Silica Gel Thin-layer Chromatography Research Articles

Ultra-sensitive lab-on-a-chip detection of Sudan I in food using plasmonics-enhanced diatomaceous thin film

Sudan I is a carcinogenic compound containing an azo group that has been illegally utilized as an adulterant in food products to impart a bright red color to foods. In this paper, we develop a facile lab-on-a-chip device for instant, ultra-sensitive detection of Sudan I from real food samples using plasmonics-enhanced diatomaceous thin film, which can simultaneously perform on-chip separation using thin layer chromatography (TLC) and highly specific sensing using surface-enhanced Raman scattering (SERS) spectroscopy. Diatomite is a kind of nature-created photonic crystal biosilica with periodic pores and was used both as the stationary phase of the TLC plate and photonic crystals to enhance the SERS sensitivity. The on-chip chromatography capability of the TLC plate was verified by isolating Sudan I in a mixture solution containing Rhodamine 6G, while SERS sensing was achieved by spraying gold colloidal nanoparticles into the sensing spot. Such plasmonics-enhanced diatomaceous film can effectively detect Sudan I with more than 10 times improvement of the Raman signal intensity than commercial silica gel TLC plates. We applied this lab-on-a-chip device for real food samples and successfully detected Sudan I in chili sauce and chili oil down to 1 ppm, or 0.5 ng/spot. This on-chip TLC-SERS biosensor based on diatomite biosilica can function as a cost-effective, ultra-sensitive, and reliable technology for screening Sudan I and many other illicit ingredients to enhance food safety.

Transfer of silica gel TLC screening methods for clarithromycin, azithromycin, and amodiaquine + artesunate to HPTLC–densitometry with detection by reagentless thermochemical activation of fluorescence quenching

ABSTRACTA previously published model process was used for the transfer of silica gel thin-layer chromatography (TLC) screening methods for clarithromycin, azithromycin, and amodiaquine + artesunate pharmaceutical formulations published in the Global Pharma Health Fund E.V. Minilab manual for the identification of counterfeit drugs to high-performance TLC–densitometry quantitative methods that can be used in support of regulatory compliance actions. In these new methods, detection of clarithromycin, azithromycin, and artesunate was achieved by thermochemical activation involving simple reagent-free heating of the layer to produce derivatives of the drugs that quench fluorescence under 254 nm ultraviolet light. Additional drugs with TLC screening methods published in the Minilab manual and/or Compendium of Unofficial Methods for Rapid Screening of Pharmaceuticals by Thin Layer Chromatography that do not naturally quench fluorescence were studied and also found to be detectable by thermochemical activation on silica gel layers. The conditions of the thermochemical activation were studied, and in situ spectra of drug zones before and after heating were obtained. Heat activation of fluorescence quenching seems to be a widely applicable detection method that is safer and more convenient than the use of chemical spray, dip, or vapor phase reagents.

Talarofuranone, a New Talaroconvolutin Analog from the Endophytic Fungus Talaromyces purpurogenus from Pouteria campechiana Seeds

An endophytic fungus Talaronyces pinpurogenus was isolated from the seeds of the popular edible fruit Pouteria campechiana. The fungus was fermented in potato dextrose agar and the fungal media were extracted with EtOAc. Chromatographic separation of the EtOAc extracts over silica gel, Sephadex LH-20 and preparative thin layer chromatography furnished a furanone analogue of talaroconvolutin A, named talarofuranone (1), along with talaroconvolutin A (2), 4-hydroxyactophenone, tyrosol and ergosterol. The structure of 1 was determined by comparing the NMR data with that of 2 and by HRFABMS.

Factors influencing induction and in vitro culture of hairy roots in Phytolacca americana L.

