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Showing papers on "Thin-layer chromatography published in 2002"


Journal ArticleDOI
TL;DR: Both root and leaf extracts were found to inhibit viral replication of the Influenza A virus and anti-inflammatory activity was found to be most pronounced in the more polar fractions.

144 citations


Journal ArticleDOI
TL;DR: The chromatographic, spectrophotometric, and spectroscopic methods usually used for the analysis of oils and fats are reviewed, with special attention to the detection, identification, and quantitation of the triacylglycerol species present in the most common edible vegetable oils.
Abstract: The chromatographic, spectrophotometric, and spectroscopic methods usually used for the analysis of oils and fats are reviewed, with special attention to the detection, identification, and quantitation of the triacylglycerol species present in the most common edible vegetable oils. Also, a review of the methods used for the identification of the regiospecific types of the triacylcglycerol species of oils and fats is presented. Methods of high-performance liquid chromatography in the normal, reversed, silver ion, size exclusion, and chiral modes of thin layer chromatography in the normal, reversed, and silver ion modes of supercritical fluid chromatography with capillary glass or stainless steel columns of capillary gas chromatography and of mass spectrometry in different modes are presented and evaluated. The different sample pretreatment methods, the chromatographic columns, the elution systems, and the detectors and detection modes that have been combined with the above methods are also reviewed. Other spectroscopic methods used for the characterization of the status of an oil or fat, such as ultraviolet, fluorescence, chemiluminescence, infrared, and nuclear magnetic resonance are also reported, selectively. The majority of the triacylglycerol species present in an oil or fat could be analyzed and identified by a particular technique of the reviewed methods, but a complete separation in one single run requires a combination of two or more of the existing techniques, especially for samples with high triacylglycerol species variability.

72 citations


Journal ArticleDOI
TL;DR: The separations of amino acids, pesticides, pharmaceutically active ingredients, phenols, and plasticizers effectively demonstrate the possibilities of the new ultrathin-layer silica-gel plates.
Abstract: The development of ultrathin-layer silica gel plates with a monolithic structure opens up a new dimension in thin-layer chromatography (TLC). The very small layer thickness of approximately 10 microm and the absence of any kind of binder in combination with the framework of this stationary phase lead to new and improved properties of these ultrathin-layer chromatographic (UTLC) silica-gel plates compared with conventional TLC and high-performance TLC (HPTLC) precoated layers. First of all, the advantages of the UTLC plates are the very short migration distances and, in combination with this, the short development times as well as the very low consumption of solvents as the mobile phase in connection with high sensitivity. The separations of amino acids, pesticides, pharmaceutically active ingredients, phenols, and plasticizers effectively demonstrate the possibilities of the new ultrathin-layer silica-gel plates. Furthermore, a comparison of UTLC, HPTLC, and TLC concerning retention behavior, efficiency, detection limits, migration times, and solvent consumption is performed effectively by the separation of caffeine and paracetamol.

63 citations


Journal ArticleDOI
TL;DR: A review of the literature concerning development of the stationary phases for thin-layer chromatography (TLC) in the last ten years is presented, finding a wide range of structural types that can be readily resolved enantiomerically by TLC.
Abstract: This paper presents a review of the literature concerning development of the stationary phases for thin-layer chromatography (TLC) in the last ten years. The silica gel remains the most important adsorbent for TLC separation. The kinetic properties of the silica-gel thin layer and the new TLC plates have been presented. Other materials used as stationary phase were alumina, zirconium oxide, Florisil, and ion-exchanger. Chemically new bonded stationary phase development is also discussed. The improvement of the separations of some organic mixtures by impregnation of silica gel, cellulose, or polyamide plates (with transition metal ions and silver salts) and their applications is presented. The impregnation of the thin layer with organic stationary phase and inclusion complexes is another method used for the enhancement of the separation efficiences. Another modality to improve the selectivity in TLC using ion-pairing as reagent of impregnation is described as well. The actual state of chiral separation by TLC is discussed with concrete references to recent advances in chiral stationary phases. The use of nonpolar chemically bonded stationary phases impregnated with transitional metal ions is presented as chiral stationary phases. The cellulose, modified cellulose, chitin, chitosan, and their derivatives are presented and their potential for the analysis of the racemates is discussed. The cyclodextrines and macrocyclic antibiotics were used with very good results for enantiomeric separation by TLC. A new separation approach with molecular imprinting polymers was reported as a chiral stationary phase in TLC. The examples provide a wide range of structural types that can be readily resolved enantiomerically by TLC.

