Phase Thin Layer Chromatography Research Articles

Study on binding affinity profile, bioactivity, and lipophilicity of selected antipsychotic drugs

Schizophrenia is a complex mental illness that affects almost 1% of the population and has no curative treatment. Currently, available neuroleptic drugs have severe limitations and induce drug-related adverse effects. Receptor binding affinity parameters and lipophilicity are important characteristics that describe the bioactivity of these drugs. Lipophilicity is an important physicochemical property of a drug, which predicts distribution, binding to plasma protein, crossing the blood–brain barrier, and biological activity. Five antipsychotic drugs (Haloperidol, Risperidone, Aripiprazole, Olanzapine, and Quetiapine) were selected and the experimental determination of lipophilicity was carried out by reverse phase thin-layer chromatography (RP-TLC) using four types of stationary phases (RP-18, CN, Diol, and NH2 modified silica gel HPTLC plates) and acetonitrile-water with increasing percentage of acetonitrile and 0.2% formic acid in each case as mobile phase. Lipophilicity parameters (mRM and RM0) calculated from the experimental chromatographic retention data were discussed in terms of the correlation with different receptor binding affinity parameters determined by computational methods.

New dihydroxycucurbitacin D's from the Namib desert endemic plant Acanthosicyos horridus (!nara)

Acanthosicyos horridus Welw. ex Hook.f. (!nara) is a leafless, thorny, melon-producing plant endemic to the hyper-arid Namib Desert. The methanol crude extract prepared from the ripe fruits of !nara afforded the known dihydroxycucurbitacin 7β-hydroxy-23,24-dihydrocucurbitacin D (1), along with four new congeners 7β,15β-dihydroxy-23,24-dihydrocucurbitacin D (2), 25-O-β-glucopyranosyl-7β-hydroxy-23,24-dihydrocucurbitacin D (3), 25-O-β-glucopyranosyl-7β-hydroxy-23,24-dihydroisocucurbitacin D (4) and 25-O-β-glucopyranosyl-7β-hydroxy-23,24-dihydro-3-epi-isocucurbitacin D (5). These compounds were isolated through a combination of preparative normal phase thin-layer chromatography (TLC) and semi-preparative reversed phase high performance liquid chromatography (HPLC). Their structures were established by comprehensive analysis of HR-ESI-MS data, 1D and 2D NMR spectroscopic data and by comparison with literature values of similar cucurbitacins. The five isolated compounds exhibited poor cytotoxic activity against the MDA-MB-231 breast cancer cell line. To the best of our knowledge, this is the first report of glycosylated cucurbitacins in Acanthosicyos horridus.

The newly synthesized thiazole derivatives as potential antifungal compounds against Candida albicans

Recently, the occurrence of candidiasis has increased dramatically, especially in immunocompromised patients. Additionally, their treatment is often ineffective due to the resistance of yeasts to antimycotics. Therefore, there is a need to search for new antifungals. A series of nine newly synthesized thiazole derivatives containing the cyclopropane system, showing promising activity against Candida spp., has been further investigated. We decided to verify their antifungal activity towards clinical Candida albicans isolated from the oral cavity of patients with hematological malignancies and investigate the mode of action on fungal cell, the effect of combination with the selected antimycotics, toxicity to erythrocytes, and lipophilicity. These studies were performed by the broth microdilution method, test with sorbitol and ergosterol, checkerboard technique, erythrocyte lysis assay, and reversed phase thin-layer chromatography, respectively. All derivatives showed very strong activity (similar and even higher than nystatin) against all C. albicans isolates with minimal inhibitory concentration (MIC) = 0.008–7.81 µg/mL Their mechanism of action may be related to action within the fungal cell wall structure and/or within the cell membrane. The interactions between the derivatives and the selected antimycotics (nystatin, chlorhexidine, and thymol) showed additive effect only in the case of combination some of them and thymol. The erythrocyte lysis assay confirmed the low cytotoxicity of these compounds as compared to nystatin. The high lipophilicity of the derivatives was related with their high antifungal activity. The present studies confirm that the studied thiazole derivatives containing the cyclopropane system appear to be a very promising group of compounds in treatment of infections caused by C. albicans. However, this requires further studies in vivo.Key points• The newly thiazoles showed high antifungal activity and some of them — additive effect in combination with thymol.• Their mode of action may be related with the influence on the structure of the fungal cell wall and/or the cell membrane.• The low cytotoxicity against erythrocytes and high lipophilicity of these derivatives are their additional good properties.Graphical abstract

In silico Plasma Protein Binding Studies of Selected Group of Drugs Using TLC and HPLC Retention Data.