To use hairy roots for producing medicinal ingredients of Phytolacca americana L. we studied the factors influencing the induction and in vitro culture. Hairy roots could be incited from the veins of cut surface (morphological lower) of P. americana L. leaf explants around 18 days after infection with the strain of Agrobacterium rhizogenes ATCC15834. The highest rooting rate, 70%, was obtained when leaf explants were pre-cultured for 1 day, infected for 20 min, and co-cultured for 4 days. The transformation was confirmed by PCR amplification of rolC of Ri plasmid and silica gel thin-layer chromatography of opines from P. americana L. hairy roots. All the hairy root lines could grow rapidly on solid exogenous phytohormone-free MS medium. Among the 9 hairy root lines, the hairy root line 2 had most rapid growth, most branched lateral roots and most intensive root hair; the root surface of some hairy root lines seemed purple or red, while that of the other hairy root line appeared white. Among liquid media MS, 1/2MS, B5 and 6,7-V tested, the best growth for hairy root lines was attained in liquid exogenous phytohormone-free MS medium. Compared with exogenous phytohormone-free MS medium, 6,7-V medium was better for synthesis and accumulation of esculento side A in hairy roots. The established optimal conditions for induction and in vitro culture of P. americana hairy roots had laid an experimental and technological foundation for production of medicinal constituents esculento side A from large scale culture of hairy roots.

Determination of chlorzoxazone, diclofenac potassium, and chlorzoxazone toxic degradation product by different chromatographic methods

The presented study was intended to design two validated, simple, and precise chromatographic methods for the determination of chlorzoxazone (CHZ) and diclofenac potassium (DIC) in the presence of chlorzoxazone nephrotoxic degradation product, 2-amino-4-chlorophenol (ACP) which was reported to be its main impurity. Reversed-phase high-performance liquid chromatography (RP-HPLC) was the first method where chromatographic separation was performed on ZORBAX Eclipse Plus C8 column using methanol—water—phosphoric acid (75:25:0.05, by volume) as the mobile phase at a flow rate of 1 mLmin−1. CHZ, DIC, and ACP retention times were found to be 4.26, 7.94, and 3.17, respectively, using photodiode array detector (DAD) at 230 nm. The calibration curves showed good linear relationships in the concentration ranges of 3–45 μg mL−1 for CHZ, 3–40 μg mL−1 for DIC, and 5–45 μg mL−1 for ACP. The second method was thin-layer chromatography (TLC) at which chromatographic separation was carried out on Merck TLC silica gel 60 F2...

Validation of a thin-layer chromatography/densitometry method for the characterization of invertase activity

This paper presents a kinetic study of invertase, a specific fructofuranosidase cloned from the Leishmania major genome. The kinetic parameters of the β-d-fructofuranosidase from Leishmania major (BfrA) were determined using Thin-Layer Chromatography (TLC) and UV-densitometry (TLC@UV) specifically developed for the separation and detection of three carbohydrates namely sucrose, glucose and fructose. Separation was performed on TLC silica gel 60 F254 plates impregnated with sodium bisulphate and citrate and heated prior to development. This fast and easy separation was performed with two successive developments using ACN/H2O 80/20 (v/v) as mobile phase. Sensitive and repeatable derivatization of sugars was achieved by dipping the plates in a solution of 4-aminobenzoic acid. Quantification was performed by UV-detection. The method was validated according to ICH guidelines Q2(R1) in terms of specificity, limits of detection and quantification, precision and robustness (with n=3 replicates and CV ≤10%). The characterization of BfrA reaction kinetic was performed by monitoring the accumulation of either glucose or fructose detected by TLC@UV. Hydrolysis of sucrose was described by the Michaelis-Menten kinetic parameters (KM; Vmax) respectively equal to 63.09±7.590mM; 0.037±0.00094mM/min using glucose production and 83.01±14.39mM; 0.031±0.0021mM/min monitoring fructose. Hydrolyses of three alternative substrates, raffinose, stachyose and inulin, were also compared and the regiospecificity of the reaction was characterized. This TLC@UV method is shown to be suitable for the refined kinetic analysis of different reactions related to the hydrolysis of sugars.

