Thin-layer Chromatography Plates Research Articles

Analysis of polyisoprene oligomers via in situ silver nanoparticle formation on thin-layer chromatography plate using matrix-assisted laser-induced desorption/ionization mass spectrometry.

The direct mass spectrometry (MS) detection of polyisoprene (PI) oligomers on a thin-layer chromatography (TLC) plate using matrix-assisted laser-induced desorption/ionization (MALDI) with silver trifluoroacetate as the cationization reagent was investigated. The spots of PI oligomers and silver trifluoroacetate on the TLC plate resulted in brown materials after UV laser irradiation. It was suggested that silver trifluoroacetate yielded Ag nanoparticles as brown materials after heating via laser irradiation. The nanoparticles behaved as an inorganic matrix and a source of Ag+ adduct in the analysis of PI oligomers. The use of organic matrices together with silver trifluoroacetate reduced the signal intensity of PI oligomers on MALDI-MS on a TLC plate. The separation of PI oligomers (polymerization degree, n = 5-11) by TLC resulted in a single elliptical spot without a clear separation after the chromatographic procedure. However, in MS imaging, differences in migration lengths based on degrees of polymerization were clearly observed and the degrees of polymerization were identified without comparison with standards.

Fluorescent probe for the detection of acetylcholinesterase inhibitors using high performance thin layer chromatography effect-directed assay in complex matrices

In recent years Bioautography has become an efficient bioassay for finding active compounds in complex matrices including extracts of; bacteria, plants or fungi. High Performance Thin Layer Chromatography (HPTLC) is a technique which allows effect-directive analysis (EDA) through the separation and identification of biologically active substances on a Thin Layer Chromatography (TLC) plate and can be run as a high throughput screening assay for enzymes. This paper presents a new bioautography method using a novel fluorescent probe derived from coumarin and its validation with Acetylcholinesterase (AChE) inhibition. This method combines the advantages of bioautography and the high sensitivity of fluorescence for detection. Combining these advantages, the limit of detection (LOD) and limit of quantification (LOQ) limits usually obtained with traditional chromophores has been reduced by three times. Therefore our new method has been applied on 14 mushroom extracts and we highlight a compound (variegatic acid) as a potentially new AChE inhibitor in X. Chrysenteron.

Comparative Study of Densitometry and Videodensitometry for Quantitating the Active Pharmaceutical Ingredients Using Thin Layer Chromatography – Systematic Review

Background: Chromatography is one of the analytical techniques widely used for the quality control process in the pharmaceutical industry. One of the analytical methods used in drug analysis is Thin Layer Chromatography (TLC). The analysis process of TLC can be performed using densitometry (scanner) or videodensitometry (videoscan). The principal analysis of densitometry (scanner) is based on the density measured from each spot on the TLC plate using a specific wavelength range, and videodensitometry (videoscan) is performed by taking pictures of the plate using a Visualizer at a specific wavelength. Objective: This review article discusses the application of densitometry and videodensitometry methods for quantitative analysis of pharmaceutical products. Methods: This study was conducted using a systematic review method using the PRISMA statement from January to April 2023. Four databases were searched: PubMed, ScienceDirect, Scopus, and Google Scholar with inclusion criteria: studies on thin layer chromatography analysis using densitometry and videodensitometry. Results: Based on the ten articles in this study, it is known that the active ingredient concentrations in pharmaceutical products can be determined using densitometry and videodensitometry. The statistical analysis results show no significant difference between the two methods' chemical concentrations of active ingredients in pharmaceutical products. Conclusion: TLC densitometry and videodensitometry is a valid methods analysis that can be used for quantitating the active pharmaceutical ingredient concentration in finished pharmaceutical products.

