Thin-layer Chromatography Research Articles

Antiseizure Activity of Mitragyna inermis in the Pentylenetetrazol-Induced Seizure Model in Mice: Involvement of Flavonoids and Alkaloids.

This study aimed to investigate whether Mitragyna inermis (Willd.) Otto Kuntze organic and aqueous extracts are able to control seizures induced by pentylenetetrazol (PTZ) in mice based on flavonoid fingerprints and alkaloidal contents. Ethanolic extract and decoction-derived fractions from roots, leaves, and stems were subjected to chromatographic fingerprinting using AlCl3 and screening for their antiseizure effects using PTZ-induced acute seizure model. From the fractions that showed potent bioactivities, plausible antiseizure alkaloids were isolated using thin layer chromatography, and their structures were elucidated using 1H NMR, 2D NMR, 13C NMR, and FAB-HR (+ve or -ve). All fractions, with the exception of the dichloromethane and hexane fractions, revealed remarkable flavonoid fingerprints. An acute PTZ-induced seizure test revealed that ethanolic extract of stem bark [500 mg/kg body weight (bw)], ethyl acetate extract of stem bark (500 mg/kg bw), and aqueous extract of leaves (300 mg/kg bw) significantly delayed the occurrence of hind limb tonic extension (HLTE); however, a non-significant delay was observed in the onset of first myoclonic jerk compared with control animals. Isolation yielded four main alkaloids: that are, pteropodine (1), isopteropodine (2), mitraphylline (3) and corynoxeine (4). Corynoxeine is a new compound derived from M. inermis. This study suggests that flavonoid fingerprints are tracers of M. inermis anticonvulsant ingredients. The stem bark ethanolic and ethyl acetate extracts and leaf aqueous extracts contain anticonvulsant bioactive principles that delay notifying the HLTE occurring in male naval medical research institute mice. Furthermore, alkaloidal contents also remain plausible bioactive anticonvulsant principles. All observations support the traditional use of M. inermis to manage epilepsy. However, further studies are needed to understand the effects of alkaloid fractions, flavonoids, and the isolated compounds as promising antiseizure agents derived from M. inermis in experimental animals.

Metabolic engineering of Saccharomyces cerevisiae for the biosynthesis of a fungal pigment from the phytopathogenic fungus Cladosporium phlei

BackgroundCladosporium phlei is a phytopathogenic fungus that produces a pigment called phleichrome. This fungal perylenequinone plays an important role in the production of a photosensitizer that is a necessary component of photodynamic therapy. We applied synthetic biology to produce phleichrome using Saccharomyces cerevisiae.ResultsThe gene Cppks1, which encodes a non-reducing polyketide synthase (NR-PKS) responsible for the biosynthesis of phleichrome in C. phlei, was cloned into a yeast episomal vector and used to transform S. cerevisiae. In addition, a gene encoding a phosphopantetheinyl transferase (PPTase) of Aspergillus nidulans was cloned into a yeast integrative vector and also introduced into S. cerevisiae for the enzymatic activation of the protein product of Cppks1. Co-transformed yeasts were screened on a leucine/uracil-deficient selective medium and the presence of both integrative as well as episomal recombinant plasmids in the yeast were confirmed by colony PCR. The episomal vector for Cppks1 expression was so dramatically unstable during cultivation that most cells lost their episomal vector rapidly in nonselective media. This loss was also observed to a less degree in selective media. This data strongly suggests that the presence of the Cppks1 gene exerts a significant detrimental effect on the growth of transformed yeast cells and that selection pressure is required to maintain the Cppks1-expressing vector. The co-transformants on the selective medium showed the distinctive changes in pigmentation after a period of prolonged cultivation at 20 °C and 25 °C, but not at 30 °C. Furthermore, thin layer chromatography (TLC) revealed the presence of a spot corresponding with the purified phleichrome in the extract from the cells of the co-transformants. Liquid chromatography (LC/MS/MS) verified that the newly expressed pigment was indeed phleichrome.ConclusionOur results indicate that metabolic engineering by multiple gene expression is possible and capable of producing fungal pigment phleichrome in S. cerevisiae. This result adds to our understanding of the characteristics of fungal PKS genes, which exhibit complex structures and diverse biological activities.