Purity Indicating TLC Method for Quantitative Determination of Phenylephrine and Dimethindine Maleate in Presence of Dimethindine Maleate Impurity: 2-ethyl pyridine in Nasal Gel

The aim of this work was to establish, optimize and validate a sensitive, selective and accurate thin layer chromatographic (TLC) method for determination of Phenylephrine (PHE), Dimetindene maleate (DM) and its major toxic impurity; 2-ethyl pyridine (EP), in raw material and nasal gel. The proposed method was applied for analysis of PHE, DM and EP over the concentration range of 1.00–10.0, 0.50–8.00 and 2.00–20.0 µg/band, respectively. The method is based on the separation of three components followed by densitometric measurement of the separated peaks at 254 nm. The separation was carried out on silica gel TLC F254 plates, using toluene: acetone: isopropyl alc.: ammonia (5.3: 2.7: 1.8: 0.4, by volume) as a developing system. The suggested method was validated according to International Conference on Harmonization guidelines and can be applied for routine analysis in quality control laboratories. The results obtained by the proposed method were statistically com-pared with the official method revealing high accuracy and good precision.

Different chromatographic methods for the simultaneous determination of vitamin E and vinpocetine in their combined dosage form and in the presence of the alkaline-induced degradation product of vinpocetine

Accurate, selective, and sensitive thin-layer chromatography (TLC)—densitometry and reversed-phase high-performance liquid chromatography (RP-HPLC) methods have been developed and validated for the simultaneous determination of vitamin E (VIT E) and vinpocetine (VINP) in the presence of the alkaline-induced degradation product of vinpocetine (DEG). The proposed TLC—densitometric method depends on the separation and quantitation of VIT E, VINP, and VINP alkaline-induced degradation product on TLC silica gel 60 F254 plates, using methanol—chloroform—ethyl acetate—glacial acetic acid—ammonia solution (6:2:2:0.5:0.1, by volume) as the developing system followed by densitometric measurement at 235 nm. The studied components were well resolved from each other with significantly different RF values of 0.81, 0.62, and 0.41 for VIT E, VINP, and DEG, respectively. On the other hand, the developed RP-HPLC method was based on the separation of the studied components using 0.05 M KH2PO4 (adjusted to pH = 3) and methanol in gradient elution mode on C8 column at a flow rate of 1.5 mL min−1 and ultraviolet (UV) detection at 235 nm. The studied components were well resolved from each other with significantly different Rt values of 10.90, 2.89, and 1.90 min for VIT E, VINP, and DEG, respectively. The developed methods were validated according to the International Conference on Harmonization (ICH) guidelines demonstrating good accuracy and precision. The results were statistically compared with those obtained by the reported method, and no significant difference was found. The developed methods are the first developed stability-indicating assay methods (SIAMs) for the analysis of the studied binary mixture.

Aktivitas Antioksidan dan Hepatoprotektor Batang Macaranga Tanarius secara In Vitro

There is strong correlation between antioxidant activity and hepatoprotector activities in vitro. Macaranga tanarius (MT) is abundant at East Kalimantan and the stems were proven to have antioxidant activity, but efficacy as hepatoprotector in vitro and active compounds is not known. The aim of this research is to examine the active fraction of M. tanarius as antioxidant and or hepatoprotector, also it’s active compounds. MT simplicia were macerated with methanol at room temperature for 3 days and repeated three times. The extracts were fractionated with increasing solvent polarity starting from n-hexane, dichloromethane, ethyl acetate (EtOAc), n-butanol and water. Crude extract and the five fractions were tested in vitro for antioxidant activity using radical scavenging activity assay using 2,2-diphenyl-1-picrylhidrazyl and hepatoprotector activity. Chromatogram profiles were done for the most active fraction using thin-layer chromatography silica gel 60 F254. Results showed the strongest antioxidant activity was EtOAc fraction with IC 50 values (6.24 + 0.96) m g/mL and contained secondary metabolites polyphenols that proven having antioxidant activity. The strongest in vitro hepatoprotector activity was also EtOAc fraction with IC 50 values (99 + 2) m g/mL . It can be concluded that EtOAc fraction of MT stems had antioxidant and hepatoprotector activity in vitro and contained secondary metabolites polyphenols with antioxidant activity.