A Thin-Layer Chromatography Method for the Determination of Essential Oil Components in Anise and Fennel Fruits

Scientific relevance. The State Pharmacopoeia of the Russian Federation, edition XIV, requires the identification of aniseed and fennel fruits by the same thin-layer chromatography (TLC) procedure using Sudan III and menthol. These markers are neither specific nor related to the therapeutic effects of these herbal drug products. The visual interpretation of chromatograms is complicated because of the low intensity of adsorption zones. Moreover, the corresponding compendial monographs do not characterise the adsorption zones specific to each of the plants. The most abundant component in aniseed and fennel essential oils, trans-anethole, would make a better reference standard from a methodological point of view.Aim. This study aimed to optimise the TLC procedure for essential oil determination in herbal drugs and herbal medicinal products of aniseed and fennel fruits and subsequently recommend it for inclusion in the relevant compendial monographs.Materials and methods. The study examined samples from several batches of herbal drugs, including aniseed and common fennel fruits, sourced from Russian manufacturers. The reference standards comprised commercial reagents, including trans-anethole, anise oil, and linalool, as well as fresh essential oils that had been steam distilled from the test samples in a Clevenger apparatus. The study was conducted by TLC. Sample preparation involved using Merck aluminium TLC plates, an IKA KS-501 digital orbital shaker, and a CAMAG Linomat 5 semi-automatic sample application system. The authors heated the plates in either a Binder ED53 drying oven or a CAMAG TLC plate heater. For visualisation, the authors selected a CAMAG TLC VISUALIZER 2 UV imaging and documentation system.Results. The informational and experimental research showed the feasibility of using trans-anethole as an identification reference standard for common anise and fennel fruits. The authors selected the optimal solvent for extracting active substances from the test products (hexane) and a detection reagent for improving visual evaluation of the chromatograms (1% sulfovanillin). The authors established characteristic adsorption zones for differentiating between aniseed and fennel fruits.Conclusions. The optimised procedure identifies the main components in the essential oils of aniseed and fennel fruits with a specific reference standard. This procedure may be recommended for inclusion in draft monographs for the corresponding herbal medicinal products.

In situ enrichment and determination of 6 kinds of caine-type anesthetics in cosmetics and rat serum by thin layer chromatography-Raman spectroscopy

A simple, economical and selective method has been established for simultaneous detection of 6 kinds of caine-type anesthetics in cosmetics and rat serum by in situ enrichment thin layer chromatography (TLC) and Raman spectroscopy. The target caine-type anesthetics, procaine hydrochloride (Pro), tetracaine hydrochloride (Tet), dibucaine (Dib), mepivacaine hydrochloride (Mep), lidocaine hydrochloride (Lid) and ropivacaine hydrochloride (Rop), were separated by TLC. The original spots (or position of Rf equal to that of the standard) of anesthetics on TLC plates were in situ enriched into much smaller ones driven by solvent from different directions, and followed by Raman measurement for quanlitative and quantitative analysis, resulting in the improvement of sensitivity and selectivity. Optimization and standardization of the experimental conditions, the composition and proportion of developing solvent, were conducted. Thus a robust and reliable approach which enabled effective separation, accurate identification and quantification has been developed with the lowest detectable amounts of 0.4, 0.2, 1.2, 1, 1 and 1 μg for Pro, Tet, Dib, Mep, Lid and Rop, respectively. The established method was successfully applied in anesthetics analysis in cosmetics (essence, cream and gel) and rat serum without complex sample pretreatment processes, and the results were verified by HPLC. It turned out that the in situ enrichment TLC-Raman technique was feasible and effective for separation and determination of 6 caine-type anesthetics in biological samples and cosmetics, and would have good prospects for on-site qualitative screening of prohibited goods and adulterants.

THIN LAYER CHROMATOGRAPHIC TECHNIQUES FOR DETECTION OF SUDAN DYES IN PALM OIL

Sudan dyes I, II, III & IV are synthetic, oil-soluble, red-coloured azo dyes. These dyes are suspected genotoxic carcinogens and have been used in the adulteration of palm oil products. Many experimental studies on animal specimen have confirmed the formation of tumour due to the presence of different Sudan dyes in food products. In this study, a Simple Thin Layer Chromatographic method is described for the qualitative detection of Sudan-I, II, III & IV in palm oil gotten from different markets. The study includes extraction of sample, preparation of Thin Layer Chromatography (TLC) plates, Separation, detection and visualization of dyes on TLC plates. The dyes were extracted with solvent Acetonitrile. Sample extracts were decanted and analysed by simple thin layer chromatography in hexane, chloroform and acetic acid solvent system. The chromatograms of samples and standards were stained with Iron (ii) chloride stain and further evaluated in term of Rf values. Out of the five samples analysed the Rf values of the colouring spots from the three samples L2, L3 and L4, matched the standards (S2). It is therefore, concluded that samples L2, L3 and L4 contain Sudan IV dye. Without using any derivation, the limit of detection (18mg/L for S2 (Sudan IV dye) and 10mg/L for SI (Sudan III dye) was determined by visually determining if a spot was visible or not at a certain concentration of standard dye.

