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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.

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In this study, the effects of CO2 addition on the growth performance and biochemical composition of the green microalga Tetradesmus obliquus cultured in a hybrid algal production system (HAPS) were investigated. The HAPS combines the characteristics of tubular photobioreactors (towards a better carbon dioxide dissolution coefficient) with thin-layer cascade system (with a higher surface-to-volume ratio). Experimental batches were conducted with and without CO2 addition, and evaluated in terms of productivity and biomass characteristics (elemental composition, protein and lipid contents, pigments and fatty acids profiles). CO2 enrichment positively influenced productivity, and proteins, lipids, pigments and unsaturated fatty acids contents in biomass. The HAPS herein presented contributes to the optimization of microalgae cultures in open systems, since it allows, with a simple adaptation-a transit of the cultivation through a tubular portion where injection and dissolution of CO2 is efficient-to obtain in TLC systems, greater productivity and better-quality biomass.

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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.

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Soybean seeds (Glycine max) were dried under real scale conditions to different final moisture content (m.c.) (9.1, 9.7, 10.9 %, and control with 16.2 %) and processed through extruding-expelling. Results indicated that soybean seed m.c. affected the composition of the soybean expeller and, thus, the oil extraction efficiency (OEE), which increased as the seed m.c. decreased. A polynomic model was proposed for predicting OEE as a function of soybean m.c., indicating that drying soybean to 10 % resulted in an OEE of approximately 65 %. A thin layer drying experiment of soybean seeds indicated that the protein dispersibility index (PDI) was not affected as regards drying air temperatures up to approximately 69 °C, and a bi-linear model with a non-pre-established break point was fitted. The real scale drying treatment in a rack type dryer (mixed flow) did not show any effect (p > 0.05) on the PDI at 80 °C, while at 115 °C a reduction (p < 0.05) was observed (PDI reduction was 0.8 and 2.1 percentage points, respectively).(AU)

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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.

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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.

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Introducción: La queratoconjuntivitis seca es una enfermedad de causa multifactorial, que afecta la producción de lágrimas y la superficie ocular, a la vez que ocasiona malestar, visión borrosa e inestabilidad de la película lagrimal. Métodos: Se realizó un estudio descriptivo y transversal de 50 pacientes con diagnóstico de queratoconjuntivitis seca, atendidos en el Centro Oftalmológico del Hospital General Docente Dr. Juan Bruno Zayas Alfonso de Santiago de Cuba, desde enero hasta julio de 2020. Objetivo: Caracterizar a los pacientes con queratoconjuntivitis seca según variables epidemiológicas clínicas y oftalmológicas. Resultados: En la serie predominaron las féminas (66,0 %), los pacientes mayores de 60 años (40,0 %), la lectura excesiva como factor de riesgo (42,0 %), la irritación, la fatiga ocular y la visión borrosa como criterios diagnósticos, además de la disminución del tiempo de rotura de la película lagrimal en 68,0 % de la muestra, entre otros resultados. Conclusión: La queratoconjuntivitis seca, desde el punto de vista clínico y epidemiológico fue similar a lo descrito en la bibliografía especializada en cuanto a los grupos de edades, sexo y principales síntomas descritos.

Introduction: The keratoconjunctivitis sicca is a disease of multifactorial cause that affects the production of tears and the ocular surface, at the same time that causes discomfort, blurred vision and instability of the lacrimal thin layer. Methods: A descriptive and cross-sectional study of 50 patients with diagnosis of keratoconjunctivitis sicca, assisted in the Ophthalmolgic Center of Dr. Juan Bruno Zayas Alfonso Teaching General Hospital in Santiago de Cuba, was carried out from January to July, 2020. Objective: To characterize patients with keratoconjunctivitis sicca according to clinical, epidemiologic and ophthalmologic variables. Results: In the series there was a prevalence of the females (66.0 %), patients over 60 years (40.0 %), excessive reading as risk factor (42.0 %), irritation, ocular fatigue and blurred vision as diagnostic criteria, besides the decrease of the lacrimal thin layer break up time in 68.0 % of the sample, among other results. Conclusion: The keratoconjunctivitis sicca was similar to that described in the specialized literature review as for the age groups, sex and main described symptoms from the clinical and epidemiologic points of view.

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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.

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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.

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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.

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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.

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Trypanosoma cruzi is the agent of Chagas disease, an infection that affects around 8 million people worldwide. The search for new anti-T. cruzi drugs are relevant, mainly because the treatment of this disease is limited to two drugs. The objective of this study was to investigate the trypanocidal and cytotoxic activity and elucidate the chemical profile of extracts from the roots of the Lonchocarpus cultratus. Roots from L. cultratus were submitted to successive extractions with hexane, dichloromethane, and methanol, resulting in LCH, LCD, and LCM extracts, respectively. Characterization of extracts was done using 1H-RMN, 13C-RMN, CC and TLC. Treatment of T. cruzi forms (epimastigotes, trypomastigotes, and amastigotes) with crescent concentrations of LCH, LCD, and LCM was done for 72, 48, and 48 h, respectively. After this, the percentage of inhibition and IC50/LC50 were calculated. Benznidazole was used as a positive control. Murine macrophages were treated with different concentrations of both extracts for 48 h, and after, the cellular viability was determined by the MTT method and CC50 was calculated. The chalcones derricin and lonchocarpine were identified in the hexane extract, and for the first time in the genus Lonchocarpus, the presence of a dihydrolonchocarpine derivative was observed. Other chalcones such as isocordoin and erioschalcone B were detected in the dichloromethane extract. The dichloromethane extract showed higher activity against all tested forms of T. cruzi than the other two extracts, with IC50 values of 10.98, 2.42, and 0.83 µg/mL, respectively; these values are very close to those of benznidazole. Although the dichloromethane extract presented a cytotoxic effect against mammalian cells, it showed selectivity against amastigotes. The methanolic extract showed the lowest anti-T. cruzi activity but was non-toxic to peritoneal murine macrophages. Thus, the genus Lonchocarpus had demonstrated in the past action against epimastigotes forms of T. cruzi but is the first time that the activity against infective forms is showed, which leading to further studies with in vivo tests.