Plasma protein binding is an important determinant of the pharmacokinetic properties of chemical compounds in living organisms. The aim of the present study was to determine the index of protein binding affinity based on chromatographic experiments. The question is which chromatographic environment will best mimic the drug–protein binding conditions. Retention data from normal phase thin-layer liquid chromatography (NP TLC), reversed phase (RP) TLC and HPLC chromatography experiments with 129 active pharmaceutical ingredients (APIs) were collected. The stationary phase of the TLC plates was modified with protein and the HPLC column was filled with immobilized human serum albumin. In both chromatographic methods, the mobile phase was based on a buffer with a pH of 7.4 to mimic physiological conditions. Chemometric analyses were performed to compare multiple linear regression models (MLRs) with retention data, using protein binding values as the dependent variable. In the course of the analysis, APIs were divided into acidic, basic and neutral groups, and separate models were created for each group. The MLR models had a coefficient of determination between 0.73 and 0.91, with the highest values from NP TLC data.

A New Zinc-based Metal Organic Framework as a Stationary Phase for Thin Layer Chromatography


 Metal organic frameworks (MOFs) are a variety of micro-porous materials which have high surface area, and permanent porosity making them possible options as chromatographic stationary phases. Herein we reported the synthesis and characterization of a new MOF structure and its utilization as a stationary phase for thin layer chromatography (TLC). [Zn(BMAB).DMF]n is a zinc-based MOF with an organic linker consists of chemically distinct binding groups which is 4-{[(1h-1,2,3-benzotriazol-1-yl)methyl]amino}benzoic acid (BMAB). This MOF was synthesized using ultra sound assisted reaction process, then activated via solvent exchange protocol to preserve its porous structure. FT-IR, UV-diffuse reflection spectroscopy (UV-DRS) and differential scanning calorimetry (DSC) were performed to characterize the synthesized MOF. Integrated data from "loss on desolvation" and atomic absorption spectrophotometry (AAS) measurements were used to define the chemical composition of the synthesized material. A specific surface area of 122.9 m2/g was determined for the activated MOF using methylene blue langmuir isotherm method. TLC plates were prepared from the activated form of the structure to investigate its chromatographic characteristics by utilizing it to separate a model mixture of benzidine and o-tolidine using n-propanol: Chloroform: Acetonitrile (50:30:20, v/v/v) as a mobile phase. The retardation factors (Rf), separation factor, and resolution (Rs) were determined via densitometric method at 310 nm to be 0.45 and 0.63 (α=2.08, Rs=1.61) for o-tolidine and benzidine; respectively. The plate was then visualized using iodine chamber method to confirm a successful separation.

Phytochemical Screening of Peronema Canescens Jack

Peronema canescens Jack, locally known as sungkai, is used as medicinal plant because it contains chemical compounds such as peronemins, catechol, quinic acid, isovanillic acid and guaiacol. The study was conducted to determine the chromatographic profile of the P. canescens leaves extract via liquid chromatography. It was found that the optimised mobile phase for thin layer chromatography (TLC) of P. canescens leaves was hexane: ethyl acetate: isopropanol (7:3:0.3). In addition, high performance liquid chromatography (HPLC) chromatograms (λ = 210 and 254 nm) of the methanol extract, run in 0.1% formic acid and acetonitrile, provided eight acceptable peaks.

Four flavonols from the seed of Hibiscus sabdariffa. Linn. growing in Binh Thuan Province

Introduction: Hibiscus sabdariffa Linn. (Malvaceae) is a medicinal plant popularly distributed in Asian countries. As of 2019, no chemical investigations from the Vietnamese plant were found. This paper reported the isolation and elucidation of compounds isolated from the seeds of Hibiscus sabdariffa Linn. (Malvaceae) growing in Binh Thuan province.
 Method: The maceration was applied to the seeds of the plant to afford the crude extract which was then fractionated by liquid-liquid extraction to obtain the ethyl acetate extract. The extract was carried out by using normal phase silica gel column chromatography and thin-layer chromatography. Analysis of spectroscopic data including HR-ESI-MS, 1D and 2D-NMR and a comparison of the NMR data with that in the literature led to the structural elucidation of isolated compounds.
 Results: Four flavonols comprising quercetin 3-O-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranoside (1), quercetin 3-O-β-D-glucopyranoside (2), quercetin (3) and kaempferol (4) were isolated from the ethyl acetate extract.
 Conclusions: This is the first time the isolated compounds were found from the seeds of this plant.