A home-based approach to demonstrate column and thin layer chromatography during the COVID-19 pandemic.

The COVID-19 pandemic caused several educational challenges. Conducting laboratory experiments was an uphill task during the pandemic. Here, we developed a low-cost and reliable home-based experimental setup to teach column and thin layer chromatography (TLC) using silica gel granules available at home. Powdered silica gel, prepared by grinding silica gel granules, was used as the stationary phase. Iso-propyl alcohol, purchased from a pharmacy, was diluted with water and used as the mobile phase. A food coloring was chromatographically separated using the designed column. Moreover, TLC plates were prepared using powdered silica gel and a drop of food coloring was separated on TLC plates using the same mobile phase. In the article, we show our experiences by providing methods used to implement this experimental setup. We assume that this experimental setup will be helpful for other universities, research institutes and schools to develop online laboratory curricula to demonstrate basic chromatography techniques required for subjects such as chemistry, biochemistry and biology.

Isolation and identification of bioactive compounds from Tinospora cordifolia stem extracts as antibacterial materials in seawater environments

The Tinospora genus is widely utilized because of its numerous bioactive compounds. This work aimed to isolate the bioactive constituents and antibacterial activities of the T. cordifolia plant. Maceration, column chromatography, and thin-layer chromatography plates were utilized to identify and visualize the extracted and isolated compounds. Total phenolics and flavonoids in the extracts and active fractions were also analysed. Substances were identified through their molecular structure and molecular mass. The names, molecular weights, and structures of the components of the test materials were verified using Fourier transform infrared (FT-IR) spectroscopy and nuclear magnetic resonance (1H NMR, 13C NMR, HMQC, and HMBC). The minimum inhibitory concentration (MIC) values were 3294, 156, and 32 µg/mL for the crude extract, active fraction, and isolate of T. cordifolia, respectively. The total phenol active fraction was 38.44 mg GAE/g, while the total flavonoid content was 79.46 mg QE/g. N-trans-Feruloyltyramine or Moupinamide, a phenol group compound with a molecular ion weight of 314 m/z (M + H)+, was successfully isolated as the bioactive compound. The moupinamide isolate may be responsible for the antibacterial activity of T. cordifolia in this work. Our findings indicate that the bioactive isolate from T. cordifolia is a potential source of green material and exhibits the potential to inhibit P. aeruginosa biofilm, which is responsible for microbial corrosion.

Synthesis of Ag-Cu-Ni Nanoparticles Stabilized on Functionalized g-C3N4 and Investigation of Its Catalytic Activity in the A3-Coupling Reaction.

In the present research, using ethylenediamine and hydrazine hydrate as the capping and reducing agents in this investigation, respectively, Ag-Cu-Ni NPs were immobilized on the functionalized g-C3N4 surface. This nanocatalyst was studied in terms of its catalytic activities for the A3-coupling reaction to synthesize propargylamine derivatives. According to the results, in the presence of 1 mL of toluene as the solvent and 20 mg of the g-C3N4-TCT-2AEDSEA-Ag-Cu-Ni nanocatalyst, the maximum efficiency of the nanocatalyst occurred at a temperature of 80 °C. Products were purified using thin-layer chromatography plates (silica gel) by employing n-hexane/ethyl acetate with a 90:10 ratio. In addition, the prominent benefits of the synthesized nanocatalyst include its high yields of the product, cost-effectiveness, recyclability, and easy separation. The novelty of the catalyst is due to the presence of Ag-Cu-Ni nanoparticles at the same time in the structure of the functionalized g-C3N4 substrate. So, Ag-Cu-Ni can be strongly connected to the substrate. The structure of the synthesized nanocatalyst was characterized using Fourier transformed infrared spectroscopy, X-ray powder diffraction, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, vibrating-sample magnetometry, and transmission electron microscopy.

