicope lunu-ankenda. This study is aimed at the isolation and biological activity screening of potential molecules from the volatile oils and extracts of Melicope lunu-ankenda in the light of traditional applications. Materials and methods Volatile oil of Melicope lunu-ankenda leaves was isolated by hydrodistillation, characterized by GC–FID, GC–MS, LRI determination, Co-GC and database searches. Major chromene-type compounds in Melicope lunu-ankenda leaf oil, evodione and leptonol, were isolated by preparative TLC and characterized by UV–Vis, IR, 1H-, 13C-, 13C-DEPT NMR and EIMS. They were also isolated from the petroleum ether and acetone extracts of the leaves of Melicope lunu-ankenda by column chromatography in petroleum ether–ethyl acetate. Their contents in leaf oil, leaf and inflorescence extracts were estimated by HPTLC. Antipyretic (Baker's yeast-induced fever test), analgesic (acetic acid-induced writhing, tail immersion assays), anti-inflammatory (carrageenan-induced paw edema) and in vitro antioxidant (DPPH radical, superoxide radical scavenging) activities of evodione and leptonol were tested. Results and conclusions Gas chromatographic analyses found 50.7% monoterpene hydrocarbons, 0.4% oxygenated monoterpenes, 3.2% sesquiterpene hydrocarbons, 0.7% oxygenated sesquiterpenes and 43.7% chromene-type compounds in Melicope lunu-ankenda leaf oil, with evodione (20.2%) and leptonol (22.5%) as its two major constituents. HPTLC estimations in the petroleum ether, acetone extracts (leaf, inflorescence) and leaf oil found evodione 1.0% (dr. wt., leaf), 1.1% (inflorescence), 0.04% (fr. wt. leaves, leaf oil), and leptonol 0.3% (leaf), 0.3% (inflorescence) and 0.04% (leaf oil). Leptonol (200 mg/kg) showed good antipyretic activity. DPPH radical scavenging assay found moderate activity for leptonol (68.7%, 500 μM), whereas evodione showed near-zero activity. A very similar trend was found in superoxide radical scavenging activity of leptonol (64.5%) and evodione (10.3%), both at 100 μg/ml. Evodione and leptonol showed moderate analgesic activities in acetic acid-induced writhing and tail immersion assays. Moderate anti-inflammatory activity was found for both evodione (59.4%) and leptonol (49.0%) at 100 mg/kg. Ethnopharmacological relevance Biological activities of evodione and leptonol isolated from Melicope lunu-ankenda justify its traditional uses as a remedy for fever, inflammation and as a tonic.

A new ceramide from a new species of Spongia sponge

Sphingolipids have been isolated from various marine organisms including algae, coelenterates, echinoderms, sponges, and tunicates. They are increasingly becoming important compounds because of their marked biological activity. It has been recently found that ceramides inhibit cholesteryl ester transfer protein (CETP) 1 . Elevation of CETP leads to atherosclerotic cardiovascular diseases 2 . A literature survey showed that ceramides are antifungal 3 , and some of these showed antimicrobial and cytotoxic activities 4, 5 . In our continuing studies on chemical constituents of marine organisms, we have examined a new species of Spongia sponge, collected from Sanya shore of Hainan Province, China, and it led to the isolation of a new ceramide, N-palmitoyl-heptacosane-1,3,5-triol (1). The sponge (3 kg, after extraction) was collected in ethanol (10 L). After soaking the sponge for several weeks, the solvent was decanted and the sponge extracted five more times with ethanol. Solvent was removed from the extracts under reduced pressure, and the combined brown colored residue was extracted with chloroform several times. The chloroformsoluble portion (10 g) was chromatographed over a column of silica gel with increasing polarities of solvent mixture starting from petroleum ether to ethyl acetate. The fraction obtained with petroleum ether–ethyl acetate, 20:80 (v/v) contained compound 1. It was further purified by crystallization from petroleum ether–ethyl acetate to obtain 1 as an amorphous white solid. FAB-MS showed the fragment peak at m/z 682 [M + 1]+. Combined with 13C NMR DEPT spectra, the molecular formula of 1 was established as C43H87NO4. The IR spectrum showed absorptions at 3302, 1643, 1544, and 1378 cm–1 and 1H NMR signals at 6.33 (1H, d, J = 7.3 Hz, exchangeable), together with 13C NMR DEPT signals at 174.5 ppm (C), suggesting that 1 contains a –CO-NHmoiety. 1H NMR signals at 0.86 ppm (6H, t, J = 6.5 Hz) and 13C NMR DEPT signals at 14.1 ppm (2CH3), combined with the very strong signal at 1.25 (br.s, many H) in the 1H NMR spectrum, but lack of upfield methine and tertiary carbon signals in the 13C NMR DEPT spectrum, revealed that 1 must be derived from two long-chain fatty acid precursors [6]. The 13C NMR DEPT spectrum of 1 further furnished 1 C, 3 CH, n CH2, and 2 CH3 (Table 1), with one quaternary carbon at 174.5 (CONH) and three methines at 54.6, 76.6, and 72.8 ppm. The FAB-MS fragmentation of 1 showed strong peaks at m/z 281 and 298. According to the nomenclature of sphingolipid mass fragmentation patterns, these peaks corresponded to the G and T fragments, respectively 7 , which revealed that 1 is a ceramide of N-palmitoyl-heptacosane-1,3,5-triol. This interpretation was further supported by hydrolysis of 1 with H2SO4–MeOH 8 . Compound 1 was hydrolyzed with 2 mol/L H2SO4–MeOH, and the hexane extract gave methyl palmitate as a unique product, which was detected by GC-MS analysis.