Separation and characterization of the antioxidant active component from Maillard reaction products in xylose-lysine system

ABSTRACT Maillard reaction products (MRPs) play a crucial role in preserving food quality due to their antioxidant capacity. In this study, we isolated and characterized the antioxidant components from MRPs using a xylose-lysine system under optimal conditions. Methylene chloride and ethyl acetate were employed for sequential extractions, and the ethyl acetate phase underwent thin-layer chromatography and silica column separation. The identified compound, 3-hydroxy-4-methyl-2(5 H)-furanone (3H4MFN), was analyzed using FT-IR, GC-MS, and NMR, revealing its volatile nature with a chemical formula of C5H6O3. Further activity analysis demonstrated that 3H4MFN exhibited higher or comparable antioxidant activity to vitamin C (VC) and vitamin B6 (VB6). This newly discovered compound shows potential as a natural antioxidant in cosmetics, food, and nutraceutical applications.

Acorus calamus L. rhizome extract and its bioactive fraction exhibits antibacterial effect by modulating membrane permeability and fatty acid composition.

Ethnopharmacological relevanceIndia's ancient texts, the Charak Samhita and Sushruta Samhita, make reference to the traditional medicinal usage of Acorus calamus L. In India and China, it has long been used to cure stomach aches, cuts, diarrhea, and skin conditions. This ability of the rhizome is attributed to its antimicrobial properties. Research studies to date have shown its antimicrobial properties. However, scientific evidence on its mode of action is still lacking. Aim of the studyAcorus calamus L. rhizome extract and its bioactive fraction exhibits antibacterial effect by modulating membrane permeability and fatty acid composition. Material and methodThe secondary metabolites in the rhizome of A. calamus L. were extracted in hexane using Soxhlet apparatus. The ability of the extract to inhibit multidrug resistant bacterial isolates, namely Bacillus cereus, Escherichia coli, Acinetobacter baumannii, and Pseudomonas aeruginosa were evaluated using checkerboard assay. Further, the extract was purified using thin layer chromatography, gravity column chromatography, and combiflash chromatography. Structure elucidation of the active compound was done using GC-MS, FT-IR, and UV–Vis spectral scan. The mode of action of the bioactive fraction was determined. Bacterial membrane damage was analyzed using SEM, membrane permeability was determined using SYBR green I and PI dye, leakage of cytoplasmic contents were analyzed using Bradford assay and Fehling’s reagent. The ability to inhibit efflux pump of A. baumannii was determined using EtBr accumulation assay and β-lactamase inhibition was analyzed using nitrocefin as substrate. Also, the biofilm inhibition of B. cereus was determined using crystal violet dye. Moreover, the effect of the bioactive fraction on the fatty acid profile of the bacterial membrane was determined by GC-FAME analysis using 37 component FAME mix as standard. ResultsAcorus calamus L. rhizome hexane extract (AC-R-H) demonstrated broad-spectrum antibacterial activity against all the isolates tested. AC-R-H extract also significantly reduced the MIC of ampicillin against all tested bacteria, indicating its bacterial resistance modulating properties. The assay guided purification determined Asarone as the major compound present in the bioactive fraction (S-III-BAF). S-III-BAF was found to reduce the MIC of ampicillin against Escherichia coli (100–25 mg/mL), Pseudomonas aeruginosa (15–3.25 mg/mL), Acinetobacter baumannii (12.5–1.56 mg/ml), and Bacillus cereus (10–1.25 mg/mL). Further, it recorded synergistic activity with ampicillin against B. cereus (FICI = 0.365), P. aeruginosa (FICI = 0.456), and A. baumannii (FICI = 0.245). The mode of action of S-III-BAF can be attributed to its ability to disturb the membrane integrity, enhance membrane permeability, reduce biofilm formation, and possibly alter the fatty acid composition of the bacterial cell membranes. ConclusionThe bioactive fraction of AC-R-H extract containing Asarone as the active compound showed antibacterial activity and synergistic interactions with ampicillin against the tested bacterial isolates. Such activity can be attributed to the modulation of fatty acids present in bacterial membranes, which enhances membrane permeability and causes membrane damage.