Effect of Sample Plates and Sample Matrix on the Quantification Capabilities of Surface-Assisted Flowing Atmospheric-Pressure Afterglow Mass Spectrometry (SA-FAPA-MS).

Ambient desorption/ionization mass spectrometry (ADI-MS) has been broadly applied to accomplish direct analysis without sample preparation or separation. However, quantification capabilities and analytical performance are sometimes limited. Here, we report signal enhancement effects and improved quantification capabilities in plasma-based ADI-MS, when a flowing atmospheric-pressure afterglow (FAPA) source is used to probe analytes on tailored thin-layer chromatography (TLC) plates. It was found that quantitative results could be achieved when the TLC plate merely served as a sampling plate without a preceding separation step. Specifically, the dynamic response of caffeine, nicotine, acetaminophen, and progesterone was investigated with FAPA-MS on a variety of different TLC surfaces (normal-phase silica, reversed-phase-modified silica, cyano [CN]-modified silica, and dimethyl [RP2]-modified silica). All analytes were studied as single-analyte standards and in a multianalyte mixture to evaluate the effect of sample plates and sample matrix on analytical performance and competitive ionization processes. Overall, dimethyl (RP2)- and CN-modified silica resulted in superior performance compared to other TLC materials. After careful optimization and without the use of internal standards, linear ranges of five orders of magnitude were accessible for caffeine and nicotine. Limits of detection down to femtomole amounts of analyte were achieved. Quantitation limits using RP2-TLC and FAPA-MS were 0.062, 0.062l, 0.31, and 14 pmol for caffeine, nicotine, progesterone, and acetaminophen, respectively. Interestingly, the presence of nicotine at relatively high amounts reduced the signal of the other analytes, an observation that was found to correlate with the differences in the enthalpy of vaporization (ΔHvap) and proton affinity. To prove the quantitative capabilities, nicotine quantification in a real matrix-heavy e-liquid sample was demonstrated using an isotopically labeled standard. The use of TLC-based surfaces with FAPA-MS can aid in the direct and quantitative mass spectrometric investigation of complex mixtures.

Evaluation of phytochemicals and amino acid profiles of four vegetables grown on a glyphosate contaminated soil in Southwestern Nigeria

Abstract Green vegetables are examples of staple plants eating in Nigeria, and are assumed to be a well-off basis of phytochemicals and amino acids that are useful for the management and prevention of infections. However, in the farming of these vegetables, glyphosate-based herbicides (GBH (round up™)) are used as control against pests invasions which has cause reasons to be concern about their effects on the phyto-constituents present in these vegetables. In this study, we evaluated the phytochemicals constituents and amino acid profile of the leaves of Telfairia occidentalis Hook F, Amaranthus viridis Linn, Celosia argentea Linn and Cnidoscolus aconitifolius (Mill.) I. M. Johnst popular edible vegetables in Southwestern Nigeria. The vegetables seeds of these plants mentioned above were acquired from Institute of Agricultural Research and Training (IAR&T) Ibadan. And on a land designed and previously treated with a GBH (round up™) the seeds were planted and allowed to grow. A destructive method of leaves after maturation was achieved by out rightly plucking them out and air-drying under shade. Phytochemical assessments were done on milled plant samples to determine the presence of ten phyto-constituents. Centrifugation of powdered samples (2 g each) with acetonitrile at 1000 rotations per minute’s (rpm) was used to extract amino acids. Thereafter the extracts were individually spotted on a thin layer chromatography (TLC) plate and developed using the mobile phase consisting of methanol: acetic acid: water in ratio 7:2:1 v/v. The visualization for the presence of amino acids was completed by spraying the developed chromatographic plates with 0.5% ninhydrin in 2-propanol solution and observed in both day light and under the ultraviolet lamp and the retention factor (R f ).calculated for the different spots developed to determine the type of amino acids present. The assessment of phytochemicals from the four vegetables reveals the presence of alkaloids, tannins and steroids in all samples while anthraquinone glycosides, terpenoids and cardiac glycosides were absent and other phytochemicals varying in them. Ssaponins was found absent in Telfairia occidentalis and flavonoids in Cnidoscolus aconitifolius respectively. The observation of the TLC plates in daylight shows that the vegetables likely contained primary, secondary and proline amino acids while the calculation of the R f values of the TLC spots observed under an ultraviolet (UV) light indicated that amino acids found in the vegetables were methionine, tyrosine, leucine, isoleucine. However, phenylalanine was found only in Celosia argentea. The study evaluated phytochemicals and amino acids parameters in four leafy vegetables grown on contaminated glyphosate based herbicide soil and assessments shows that their medicinal properties were not altered with the minimal exposure to contaminant.

