Increasing Analytical Quality by Designing a Thin-Layer Chromatography Scanner Method for the Determination of the Radiochemical Purity of Radiopharmaceutical Sodium Iodide 131I Oral Solution.

The goal of this study was to apply the principles of analytical quality by design (AQbD) to the analytical method for determining the radiochemical purity (PQR) of the radiopharmaceutical sodium iodide 131I oral solution, utilizing thin-layer chromatography (TLC) with a radio-TLC scanner, which also enables the evaluation of product quality. For AQbD, the analytical target profile (ATP), critical quality attributes (CQA), risk management, and the method operable design region (MODR) were defined through response surface methodology to optimize the method using MINITAB® 19 software. This study encompassed the establishment of a control strategy and the validation of the method, including the assessment of selectivity, linearity, precision, robustness, detection limit, quantification limit, range, and the stability of the sample solution. Under the experimental conditions, the method parameters of the TLC scanner were experimentally demonstrated and optimized with an injection volume of 3 µL, a radioactive concentration of 10 mCi/mL, and a carrier volume of 40 µL. Statistical analysis confirmed the method's selectivity for the 131I iodide band Rf of 0.8, a radiochemical impurity IO3- Rf of 0.6, a linearity from 6.0 to 22.0 mCi/mL, and an intermediate precision with a global relative standard deviation (RSD) of 0.624%. The method also exhibited robustness, with a global RSD of 0.101%, a detection limit of 0.09 mCi/mL, and a quantification limit of 0.53 Ci/mL, meeting the prescribed range and displaying stability over time (at 0, 2, and 20 h) with a global RSD of 0.362%, resulting in consistent outcomes. The development of a method based on AQbD facilitated the creation of a design space and an operational space, with comprehensive knowledge of the method's characteristics and limitations. Additionally, throughout all operations, compliance with the acceptance criteria was verified. The method's validity was confirmed under the established conditions, making it suitable for use in the manufacturing process of sodium iodide 131I and application in nuclear medicine services.

Characterization of Cosmos sulphureus Cav. (Asteraceae): Phytochemical Screening, Antioxidant Activity and Chromatography Analysis.

Cosmos sulphureus Cav. (Asteraceae), and endemic plant of Mexico is used in herbal medicine. In this study, the phytochemical composition, phenolic content, and antioxidant activity of ethanolic and methanolic extracts from C. sulphureus leaves and flowers were determined. The phytochemical analysis showed the presence of compounds such as terpenoids, phenolic compounds, tannins, and flavonoids and the absence of alkaloids, saponins, glycosides, and anthraquinones. The experimental results showed that the extracts have high contents of phenolic, flavonoid, and condensed tannins contents. The phenolic compounds identified in the C. sulphureus extracts by high-performance thin-layer chromatography (HPTLC) include phenolic acids such as chlorogenic acid and caffeic acid as well flavonoids such as rutin and quercetin. The C. sulphureus extracts showed a relevant free radical scavenging activity, ferric-reducing antioxidant power, lipid peroxidation inhibition ability, and oxygen radical antioxidant capacity. This research highlights the phytochemical profile and antioxidant activity of phenolic compounds-rich extracts from C. sulphureus leaves and flowers.

Echinodorus macrophyllus fraction with a high level of flavonoid inhibits peripheral and central mechanisms of nociception.

BACKGROUND AND AIM: Echinodorus macrophyllus (Kunth.) Micheli is popularly used for acute and chronic inflammatory conditions. The anti-inflammatory activity was previously demonstrated for its flavonoid-enriched fractions. The aim of this work assessed the antinociceptive properties of both aqueous extract and its fractions. EXPERIMENTAL PROCEDURE: The antinociceptive activity was determined by acetic acid-induced writhing, formalin test, tail immersion test, hot-plate test, xylene-induced ear edema methods, and the evaluation of its mechanism was performed in the writhing model. The aqueous extract of Echinodorus macrophyllus (AEEm) was fractionated, yielding Fr20, and Fr40. Fr40 composition was determined by HPLC-DAD-ESI-MS. RESULTS AND CONCLUSION: Fr20 (all doses) and Fr40 (100 mg/kg) reduced the nociception in the tail-flick model. Both fractions increased the percentage of maximum possible effect with 25 mg/kg, in the hot-plate assay, at 60 min, while AEEm reduced pain only with 50 and 100 mg/kg. There was a reduction in xylene-edema index, with Fr40 (25 mg/kg), AEEm (50 mg/kg) and Fr20 (50 mg/kg). All doses of AEEm, Fr20, and Fr40 reduced both phases of the formalin model. In the abdominal contortion model, Fr40 presented the highest activity, reducing 96% of contortions and its antinociceptive mechanism was evaluated. The results indicated the involvement of NO and adrenergic activation pathways. The main components of Fr40 are swertisin, swertiajaponin, isoorientin 7,3'-dimethyl ether, swertisin-O-rhamnoside, isoorientin, isovitexin, isovitexin-Orhamnoside, and isovitexin-7-O-glucoside. The aqueous extract of E. macrophyllus leaves and its fractions exhibited significant analgesic effect, mediated through both peripheral and central mechanisms being considered a potentially antinociceptive drug.