Bioassay guided purification of cytotoxic natural products from a red alga Dichotomaria obtusata

Different solvent extracts of Dichotomaria obtusata (J. Ellis & Solander) Lamark, Galaxauraceae, a red algae collected from the coast of Bushehr in the Persain Gulf, was investigated for its cytotoxic properties and chemical constituents. The fresh alga, after extraction with methanol and dichloromethane were combined and partitioned between water, dichloromethane and ethyl acetate. The above fractions were then tested against MOLT-4 (human lymphoblastic leukemia) cancer cell line. The IC50 values of the dichloromethane and ethyl acetate layers of the crude extract were 29.8±3.1 and 30.6±7.9μg/ml against MOLT-4 cells, respectively, while the water layer showed a week activity with IC50>50μg/ml. After fractionation of the active extracts using open column chromatography over silica gel and preparative thin layer chromatography purification, two terpenoid derived compounds, trans-phytol palmitate and γ-tocopherol were isolated from the dichloromethane and ethyl acetate extracts. The structures of the compounds were elucidated using different spectral data including 1H NMR, 13C NMR, HSQC, HMBC and EI-MS. The IC50 values of compounds trans-phytol palmitate, γ-tocopherol and an undetermined mixture of compounds (F-13-14) were determined as 43.4±1.6, – and 20.3±6.2μg/ml against LS180 (human colon adenocarcinoma); 53.2±9.3, >100 and 27.6±6.9μg/ml against MCF-7 (human breast adenocarcinoma) and 40.0±4.1, 48.8±1.8 and 15.9±0.3μg/ml against MOLT-4 cell lines, respectively, which were comparable to the IC50 values of standard anticancer agent, cisplatin against the same cell lines. The red algae collected from the Persian Gulf contained substances that could inhibit the growth of human cancer cell lines and may represent a natural source for the discovery of novel anticancer agents.

Thin-layer chromatography and chemometric analysis in the fingerprinting of selectedScutellariaspecies

Seven different Scutellaria species were analyzed using the extraction procedure (Soxhlet apparatus, dichloromethane, and methanol as solvents) and thin-layer chromatography method. Selected standards of flavonoids and phenolic acids (caffeic acid, chlorogenic acid, ferulic acid, baicalein, wogonin, baicalin, chrysin, quercetin, scutellarin, hesperetin, hesperidin, apigenin, luteolin, rutin, and kaempferol) were separated using silica gel thin-layer chromatography (TLC) plates with the mobile phase consisting of ethyl acetate—toluene—formic acid (5:4.9:0.1, v/v) for dichloromethane and methanolic extracts. Dichloromethane extracts were also developed using cyanopropyl-bonded silica gel with the following mobile phases: propan-2-ol—n-heptane—formic acid (5:4.9:0.1, v/v) and methanol—water—formic acid (6:3.9:0.1, v/v), and after drying, they were sprayed using the anisaldehyde reagent. In the case of methanolic extracts, the same non-aqueous eluent was used and the aqueous eluent consisting of methanol—wate...