Optimization of ultrasonic pretreatment and analysis of chlorogenic acid in potato leaves

Chlorogenic acid (CA) is an effective ingredient that can strengthen immunity during following the COVID-19 era. The current cost of CA is high owing to its complex purification process and low yield (approximately 2%). In this study, a one-step path orthogonal experiment was designed based on the results from Gauss calculation, which consisted of acidity, coordination, and hydrolysis in molecules. The optimized extraction conditions were 60 ℃, 60 min, 1:20 liquid ratio, and 40% ethanol in a nitrogen atmosphere controlled using a device of our own design, which led to CA yields of up to 6.35% from potato leaves. The purified CA was analyzed using high-performance liquid chromatography, thin-layer chromatography, ultraviolet–visible spectroscopy, and molecular fluorescence. This accurate and reproducible method can not only be used to obtain high yields of CA but can also be used for the quality control of active plant products and their isomers.

Exploring the therapeutic potential of Cynanchum tunicatum (Retz.) Alston- assessment of phytochemicals and biological activities

Cynanchum tunicatum (Retz.) Alston is native to the Asian region and is distributed in the tropical areas of India and Sri Lanka. The aim of this study is to explore the phytochemical composition, antioxidant potential, and anti-inflammatory properties of C. tunicatum. Metabolic profiling was carried out using phytochemical screening to detect and quantify the secondary metabolites. To evaluate the potential secondary metabolites using the standard methods, Fourier transform infrared (FTIR), High-Performance Thin Layer Chromatography (HPTLC) and Gas Chromatography–Mass Spectrometry (GC–MS) from organic extracts of C. tunicatum and its biological activities. FTIR investigated peaks that represent alkane and aromatic compounds. GC–MS revealed the presence of 22 constituents such as 1-Hexacosene (0.145 %), l-(+)-Ascorbic acid 2,6-dihexadecanoate (8.129 %), Campesterol (5.243 %), Beta −Amyrin (10.614 %), Lupeol (13.061 %), Octadecanoic acid (0.751 %) are the major active compounds present. HPTLC fingerprinting confirms the bioactive compounds such as colchicine, strychnine, coumarin etc. which are represented with corresponding Rf values. Among all the extracts of C. tunicatum methanolic extract showed highest antioxidant activities. In 2,2-diphenylpicrylhydrazyl method exhibit the IC50 of (38.91 µg/mL), Ferric reducing antioxidant power assay (1.6 µg/mL), total antioxidant assay (IC50 = 32.91 µg/mL) and IC50 of anti-inflammatory activity (42.31 µg/mL) respectively. These findings enrich the knowledge of the species Cynanchum tunicatum for the possible application as a source of bioactive compounds in drug discovery.

Isolation and Characterization of Glucocorticoid Steriod from the Leaf of Rauvolfia vomitoria

Isolation and Characterization of Glucocorticoid Steriod from the Leaf of Rauvolfia vomitoria

Probing Glycerolipid Metabolism using a Caged Clickable Glycerol-3-Phosphate Probe.

In this study, we present the probe SATE-G3P-N3 as a novel tool for metabolic labeling of glycerolipids (GLs) to investigate lipid metabolism in yeast cells. By introducing a clickable azide handle onto the glycerol backbone, this probe enables general labeling of glycerolipids. Additionally, this probe contains a caged phosphate moiety at the glycerol sn-3 position to not only facilitate probe uptake by masking negative charge but also to bypass the phosphorylation step crucial for initiating phospholipid synthesis, thereby enhancing phospholipid labeling. The metabolic labeling activity of the probe was thoroughly assessed through cellular fluorescence microscopy, mass spectrometry (MS), and thin-layer chromatography (TLC) experiments. Fluorescence microscopy analysis demonstrated successful incorporation of the probe into yeast cells, with labeling predominantly localized at the plasma membrane. LCMS analysis confirmed metabolic labeling of various phospholipid species (PC, PS, PA, PI, and PG) and neutral lipids (MAG, DAG, and TAG), and GL labeling was corroborated by TLC. These results showcased the potential of the SATE-G3P-N3 probe in studying GL metabolism, offering a versatile and valuable approach to explore the intricate dynamics of lipids in yeast cells.