55 citations


Journal ArticleDOI
TL;DR: In this paper, a thin-layer chromatographic analysis was carried out on silica gel plates, using different eluants and detection reagents, and the analytical recoveries were satisfactory.

48 citations


Journal ArticleDOI
TL;DR: The selectivities of TLC systems were compared by use of correlations between RF(II) and RF(I) (by analogy with two-dimensional TLC) and the greatest spread of points, indicative of individual selectivity, was obtained for nonaqueous mobile phases on silica and aqueousMobile phases on octadecyl silica adsorbent wettable with water.

43 citations


Journal ArticleDOI
TL;DR: Two-dimensional thin-layer chromatography on a cyanopropyl-bonded polar stationary phases has been used to separate phenolic compounds occurring in Flos Sambuci L..
Abstract: Two-dimensional thin-layer chromatography on a cyanopropyl-bonded polar stationary phases has been used to separate phenolic compounds occurring in Flos Sambuci L. The separation was realized by development of the chromatographic plate in two directions with different mobile phases in each direction. Optimum systems were selected by analysis of retention data obtained for a variety of concentrations of polar solvents in a non-polar diluent ( n -hexane) for NP TLC and polar solvents in water for RP TLC, both on thin layers of cyanopropyl-bonded polar adsorbents. The first development was performed by with a non-aqueous mobile phase and the second with an aqueous mobile phase. Eight flavonoids and three phenolic acids were separated by use of the method described.

38 citations


Journal ArticleDOI
TL;DR: This paper presents a systematic literature review of ion-exchange chromatography and gel permeation chromatography, respectively, which have been used in the determination of homogeneity and purification of Na6(CO3)2 in the absence of Na2CO3 in the presence of Na3.

32 citations


Journal ArticleDOI
TL;DR: The lipophilicity (R(Mo)) and specific hydrophobic surface area of seven 1,2-benzisothiazol-3(2H)-ones have been determined by reversed-phase TLC and the effect of different mobile-phase modifiers on the retention has been studied.

28 citations


Journal ArticleDOI
TL;DR: In this paper, the distribution of tannins and flavonoids in E. cicutarium, E. manescavi, and E. pelargoniiflorum were examined by TLC on unmodified silica gel.
Abstract: Natural phenolic compounds, e.g. ellagitannins, gallotannins, and flavonoid glycosides, from the aerial parts of Erodium cicutarium ( Geraniaceae ) have been isolated and identified. The structures of these compounds were determined by conventional methods of analysis and confirmed by MS and NMR spectral analysis. The distribution of tannins and flavonoids in E. ciconium, E. cicutarium, E. manescavi , and E. pelargoniiflorum were examined by TLC on unmodified silica gel and on silica gel chemically modified with polar and nonpolar groups (HPTLC Si 60, HPTLC Si 60 LiChrospher, HPTLC diol, HPTLC CN, and HPTLC RP-18W).

28 citations


Journal ArticleDOI
TL;DR: The proposed method was found to be useful for the routine analysis of pharmaceuticals and pharmacokinetic studies in human urine samples and showed good linear relationship over the concentration range 10-80 ng.