New and sensitive TLC method to measure trans-resveratrol in Physalis peruviana

ABSTRACTtrans-Resveratrol is a polyphenolic compound belonging to the group of stilbenes. The compound has gained increasing interest over the last few years. In this study, the authors present a new way to measure trans-resveratrol in fresh and dried fruits like goldenberries (Physalis peruviana L.) using a combination of a “Quick, Easy, Cheap, Effective, Rugged and Safe” extraction, a thin-layer chromatography (TLC) separation on TLC silica gel 60 plates (Merck, 1.05554) and chemiluminescence detection. A mixture of ethyl acetate, cyclohexane, and n-butanol (9 + 9+2, v/v) was chosen as mobile phase. The Rf-value for trans-resveratrol is 0.78. The method presented is specific and offers a limit of quantification of 20.3 ng trans-resveratrol per band. Our results indicate that goldenberries seem to be a richer source of trans-resveratrol than red wine.

Antifouling Activity of Lipidic Metabolites Derived from Padina tetrastromatica.

An attempt has been made to identify the potential seaweed for antifouling property due to the growing need for environmentally safe antifouling systems. The antibacterial, antimicroalgal, and antimussel foot adherence potentials of methanol, dichloromethane, and hexane extracts of the chosen seaweeds such as Padina tetrastromatica, Caulerpa taxifolia, and Amphiroa fragilissima have been compared against copper sulfate. Among the extracts, the maximum antibacterial activities were exhibited by the methanol extract of P. tetrastromatica. The minimum inhibitory concentration (MIC) of the methanolic extract of P. tetrastromatica was found to be 10 and 1μg/ml against test biofilm bacteria and diatoms, respectively. The antimussel foot adherence assay indicated that the extract had inhibited the foot adherence of the green mussels Perna viridis with the effective concentration (EC50) of 25.51 ± 0.03μg/ml, and lethal concentration for 50% mortality (LC50) was recorded at 280.22 ± 0.12μg/ml. Based on the prolific results, the crude methanolic extract of P. tetrastromatica was subjected to purification using silica gel column and thin-layer chromatography (TLC). Then, the active compounds of the bioassay-guided fraction (F13) were identified using gas chromatography coupled with mass spectroscopy (GC-MS), and it was observed that fatty acids were the major components, which may be responsible for the antifouling properties.

Isolation and Identification of a Flavone Apigenin from Marine Red Alga Acanthophora spicifera with Antinociceptive and Anti-Inflammatory Activities.

Physicochemical investigation of the red alga Acanthophora spicifera (Vahl) Borgesen, collected from Al-Shoaiba coast, Red Sea, Saudi Arabia, led to the isolation of a flavone from the algal tissue with acetone. Preparative chromatography on silica gel thin-layer chromatography was used for the separation of the flavone and eluted with the methanol:chloroform:ethyl acetate (1:7:2) solvent system. The physicochemical analyses infrared, mass spectra, and ultraviolet spectra in addition to shift reagents (NaOMe, NaOAc, NaOAc + H3BO3, AlCl3, and AlCl3 + HCl) were used for the identification and elucidation of the structure of the flavone compound (4,5,7-trihydroxy flavonoids). The flavone compound was identified as apigenin bycomparing its physicochemical data with those in the literature. Analgesic and anti-inflammatory activities of apigenin were evaluated. Apigenin showed promising analgesic and anti-inflammatory activities in the hot plate test and writhing test in mice as well as tail-immersion tests and carrageenan-induced paw edema and cotton pellet-induced granuloma formation in rats. It is concluded that apigenin possesses potent analgesic, anti-inflammatory, and antiproliferative activities, which might be due to the inhibition of PGE2 as well as proinflammatory cytokines such as interleukin-1β, interleukin-6, and tumor necrosis factor-α.