Antimicrobial Activity of Fungal Endophytes Associated with Peperomia argyreia (Piperaceae)

The endophytic fungal biodiversity of unique plants like Peperomia argyreia (Miq.) É. Morren (Piperaceae) has antimicrobial properties and can be employed for infection treatment. Fungal isolates were obtained from appropriately treated plant tissues cultured in solid media, characterized by morphology, and identified by molecular biology using ITS and NL primers. The antimicrobial properties of fungal extracts were analyzed by combining microdilution and bioautographic assays complemented with metabolic profiling by automated thin-layer chromatography and 1H NMR techniques. Thirty-one filamentous fungi were isolated and characterized by ITS and/or D1/D2 region amplification of rDNA, identified as Thermothielavioides, Trichoderma, Cyphellophora, Cladosporium, Arcopilus, Plectosphaerella; Chaetomium, Sporothrix, Alboefibula, and Penicillium. Thermothielavioides spp. inhibited Staphylococcus aureus ATCC 25923; moreover, Penicillium westlingii P4 showed inhibitory activity on Ascochyta rabiei AR2. The bioactivity-guided fractionation of the EtOAc extract (MIC = 62.5 μg/mL) of P. westlingii P4 allowed the purification of citrinin as the main inhibitory compound (MIC = 62.5 μg/mL). Peperomia argyreia harbors a rich and diverse endophytic community able to produce bioactive molecules. Citrinin, with a minor influence of volatile compounds biosynthesized by P. westlingii P4, was responsible for the inhibition of A. rabiei AR2.

Exploring the Role of Active Photosynthetic Pigments in Tomato (Solanum lycopersicum) Crop Growth Process

Photosynthesis is a necessary process for plants during which light energy is absorbed via pigments present in leaves for essential processes and needs of the particular plant. This work identified and studied the active photosynthetic pigments in tomato crop (Solanum lycopersicum) at each growth stage and grown in an open field under Sahelian conditions. Phytochemical screening, UV-visible and Fourier transform infrared spectroscopy, and thin layer chromatography analyses were done on tomatoes leaves samples. The results, first, revealed the presence of phytoconstituents such as triterpenoids and carotenoids. Then, UV spectra combined with FTIR and thin layer chromatography showed that chlorophylls (a and b), xanthophyll (lutein) and carotene (mostly β) are being synthesized at different proportions during all growth stages. Besides, the photosynthetic pigments showed more activity during the flowering stage than at the other growth stages. The various action spectra showed intense absorption within the intervals 400 – 510 nm and 560 – 710 nm which seem to be vital radiation ranges for photosynthesis.  Knowing these optimum plant’s needs can help in a choice of better outdoor and indoor cultivation conditions that can ensure necessary radiations for optimum plant growth.

Paris polyphylla Sm. characterized extract infused ointment accelerates diabetic wound healing in In-vivo model