Effect-directed analysis in food by thin-layer chromatography assays.

Thin-layer chromatography (TLC) is widely used for food analysis and quality control. As an open chromatographic system, TLC is compatible with microbial-, biochemical-, and chemical-based derivatization methods. This compatibility makes it possible to run in situ bioassays directly on the plate to obtain activity-profile chromatograms, i.e., the effect-directed analysis of the sample. Many of the properties that can be currently measured using this assay format are related to either desired or undesired features for food related products. The TLC assays can detect compounds related to the stability of foods (antioxidant, antimicrobial, antibrowning, etc.), contaminants (antibiotics, pesticides, estrogenic compounds, etc.), and compounds that affect the absorption, metabolism or excretion of nutrients and metabolites or could improve the consumers health (enzyme inhibitors). In this article, different food related TLC-assays are reviewed. The different detection systems used, the way in which they are applied as well as selected examples are discussed.

Identification of type B trichothecenes and zearalenone in Chilean cereals by planar chromatography coupled to mass spectroscopy.

High-performance thin-layer chromatography (HPTLC) and HPTLC coupled with mass spectrometry (MS) methods were described for the simultaneous determination of zearalenone (ZEA); type B trichothecenes (TCT-B); nivalenol (NIV) and deoxynivalenol (DON) along with its acetylated derivatives: 3-acetyldeoxynivalenol (3-ADON) and 15-acetyldeoxynivalenol (15-ADON). The extract samples were cleaned-up with Bond Elut Mycotoxin® solid-phase extraction cartridges. Then, separation was performed on HPTLC silica gel 60 F254 plates using toluene, ethyl acetate and formic acid (1:8:1 v/v/v) as mobile phase. Derivatisation was then performed with 10% aluminium trichloride in 50% methanol. Mycotoxin standards and spiked cereals grains were identified by UV spots at 366 nm, with retention factors (RF) of 0.20 (NIV), 0.39 (DON), 0.45 (15-ADON), 0.50 (3-ADON) and 0.60 (ZEA). Some parameters of validation were determined. Calibration data (n = 5) fitted a linear regression model with determination coefficients, R2 > 0.99. The recovery was determined in triplicate at two levels, ranging from 84.3 ± 2.2% to 114.2 ± 11.7%. Detection limits ranged from 80 to 120 µg kg-1 and quantification limits ranged from 120.0 to 200 µg kg-1. The analysis by HPTLC/electrospray (ESI)-MS in negative mode confirmed the presence of TCT-B and ZEA standards in Chilean cereals with mass signals at m/z 355, 371, 337, and 317 for DON, NIV, 3-ADON and 15-ADON, and ZEA, respectively.

Simple chemical tests to identify Cannabis derivatives: Redefinition of parameters and analysis of concepts.

The chemical identification of Cannabis is commonly carried out using the Duquenois-Levine (DL) colorimetric test. On the other hand, its active substances called cannabinoids are differentiated by thin-layer chromatography (TLC). This work aims to optimize parameters of these two chemical tests using different samples of Cannabis in natura and previously heated (decarboxylated), as well as their isolated bioactive and possible false positives. The efficiency of the DL test without using ether and aliphatic aldehyde was evaluated, comparing the removal or not of the solid sample from the reaction medium after applying different concentrations of the vanillin ethanolic solution. The chemical properties of different cannabinoids and solvents were estimated and correlated with the TLC retention factors. DL tests applied directly to the plant matrix did not show the expected color, even using a high concentration of vanillin. However, obtaining ethanolic extracts from the samples using low vanillin concentration was sufficient without detecting false positives described in the literature. Cannabinoids with high dipole moment ( µ ) were poorly eluted in TLC, indicating a great interaction with the stationary phase. Their identifications could be conducted based on their distinct lipophilic characteristics ( log P OW ) and the choice of a more polar solvent mix ( µ mix ). It is concluded that the DL test can be conducted with reagents of less toxicity, but it is necessary to remove the plant matrix from the reaction medium. The correlation of the TLC results with the chemical properties of cannabinoids and solvents was consistent and can be extrapolated for more complex analyses.

