A paper-based analytical device coupled with electrochemical detection for the determination of dexamethasone and prednisolone in adulterated traditional medicines.

The adulteration of herbal medicines by dexamethasone or prednisolone is regarded as a serious problem in many communities. Herein, a novel platform for the separation and quantification of both target steroids in herbal medicines based on electrochemical paper-based analytical devices (ePADs) has been created. The ePAD was composed of Whatman SG81 chromatography paper, 3D-printed devices and a commercial screen-printed electrode. Whatman SG81 silica-coated paper was used for the separation of dexamethasone and prednisolone based on the difference in their partition coefficients during the flow of the mobile phase. The optimal mobile phase was composed of 60% ethyl acetate in cyclohexane and required 7 min for separation. The separated steroids on the paper were then quantified by electrochemical detection using differential pulse voltammetry, in which the 3D-printed devices facilitated the measurement. Analytical detection ranges of 10-500 µg mL-1 were obtained for both dexamethasone and prednisolone (r2 = 0.988 and 0.994, respectively). The limits of detection for dexamethasone and prednisolone were 3.59 and 11.98 µg mL-1, respectively, whereas the limits of quantification were 6.00 and 20.02 µg mL-1, respectively. The amounts of both target steroids derived from real herbal medicine samples determined by the proposed method were comparable to those obtained with assays using standard high-performance liquid chromatography. In addition, a simple evaporation step can be used to increase the concentration of the samples before analysis. These ePADs are simple, low-cost, rapid, and very promising for on-site quantitative detection.

Quantitation of anthocyanins in elderberry fruit extracts and nutraceutical formulations with paper spray ionization mass spectrometry.

The ability to rapidly identify and quantitate, over a wide range of concentrations, anthocyanins in food and therapeutic products is important to ensuring their presence at medicinally significant levels. Sensitive, yet mild, analysis conditions are required given their susceptibility to degradation and transformation. Paper spray ionization has been used to detect and quantify the levels of anthocyanin levels in extracts of fresh and dried elderberries, and elderberry stems, as well as 3 commercially available nutraceutical formulations. The component cyanidin glucosides, including cyanidin-3-sambubioside, cyanidin-3-glucoside, cyanidin-3,5-diglucoside, cyanidin-3-sambubioside-5-glucoside, and the aglycone cyanidin, were readily detected in a range of sources. Quantitation was achieved by establishing a calibration plot from dilutions of a stock solution of cyanidin-3,5-diglucoside containing malvidin-3,5-diglucoside as an internal standard at a fixed concentration. The same standard was used to quantify the anthocyanin content in the fruit and nutraceutical formulations. Wide 5-fold variations in anthocyanin concentration were detected in the nutraceutical formulations from different suppliers ranging from 1050 to 5430 mg/100 g. These concentrations compared with 500 to 2370 mg/100 g measured in the dried stems and fruit, respectively.

Sugar composition of the pectic polysaccharides of charophytes, the closest algal relatives of land-plants: presence of 3-O-methyl-D-galactose residues.

BACKGROUND AND AIMS: During evolution, plants have acquired and/or lost diverse sugar residues as cell-wall constituents. Of particular interest are primordial cell-wall features that existed, and in some cases abruptly changed, during the momentous step whereby land-plants arose from charophytic algal ancestors. METHODS: Polysaccharides were extracted from four charophyte orders [Chlorokybales (Chlorokybus atmophyticus), Klebsormidiales (Klebsormidium fluitans, K. subtile), Charales (Chara vulgaris, Nitella flexilis), Coleochaetales (Coleochaete scutata)] and an early-diverging land-plant (Anthoceros agrestis). 'Pectins' and 'hemicelluloses', operationally defined as extractable in oxalate (100 °C) and 6 m NaOH (37 °C), respectively, were acid- or Driselase-hydrolysed, and the monosaccharides analysed chromatographically. One unusual monosaccharide, 'U', was characterized by (1)H/(13)C-nuclear magnetic resonance spectroscopy and also enzymically. KEY RESULTS: 'U' was identified as 3-O-methyl-D-galactose (3-MeGal). All pectins, except in Klebsormidium, contained acid- and Driselase-releasable galacturonate, suggesting homogalacturonan. All pectins, without exception, released rhamnose and galactose on acid hydrolysis; however, only in 'higher' charophytes (Charales, Coleochaetales) and Anthoceros were these sugars also efficiently released by Driselase, suggesting rhamnogalacturonan-I. Pectins of 'higher' charophytes, especially Chara, contained little arabinose, instead possessing 3-MeGal. Anthoceros hemicelluloses were rich in glucose, xylose, galactose and arabinose (suggesting xyloglucan and arabinoxylan), none of which was consistently present in charophyte hemicelluloses. CONCLUSIONS: Homogalacturonan is an ancient streptophyte feature, albeit secondarily lost in Klebsormidium. When conquering the land, the first embryophytes already possessed rhamnogalacturonan-I. In contrast, charophyte and land-plant hemicelluloses differ substantially, indicating major changes during terrestrialization. The presence of 3-MeGal in charophytes and lycophytes but not in the 'intervening' bryophytes confirms that cell-wall chemistry changed drastically between major phylogenetic grades.