Journal ArticleDOI
TL;DR: The present work was undertaken to use unimpregnated, thin layers of silica gel F254 as an adsorbent and to develop economical and convenient methods for the separation of β-lactam and fluoroquinolone antibiotic drugs.
Abstract: The misuse of antibiotics is frequent and has several undesirable consequences. It is expensive and may obscure the nature of the illness and delay recovery. The most important example of misuse is the treatment of fever without attempting to make a specific diagnosis, an improper dose and the route of administration, the use of two or more drugs when only one is necessary, and the use of a new antibiotic without becoming familiar with its properties. Fatal cases due to penicillin injections are well known. The main reason behind this type of case is the non-performance of preallergy prior to injection. Such medico legal cases are received from modern urban areas as well as from rural areas. Cases of abuse of antibiotic drugs when submitted to laboratories cause problems to the analyst in getting rapid and correct results. Although a review of the literature has revealed that attempts were carried out by earlier workers to find some suitable methods using the TLC technique, not much in the way of a systematic approach has been done. Ampicillin, amoxycillin, benzylpenicillin, benzathine penicillin, becampicillin, cloxacillin, cephalexin, cefotaxime, ceftriaxone, cefadroxil, cefazolin and penicillin G procaine are semi-synthetic cephalosporin β-lactam antibiotics that are active against both Gram-positive and Gram-negative bacteria1 and are widely used for the treatment of infections. Ciprofloxacin (CFLX), norfloxacin (NFLX), enrofloxacin (EFLX), sparfloxacin (SFLX), ofloxacin (OFLX) and pefloxacin (PFLX) are fluorinated quinolone synthetic broadspectrum antibacterial drugs. These fluorinated quinolones are active against many Gram-positive and Gram-negative bacteria through inhibition of their DNA gyrase.2 A literature survey has revealed various TLC methods for the selective separation and simultaneous determination of βlactam3–10 and fluoroquinolone11–16 antibiotic drugs from biological fluids and pharmaceutical formulations. Wagman and Weinstein17 reviewed TLC procedures useful for the identification and differentiation of numerous antibiotics, including penicillins. Belal et al.3 reviewed fluoroquinolone antibiotic drugs up to 1998. Sherma and Fried18 providing more detailed information on the TLC of antibiotics. Hendrickx et al.19 described the separation of 18 penicillins on silica gel and silanized silica gel using 35 mobile phases. Official microbiological methods for determining these drugs suffer from high variability and time-consuming procedures. To overcome this lack of sensitivity and selectivity, thin-layer chromatographic (TLC) and liquid-chromatographic (LC) methods have been developed, which have been reviewed by Moats.20 The present work was undertaken in order to use unimpregnated, thin layers of silica gel F254 as an adsorbent and to develop economical and convenient methods for the separation of β-lactam and fluoroquinolone antibiotic drugs.

Journal ArticleDOI
TL;DR: In this article, plots of R F against modifier concentration, Cmod, are reported for chromatography of thirty-one moderately polar pesticides in systems of the type silica-heptane + modifier (ethyl acetate, tetrahydrofuran, and dioxane).
Abstract: Summary In addition to the fifty pesticides investigated in the first three parts of this study, in this paper plots of R F against modifier concentration, Cmod, are reported for chromatography of thirty-one moderately polar pesticides in systems of the type silica–heptane + modifier (ethyl acetate, tetrahydrofuran, and dioxane).

Journal ArticleDOI
TL;DR: In this article, a 2D graft planar chromatography (GPC) was proposed, in which chromatographic plates are connected for capillary-controlled planar TLC.
Abstract: Of the many chromatographic methods currently available, thin-layer chromatography (TLC) is widely used for the rapid analysis of plant extracts. Although, most practical planar chromatographic problems can be solved by use of a single TLC plate, the power of one-dimensional TLC is often inadequate for clean resolution of the compounds present in complex samples. A marked improvement of the separation for such samples can be achieved by multidimensional (MD) separation procedures. One possible form of multidimensional planar separation is the form of 2D TLC known as graft planar chromatography in which chromatographic plates are connected for capillary-controlled planar chromatography. In this variant of 2D TLC the first development can be performed on an RP-18W HPTLC plate and that in the perpendicular direction on a silica gel TLC plate.

Journal ArticleDOI
TL;DR: A procedure for isolation of cyclic AMP by thin-layer chromatography on silica gel is described, which provides a novel and convenient technique for the assay of adenylyl cyclase.

Journal ArticleDOI
TL;DR: It was possible to characterise the mixture of oligosaccharides used as prebiotics in the formulas now available on the market and this work confirmed that breast-fed infants have a microbic intestinal flora characterised by a marked predominance of bifidobacteria and lactic acid bacteria.

Journal ArticleDOI
TL;DR: Optimal performance laminar chromatography and automated multiple development chromatography are relatively recent techniques of planar Chromatography that can be applied with success in plant material analysis and compare with those of thin-layer chromatography.
Abstract: Optimal performance laminar chromatography and automated multiple development chromatography are relatively recent techniques of planar chromatography that can be applied with success in plant material analysis. Therefore, these methods are used to study plant extracts and constituents belonging to different chemical classes of secondary metabolism: heterocyclic oxygen compounds (coumarins, flavonoids, and anthocyanins), alkaloids and quaternary ammonium salts, cannabinoids, essential oils, ginsenosides, and cardiac heterosides. Generally, the results obtained with these methods are good, and in most cases they compare with those of thin-layer chromatography.