Quantitative Analysis of Rutin by HPTLC and In Vitro Antioxidant and Antibacterial Activities of Phenolic-Rich Extracts from Verbesina sphaerocephala.

Verbesina sphaerocephala A. Gray, like other wild plants of the genus Verbesina, has been used in herbal medicine. There is information for other species of the genus related to their phenolic content, antioxidant capacity, and isolation of bioactive compounds with antimicrobial activity. However, there are no reports for V. sphaerocephala, although it has an important presence in the state of Michoacán, México. In this study, the phenolic composition, quantification of rutin, and in vitro antioxidant and antibacterial activities of methanolic extracts from V. sphaerocephala leaves and flowers were determined. The results showed that all the investigated extracts have high phenolic and flavonoid contents. The flavonoid rutin was identified in all the extracts from V. sphaerocephala by high-performance thin-layer chromatography (HPTLC). The V. sphaerocephala extracts showed scavenging activity against DPPH• and ABTS•+ radicals (IC50 and 5.83 ± 0.50 and 0.93 ± 0.01 mg/mL, respectively) as well as relevant antioxidant capacity (51.05 ± 0.36 mg of ascorbic acid/g of dry tissue). The experimental results show that V. sphaerocephala extracts possessed a strong antimicrobial activity against Escherichia coli and Staphylococcus aureus bacteria. This research indicates that V. sphaerocephala could be considered as a potential source of natural compounds from the point of ethnopharmacological usage.

In Vitro Antifungal Activity of Plant Extracts on Pathogenic Fungi of Blueberry (Vaccinium sp.).

Three pathogenic fungi of blueberry (Vaccinium spp.) responsible for dieback disease, identified as Pestalotiopsis clavispora, Colletotrichum gloeosporioides and Lasiodiplodia pseudotheobromae, were isolated in the northwestern region of the state of Michoacán, Mexico. The mycelial growth in vitro of these fungi was inhibited by extracts from Lantana hirta, Argemone ochroleuca and Adenophyllum porophyllum, medicinal plants collected in Sahuayo, Michoacán, Mexico. The extracts showed different degrees of inhibition; the most effective were: M5L extract from L. hirta and M6LFr extract from A. ochroleuca, both of which inhibited 100% of the mycelial growth of P. clavispora and C. gloeosporioides; and M4LS extract from A. porophyllum, which inhibited 100% of the mycelial growth of the three pathogens. The extracts were fractionated by thin layer and column chromatography, and the most active fractions were analyzed by gas chromatography-mass spectrometry. The major compounds identified in L. hirta extract were Phytol and α-Sitosterol. The compounds identified in A. ochroleuca were Toluene and Benzene, 1,3-bis(3-phenoxyphenoxy)-. In A. porophyllum, the compound identified was Hexanedioic acid, bis(2-ethylhexyl) ester. These results show the potential of L. hirta, A. ochroleuca and A. porophyllum as a source of antifungal compounds.

Color determination method and evaluation of methods for the detection of cannabinoids by thin-layer chromatography (TLC).

Cannabis sativa is the drug of abuse most cultivated, trafficked, and consumed worldwide. One of several techniques used to detect cannabinoids is based on the thin-layer chromatography (TLC). However, the designation of the colors observed can be inaccurate and not reproducible. The designation of colors goes beyond physical and physiological aspects, because what is conventionally called color is a socio-cultural construction. Thus, the objective of this paper was to evaluate the different TLC methods to detection of cannabinoids, and apply standardization method in naming of colors. TLC analysis performed using silica gel 60 F254 as a stationary phase. Three mobile phase compositions [hexane:chloroform (8:2 v:v), hexane:ethyl ether (8:2 v:v), and chloroform:hexane (8:2 v:v)], as well as, two different solutions of Fast Blue B salt (FBBS, Azoic Diazo No. 48) and Fast Blue RR (FBRR, Azoic Diazo No. 24) were evaluated. Determination of colors names was realized through the Sci-Chromus® software. The best resolution was obtained using hexane:ethyl ether (8:2 v:v) as a mobile phase. It was observed that although the cannabidiol (CBD), delta-9-tetrahydrocannabinol (Δ9 -THC), cannabinol (CBN), and cannabigerol (CBG) were detect using both the FBBS- and FBRR-acidified solutions, the best visualization was achieved using the latter reagent. To the best of our knowledge, this is the first study that applied and demonstrated a method for standardization and denomination of colors in the TLC analysis of cannabinoids. This method was able to reduce the subjectivity in naming the colors observed and presented several application possibilities.