Ethnopharmacological relevanceThe dried rhizome of Paris polyphylla Sm. is extensively used by traditional healers in India, China, and Vietnam to treat skin inflammation, cut wounds, uterine and traumatic bleeding, and cancer. Aim of the studyThe traditional use of P. polyphylla rhizomes for treating wounds and bleeding has been reported previously. However, the potential of P. polyphylla in the treatment of diabetic wounds has not yet been explored. Our present study focused on the investigation of the wound-healing activity of P. polyphylla infused ointment in streptozotocin (STZ)-induced diabetic rats to validate the traditional claim. Materials and methodsHydroalcoholic extract of the dried rhizomes of P. polyphylla were quantified by validated and optimized HPTLC (High-performance thin layer chromatography) method for Paris saponin VII, Dioscin and Polyphyllin V. The extract was used to prepare P. polyphylla ointments (5 and 10%). P. polyphylla ointment was subjected to physiochemical analysis and skin irritation test. Thirty STZ-induced diabetic adult male Wistar albino rats were divided into five groups (n = 6) and a circular excision wound was created. P. polyphylla ointment, ointment base (OB), and standard (STD) (Povidone Iodine 10%) were administered topically. The wound area of all groups were recorded every six days and compared with that of control. The epithelization period of each group was recorded. On day 18, the histopathological study of skin tissues of all groups was performed using hematoxylin and eosin (H&E) and Mallory's trichrome (MT). ResultsMarker analysis and quantification of phytomolecules in hydroalcoholic extract ofP. Polyphylla were found to be of paris saponin VII (3.28 ± 0.08% w/w), dioscin (1.94 ± 0.12% w/w), and polyphyllin V (1.87 ± 0.84% w/w). A physiochemical study of P. polyphylla ointment showed that the prepared ointment was within an acceptable range and was not irritable to the skin. Daily topical administration of 10% P. polyphylla ointment (PP10) for 18 days completely healed the STZ-induced diabetic wounds. On day 18, the 5% P. polyphylla ointment (PP5) showed 99.1 ± 2.9% wound closure, while that of the standard and control was 78.4 ± 7.3% and 18.5 ± 5.9%, respectively. The epithelialization period of PP10 was 18 days, whereas that of the control was 28 days. Histopathological analysis of the progression of PP10 and PP5 wounds showed a decrease in inflammatory cells, regenerated epithelial layer, keratosis layer, hair follicles, fibroblasts, and collagen. Upon collagen intensity quantification of MT stained sections, an increase in collagen density of PP10 and PP5 treated groups was observed, showing accelerated wound healing potential of P. polyphylla extract in diabetic wounds compared to the standard ointment. ConclusionThis study suggested the potential of P. polyphylla rhizomes derived formulation to treat diabetic wounds, although the plant is traditionally used to treat normal wounds. The results indicate the validation of traditional claim, which has been explored commercially in industrial aspect.

Reversed-phase thin-layer chromatography and ultra-performance liquid chromatography/mass spectrometry to estimate the drug likeness of phosphodiesterase 10A inhibitors with phthalimide core

AbstractLipophilicity is a physicochemical parameter well known as a decisive factor for predicting the successful development of a drug. Thus, a balance between potency and physicochemical properties during medicinal chemistry optimization is needed. In this study, the lipophilicity of isoindole-1,3(2H)-dione derivatives designed as phosphodiesterase 10A (PDE10A) inhibitors was determined by chromatographic [reversed-phase thin-layer chromatography (RP-TLC) and ultra-performance liquid chromatography/mass spectrometry (UPLC/MS)] and in silico methods. To assess the correlation between the obtained lipophilicity parameters, principal component analysis (PCA) was performed. logP values obtained by chromatographic (logPRP-TLC and logPUPLC/MS) and in silico methods were compared using the PCA method. The results of PCA revealed that logPUPLC/MS and in silico clogP provided by the ChemDraw program were highly correlated. Compounds’ drug likeness was screened, and the pharmacokinetic properties were predicted. All the investigated compounds displayed drug-likeness properties, and they met the criteria of Lipinski’s rule of five, which predicted the oral bioavailability of drug candidates. Analysis of the influence of physicochemical properties on the biological activity showed that the compounds with increased potency on PDE10A had significantly higher topological polar surface area (TPSA) values. The blood‒brain barrier permeability and the hemolytic activity of model compound 18 were examined. The model compound 18 displayed no toxicity effect on erythrocytes in the hemolytic assay and good parallel artificial membrane permeability. The results showed that phthalimide compounds with benzimidazole moiety are a source of compound-targeted inhibition of PDE10A with balanced physicochemical and drug-likeness properties.