Journal ArticleDOI
TL;DR: In this article, the combined use of four different liquid chromatographic methods is proposed for determination of alkaloid content of poppy capsules, including multilayer overpressured-layer chromatography (MLOPLC), NPHPTLC, normal-phase high-performance thin layer chromatography combined with densitometric evaluation, and a rapid RPHPLC (reversed phase highperformance liquid chromatography) method.
Abstract: Poppy capsules with a high alkaloid content are of great importance to the pharmaceutical industry, because approximately 35 000 tons of straw (capsule with short stem), 350 tons of straw concentrate, and 1000 tons of opium are used annually for extraction of morphinane alkaloids. The combined use of four different liquid chromatographic methods is proposed for determination of alkaloid content. In the first, semi-quantitative, method screening is performed by multilayer overpressured-layer chromatography (MLOPLC) in which 142 samples are separated on silica as stationary phase within 5 s per sample. If the morphine content is >1.3% it is then measured quantitatively by NPHPTLC (normal-phase high-performance thin-layer chromatography) combined with densitometric evaluation. A second, quantitative, determination is always performed by means of a rapid RPHPLC (reversed-phase high-performance liquid chromatography) method in which the separation time is less than 4 min per sample. If the difference between the alkaloid content measured by use of the last two methods is >12% a confirmatory RPHPLC method with increased selectivity and analysis time (15 min) must be used. The high throughput strategy presented has been used for analysis of ca. 15 000 samples per year, per genotype. Systematic selection, cross-breeding, and this analytical strategy with combined planar and column liquid chromatographic methods resulted in the discovery of two new candidate cultivars with high morphine (ca. 2%) and thebaine (ca. 1.5%) content.

Journal ArticleDOI
TL;DR: In this article, a thin-layer chromatographic analysis of trehalose content in sugar-rich products was successfully standardised using silica gel impregnated with phosphotungstic acid of pH 2.5, a solvent system of n -butanol: pyridine: water 8:4:3, and 6.5 mM N-(1-naphthyl)-ethylenediamine dihydrochloride in methanol, containing 3% H 2 SO 4 as the spraying agent.

Journal ArticleDOI
TL;DR: In this article, the thin-layer chromatographic behavior of cholic acid and fourteen of its synthetic derivatives has been studied in six reversed-phase and three normal-phase systems.
Abstract: The thin-layer chromatographic behavior of cholic acid and fourteen of its synthetic derivatives has been studied in six reversed-phase and three normal-phase systems. Four significantly different adsorbents were used — RP-18-silica, CN-silica, polyacrylonitrile adsorbent, and unmodified silica gel. Reversed-phase chromatography was performed with water-organic modifier (methanol, dioxane, or acetone) binary mobile phases of widely variable composition. An approximately linear relationship was obtained between R M values and the amount of organic modifier in the mobile phases investigated. The effect of mobile-phase composition on retention has been considered and the selectivity of the chromatographic systems is also discussed. Separation mechanisms are proposed on the basis of the results obtained. A positive solvation effect was proposed as a predominant factor determining retention under normal-phase conditions whereas hydrophobic interactions of the substances with non-polar parts of the adsorbents w...

Journal ArticleDOI
TL;DR: In this paper, the retention constants determined for the amides are discussed in terms of the physicochemical properties of the solute and the stationary and mobile phases, derived by extrapolation from retention in reversed-phase chromatography.
Abstract: The chromatographic behavior of newly synthesized para -substituted propanoic acid amides has been studied in normal- and reversed-phase thin-layer chromatography. The retention mechanism on different TLC supports was investigated. The retention constants determined for the amides are discussed in terms of the physicochemical properties of the solute and the stationary and mobile phases. R M,w , derived by extrapolation from retention in reversed-phase chromatography, was correlated with hydrophobic parameters π and log P , calculated by the Rekker fragmental method and by use of the commercial program ACD/log P .

Journal ArticleDOI
TL;DR: High performance thin layer chromatography (HPTLC) was used to analyze neutral lipids and phospholipids in the cercariae of a Puerto Rican strain of Schistosoma mansoni, the first study to provide quantitative data on neutral lipid concentrations on a per cerbaria basis for S. mansoni.
Abstract: High performance thin layer chromatography (HPTLC) was used to analyze neutral lipids and phospholipids in the cercariae of a Puerto Rican strain of Schistosoma mansoni. The cercariae were obtained following isolation of Biomphalaria glabrata snails (NMRI strain) experimentally infected with S. mansoni miracidia. Cercariae were pelleted to contain from 1000 to 10,000 organisms per 1.5 mL of artificial spring water and then extracted in chloroform–methanol (2 : 1). The lipid extract was analyzed by previously published silica gel HPTLC methods, using a petroleum ether–diethyl ether–acetic acid (80 : 20 : 1) mobile phase and detection with phosphomolybdic acid spray reagent for neutral lipids. Visual observations of the chromatograms showed that the most abundant neutral lipids in the cercariae were free fatty acids and free sterols along with two additional faster moving zones that did not match the methyl oleate and cholesteryl oleate standard zones. Quantification of the free fatty acid and free...