Antifungal activity of Brazilian red propolis extract and isolation of bioactive fractions by thin-layer chromatography-bioautography.

OBJECTIVES: This study set out to highlight the in vitro and in vivo antifungal activity of an Ethanolic Extract of Red Brazilian Propolis (EERBP) and identify bioactive fractions effective against Colletotrichum musae. METHODS: Active fractions were detected by the thin-layer chromatography-bioautography method and characterised by HPLC-MSn. RESULTS: The in vitro results showed that EERBP had strong antifungal properties againstC. musae (81 ± 1% inhibition at 1.6 g GAE L-1). Medicarpin, (3S)-vestitol and (3S)-neovestitol were the main compounds identified in the EERBP extract (45% of all detected peaks). Two isolated fractions displayed inhibition percentages of 35 ± 4 and 42 ± 1%, respectively, on C. musae mycelial growth compared to the EERBP extract. The biological activity of the two fractions displayed an additive effect. CONCLUSION: A further in vivo investigation revealed that EERBP is a potential natural alternative for controlling banana crown rot.

Functionality of Agave Bagasse as Supplement for the Development of Prebiotics-Enriched Foods.

Agave bagasse is a fibrous-like material obtained during aguamiel extraction, which is also in contact with indigenous microbiota of agave plant during aguamiel fermentation. This plant is a well-known carrier of the prebiotic fructan-type carbohydrates, which have multiple ascribable health benefits. In the present work, the potential of ashen and green agave bagasse as functional ingredients in supplemented cookies was studied. For its application, the chemical, functional, properties of agave bagasses and formulated cookies were evaluated, as well as the physical properties of cookies. Chemical characterization was carried out by the proximate analysis of both bagasses and cookies, besides, the analysis of oligosaccharides was made by thin-layer chromatography and high-performance anion-exchange chromatography. In the same way, functional properties such as oil holding capacity, organic molecule absorption capacity, swelling capacity, and water holding capacity were analyzed in both agave bagasses and supplemented cookies. Finally, modifications in color and texture due to bagasse addition was studied through an analysis of total color difference and a penetrometric test, respectively. In this sense, ashen and green agave bagasses demonstrated chemical and functional properties for use in the food industry, since they increased oil holding capacity of cookies and transferred prebiotic fructooligosaccharides to both agave bagasse formulations, which remain active as a prebiotic ingredient in cookies after in vitro digestion and cookie manufacture, including thermal treatment. Hence, agave bagasse could be considered a valuable alternative for the addition of the nutritionally-relevant dietary fiber in healthier foods.

Development and validation of a high-performance thin layer chromatography method for the simultaneous quantitation of α- and γ-mangostins in Thai stingless bee propolis

ABSTRACT Stingless bees (Apoidea) are widely distributed and commercially cultivated in artificial hives in fruit gardens. Their propolis are commonly used in traditional medicine to treat various diseases (e.g., abscesses, inflammations, and toothaches) and as a constituent of numerous health products. Thus, this study aimed to (i) develop and validate a high-performance thin layer chromatography method for the quantitation of major active constituents (α- and γ-mangostins) in propolis produced by five stingless bee species (Tetragonula fuscobalteata Cameron, T. laeviceps Smith, T. pagdeni Schwarz, Lepidotrigona terminata Smith, and L. ventralis Smith) cultivated in Thai mangosteen orchards and (ii) determine an optimal extraction solvent. Separation was performed on a silica gel 60 F254 plate using toluene/ethyl acetate/formic acid (8:2:0.1, v/v/v) as a mobile phase, and the developed method was validated to assure its linearity, precision, accuracy, and limits of detection/quantitation. Propolis extract from T. fuscobalteata exhibited the highest mangostin content, and acetone was shown to be more a more effective extraction solvent than dichloromethane, ethanol, or methanol. Thus, the simplicity and reliability of the developed method make it well suited for the routine analysis (e.g., for quality control) of commercial products containing stingless bee propolis.