Antimicrobial studies on the leaves of <i>Earva Javanica</i>

Leaves of Aerva javanica (Family:Amaranthaceae) were extracted withpetroleum ether, ethyl acetate and methanol. The crude extracts wereinvestigated for its antibacterial activity against Bacillus subtilis ,Bacillus cerus, Staphylococcus aureus, Escherichia coli, Proteus vulgaris, Shigella dysenteriae and antifungal activity against Aspergillus flavus, Aspergillus niger and Candida albicans. The extracts showed significant antibacterial activity in the order methanol, ethyl acetate and petroleum ether and methanol and ethyl acetate extract showed moderate antifungal activity while petroleum ether extract did not showed any activity against all the microorganisms tested. How ever, the antibacterial, antifungal activity of the methanol extract of the leaves was found to be most effective against all the organisms.

Simple preparation of new N-aryl-N-(3-indolmethyl) acetamides and their spectroscopic analysis

Objectives. To prepare new indolic molecules and characterize them by spectroscopic methods. Materials and methods: All reagents were purchased from Aldrich, commercial grade. The purity of the products and the composition of the reaction mixtures were mon itored by thin layer chromatography over Silufol UV 254 0.25 mm-thick chromatoplates. Product isolation and purification were performed by column chromatography (SiO 2 ), using ethyl acetate-petroleum ether mixtures as eluents. Results. The synthesis of new N-aryl-N-(3indolmethyl) acetamides based on first step iminization reaction of indol-3-carbaldehyde is accomplished. The structures of the C-3 substituted indoles were confirmed by 1 H-NMR and 13 C-NMR studies supported by inverse-detected 2D NMR experiments and also through monocrystal X-ray diffraction. Conclusions. An efficient, economic, and fast synthetic route was designed to the construction of the N-aryl-N-(3-indolmethyl) acetamides, structural analogues of some alkaloids.

Planar chromatography of cholic acid-derivedcis-transisomeric bis-steroidal tetraoxanes

Seven pairs of cis-trans isomers of bis-steroidal tetraoxanes have been examined by both normal-phase (NP) and reversed-phase (RP) planar chromatography. Unmodified silica gel was used with ethyl acetate-toluene and ethyl acetate-petroleum ether as mobile phases in typical normal-phase systems. CN-silica with the mobile phases methanol-water and acetone-water and RP-18 silica with water-organic modifier (methanol, acetone, or dioxane) mobile phases were used as reversed-phase systems. For the RP systems a good linear correlation was established between R M values and amount ([%] ν/ν ) of organic modifier in the mobile phase (usually r > 0.99). It was found that under both NP and RP conditions cis isomers were more weakly retained than the corresponding trans isomers. The only exception to this was the chromatographic behavior of C(24) methyl esters. It was established that increasing the polarity of substituents at C(24) and C(24a) led to stronger retention in NP systems, i.e. weaker retention in RP syste...

Determination of antibacterial and antioxidant potential of some medicinal plants from saurashtra region, India.

Many plants used in Saurashtra folk medicine have been reported to exhibit high antibacterial and antioxidant activities. In the present study, some parts of five plants, Guazuma ulmifolia L., Manilkara zapota L., Melia azedarach L., Syzygium cumini L. and Wrightia tomentosa R.& S., were evaluated for their antibacterial activity, total phenol content, flavonoid content, 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity and phytochemical analysis, using successive extraction by cold percolation method with petroleum ether, ethyl acetate, methanol and water. In vitro antibacterial activity was evaluated against five bacterial strains viz. Bacillus subtilis, Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella typhimurium and Enterobacter aerogenes by agar well diffusion method. Among the plants screened, W. tomentosa leaf and fruit showed the best antibacterial activity. The Gram-positive bacteria were more susceptible than Gram-negative bacteria. Methanol extract of M. zapota showed the best 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity. Highest total phenol content was shown by M. zapota and S. cumini in methanol extract, while highest flavonoid content was shown by W. tomentosa stem in petroleum ether extract and ethyl acetate extract. In all the plants, cardiac glycosides and triterpenes were more as compared to other phytoconstituents.

Supercritical fluid extraction of paeonol from Cynanchum paniculatum (Bge.) Kitag. and subsequent isolation by high-speed counter-current chromatography coupled with high-performance liquid chromatography-photodiode array detector

Supercritical fluid extraction (SFE) was used to extract paeonol from Cynanchum paniculatum (Bge.) Kitag. The extraction conditions including pressure, temperature, time and sample particle size were optimized with an orthogonal test. Under the optimized conditions of 15 MPa, 55 °C, 1.5 h and a sample particle size of 40–60 mesh, the process was repeated 10 times, and the extract was then collected. The yield of the crude extract from preparative SFE was 6.02%, which contained paeonol 72.02%. Paeonol of crude extract obtained by SFE, Ultrasonic Extraction (UE), Microwave-Assisted (MA), Steam Distillation (SD) and Soxhlet Extraction (SE) were further analyzed by HPLC-PDA to compare the extraction methods, and SFE is considered as the optimum one among the five processes. The SFE extract obtained was then purified successfully by high-speed counter-current chromatography (HSCCC) with a two-phase solvent system composed of petroleum ether–ethyl acetate–methanol–water (2:6:3:4, v/v) in one-step separation. From 2.42 g of the crude extract, 1.07 g of paeonol was obtained at 99.4% purity as determined by HPLC-PDA. These results indicate that SFE and HSCCC are very powerful techniques for the extraction and purification of paeonol from C. paniculatum.