Antibacterial activity of Dioscorea bulbifera Linn. extract and its active component flavanthrinin against skin-associated bacteria

BackgroundDioscorea bulbifera Linn. has been used for wound care in Thailand. However, a comprehensive evaluation of its antibacterial activity is required. This study aimed to investigate the antibacterial efficacy of D. bulbifera extract against skin-associated bacteria and isolate and characterize its active antibacterial agent, flavanthrinin.MethodsAir-dried bulbils of D. bulbifera were pulverised and extracted with hexane, dichloromethane, ethyl acetate, methanol, ethanol, and distilled water; vacuum filtered; concentrated; freeze-dried; and stored at -20 ºC. Antibacterial activity of the extracts was assessed using microdilution techniques against several skin-associated bacteria. Thin-layer chromatography (TLC) bioautography was used to identify the active compounds in the extract, which were fractionated by column chromatography and purified by preparative TLC. The chemical structures of the purified compounds were analysed using nuclear magnetic resonance (NMR). The cytotoxicity of the extract and its active compounds was evaluated in Vero cells.ResultsThe ethyl acetate extract exhibited distinct inhibition zones against bacteria compared to other extracts. Therefore, the ethyl acetate extract of D. bulbifera in the ethyl acetate layer was used for subsequent analyses. D. bulbifera extract exhibited antibacterial activity, with minimum inhibitory concentrations (MICs) of 0.78–1.56 mg/mL. An active compound, identified through TLC-bioautography, demonstrated enhanced antibacterial activity, with MICs of 0.02–0.78 mg/mL. NMR analysis identified this bioactive compound as flavanthrinin. Both D. bulbifera extract and flavanthrinin-containing fraction demonstrated potent antibacterial activity against Staphylococcus aureus, methicillin-resistant S. aureus (MRSA), and S. epidermidis. The flavanthrinin containing fraction demonstrated low cytotoxicity against Vero cells, showing CC50 values of 0.41 ± 0.03 mg/mL. These values are lower than the MIC value, indicating that this fraction is safer than the initial ethyl acetate extract.ConclusionsDioscorea bulbifera extract and its bioactive component flavanthrinin demonstrated significant antibacterial activity against the skin-associated bacteria Staphylococci, including MRSA. Flavanthrinin has potential as a complementary therapeutic agent for managing skin infections owing to its potent antibacterial effects and low cytotoxicity.

Camptothecin and its Analogs: High-Yielding Ophiorrhiza Species from Sri Lanka for Sustainable Anticancer Compound Production

Introduction: Camptothecin (CPT) is pivotal in cancer treatment, derived from various CPT-producing plant species, and is a fundamental component in synthesizing valuable cancer drugs like Irnotican and Topotecan. Sourcing from nature poses conservation issues, fostering interest in the herbaceous Ophiorrhiza plant as a more sustainable alternative. Ophiorrhiza species in Sri Lanka lack comprehensive study, warranting exploration for echo-friendly anticancer compound production. Objectives: This study examines CPT and analog content in Ophiorrhiza mungos, O. pectinata, and O. rugosa across diverse Sri Lankan regions. Methods: The study employs Thin Layer Chromatography (TLC), High-Performance Liquid Chromatography-DAD (HPLC-DAD), and Liquid Chromatography-Mass Spectrometry (LC-MS) to quantify and confirm CPT and its analogs. Results: Significant variations in the content of CPT and its analogs were observed among plant parts and regions. O. mungos from Deraniyagala and Bibile regions notably exhibited elevated CPT levels in fruits and roots. O. rugosa var. Angustifolia and O. pectinata also exhibited a considerable content of CPT in their roots, though it was significantly lower (p < 0.005) than O. mungos. Conclusion: The study validates analytical methods for specificity, linearity, precision, accuracy, and sensitivity per ICH guidelines. The results indicate that Ophiorrhiza species, especially O. mungos and O. rugosa var. Angustifolia holds the potential to be a sustainable source of CPT. Optimizing cultivation practices offers an eco-friendly solution for anticancer compound production, alleviating species threats and conserving biodiversity.