An analytical strategy for the identification of carbamates, toxic alkaloids, phenobarbital and warfarin in stomach contents from suspected poisoned animals by thin-layer chromatography/ultraviolet detection.

In this study, an analytical strategy to identify brucine, strychnine, methomyl, carbofuran (alkaline compounds), phenobarbital, and warfarin (acid compounds) using thin-layer chromatography (TLC) screening with ultraviolet (UV) detection at 254 nm in stomach content is shown. The optimum mobile phase was found to be a chloroform: ethyl acetate: diethylamine (0.5:8.5:1) mixture for alkaline substances while a mixture of chloroform: acetone (9:1) has given better results for acidic substances. As for extraction, an equal proportion between distillated water and crude material (1:1) is required. For alkaline compounds, a filtration system was created in order to avoid any interferences from the biological matrix while for acidic compounds only centrifugation (4000 rpm/10 minutes) was required to obtain an appropriate sample. After the respective pretreatments, a one-step liquid-liquid extraction (LLE) has been employed for alkaline substances using a 3 mL of chloroform: ethyl ether (2:1) mixture for 2 min while acidic analytes used 3 mL of chloroform only during 5 min. For both methodologies described, the respective organic layers were dried down and re-suspended with 50 µL of methanol for further TLC plate application. The methodologies have been developed, successfully validated and applied to gastric contents from real case samples of suspected animal poisoning. Positive results from TLC/UV screening were confronted with HPLC-UV and confirmed by GC-MS.

Using fluorescent lipids contributes to the active learning of principles underlying lipid signaling.

The concepts of phospholipase activity is often taught in undergraduate biology and biochemistry classes and reinforced in laboratory exercises. However, very rarely does the design of these exercises allow students to directly gain experience in the use of modern instruments such as digital imaging systems and fluorescence spectrophotometers. The laboratory exercise described here involves the use of fluorescent lipids to evaluate phospholipase activity. Students use thin layer chromatography (TLC) to understand how lipids change under different conditions (i.e. abiotic and biotic stress). They explore strategies to separate, visualize and quantify lipids by TLC, digital imaging, and fluorometry. They also have increased opportunities for hands-on practise with experimental design, liposome sample preparation, and implementation of instrumentation commonly used by experienced researchers; all while learning and applying fundamental concepts about lipids. © 2018 International Union of Biochemistry and Molecular Biology, 47(1):100-105, 2018.

Detection of cytokinins and auxin in plant tissues using histochemistry and immunocytochemistry.

We report a new method for histochemical localization of cytokinins (CKs) in plant tissues based on bromophenol blue/silver nitrate staining. The method was validated by immunohistochemistry using anti-trans-zeatin riboside antibody. Indole-3-acetic acid (auxin, IAA) was localized by anti-IAA antibody in plant tissues as a proof for IAA histolocalization. We used root sections, because they are major sites of CKs synthesis, and insect galls of Piptadenia gonoacantha that accumulate IAA. Immunostaining confirmed the presence of zeatin and sites of accumulation of IAA indicated by histochemistry. The colors developed by histochemical reactions in free-hand sections of plant tissues were similar to those obtained by thin layer chromatography (TLC), which reinforced the reactive sites of zeatin. The histochemical method for detecting CKs is useful for galls and roots, whereas IAA detection is more efficient for gall tissues. Therefore, galls constitute a useful model for validating histochemical techniques due to their rapid cell cycles and relatively high accumulation of plant hormones.

Phenolic compounds from Viscum album tinctures enhanced antitumor activity in melanoma murine cancer cells.