Antiscorpion Venom Activity of an Aromatic Compound having Carbohydrate Moiety Isolated from Hemidesmus indicus (Anantamul) Root Extract in Experimental Animal Models

The present study established the anti scorpion venom activity of an aromatic compound purified from the Indian medicinal plant Hemidesmus indicus (anantamul) root extract in experimental animals. The compound (H.I-1) was isolated by silica gel column chromatography and thin layer chromatography and spectral analysis was done by IR and H1 NMR. Animal ethical clearance was obtained before experiment. Anti scorpion venom activity was evaluated using various in vivo tests, urine qualitative analysis, renal toxicity markers (urea and creatinine), hepatotoxicity markers (AST and ALT), myotoxic markers (LDH and CPK) and oxidative stress markers (LPO, GPX and GSH) in animal models. Statistical analysis was done by one way ANOVA, values expressed as mean±SEM, P<0.05 was considered as statistically significant. Silica gel column chromatography I & II produced an active compound (H.I-1) which gave a single spot on TLC. IR and H1 NMR studies revealed that H.I-1 was aromatic compound having sugar (rhamnose) moiety. It could neutralize scorpion (Heterometrus bengalensis) venom induced hepatotoxicity, renal toxicity, myotoxicity and oxidative stress in experimental animals. These observations confirmed that the aromatic compound H.I-1, isolated from Hemidesmus indicus root extract might be useful in scorpion envenomation and warrants further detailed studies.

DETERMINATION OF SIBUTRAMINE ADULTERATED IN HERBAL SLIMMING PRODUCTS USING TLC DENSITOMETRIC METHOD

Determination of sibutramine adulterated in herbal slimming product using thin layer chromatography (TLC) densitometric method with TLC silica gel 60 F 254 aluminium plate as stationary phase and mixture of toluen-diethylamine (10:0.3) as mobile phase has been developed. The calibration curve in the concentration range of 0.50 to 5.00 µg/spot showed good linier relationship (r 2 = 0.9986). The limit of detection and quantitation (LOD and LOQ) were 217.5 ng and 724.9 ng/spot, respectively. The method gave satisfactory specificity, linierity, precision and accuracy validation criteria and was applied for determination of sibutramine in herbal slimming products obtained from several drugstrores in Depok City, West Java, Indonesia. Results of the determination showed that six of seven samples analyzed were detected containing sibutramine HCl with the concentration of 2.45 - 26.24 mg in a single dosage of slimming herbal products

Isolation and characterization of an antifungal compound 5-hydroxy-7,4'-dimethoxyflavone from Combretum zeyheri.

BackgroundCombretum zeyheri, belongs to the family Combretaceae and is one of the most popular herbal plants in tropical and subtropical countries. The leaves of Combretum zeyheri have been used as herbal medicine and have been reported to have pharmacological activity which includes anti-bacterial, anti-fungal, anticancer and antioxidant properties. The goal of this study was to isolate, identify and characterize compounds from C. zeyheri leaves which are responsible for its antifungal activity.MethodsThe preliminary isolation of C. zeyheri active compounds was carried out using chromatographic techniques which include sephadex gel column chromatography, silica gel column chromatography and thin-layer chromatography (TLC). The isolated compounds were then investigated for their antifungal activity using broth dilution assay. The combined effect of the most potent compound and an antifungal drug miconazole was investigated using the checkerboard assay. Time-kill assays were conducted for the combinations using the colony counting method. The mechanism of action of 5-hydroxy-7,4’-dimethoxyflavone as a potent antifungal agent was investigated by determining its inhibitory activity on Candida albicans drug efflux pumps using the ciprofloxacin assay. The ability of 5-hydroxy-7,4’-dimethoxyflavone to inhibit antioxidant enzymes as well as the biosynthesis of ergosterol were also investigated.ResultsA total of four pure compounds (A-D) were isolated from C. zeyheri leaf extract. Compound B (5-hydroxy-7,4’-dimethoxyflavone) was found to be active against Candida albicans using broth dilution method. This compound was also found to have synergistic activity on growth of C. albicans when combined with miconazole, completely inhibiting growth after only 4 hrs of incubation. Analysis of ergosterol content from Candida albicans showed a time-dependent decrease to 91 % and 63 % at 16 and 24 hrs respectively, in cells treated with ½ MIC of 5-hydroxy-7,4’-dimethoxyflavone. The compound 5-hydroxy-7,4’-dimethoxyflavone also showed inhibition of both the drug efflux pumps (with IC50 = 51.64 μg/ml) and the antioxidant enzymes (at 5 μM).ConclusionThe compound 5-hydroxy-7,4’-dimethoxyflavone may be partly responsible for the reported antifungal activity of C. zeyheri, and may serve as a potential source of lead compounds that can be developed as antifungal phytomedicines.