Accurate and rapid quantification of tea saponins using a thin-layer chromatography (TLC) method based on hemolysis and machine vision

Tea saponins are increasingly used in the food industries due to their biological activities. Current methods for the quantification of tea saponins are either inaccurate or time consuming and costly. In this study, a quantitative thin-layer chromatographic (TLC) method using machine vision and based on the hemolytic activity (HA) of tea saponins was developed. The optimized method consisted of ethanol extraction, sample loading, separation, color development, and smartphone-machine vision quantification. The new HA-TLC method was compared with UV spectrophotometric and liquid chromatographic methods, and achieved higher precision (RSD% = 0.75%) and accuracy (96.4%-106.2% recovery), with a limit of detection of 0.285 μg and limit of quantification of 0.95 μg. The method enables simultaneous qualitative and quantitative determination of saponins from different parts of tea plant extracts with high specificity, yet rapid and inexpensive, with high throughput and low solvent consumption, providing new options for saponin analysis in the food industry.

Valorization and kinetic modeling of biosurfactant produced by Kocuria marina DAGII: substitute for chemical surfactant

Microbial biosurfactant has wide applications in industrial sectors owing to their eco-friendly and biocompatible nature giving, an alternative to chemically synthesized surfactants. In our study, Kocuria marina DAG II, an isolated bacterium was observed to produce a biosurfactant. The production of biosurfactant was established by oil-spreading (3.72 ±0.15 cm), drop collapse and CTAB (Cetyltrimethyl ammonium bromide) assay. Biosurfactant activity was re-confirmed by the reduction in surface tension of uninoculated broth from 68.52 mN/m to 47.40±0.57 mN/m.Chemicalcharacterization study of the biosurfactant was done by TLC (thin-layer chromatography) indicating the presence of proteins (Rf= 0.78±0.08), lipids (Rf=0.79±0.09), and polysaccharides (Rf=0.81±0.06).FTIR and NMR (1HNMR and 13CNMR) studies confirmed the presence of different functional groups and revalidating the presence of amino acids, lipids and polysaccharides in the biosurfactant.From the optimization study, the highest production of biosurfactant having a yield of 3.05g/L ± 0.05was obtained attemperature of 31°C and pH 8, when kept for an incubation period of 88 hrs. Addition of rancidand waste frying mustard oil and used engine oil could enhance the production of biosurfactant by Kocuria marinaDAGII hence substantiating the concept of value added biosurfactant production from waste.Kinetic modeling showed good fit between experimental and predicted values using Gompertz model with R2 values of 0.99 and 0.99. The biosurfactant exhibited radical scavenging activity through DPPHand ABTS assays with IC50 values of 1.29 mg/ml and 0.56 mg/ml respectively.The biosurfactant produced by Kocuria marina DAG II could be utilized for various applications, bypassing the need of a synthetic surfactant.

Degradation kinetics of lycopene from red amaranth & preparation of winter melon jelly using this lycopene and comparison with commercial jelly

This study was conducted to observe the storage conditions, such as solvent and temperature, of lycopene content and degradation kinetics from red amaranth (Amaranthus gangeticus). Jelly was prepared using the extracted lycopene, the physicochemical properties and lycopene content. The extract with the maximum amount of lycopene was obtained by extraction with hexane, acetone and ethanol (2:1:1),50 ± 9 mg/kg. Higher lycopene degradation was observed at refrigerated temperature as compared to ambient temperature in hexane acetone (6:4) solvent throughout the storage periods. In this period, the initial lycopene concentration was measured to be 17 ± 8 mg/kg, whereas at the end of the storage time, it was found to be 3.0 ± 0.8 mg/kg. Hence, the results indicate that the hexane, acetone, and ethanol (in a ratio of 2:1:1) solvent method is viable for extracting and purifying lycopene from red amaranth at refrigerated temperature. This lycopene can serve as both a natural colorant and a value-added product. However, it is worth noting that lycopene can also be extracted and purified using recrystallization, column chromatography, and thin-layer chromatography (TLC) methods. The Winter melon jelly using lycopene from red amaranth contained moisture 29.6 %, ash 0.67 %, acidity 0.35 %, reducing sugar 26.8 %, non-reducing sugar 35.4 %, total soluble solid 66°brix and lycopene content 26.04 mg/kg. Proper utilization of lycopene extracted from red amaranth during the preparation of bakery, confectionary, baby food etc., may help and encourage the development of small-scale industries in the country.