Isolation and sequence determination of tetrapeptide from Selaginella bryopteris.

A simple and inexpensive paper chromatographic method was developed for the isolation of a small peptide from Selaginella bryopteris fronds. The content of peptides is low in most plants and the isolation and purification procedure is troublesome. This method may be used as a first step for the detection of small peptides in the plant extracts. De novo sequence determination by tandem mass spectrometry indicated that the peptide is a tetrapeptide.

Paper analytical devices for fast field screening of beta lactam antibiotics and antituberculosis pharmaceuticals.

Reports of low-quality pharmaceuticals have been on the rise in the past decade, with the greatest prevalence of substandard medicines in developing countries, where lapses in manufacturing quality control or breaches in the supply chain allow substandard medicines to reach the marketplace. Here, we describe inexpensive test cards for fast field screening of pharmaceutical dosage forms containing beta lactam antibiotics or combinations of the four first-line antituberculosis (TB) drugs. The devices detect the active pharmaceutical ingredients (APIs) ampicillin, amoxicillin, rifampicin, isoniazid, ethambutol, and pyrazinamide and also screen for substitute pharmaceuticals, such as acetaminophen and chloroquine that may be found in counterfeit pharmaceuticals. The tests can detect binders and fillers such as chalk, talc, and starch not revealed by traditional chromatographic methods. These paper devices contain 12 lanes, separated by hydrophobic barriers, with different reagents deposited in the lanes. The user rubs some of the solid pharmaceutical across the lanes and dips the edge of the paper into water. As water climbs up the lanes by capillary action, it triggers a library of different chemical tests and a timer to indicate when the tests are completed. The reactions in each lane generate colors to form a "color bar code" which can be analyzed visually by comparison with standard outcomes. Although quantification of the APIs is poor compared with conventional analytical methods, the sensitivity and selectivity for the analytes is high enough to pick out suspicious formulations containing no API or a substitute API as well as formulations containing APIs that have been "cut" with inactive ingredients.

Validação do método de análise capilar preconizado por hugo platz para o controle de qualidade de tinturas-mães / Validation of Hugo Platz´s method of capillary analysis for quality control of mother tinctures

Um dos insumos mais utilizados na manufatura de medicamentos homeopáticos é a tintura-mãe. Um método aparentemente útil para o controle de qualidade das tinturas-mães é a análise capilar. Este método analítico, tornado público no início do século passado por Hugo Platz, caiu em desuso após o advento de técnicas cromatográficas mais modernas. Embora empregue técnicas simples e de baixo custo, não há estudos de validação da análise capilar. O presente ensaio teve por objetivo validar o método de análise capilar utilizado no controle de qualidade de tinturas-mãe. Para tanto foram obtidos os espectros capilares das tinturas-mãe de Aconitum napellus L., Strychnos nux vomica L. e Anemone pulsatilla L. provenientes de fornecedores nacionais qualificados pela Associação Brasileira de Farmacêuticos Homeopatas. Os atributos avaliados foram precisão, reprodutibilidade e seletividade. Os resultados alcançados recomendam a utilização do método de análise capilar, conforme proposto por Platz, nas análises qualitativas de tinturas-mãe.

Mother tinctures are one of the most common starting materials used in the elaboration of homeopathic medicines. Capillary analysis seems a useful method for quality control of mother tinctures. This method was publicized in the beginning of the 20th century by Hugo Platz to fell into disuse following the development of the modern chromatographic techniques. Despite the simple techniques involved, and the low cost of the overall method, no studies of validation have yet been performed of Platz´s capillary analysis. The present study sought to validate capillary analysis for quality control of mother tinctures. The capillary spectra of mother tinctures of Aconitum napellus L., Strychos nux vomica L. e Anemone pulsatilla L. provided by Brazilian suppliers certified by the Brazilian Association of Homeopathic Pharmacists were obtained. The attributes evaluated were accuracy, reproducibility and selectivity. The results allow recommending the use of capillary analysis as formulated by Platz for qualitative analysis of mother tinctures.