Journal Article
TL;DR: The results obtained show that TLC based on MIPs could be applied in the direct separation of several beta-adrenergic drugs and offers a rapid, sensitive and reliable method for quality control for these drugs.
Abstract: Molecular imprinted polymers (MIPs) of S-timolol were prepared as chiral stationary phases (CSPs) in thin layer chromatography (TLC). The resolution of the enantiomers of some cardiovascular drugs, including propranolol, atenolol, timolol, nadolol, nifedipine and verapamil were investigated on these CSPs. A mobile phase system of either methanol or acetonitrile was used and the effects of acetic acid content of the mobile phases were also investigated. The best resolution was achieved for enantioseparation of propranolol, timolol and atenolol on plates based on MIP of (-)-S-timolol using methacrylic acid as functional monomer (alpha = 1.52, 1.6, 1.59) respectively, using acetonitrile containing 5% acetic acid and (alpha = 1.47, 1.52, 1.5) in methanol containing 1% acetic acid as mobile phases. The results obtained show that TLC based on MIPs could be applied in the direct separation of several beta-adrenergic drugs. As the side chains on beta-blockers are similar, it is possible that this method could also be used for the resolution of other racemates in this family of drugs. Racemic drugs structurally related to print molecule, were completely resolved into two spots with the MIP plates. In general the retention of (+)-R-isomers was greater than that of (-)-S-isomers, indicating lower stereoselectivity of the MIPs to the dextrorotatory isomers. The method offers a rapid, sensitive and reliable method for quality control for these drugs.

Journal ArticleDOI
TL;DR: A new ecdysteroid glycoside, 2-deoxy-20-hydroxyecdysone 22-O-beta-D-glucopyranoside, is isolated from the herb Silene italica ssp.
Abstract: A new ecdysteroid glycoside, 2-deoxy-20-hydroxyecdysone 22-O-beta-D-glucopyranoside, is isolated from the herb Silene italica ssp. nemoralis (Waldst. and Kit.) Nyman. The compound is purified with multistep chromatography, such as classical column chromatography on alumina and droplet countercurrent distribution. Also, it is expanded using twice low-pressure reversed-phase liquid column chromatography. Chromatography in four steps results in the purified 2-deoxy-20-hydroxyecdysone 22-O-beta-D-glucopyranoside. Two other ecdysteroids have also been separated, including the formerly identified integristerone A and 24(28)-dehydromakisterone A.

Journal ArticleDOI
TL;DR: Commercially available phytol tested was found to be highly stimulatory to oospore formation of both fungi, and was active even at the concentration of 1 ng/basal medium disc.
Abstract: Phytophthora cactorum and P. parasitica formed oospores on basal medium supplemented with corn oil or crude soybean lecithin. The non-saponifiable fraction from these two supplements were stimulatory to oospore formation of both fungi, but the saponifiables were stimulatory to only P. cactorum. When the non-saponifiables were subjected to Florisil column chromatography, the fraction eluted with 25% diethyl ether in hexane was the most stimulatory. Thin layer chromatography (TLC) separated this fraction into three active bands. Among them, the two non-digitonide TLC bands were further separated by high performance liquid chromatography (HPLC), and the active fractions were isolated for gas chromatography-mass spectrometry (GC-MS) analysis. Compounds identified were 3-eicosyne, β-farnesene, tetradecane (2, 6, 10-trimethyl), docosane, hexadecanol (2-methyl), phytol, and pentatriacontane. Commercially available phytol tested was found to be highly stimulatory to oospore formation of both fungi. It was active even at the concentration of 1 ng/basal medium disc.

Journal Article
TL;DR: The assay proved inexpensive, accurate and reproducible with a limit of detection of 100 ng/ml that makes it suitable for bioavailability studies.
Abstract: A simple assay method for theophylline in plasma using thin layer chromatography (TLC) was developed. The method involves extraction of the drug and internal standard (acetaminophen) by chloroform-isopropanol (75:25) followed by separation on TLC silica plates using a mixture of acetic acid, isopropanol, toluene (1: 12: 6), as the eluting solvent. Both peak height ratios and peak are ratios showed high correlation coefficient (r>0.98, p<0.001). However we used peak heights for the determinations. Within-day and between-day coefficients of variation were less than 4.4% and 7.8% respectively. The assay proved inexpensive, accurate and reproducible with a limit of detection of 100 ng/ml that makes it suitable for bioavailability studies.