Intermolecular π-π interactions-induced aggregation based on bispyrene for ultrasensitive detection of picric acid (PA) and 2,4-dinitrophenol (DNP)

It was still important to explore excimer emission-based fluorescence probes for nitroaromatics detection by formation or destruction of pyrene excimer with strong emission change. In this work, we have synthesized a simple bis(pyrene) derivative (BisPyH) and studied its optical behavior by using UV–vis and fluorescent spectroscopy. In pure DMSO solution, it emitted a weak blue fluorescence due to the formation of excimer states, on the contrary, the BisPyH in the DMSO/H2O (v/v, 1:1) mixture solution was self-assembled to form aggregates via intermolecular π-π interactions among pyrene units, giving almost 10-fold fluorescence enhancement compared to that in pure DMSO solution. The formed aggregates just offered a perfect platform for the selective detection PA and DNP explosives by quenching the bright green intermolecular-excimer emission in competitive environment. BisPyH exhibited a limit of detection (LOD) towards PA, and DNP as low as 7.32 × 10−8, and 8.11 × 10−8 M, respectively. Subsequently, the fluorescence quenching mechanism was demonstrated by the density functional theory (DFT), UV–vis and fluorescence spectra, SEM, and the quenching constants. Furthermore, filter paper strips and thin-layer chromatography (TLC) plates coated with BisPyH were able to detect PA and DNP in the practical application.

Bio-screening and quantification of methyl paraben in vinegar and coconut juice separated by HPTLC

As a widely used food preservative, methyl paraben was experimentally evidenced with serious hormone-like adverse effects. Herein, a high performance thin-layer chromatography platformed bioluminescent bioautography and image analysis for the selective quantification and confirmation of methyl paraben was proposed and validated in vinegar and coconut juice. First, the detectability of the bioautography to the analyte on different layer materials was estimated, revealing that normal silica gel was the best choice. After that, the liquid of sample extract and working solution were separated to overcome the background noises due to co-extracted matrices. The separation result was then coupled to the optimized bioautography, enabling instant and straightforward screening of the targeted compound. For accurate quantification, bioluminescent inhibition pattern caused by the analyte was processed by image analysis, giving useful sensitivity (LOD > 16 mg/kg), precision (RSD < 10.1 %) and accuracy (spike-recovery rate 76.9 %–112.2 %). Finally, the suspected result was confirmed by determining its MS fingerprint, further strengthening the reliability of screening.

Magnetic field assisted centrifugal acceleration thin-layer chromatography: An approach to investigate the magnetic field effects on separation parameters including retention factor difference, selectivity factor, and resolution

The effect of internal and external magnetic fields on the separation of antifungal drugs by centrifugal acceleration thin-layer chromatography was reported for the first time. External and internal magnetic fields were applied using neodymium magnets and CoFe2O4@SiO2 ferromagnetic nanoparticles. Separation of ketoconazole and clotrimazole was performed using a mobile phase consisting of n-hexane, ethyl acetate, ethanol, and ammonia (2.0:2.0:0.5:0.2, v/v). The influence of the magnetic field on the entire chromatographic system led to changes in the properties of the stationary and mobile phases and the analytes affecting the retention factor, shape, and width of the separated rings. The extent of this impact depended on the structure of the analyte and the type and intensity of the magnetic field. In the presence of the external magnetic field, there were more significant changes in the chromatographic parameters of the drugs, especially the width of the separated rings, and ketoconazole was more affected than clotrimazole. The changes are conceivably due to the effect of the magnetic field on the analyte distribution between the stationary and mobile phases, which is also caused by the possibility of the magnetic field affecting the viscosity, surface tension, and surface free energy between the stationary and mobile phases.