Polyphenolic compounds in Scopolia caucasica Kolesn. ex Kreyer (Solanaceae).

The qualitative and quantitative determinations of coumarins, phenolic acids and flavonoids in the leaves and underground parts of Scopolia caucasica using paper chromatography and HPLC methods were described. From the leaves of this plant, kaempferol 3-O-(2-glucosyl)-galactoside-7-O-glucoside, kaempferol 3-O-(2-glucosyl)-galactoside and quercetin 3-O-glucoside were isolated and identified by spectroscopic methods (UV, 1H- and 13C-NMR).

Microplate assay for inhibitors of the transpeptidase activity of PBP1b of Escherichia coli.

The transpeptidase (TP) activity of penicillin-binding proteins (PBPs), target of the beta-lactam antibiotics, is a well-validated antibacterial drug target. The TP activity of PBP1b converts un-cross-linked peptidoglycan to the cross-linked form. Directly measuring TP activity is difficult because cross-linked and un-cross-linked peptidoglycan have very similar chromatographic properties. The authors report a microdilution plate method to directly measure the TP enzyme activity, uncoupled from the transglycosylase (TG), for detection of TP inhibitors. Escherichia coli membranes were incubated with 100 mM ampicillin, followed by removal of unbound ampicillin. The substrate for the TP, un-cross-linked peptidoglycan, was prepared by incubating these membranes with peptidoglycan sugar precursors, 1 of which was radiolabeled. Subsequently, solubilized PBP1b was added and TP activity assayed. The cross-linked peptidoglycan formed was monitored by addition of wheat germ agglutinin scintillation proximity assay beads plus N-laurylsarcosine, which selectively captures cross-linked peptidoglycan. The PBP1bcatalyzed activity was inhibited by penicillin G but not by cephalexin or cephradine, which have higher affinity for PBP1a. Moenomycin, a TG inhibitor, also inhibited TP activity. Because this is a true enzyme assay, it has the potential to detect novel, non-beta-lactam TP inhibitors and could lead to the discovery of new antibacterial agents.

Selective determination of mimosine and its dihydroxypyridinyl derivative in plant systems.

Our observations on the growth stimulatory nature of mimosine, (beta-(3-hydroxy-4-pyridon-1-yl)-L-alanine), the toxic non-protein plant amino acid, in some model experimental systems, warranted sensitive and selective routine estimations. For the determination of both mimosine and DHP, an indirect spectrophotometric method was developed based on their individual reaction with known excess of DZSAM and by estimating the remaining DZSAM with N-(1-naphthyl)ethylene-diamine (NEDA). The resultant decrease in the secondary coupled product was measured at 540 nm. On equimolar basis, DHP had 40% of the reactivity of mimosine while interference from other relevant compounds was 15-35%. The determination of mimosine and DHP in tissue samples under different physiological conditions was effected after paper chromatographic separation of mimosine and DHP with distinctly differing Rf, from other compounds. The indirect method is superior in terms of absolute selectivity, sensitivity and ease of applicability with linear decreases in absorbance, proportional to increasing concentrations of mimosine from 0.1 to 0.75 microM or DHP from 0.2 to 1.5 microM and with recoveries of 99.2 to 100.5%.

[Study on the purification and scavenging free radical activity of water soluble polysaccharide of leave in Hippohae rhamnoides L].

The crude polysaccharide was extracted from Leave in Hippohae rhamnoides L. with hot water, and precipitated by ethanol. The crude polysaccharide has been fractionated by acidic ethanol. Three fractions (SJ1, SJ2, SJ3) were got respectively. SJ2 deproteinizationed by the combined methods of enzyme and Seveage, purified by DEAE-Sephadex A-25 gel filtration. PC analysis indicated that SJ22 is composed of Xyl,Ara,Glc,Gal,GaL A. The identification of purify by Sepharose CL-4B, paper chromatography and cellulous acetate electrophoresis showed it was homogeneous. Typical absorption of polysaccharides was shown in its IR spectrum. It contained a-glucosidic bonds by IR analysis. It had typical absorption of protein by UV scaning. SJ22 is first isolated from Leave in Hippohae rhamnoides L Scavenging free radical experiment showed that SJ22 was effective in scavenging superoxideradical and hydroxylradical, but only a little effective in scavenging lipid radical.

Structural studies on pectin from marsh cinquefoil Comarum palustre L.