Cancer is one of the biggest problems in public health worldwide. Plants have been shown important role in anticancer research. Viscum album L. (Santalaceae), commonly known as mistletoe, is a semi-parasitic plant that grows on different host trees. In complementary medicine, extracts from European mistletoe (Viscum album L.) have been used in the treatment of cancer. The study was conducted to identify chemical composition and antitumor potential of Viscum album tinctures. Chemical analysis performed by high resolution chromatography equipped with high resolution mass spectrometer identified caffeic acid, chlorogenic acid, sakuranetin, isosakuranetin, syringenin 4-O-glucoside, syringenin 4-O-apiosyl-glucoside, alangilignoside C and ligalbumoside A compounds. Some of these compounds are probably responsible for the reduction of tumoral cellular growth in a dose-dependent manner. It was observed that melanoma murine cells (B16F10) were more sensitive to V. album tinctures than human leukaemic cells (K562), besides non-tumoral cells (MA-104) had a much lower cytotoxicity to them. Apoptotic-like cells were observed under light microscopy and were confirmed by a typical DNA fragmentation pattern. Additionally, flow cytometry results using Annexin-V/FITC permitted to quantify increased expression of early and late apoptotic markers on tumoral cells, confirming augmented Sub G0 population, which was probably associated with a consistent decrease in G1, and an increase in S or G2/M populations. Results indicate the chemical composition of V. album tinctures influences the mechanisms of in vitro tumoral cell death, suggesting a potential use in cancer pharmacotherapy research.

TLC separation and antioxidant activity of flavonoids from Carissa bispinosa, Ficus sycomorus, and Grewia bicolar fruits

BACKGROUND: Carissa bispinosa, Ficus sycomorus, and Grewia bicolar are edible fruit plants that grow in the wild. The plants produce yellow-, red-, and purple-colored fruits and thus can be good sources of flavonoids for fighting oxidative reactions in humans, food, and the pharmaceutical industry. The present study aimed at isolating flavonoids from C.bispinosa, F. sycomorus, and G. bicolar fruits and determining their antioxidant activity using the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and 2, 2-azino-bis 3-ethylbenz-thiaz-oline-6-sulfonic acid (ABTS) model radical assays. METHODS: Analytical and preparative thin-layer chromatography was used to isolate flavonoids from the fruits using methanol/chloroform/hexane (7:2:1,v/v/v) as a mobile phase system. The ABTS and DPPH radical scavenging methods were used to test for the antioxidant activity of the samples, using quercetin and catechin as reference standards. RESULTS:Thin-layer chromatographic profiling revealed two different types of flavonoids from each plant.C. bispinosa yielded two flavonoid bands, Rfvalues 0.11 and 0.38;G. bicolaryielded two flavonoid bands,Rfvalues 0.63 and 0.81; andF.sycomorus also yielded two types of flavonoids, Rfvalues 0.094 and 0.81. All the extracted flavonoids exhibited significant antioxidant activity of over 80% at a concentration of 200 mg/L. The order of radical scavenging activity for the 200-mg/Lsamples is G. bicolar Rf(0.81) >C. bispinosa Rf(0.113) >F. sycomorus Rf(0.094) >F. sycomorus Rf(0.047) >C. bispinosa Rf(0.38) >G. bicolar Rf(0.63).G. bicolar(Rf= 0.81) exhibited antioxidant activitythat was superior to that of catechin. CONCLUSION:The present study results show that C. bispinosa,F. sycomorus,and G. bicolar contain different flavonoid types with significant antioxidant activity of over 80% at a concentration of 200 mg/L. Therefore, the fruits can be used as a source of natural antioxidants which can be used as nutraceuticals to promote health, as preservatives to delay peroxidation of foods, and as flavoring for packed foods.

A Novel Raw Starch Hydrolyzing Thermostable α-Amylase Produced by Newly Isolated Bacillus mojavensis SO-10: Purification, Characterization and Usage in Starch Industries

ABSTRACT The aim of this study is the production, purification, and characterisation of thermostable raw starch hydrolyzing α-amylase produced by Bacillus mojavensis SO-10. The maximum production conditions of α-amylase were found at 36th hour, 35 °C and pH 7.0. We utilized three steps to purify the thermostable α-amylase and as a result, 34-fold and 18% yield were obtained. The molecular weight of purified α-amylase was determined as 73 kD. The Km and Vmax rates were detected as 0.010 mM and 3.38 µmol min−1, respectively. This purified α-amylase exhibited the highest activity at pH 5.0-6.0 and 70 ºC and showed stability over a wide variety of pH and temperature at 4.0-8.0, and 40-50 ºC, respectively. The thermostable purified α-amylase exhibited stability in the presence of denaturing agents and heavy metal ions. The purified enzyme hydrolyzed the raw starches of corn and wheat grains in the ratio of 36.7% and 39.2% respectively. The end-yields of soluble starch hydrolysis were analyzed by thin-layer chromatography (TLC). In addition, the usage of purified α-amylase in clarification of apple juice and domestic washing detergent industries were evaluated.