Lipophilicity Determination of Quaternary (Fluoro)Quinolones by Chromatographic and Theoretical Approaches.

Lipophilicity is a vital physicochemical parameter of a molecule, which affects several biological processes such as absorption, tissue distribution, and pharmacokinetic properties. In this study, evaluation of lipophilicities of a series of novel fluoroquinolone-Safirinium dye hybrids using chromatographic and computational methods is presented. Fluoroquinolone-Safirinium dye hybrids have been synthesized as new dual-acting hydrophilic antibacterial agents. Reversed phase thin-layer chromatography and micellar electrokinetic chromatography experiments were carried out. Furthermore, logP values of the target structures were predicted by means of different software platforms and algorithms. In order to assess similarities and dissimilarities of the obtained lipophilicity indexes, cluster analysis and sum of ranking differences were performed. The significant differences of calculated logP values (α = 0.05, p < 0.001) indicated that an experimental approach is necessary for lipophilicity prediction of this class of antibiotics. Chromatographic data indicated that the newly synthesized hybrid (fluoro)quinolone-based quaternary ammonium derivatives show less lipophilic character than the parent (fluoro)quinolones. Additionally, the chromatographically obtained lipophilicity indexes were evaluated for possible application in quantitative retention–activity relationships. The established lipophilicity models have the potential to predict antimicrobial activities of a series of quaternary (fluoro)quinolones against Bacillus subtilis, Escherichia coli, and Proteus vulgaris.

Synthesis, antimicrobial activity, and determination of the lipophilicity of ((cyclohex-3-enylmethylene)hydrazinyl)thiazole derivatives

Synthesis and investigation of antimicrobial activity of fifteen novel thiazoles containing cyclohexene moiety are presented. Among the derivatives, compounds 3a–3d, 3f, 3n, and 3o showed very strong activity against the reference Candida spp. strains with MIC = 0.015–3.91 µg/ml. The activity of these compounds is similar and even higher than the activity of nystatin used as positive control. Compounds 3d, 3f, 3n, 3o showed the highest activity with very strong effect towards most of yeasts isolated from clinical materials with MIC = 0.015–7.81 µg/ml. The cytotoxicity studies for the most active compounds showed that Candida spp. growth was inhibited at noncytotoxic concentrations for the mammalian L929 fibroblast. In addition, a good correlation was obtained between lipophilicity of compounds determined using reversed phase thin-layer chromatography and their antifungal activity.

Bioactive compounds from the leaf extract of Bauhinia galpinii (Fabaceae) used as antidiarrhoeal therapy in southern Africa

Bauhinia galpinii N. E. Br is a shrub or small tree that grows 3–9 m tall throughout South Africa in nature and as ornamental plant. Various parts of the plant are used to cure gastrointestinal tract (GIT) disorders, epilepsy, convulsion, infertility, and amenorrhoea. Despite popular use, the phytochemicals responsible for the medicinal efficacy of the plant has not been exhaustively investigated.Bioautography-guided fractionation was used to isolate the antimicrobial phytochemicals of the acidified 70% acetone leaf extract. A combination of open column chromatography using silica gel 60, Sephadex LH-20, normal phase thin-layer chromatography (TLC) on precoated Kieselgel 60F254 plates and the spots visualized under UV366 and UV254 light, and spray reagents (vanillin/sulphuric acid) were used to isolate compounds. The compounds were identified by UV spectra, extensive 1D and 2D NMR spectroscopy, mass spectrometry and comparison of the data with those reported in the literature. The antimicrobial activity of isolated compounds was determined against Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853), Staphylococcus aureus (ATCC 29213), Enterococcus faecalis (ATCC 29212), Candida albicans (ATCC 10231), clinical isolates of Cryptococcus neoformans, Aspergillus fumigatus, C. albicans (M0824), C. albicans (M0825), C. albicans (1051604),and C. albicans (1051608) using a serial dilution microplate method.Result: Six compounds including two novel (24-Isopropylcholest-5-en-3,8-diol(1) and 5, 7, 4′ 5′ tetrahydroxy-2′-methoxyflavone (isoetin 2′ methyl ether) (4)) and four known (3, 5, 7, 3′, 4′-pentahydroxyflavone (quercetin) (2); 3, 5, 7, 3′, 4′, 5′-hexahydroxyflavone (myricetin) (3); quercetin-3-O-β-galactopyranoside (5) and myricetin-3-O-β-galactopyranoside (6)) were isolated and characterised. The isolated compounds inhibited antimicrobial growth with MICs ranging between 3.9 and 125 μg/.The results may provide a rational support for the traditional use of Bauhinia galpinii leaf in the treatment of infectious gastrointestinal disorders, since antimicrobial compounds especially the flavonoids isolated from the 70% acetone extract may also present in the traditional water extract. They could be responsible for the broad spectrum of antimicrobial activity of B. galpinii extract.