Novel Hyperspectral Analysis of Thin-Layer Chromatographic Plates-An Application to Fingerprinting of 70 Polish Grasses.

The advantages of hyperspectral imaging in videodensitometry are presented and discussed with the example of extracts from 70 Polish grasses. An inexpensive microscope camera was modified to cover the infrared spectrum range, and then 11 combinations of illumination (254 nm, 366 nm, white light), together with various filters (no filter, IRCut, UV, cobalt glass, IR pass), were used to register RGB HDR images of the same plate. It was revealed that the resulting 33 channels of information could be compressed into 5-6 principal components and then visualized separately as grayscale images. We also propose a new approach called principal component artificial coloring of images (PCACI). It allows easy classification of chromatographic spots by presenting three PC components as RGB channels, providing vivid spots with artificial colors and visualizing six principal components on two color images. The infrared region brings additional information to the registered data, orthogonal to the other channels and not redundant with photos in the visible region. This is the first published attempt to use a hyperspectral camera in TLC and it can be clearly concluded that such an approach deserves routine use and further attention.

PHYTOCHEMICAL SCREENING, TLC PROFILE AND 1H NMR ANALYSIS OF Passiflora foetida EXTRACTS

Passiflora foetida also known as red fruits passionflower is widely found in Malaysia. Previous studies on this plant reported its therapeutic properties such as anticancer, antidiabetic, anti-hyperpigmentation, antioxidant, analgesic, anti-inflammatory, anti-acetylcholinesterase, and antimicrobial activities. In this study, different parts of the plant (aerial, stem, leaf and fruit) were used for the phytochemical screening such as alkaloid, flavonoid, terpenoid and saponin tests. The aerial, leaf and stem parts show positive results in all tests, however, there are slightly different in color intensity of each test. The fruit, except for terpenoid, shows positive results in alkaloid, flavonoid and saponin tests. Then, thin layer chromatography (TLC) profile was carried out in various solvent systems including chloroform/methanol (9:1) solvent system and ethylacetate/hexane (1:9). The TLC profile shows that chloroform/methanol (9:1) solvent system give better separation of compounds as compared to ethylacetate/hexane (1:9) solvent system. There are characteristic spots found on the TLC plate that possibly attributed to the presence of flavonoids, steroids, and terpenoids. Moreover, the fresh aerial part extract of P. foetida was analyzed using 1H-NMR and found some signals that indicated the presence of phenolic and flavonoid compounds in the extract. This study can act as a preliminary study that provides the information on the metabolite profile of different parts of P. foetida and might be useful for the future study.

ANALYSIS AND CHEMICAL PROFILING OF HONEY USING 1H-NMR SPECTROSCOPY, FTIR SPECTROSCOPY AND TLC USING VARIOUS CHROMOGENIC REAGENTS FOR DERIVATIZATION

Objective: Honey is a natural sweet substance known for various health benefits and is used in many traditional medicines and dietary supplements. It contains various bioactive constituents like sugars, amino acids, polyphenols, flavonoids and various minerals. Quality control of honey is an essential part for ensuring its health benefits and therapeutic usage. In the present study, honey was analyzed by using various spectroscopic approaches and physicochemical methods. Methods: The samples of honey were analyzed by Thin-layer Chromatography (TLC) derivatization, ATR-FTIR, and 1H-NMR fingerprint and the total phenolic content (TPC) and total flavonoid contents (TFC) were measured by Uv-Vis spectrophotometry and analysis were carried out for various physicochemical parameters of honey. Results: All the physicochemical parameters of the honey were as per the desired quality. The UV-Vis analysis was successfully used in the determination of total phenolics and flavonoid contents in the samples of honey. TLC analysis showed the presence of flavonoids, phytosterols, phenolics, sugars and carbohydrates in honey. The Thin-Layer chromatography analysis showed good resolution for various components of honey on the TLC plates. The FTIR analysis showed the presence of various functional groups characteristic of amino acids, carbohydrates and sugars, which was further supported by 1H NMR chemical profiling. Conclusion: In the present work, the application of various spectroscopic techniques and physicochemical tests were found to be useful in analysis of honey.