Pectin with [alpha]D(20) +192 degrees (c 0.1; water), named comaruman, was isolated from marsh cinquefoil Comarum palustre L., which is widespread in the European North. The sugar chain of comaruman contains residues of D-galacturonic acid (64%), D-galactose (13%), L-rhamnose (12%), L-arabinose (6%), and trace amounts of xylose and glucose. Partial acid hydrolysis and digestion with pectinase demonstrated that comaruman composed of the backbone comprised regions of linear alpha-1,4-D-galactopyranosyl uronan interconnected by numerous residues of alpha-1,2-L-rhamnopyranose. In addition to the backbone (core of the macromolecule), ramified regions are involved in comaruman and comprise alpha-2,4-L-rhamno-alpha-4-D-galacturonan with side chains consisting mainly of beta-1,4-linked residues of D-galactopyranose. The ramified region contains additionally residues of 5-O-substituted arabinofuranose and 3- and 6-O-substituted galactopyranose. The present 3,4- and 4,6-di-O-substituted residues of galactopyranose appear to be branching points of the side chains. Some galactopyranose residues were found to occupy the terminal positions of the side chains or appeared to be single sugar residues attached to the side chains. Methylation analysis data indicated that comaruman contains residues of terminal, 3- and 3,4-di-O-substituted galactopyranosyl uronic acid, which appeared to be constituents of the side chains, and the latter represented additionally branching points of the backbone.

Phenolic sodium sulphates of Frankenia laevis L.

Four new phenolic anionic conjugates have been isolated from the whole plant aqueous alcohol extract of Frankenia laevis L. Their structures were established, mainly on the basis of ESI-MS, 1D and 2D NMR spectroscopic evidence, as gallic acid-3-methyl ether-5-sodium sulphate, acetophenone-4-methyl ether-2-sodium sulphate, ellagic acid-3,3'-dimethyl ether-4,4'-di-sodium sulphate and ellagic acid-3-methyl ether-4-sodium sulphate.

Flavonoids from Argentine Tagetes (Asteraceae) with antimicrobial activity.

The flavonoids, constituting one of the most numerous and widespread groups of natural plant constituents, are important to humans not only because they contribute to plant colors but also because many members are physiologically active. These low-molecular-weight substances, found in all vascular plants, are phenylbenzopyrones. Over 4000 structures have been identified in plant sources, and they are categorized into several groups. Primarily recognized as pigments responsible for the autumnal burst of hues and the many shades of yellow, orange, and red in flowers and food, the flavonoids are found in fruits, vegetables, nuts, seeds, stems, flowers, and leaves as well as tea and wine and are important constituents of the human diet. They are prominent components of citrus fruits and other food sources. Flavonols (quercetin, myricetin, and kaempferol) and flavones (apigenin and luteolin) are the most common phenolics in plant-based foods. Quercetin is also a predominant component of onions, apples, and berries. Such flavanones as naringin are typically present in citrus fruit, and flavanols, particularly catechin, are present as catechin gallate in such beverages as green or black tea and wine. Some major sources of flavonoids are outlined in Table 1. The daily intake of flavonoids in humans has been estimated to be approx 25 mg/d, a quantity that could provide pharmacologically significant concentrations in body fluids and tissues, assuming good absorption from the gastrointestinal tract. Biological activity of flavonoids was first suggested by Szent-Gÿorgyi 1938, who reported that citrus peel flavonoids were effective in preventing the capillary bleeding and fragility associated with scurvy. The broad spectrum of biological activity within the group and the multiplicity of actions displayed by a certain individual members make the flavonoids one of the most promising classes of biologically active compounds.

[Study of degradation of flavonols in the mutants of poppy (Papaver somniferum L.)]. / Izuchenie degradatsii flavonolov u mutantov maka (Papaver somniferum L.)

We studied flavonol-degrading activity of cell-free extracts from petals of the flower color and structure mutants. The relationship between degradation of flavonols (kaempferol, quercetin, and myricetin) and biosynthesis of anthocyanins has been revealed. The highest flavonol-degrading activity has been revealed in white flower mutants towards all substrates, particularly, quercetin. The mutations inhibiting synthesis of an anthocyanin pelargonidin provide for synthesis of various quantities of cyanidin in the petals. The flavonol-degrading activity considerably increases with the content of cyanidin. A similar relationship has been revealed in the mutants synthesizing both cyanidin and pelargonidin. The plants accumulating considerable quantities of pelargonidin in their petals have accordingly higher flavonol-degrading activity and predominantly hydrolyze kaempferol. The plants forming additional pods in their flower (pistillody) have higher flavonol-degrading activity as compared to the anther-in-petal and doubleness mutants.