Chemical constituents of Euphorbia tirucalli L.

Euphorbia tirucalli has not been chemically studied much in Vietnam. This research described the isolation and elucidation of compounds isolated from the plant collected in Binh Thuan. Multiple chromatographic methods were applied, including normal phase silica gel column chromatography and thin-layer chromatography. Seven compounds were isolated and their chemical structures were elucidated by spectroscopic analysis as well as comparing their data with the ones in the literature. They are arjunolic acid (1), eriodictyol (2), quercitrin (3), afzelin (4), scopoletin (5), 3,3′,4- trimethylellagic acid (6), and gallic acid (7). Among them, compound 1 a major component was isolated for the first time in Euphorbia genus, while three compounds 2, 4, and 5 were isolated from this species for the first time.

A further investigation on the chemical constituents from Euphorbia tirucalli growing in Binh Thuan province

Introduction: Euphorbia tirucalli L. is a medicinal plant popularly distributed in Asian countries. In Vietnam, only one study on the polar extract the plant Euphorbia tirucalli growing in Binh Thuan province, Vietnam was reported, revealing several phenolic components. As of 2019, no chemical reports on the non-polar extract from the Vietnamese plant were found. This research described the isolation and elucidation of compounds isolated from the non-polar extract of E. tirucalli growing in Binh Thuan province.&#x0D; Method: The n-hexane extract of this plant was carried out by using normal phase silica gel column chromatography, thin-layer chromatography, and gel chromatography (Sephadex LH-20). Analysis of spectroscopic data and a comparison of the NMR data with that in the literature led to the structural elucidation of isolated compounds.&#x0D; Results: Three terpenoid compounds, euphol (1), lupenone (2), and vomifoliol (3), along with ergosterol peroxide (4), ferulic acid (5), and vanillic acid (6) were isolated and elucidated.&#x0D; Conclusions: Among them, compound 3 and 4 were reported in the first time from E. tirucalli.&#x0D;

Comparison of Phenolic Compound Separations by HPTLC and PPEC with SDS as the Mobile Phase Component.

The application of the surfactant (sodium dodecyl sulphate, SDS) as the component of the water-organic mobile phase in thin-layer chromatography and pressurized planar electrochromatography is presented. The influence of various variables on the separation of various phenolic compounds (flavonoids and phenolic acids) as model compounds with systems containing surfactant is discussed. The effect of concentration of butanol and SDS as well as pH of the mobile phase buffer on migration distance of the solute zones is investigated. The presence of SDS in the eluent affects the butanol solubility in the mobile phase. It allows using higher organic solvent concentration systems compared with the mode without surfactant. The amount of SDS in the eluent has the effect on the solute retention, whereas the eluent buffer pH affects the migration distances of ionisable phenolic acids both in HPTLC and PPEC. The migration distances of flavonoid glycosides are considerably longer than those of pure flavonoids. Considering second group of investigated solutes, derivatives of the benzoic acid migrate longer distances in comparison with the cinnamic acid ones. In addition, in the majority of experiments, ionisable compounds (phenolic acids) migrate longer distances in PPEC than nonionisable compounds (flavonoids). Additionally, the order of solutes differs in the PPEC and HPTLC system.

Radial multi-stationary phase thin-layer chromatography for the field-ready fingerprinting of herbal materials

A novel TLC plate design that features multiple screen printed phenyl- and octyl-modified silica gel stationary phases configured as radial sectors was developed for the in-field screening of herbal materials.