Rapid, convenient, and ultrasensitive point-of-care sensing of histamine from fish: A Portable chromatographic platform based on derivatization reaction

Food poisoning caused by histamine ingestion is one of the prevalent allergies associated with fish consumption in the world. Reliable detection of histamine from fish by a portable platform was of urgent importance to food safety. A portable technology for on-site monitoring of histamine in tuna was established through combined azo-derivatized thin-layer chromatography (TLC) with surface-enhanced Raman scattering (SERS) spectroscopy. The real tuna meat sample was directly applied onto the portable sensor for the separation of histamine and azo-derivatizing of histamine was reacted on the TLC plate. The colorless histamine was visualized by azo-derivatization after spraying Pauly reagent onto the diatomite TLC plate. The molecule information and concentration of the histamine was measured and calculated by SERS spectra. Diatomite TLC plate was capable of separating histamine with 1.32 × 10−7 M of Au colloid for the SERS enhancement. Accordingly, the limit of detection of histamine from mixture sample could achieve 2.8 × 10−4 ppm. These results indicated that the portable azo-derivatized TLC-SERS sensor not only visualizes the histamine but also improves the intensity of the Raman spectra. The azo-derivatized TLC-SERS sensor could be applied for rapid, convenient, and ultrasensitive point-of-care sensing of histamine in fish.

Upotreba izoliranog monomera lignina iz crnog luga dobivenoga od praznih grozdova palmina ploda kao prebiotika

Waste is generated in the form of black liquor during pulp processing. Furthermore, lignin, the main ingredient of black liquor, contains a phenylpropanoid compound with prebiotic and antimicrobial activity. Also, it is a component of lignocellulose that has prebiotic and antimicrobial activity effects due to its indigestible nature and it comprises phenylpropanoid components. Therefore, this study examines and identifies the lignin purification and test results of its prebiotic activity. The technique used to identify lignin fraction is called Thin Layer Chromatography (TLC) and Gas Chromatography-Mass Spectrometry (GC-MS) plates. Prebiotic activity tests were performed using the calculation of total bacteria on the growth of Lactobacillus casei. The results showed that the purification process using CHCl3, 3 % MeOH:CHCl3, 20 % MeOH:CHCl3, and MeOH yielded 10.68 %, 6.34 %, 11.38 % 44.85 %, respectively. The 3 % MeOH:CHCl3 fraction contained benzaldehyde, 4- hydroxy-3,5- dimethoxy, 1-methylbutyl hexadecanoate, oleic acid, and di-2-ethylhexyl phthalate. The 3 % MeOH:CHCl3 fractionate with a concentration of 15 % also showed a prebiotic activity for L. casei at 6.1 x 102 colonies/mL.

A new multiresidue thin layer chromatography–ultraviolet detection method for the rapid determination of six herbicides residue applied as ready mix formulation for rice

AbstractThe purpose of this study was to develop a new multiresidue thin‐layer chromatography analysis method for the simultaneous analysis of herbicides in soil and plant samples. A new liquid‐liquid extraction method was also developed for the extraction and identification of herbicides from the soil, rice grain, and straw samples. The thin layer chromatography‐ultra violet technique with silica gel 60 F254 thin layer chromatography plates, using a solvent system consisting of ethyl acetate, hexane, benzene, and methanol was found to be most effective in simultaneous separation and identification of all herbicides with retention factor in the range of 0.21–0.91. The impurities and matrix effects from soil, water, grain, and straw were minimal and did not interfere with the identification of any targeted herbicide. The method developed is found suitable to detect residues of herbicides in the soil, rice grains, and straw samples with a limit of determination of 0.1–0.01 mg/kg. The validation parameters of the developed method were satisfactory and therefore can be successfully used for the simultaneous determination of the herbicides in the soil, water, and plant samples. This method can also be used to determine these herbicides in other environmental samples as well as in Forensic analysis of biological/non‐biological samples.