Journal ArticleDOI
TL;DR: Using the charge difference between Rev.1 and Gen.1 at elevated pH, a simpler, more efficient purification scheme is developed that eliminates the yield-limiting preparative TLC step used in the pilot study.
Abstract: High-speed countercurrent chromatography (HSCCC) is a support-free liquid–liquid partition chromatography (Ito, Y. Crit. Rev. Anal. Chem. 1986, 17 (1), 65–143[1]). As an important separation technique, it eliminates complications between solutes and solid supports and has been used for preparative separation and purification for natural products in recent years. Using a series of chromatographic procedures, four triterpenoid saponins, arganine A, arganine C (Rev. 1), arganine D, and tieghemelin (Gen. 1) were isolated from the seed of the fruit of the rain forest tree, Tieghemella heckelli. In an initial pilot study, a HSCCC and preparative thin layer chromatography were used to isolate the herpesvirus entry inhibitors, Rev.1 and Gen.1, two compounds that are structurally identical except at position C-3 of the aglycone where in Rev.1 the sugar moiety is glucose and in Gen.1, it is glucuronic acid. Utilizing the charge difference between Rev.1 and Gen.1 at elevated pH, we were able to develop a si...

Journal ArticleDOI
TL;DR: Column chromatography and normal-and reversed-phase TLC have been used for the purification, separation, and isolation of coumarins from the fruits of Peucedanum tauricum Bieb as discussed by the authors.
Abstract: Column chromatography and normal- and reversed-phase TLC have been used for the purification, separation, and isolation of coumarins from the fruits of Peucedanum tauricum Bieb. (Umbelliferae = Apiaceae). Preliminary purification of the coumarin sediment obtained from a petroleum ether extract was performed by preparative column chromatography on silica gel with a gradient of ethyl acetate in dichloromethane as mobile phase, and by preparative reversed-phase thin-layer chromatography with 90% aqueous MeOH as mobile phase. Preparative normal-phase TLC with cyclohexane and ethyl acetate as mobile phase, then re-chromatography with more selective mobile phase mixtures of ethyl acetate, dichloromethane, n-heptane, and acetonitrile enabled isolation of four crystalline coumarins (A-D). All the steps of these procedures were monitored by analytical TLC (with detection by UV illumination at λ = 366 nm and densitometric scanning at λ = 320 nm). Isolated crystalline coumarins were identified by comparison with standards in analytical TLC and in RPHPLC with gradient elution, and by melting point (m.p.) measurement and UV spectroscopy. Two were identified as isoimperatorin (A), and bergapten (C); this is the first time these compounds have been isolated from P. tauricum Bieb.

Journal ArticleDOI
TL;DR: In this paper, the separation of nicotinic acid and its derivatives on different stationary phases (silica gel, a mixture of silica gel and kieselguhr, polyamide 11, and RP-18) have been compared.
Abstract: Separations of nicotinic acid and its derivatives on different stationary phases (silica gel, a mixture of silica gel and kieselguhr, polyamide 11, and RP-18) have been compared Relationships between R M values and mobile-phase composition were determined for ten nicotinic acid derivatives The results can be used to predict conditions suitable for extraction of the derivatives of nicotinic acid investigated

Journal ArticleDOI
TL;DR: In this article, a bioassay-guided chromatographic separation using silica gel, Sephadex LH-20, octadecyl SILICA gel, thin layer chromatography, and high performance liquid chromatography was performed to isolate the anticomplementary substances.
Abstract: Chloroform and ethyl acetate extracts of the edible part of Cucurbita moschata Duch, which is commonly used as an oriental medicine as well as a popular food source, showed significant anticomplementary activities on the classical pathway of the complement system. Bioassay-guided chromatographic separation using silica gel, Sephadex LH-20, octadecyl silica gel, thin layer chromatography, and high performance liquid chromatography was performed to isolate the anticomplementary substances. Among the isolated substances, apigenin, phytosterols, and mixture of fatty acids, which were identified by nuclear magnetic resonance and gas chromatography-mass spectrometry, presented the strongest activities. Especially, phytosterols and mixture of saturated fatty acids isolated from the ethyl acetate extracts had 0.74 and 0.67 mg/ml as IC50, respectively, indicating that the ethyl acetate extraction is the best way to isolate the anticomplementary substances from Cucurbita moschata Duch.