Triterpenoids from the wood of Willughbeia cochinchinensis

From the wood of n-hexane extract of Willughbeia cochinchinensis, perform column chromatography on a normal phase silica gel with n-hexane: ethyl acetate obtained in 8 fractions. From GD-D and GD-F fractions, multiple column chromatography on silica gel was performed in combination with normal and reverse phase thin-layer chromatography, four triterpene compounds as epifriedelanol (1), taraxeryl acetate (2), ambolic acid (3) and α- amyrin (4) were isolated. Their chemical structures were determined by spectrocopic methods as well as comparing with data in the literature. These compounds were isolated for the first time from Willughbeia cochinchinensis.

APPLICATION OF THIN LAYER CHROMATOGRAPHY IN EXAMINATION OF THE BIOLOGICAL ACTIVITY PARAMETERS OF AZO DYES

Thanks to the wide range of applications, azo dyes have a special place among synthetic dyes. Also, the application of azo dyes is conditioned by their impact on humans and the environment. Lipophilicity as one of the most important molecular descriptors indicating the potential biological activity of the compound is determined experimentally for selected derivatives of azo dyes using reversed phase thin-layer chromatography (RP TLC18 F254s) in the mixtures of water and two organic modifiers. By using the relevant software packages for the studied azo dyes, the values of partition coefficient (log P) were calculated as standard measure of lipophilicity, important pharamacokinetic predictors and the values of the effective concetration (EC50) as the criteria of acute toxicity for different test organisms. The relationships between chromatographic parameters (RM 0 and m) and calculated biological activity parameters were studied by linear regression analysis.

Extraction, isolation and characterization of depsidones from Usnea baileyi (Stirt.) Zahlbr collected from tree barks in Tam Bo Mountain of Di Linh, Lam Dong Province, Viet Nam

Chemical data on the lichen Usnea baileyi are scarce. The current investigation reports the extraction, isolation and characterization of depsidones from this lichen collected in Lam Dong Province. Eight depsidones were isolated and elucidated, including methylstictic acid (1), stictic acid (2), cryptostictic acid (3), 8’-O-methylmenegazziaic acid (4), menegazziaic acid (5), 8’- O-methylconstictic acid (6), constictic acid (7), and hypoconstictic acid (8). Multi chromatographic methods comprising normal phase silica gel column chromatography and thin layer chromatography were applied to the crude acetone extract to isolate and purify compounds 1-8. Their chemical structures were elucidated by spectroscopic analysis as well as comparing their data with ones in the literature.

Traditional dishes consumed in Zimbabwe and high-performance liquid chromatography (HPLC) quantitation of their antioxidant phytochemicals

Diabetes type 2, cancers, hypertension and obesity have become problematic diseases worldwide calling for more studies on their prevention and management. Antioxidant phytochemicals have shown potential to reduce cases of such chronic diseases therefore the present study quantified antioxidant phytochemicals in traditional dishes consumed in Zimbabwe. Traditional dishes are readily available therefore are cheap and accessible sources of food. Antioxidant phytochemicals were extracted using matrix solid phase dispersion and thin layer chromatography coupled to 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and then quantified using high performance liquid chromatography. The levels of antioxidant phytochemicals ranged from 2 ± 0.5 to 620 ± 3 mg/g for the ethanol extract and 20 ± 3 to 377 ± 5 mg/g for the ethyl acetate extract. Type and amounts of antioxidant phytochemical present in a dish depended upon the thick porridge and relish combination selected. Combinations involving wild vegetables as relish consisted of better levels of antioxidant phytochemicals than meat combinations. No dish consisted of all the types of antioxidant phytochemicals therefore it is necessary to eat a variety. Key words: Diabetes type 2, cancers, hypertension, obesity, phytocompounds.

Silicon diimide gel as an efficient stationary phase in thin layer chromatography for acid-sensitive organic compounds.

We report the use of mesoporous silicon diimide gel as a basic stationary phase in thin layer chromatography for the characterisation and purification of acid-sensitive compounds. The gel is prepared by a simple sol-gel process and exhibits a large specific surface area, almost monodisperse pores and basic properties due to free-hanging amine groups.

アフラトキシンの薄層クロマトグラフィーの移動相の改善とアフラトキシン産生菌におけるジクロルボスの効果の解析

アフラトキシンの薄層クロマトグラフィーの移動相の改善とアフラトキシン産生菌におけるジクロルボスの効果の解析