Highly selective colorimetric and fluorometric chemosensor for cyanide on silica gel and DMSO/H2O (7:3 v/v) mixed solvent and its imaging in living cells

The chemosensor 2,3-bis((E)-((2-hydroxynaphthalen-1-yl)methylene)amino)maleonitrile (1) has been synthesized using 2-hydroxy-1-napthaldehyde and 2,3-diaminomaleonitrile and characterized. Sensor 1 exhibits selective binding with CN− in dimethyl sulfoxide (DMSO)/H2O (7:3 v/v) and DMSO/aqueous Tris (Tris(hydroxymethyl)aminomethane) buffer (7:3 v/v, 10mM, pH 7.2) media with significant changes in its UV–visible and fluorescence spectra. Titration of 1-Zn(II) complex with CN− ion in DMSO/aqueous Tris buffer (7:3 v/v, 10mM, pH 7.2) regenerates the free sensor 1, as supported by UV–visible spectra. 1H NMR titration of 1 with CN‒ in (CD3)2SO confirms the hydrogen-bonding interaction between the two OH groups of the former and the latter in bidentate manner. Sensor 1 impregnated on silica gel thin layer chromatography (TLC) strip followed by dipping in anion solutions in DMSO/H2O (7:3 v/v) generates yellow to red spectacular colour change with CN− ion selectively which can be exploited as potential tool for ready-made detection of toxic CN− ion in environmental and analytical chemistry. Similar visual change in colour for 1 is observed selectively with CN− also when both of them are taken in DMSO/H2O (7:3 v/v) solution. Sensor 1 is used as an imaging reagent for detection of the cellular uptake of CN− ion in Baby Hamster Kidney (BHK-21) cells.

Perilla frutescensExtract Ameliorates Acetylcholinesterase and Trimethyltin Chloride-Induced Neurotoxicity

One of the critical features of Alzheimer's disease is cognitive dysfunction, which is, in part, due to decreases in acetylcholine (ACh). The ethanol extract of Perilla frutescens was selected for isolating the acetylcholinesterase (AChE) inhibitor based on preliminary screening. In vivo behavioral tests were performed to examine the effects of the P. frutescens extract on trimethyltin chloride-induced impairment of learning and memory in mice. A diet containing P. frutescens extract effectively reversed learning and memory impairment on the Y-maze and passive avoidance tests. To isolate the active compound from the P. frutescens extract, solvent partitioning, silica gel open column chromatography, thin-layer chromatography, and high-performance liquid chromatography were used. The AChE inhibitor was identified as rosmarinic acid.

Thin-Layer Chromatography—Densitometry and Thin-Layer Chromatography—Image Analysis for Screening Bile Acid-Binding Activities of Thai Edible Plants

Despite the fact that many researchers have developed different methods for the determination and detection of bile acid sequestrant, the analytical instruments are still quite costly, and expertise is usually required. In order to avoid the above-mentioned problems, simple, rapid, effective, and inexpensive methods to evaluate bile acid-binding are essential. The purpose of this study was to develop a simple and rapid thin-layer chromatography (TLC)—image analysis method to quantitatively determine the bile acid-binding activity of ten edible ethanolic plant extracts. The method was carried out by using TLC silica gel 60 F254 plate with the mobile phase composed of chloroform, methanol, and acetic acid (7:2:1 v/v). The chromatograms were analyzed with image analysis software (ImageJ). The method provided good linearity, accuracy, reproducibility, and selectivity for the determination of bile acid-binding activity. Litsea petiolata extract was found to show the most potent bile acid-binding activity compa...