Quantitative analysis of polyphenolic compounds in two different cultivars of marigold (Tagetes erecta L.) using high-performance thin-layer chromatography

Marigold (Tagetes erecta L.), a popular ornamental plant of the family Asteraceae, is commonly cultivated in many countries, including India, for its decorative flowers. The plants grow easily in a variety of soil and climatic conditions and have been reported to damage the nematode population of soil and control indirectly harmful microbes. High-performance thin-layer chromatography (HPTLC) was utilized in the present study, with a view to identify some important biologically active compounds in the flowers and leaves of two cultivars of marigold, Pusa Narangi Gainda (PNG) and Pusa Basanti Gainda (PBG). Quantitative analyses were carried out using silica gel thin-layer chromatography (TLC) plates and toluene–ethyl acetate–formic acid (T-E-F) (13:11:2 v/v/v) as the mobile phase used. Bands of gallic acid, caffeic acid, quercetin, p-coumaric acid, and kaempferol were observed. The results revealed a greater number of compounds in leaves than in flowers, and that the cultivar PNG accumulated a greater number of compounds than PBG. Gallic acid was found in leaves and flowers of both cultivars; however, it was found maximum in the flowers of cultivar PBG. Caffeic acid and quercetin were detected in the leaves of both cultivars, whereas p-coumaric acid was detected only in the leaves and kaempferol only in the flowers of cultivar PNG. The information generated in this report may be meaningfully used for the furtherance of research on marigolds as a natural source of antioxidants, insecticides, herbicides, etc.

RP-HPTLC fingerprinting of secondary metabolites from Nephrolepis exaltata and Cycasrevoluta

This study aims to develop a quantitative fingerprinting between two evolutionary close plant species Nephrolepis exaltata (L.) Schott and Cycas revoluta Thunb. The crude plant extracts were prepared in 1:1:1, v/v/v: Ethyl Acetate: n-Hexane: Methanol (AR) solvent system through cold extraction for 24 Hrs. The plant extracts were diluted (10 mg/mL) with a similar solvent system spotted (10 μL) on silica gel 60 F254 thin-layer chromatography plates. Five mobile phases (i) tetrahydrofuran (THF): toluene: formic acid: water (16:8:2:1) (ii) toluene: ethyl acetate: diethylamine (7:2:1) (iii) toluene: ethyl acetate: formic acid (7:3:0.1) (iv) n-hexane: ethyl acetate (7.2:2.9) (v) toluene: methanol (9:1) were used. The results were scanned at 254 nm, 366 nm, and in visible white light. This study gave minimum compact spots between Rf 0.06 to 0.051 corresponding to terpenoids, simultaneously for flavonoids spots were found between Rf 0.004 to 0.910. Total eight phenolic bands were found in Cycas revoluta among which five was found in leaf extract with Max RF of 0.033, 0.093, 0.273, 0.901 and 0.964 whereas three bands were found in stem extract with Max Rf of 0.007, 0.897 and 0.954. The presence of fifteen different types of flavonoids was determined by the flavonoids profile at Rf 0.004, 0.027, 0.047, 0.073, 0.134, 0.230, 0.303, 0.369, 0.369, 0.427, 0.514, 0.631, 0.703, 0.757, 0.846 and 0.910 for Nephrolepis exaltata. HPTLC fingerprint has shown several peaks with different Rf for different mobile phases. The fingerprinting would be helpful in the identification, and authentication of these species ecologically and therapeutically.

High dynamic range in videodensitometry—a comparative study to classic videoscanning on Gentiana extracts

The advantages of high dynamic range (HDR) imaging in videodensitometry are presented and discussed on the example of Gentiana extract thin-layer fingerprints visualized under 254 nm. An inexpensive microscope camera, together with security surveillance lens, mounted instead of original camera on videodensitometry chamber, allows to grab HDR images with high tonal range using Python scripts and OpenCL library. HDR imaging preserves linearity in whole tonal range and does not destroy details in the brightest and darkest plate regions, so it can be seen as a good alternative to classical videodensitometry. Moreover, the tonemapping of HDR images can be used to present a plate photograph with enhanced visibility of weak spots and other details. Principal component analysis done on nine classic exposures and HDR image proves that HDR image contains the highest amount of extracted information from the thin-layer chromatographic plate.