Fructooligosaccharides integrity after atmospheric cold plasma and high-pressure processing of a functional orange juice.

In this study, the effect of atmospheric pressure cold plasma and high-pressure processing on the prebiotic orange juice was evaluated. Orange juice containing 7g/100g of commercial fructooligosaccharides (FOS) was directly and indirectly exposed to a plasma discharge at 70kV with processing times of 15, 30, 45 and 60s. For high-pressure processing, the juice containing the same concentration of FOS was treated at 450MPa for 5min at 11.5°C in an industrial equipment (Hyperbaric, model: 300). After the treatments, the fructooligosaccharides were qualified and quantified by thin layer chromatography. The organic acids and color analysis were also evaluated. The maximal overall fructooligosaccharides degradation was found after high-pressure processing. The total color difference was <3.0 for high-pressure and plasma processing. citric and ascorbic acid (Vitamin C) showed increased content after plasma and high-pressure treatment. Thus, atmospheric pressure cold plasma and high-pressure processing can be used as non-thermal alternatives to process prebiotic orange juice.

Análisis espectroscópico del precipitado formado de la mezcla de Hipoclorito de Sodio y Clorhexidina . Estudio In Vitro . Parte II

l objetivo de este estudio fue analizar el precipitado formado por la interacción de dos disoluciones acuosas: una de hipoclorito de sodio al 5.25% y otra de gluconato de clorhexidina al 2%, por medio de cromatografía de capa fina (TLC) y un análisis detallado de espectroscopia de resonancia magnética nuclear (RMN-¹H a 600 MHz y RMN-¹³C a 100 MHz) en una y dos dimensiones. Para esto, se establecieron 3 grupos de estudio: el Grupo A correspondiente a gluconato puro de clorhexidina que fue liofilizado y secado al vacío, el Grupo B: los precipitados obtenidos al combinar 2 ml de la disolución de gluconato de clorhexidina con 2 ml de la disolución de hipoclorito de sodio y el Grupo C, una muestra comercial de PCA (4-Cloroanilina 98%,). El sólido correspondiente al grupo B, fue lavado, centrifugado y seco en estufa de vacío sin calentamiento por más de 72 horas. Una vez seco, se corrieron placas de capa fina (TLC) en diversas mezclas de elución, y se encontró que el precipitado consistía de una mezcla compleja de sustancias similares a la clorhexidina y que no poseía PCA. Los análisis de espectroscopia de resonancia magnética nuclear mostraron que la señal del carbono base del grupo amino de la PCA, a δ/146.5 ppm (grupo C), no se encontraba en el espectro de ¹³C de las muestras del grupo B lo que implica, la ausencia de PCA en la muestra B. El análisis del grupo B por medio de la misma técnica, mostró una mezcla compleja de señales que corresponden probablemente, a estructuras similares a la clorhexidina y a potenciales derivados aromáticos con una estructura similar a esta, nuevamente, no se encuentran evidencias de PCA.

he aim of this study was to analyze the precipitate formed by the mixture of 5,25% sodium hypochlorite (NaOCl) and 2% chlorhexidine (CHX) through thin layer chromatography and nuclear magnetic resonance spectroscopy (RMN-¹H, 600 MHz and RMN-¹³C to 100 MHz) 1D and 2D spectra. Thus, the following groups were established: Group A corresponds to a pure freeze-dried chlorhexidine gluconate , Group B made-up by a combination of 2ml of chlorhexidine 2% and sodium hypochlorite 5.25% and Group C was a commercial sample of PCA (4-Chloroaniline 98%). The samples of group B were rinsed with distillated water and spinned during 15 minutes at 25°C, the supernatant was eliminated by vacuum and vacuum chamber for 72 hours without heating. Finally, the solid was grinded and dried in vacuum chamber for 24 hours without heating. Thin layer chromatography, shows that sample B were composed by more than one chemical substance and Chlorexidine, the RMN-¹³C showed that the signal of the amino group characteristic of PCA appears down field (δ/146.5 ppm) in C group, meanwhile in group B appears up field (δ/129ppm), which demonstrates the absence of PCA during the process. The analysis of Group B by RMN-¹³C results also, in different signals of low intensity that correspond to similar structures to chlorhexidine and potential aromatics derivatives with similar characteristics structures to chlorhexidine.