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The dictyochophyte microalga Pseudochattonella verruculosa was responsible for the largest farmed fish mortality ever recorded in the world, with losses for the Chilean salmon industry amounting to US$ 800 M in austral summer 2016. Super-scale climatic anomalies resulted in strong vertical water column stratification that stimulated development of a dynamic P. verruculosa thin layer (up to 38 µg chl a L-1) for several weeks in Reloncaví Sound. Hydrodynamic modeling (MIKE 3D) indicated that the Sound had extremely low flushing rates (between 121 and 200 days) in summer 2016. Reported algal cell densities of 7000-20,000 cells mL-1 generated respiratory distress in fish that was unlikely due to low dissolved oxygen (permanently >4 mg L-1). Histological examination of salmon showed that gills were the most affected organ with significant tissue damage and circulatory disorders. It is possible that some of this damage was due to a diatom bloom that preceded the Pseudochattonella event, thereby rendering the fish more susceptible to Pseudochattonella. No correlation between magnitude of fish mortality and algal cell abundance nor fish age was evident. Algal cultures revealed rapid growth rates and high cell densities (up to 600,000 cells mL-1), as well as highly complex life cycle stages that can be easily overlooked in monitoring programs. In cell-based bioassays, Chilean P. verruculosa was only toxic to the RTgill-W1 cell line following exposures to high cell densities of lysed cells (>100,000 cells mL-1). Fatty acid profiles of a cultured strain showed elevated concentrations of potentially ichthyotoxic, long-chain polyunsaturated fatty acids (PUFAs) (69.7% ± 1.8%)- stearidonic (SDA, 18:4ω3-28.9%), and docosahexaenoic acid (DHA, 22:6ω3-22.3%), suggesting that lipid peroxidation may help to explain the mortalities, though superoxide production by Pseudochattonella was low (< 0.21 ± 0.19 pmol O2- cell-1 h-1). It therefore remains unknown what the mechanisms of salmon mortality were during the Pseudochattonella bloom. Multiple mitigation strategies were used by salmon farmers during the event, with only delayed seeding of juvenile fish into the cages and towing of cages to sanctuary sites being effective. Airlift pumping, used effectively against other fish-killing HABs in the US and Canada was not effective, perhaps because it brought subsurface layers of Pseudochattonella to the surface, or and it also may have lysed the fragile cells, rendering them more lethal. The present study highlights knowledge gaps and inefficiency of contingency plans by the fish farming industry to overcome future fish-killing algal blooms under future climate change scenarios. The use of new technologies based on molecular methods for species detection, good farm practices by fish farms, and possible mitigation strategies are discussed.

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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.

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BACKGROUND: It is estimated that 20% of the general population is sensitized to some kind of contact allergen. Contact dermatitis is one of the major occupational diseases worldwide. This disease has a higher prevalence in the female gender and is more frequently observed in the third or fourth decade of life. The main objective of this study was to describe the main sociodemographic and clinical characteristics of patients with contact dermatitis treated in the Allergy Unit of the San Juan De Dios Hospital - Caja Costarricense de Seguro Social. METHODS: Clinical records of contact dermatitis outpatients from a single hospital were analyzed, in a 4-year retrospective observational study. RESULTS: At the time of the patch testing, patients showed a mean age of 42.2 years. Disease frequency was higher in the female population (female/male ratio of 4.2:1) and in patients mostly dedicated to household workchores. Most patients presented several years of disease history, and the hands were the highest affected body part. Patch testing revealed that nickel sulfate, Cl+Me-Isothiazolinone (Kathon CG), and thimerosal were allergens regularly associated with contact dermatitis in the analyzed population. CONCLUSIONS: To a great extent, sociodemographic and clinical characteristics identified in these patients resemble what is reported in other regions, including the Americas and worldwide. It is worth highlighting a high female proportion rate probably related to cultural aspects, a smaller percentage of irritant contact dermatitis that may be associated to institutional patient management, and a slight difference in the most common allergens when compared to other published studies.

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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.

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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.

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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.

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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.

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Pumpkin seeds are a major agricultural waste from the fresh-cut produce industry. The objective of this study was to investigate the drying behavior of untreated, whole pumpkin seeds in a fluidized bed dryer at 50-80 °C (2.87 m/s), with a view to producing a high-quality pumpkin powder from dried seeds. Seeds were dried at 50-80 °C to an average equilibrium moisture value of 0.035 to 0.006 g H2O/g DM (3.4 to 0.6% wb). Drying occurred in the falling rate period only and drying rate constants ranged from 0.0226 to 0.0900 1/min with corresponding diffusivity values for the first falling-rate period ranging from 4.68 to 18.63 × 10-10 m2/s. The activation energy (Ea)-for the first falling rate period was determined to be 43.9 kJ/mol. Of the nineteen thin layer models tested, the Alibas model could be successfully used as a general model to predict the Moisture Ratio (MR) data for all temperatures investigated. After drying, seeds were blended to produce powders, which were found to be high in fat, crude protein and fiber.