[Fingerprint analyses of fructus Forsythiae].

OBJECTIVE: To provide application basis of the Forsythia suspensa by studying the difference of HPLC-FP of F. suspensa fructification (medicinal materials). METHOD: Comparative work was done on F. suspensa produced in different areas, on different parts of Forsythia suspensa, and on the pseudo preducts with methods of HPLC-FP. RESULT: Different FP characteristics were shown respectively by different samples, which were from different producing areas, from different parts, and the pseudo products including the fructification of Syringa reticulata var. and F. viridissimac. CONCLUSION: The FP can be used to distinguish the F. suspensa coming from different producing areas and different sources.

Fingerprint analyses of fructus Forsythiae / 中国中药杂志

<p><b>OBJECTIVE</b>To provide application basis of the Forsythia suspensa by studying the difference of HPLC-FP of F. suspensa fructification (medicinal materials).</p><p><b>METHOD</b>Comparative work was done on F. suspensa produced in different areas, on different parts of Forsythia suspensa, and on the pseudo preducts with methods of HPLC-FP.</p><p><b>RESULT</b>Different FP characteristics were shown respectively by different samples, which were from different producing areas, from different parts, and the pseudo products including the fructification of Syringa reticulata var. and F. viridissimac.</p><p><b>CONCLUSION</b>The FP can be used to distinguish the F. suspensa coming from different producing areas and different sources.</p>

Qualitative detection of selenium in fortified soil and water samples by a paper chromatographic-carboxyl esterase enzyme inhibition technique.

Thevetia peruviana seed carboxyl esterase was employed as a biosensor for the detection of selenium compounds by an enzyme inhibition technique on paper chromatograms. The selenium compounds (sodium selenite and selenium dioxide) appeared as white spots on a magenta background due to the inhibition of Thevetia peruviana seed carboxyl esterase (substrate 1-naphthyl acetate, coupling reagent Fast blue B salt). The minimum detectable amounts were about 5 microg of sodium selenite and 5 microg of selenium dioxide. Many other animal and plant carboxyl esterases gave no inhibition spot under the same conditions. Soil and water samples were fortified with sodium selenite and selenium dioxide. A procedure for preparing test solutions and conditions for paper chromatography was established.

A new flavonoid from Limonium axillare.

A new flavonol glycoside identified as myricetin 3-O-beta-D-sorboside (1) has been isolated from the leaves of L. axillare. The new compound showed a moderate inhibition of Ehrlich ascites carcinoma cells.

Quality control of baccharis trimera (less.) dc. (asteraceae) hydroalcoholic extracts / Quality control of baccharis trimera (less.) dc (asteraceae) hydroalcoholic extracts

Control de calidad de extractos hidroalcohólicos de baccharis trimera (less) dc (asteraceae), la parte aérea de baccharis trimera (less) dc, utilizada comomateria prima vegetal en la preparación de productos fitoterápicos, fué analizada por métodos botánicos, químicos, fisicoquímicos y tecnológicos. Se preparó el extracto hidroalcohólico y se comparó su calidad con la de un extracto acuoso, a través de ensayos sensoriales y fisicoquímicos. Para determinar la calidad de los extractos se empleó cromatografía en papel, en capa fina, líquida al vacío y líquida de alta resolución, utilizándose como sustancias marcadoras la eupatorina y la 3-O-metilquercetina. Con excepción de la cromatografía en capa fina, el resto de las técnicas cromatográficas mencionadas, demostraron ser adecuadas para el control de la calidad de extractos de Baccharis trimera(AU)

Quality control of baccharis trimera (less.) dc. (asteraceae) hydroalcoholic extracts / Quality control of baccharis trimera (less.) dc (asteraceae) hydroalcoholic extracts

Control de calidad de extractos hidroalcohólicos de baccharis trimera (less) dc (asteraceae), la parte aérea de baccharis trimera (less) dc, utilizada comomateria prima vegetal en la preparación de productos fitoterápicos, fué analizada por métodos botánicos, químicos, fisicoquímicos y tecnológicos. Se preparó el extracto hidroalcohólico y se comparó su calidad con la de un extracto acuoso, a través de ensayos sensoriales y fisicoquímicos. Para determinar la calidad de los extractos se empleó cromatografía en papel, en capa fina, líquida al vacío y líquida de alta resolución, utilizándose como sustancias marcadoras la eupatorina y la 3-O-metilquercetina. Con excepción de la cromatografía en capa fina, el resto de las técnicas cromatográficas mencionadas, demostraron ser adecuadas para el control de la calidad de extractos de Baccharis trimera