TLC Studies Research Articles

Pharmacognostical and phytochemical studies on roots of Bombax ceiba Linn.

Context: Bombax ceiba Linn. (Bombacaceae) is a well-known plant for its antihypertensive, antioxidant, antidiabetic, aphrodisiac and uterine tonicity properties. Aims: To study pharmacognostical, physicochemical and phytochemically the roots of this plant. Methods: Pharmacognostical study included the macroscopic characters like size, color, surface characteristics, texture, fracture characteristics and odor of the roots. The intact root as well as powdered drug were studied under a microscope to analyze the cellular characteristics of the drug. Physicochemical parameter like extractive values, loss on drying (LOD), total ash, water-soluble and acid insoluble ash, foaming index and hemolytic index of Bombax ceiba root powder were determined as per WHO guidelines. Preliminary phytochemical screening and qualitative chemical examination studies have been carried out for the various phytoconstituents. HPTLC have also carried out using cyclohexane: diethyl ether: ethyl acetate as mobile phase. Results: Chemical evaluation and TLC studies shown presence of alkaloids, glycosides, flavonoids, steroids, saponins and tannins. The microscopic characters have shown presence of cork, cambium, xylem vessels, stone cells, starch grains, calcium oxalate crystals and phloem fibers. Microscopy analysis of the powder included the cork cells, fibers, calcium oxalate crystals and vessel. The presence of steroids was confirmed in HPTLC fingerprinting studies. Conclusions: Pharmacognostical and preliminary phytochemical screening of Bombax ceiba roots will be useful in order to authenticate, standardize and avoid any adulteration in the raw material. The diagnostic microscopic characters and physicochemical data will be helpful in the development of a monograph. The chromatographic fingerprinting profile can be used to standardize extracts and formulations containing Bombax ceiba roots.

Osmium(VIII) catalyzed and uncatalyzed oxidation of a hemorheologic drug Pentoxifylline by alkaline copper(III) periodate complex: A comparative kinetic and mechanistic approach

The oxidation of a hemorheologic drug, Pentoxifylline (PTX) by diperiodatocuprate(III) (DPC) has been investigated both in the absence and presence of Osmium(VIII) catalyst in aqueous alkaline medium at a constant ionic strength of 0.30 mol dm −3 spectrophotometrically. The stoichiometry was same in both the cases, i.e., [PTX]/[DPC] = 1:2. In both catalyzed and uncatalyzed reactions, the order of the reaction with respect to [DPC] was unity while the order with respect to [PTX] was <1 over the concentration range studied. The rate increased with an increase in [OH −] and decreased with an increase in [ IO 4 - ] in both the cases. The order with respect to [Os(VIII)] was unity. The reaction rates revealed that Os(VIII) catalyzed reaction was about sixfold faster than the uncatalyzed reaction. The reaction products were identified by TLC and spectral studies including LC–MS. Suitable mechanisms were proposed. The reaction constants involved in different steps of the reaction mechanisms were calculated for both cases. The catalytic constant ( K C) was also calculated for catalyzed reaction at different temperatures. The activation parameters with respect to slow step of the mechanism and also the thermodynamic quantities were determined. Kinetic experiments suggest that [Cu(H 2IO 6)(H 2O) 2] is the reactive copper(III) species and [OsO 4(OH) 2] 2− is the reactive Os(VIII) species.

Diabetes-induced Testicular Disorders Vis-a-vis Germ Cell Apoptosis in Albino Rat: Remedial Effect of Hexane Fraction of Root of Musa paradisiaca and Leaf of Coccinia indica

The present study was designed to investigate diabetes induced germ cell apoptosis in testis and its protection by treatment with hexane fraction of hydro-methanolic extract of root of Musa paradisiaca and leaf of Coccinia indica in composite manner. Testicular oxidative stress injury was reflected by diminution in the activities of antioxidant enzymes such as catalase, peroxidase, superoxide dismutase and glutathione-s-transferase along with elevation in levels of conjugated diene and thiobarbituric acid reactive substances in diabetic condition. Serum testosterone and insulin levels were decreased in association with elevation in apoptosis of pancreatic islet cells in diabetic rats. Giant cells number along with elevation i nt he number of apoptotic cells were noted in seminiferous tubules in diabetic model animals. Significant improvements in the levels of blood glucose, serum insulin and testosterone and testicular oxidative stress parameters were noted versus control after treatment of said fraction at a dose of 2 mg (1 : 3)/0.2 ml olive oil per 100 g body weight per day for 45 days to diabetic rats. Numbers of giant cells in seminiferous tubules, apoptotic germ cells and apoptotic pancreatic islet cells were decreased significantly in fraction treated diabetic group versus control. From UV-spectroscopic and TLC studies in connection with phytochemical screening of the said fraction, phenol, flavonoid and alkaloid types of compound were found. From these results it may be concluded that the active ingredient(s) present in hexane fraction of root ofMusa paradisiaca and leaf of Coccinia indica have the potential to correct diabetes-induced testicular germ cell apoptosis.

Evaluation of the Effect of Surfactants on the Adsorption and Movement of Carbaryl in Soils of Divergent Texture

The adsorption and movement of carbaryl on soils in surfactant-free and surfactant (cationic, non-ionic, anionic) solutions of different critical micelle concentrations (CMCs) has been studied using batch equilibrium and soil thin layer chromatography (soil TLC) techniques. The adsorption of carbaryl in surfactant-soil-water systems followed the order cationic > anionic > non-ionic as anticipated from the Freundlich constant, KF, and distribution coefficient, KD, values. The Rf values obtained from soil TLC studies were inversely proportional to the KF and KD values. The affinities of carbaryl towards organic carbon and the clay content of the soil were compared using the KOC and KC values. The behaviour of carbaryl in surfactant-soil-water systems mainly depends on the degree of hydrophobicity of the pesticide and the type and concentration of surfactant used. The K*D/KD ratios were used to evaluate the remediation efficiency of surfactants and it was found that anionic surfactant is a better choice for ...

Adsorption and Movement of Carbofuran in Four Different Soils Varying in Physical and Chemical Properties

Laboratory studies were conducted to determine the adsorption and movement of carbofuran on four divergent textured Indian soils at a fixed volume fraction (fs = 0.1) of methanol/water mixtures using batch equilibrium and soil thin layer chromatography (soil TLC) techniques. The measured equilibrium adsorption isotherms for silt loam (FSL and ASL) and loam (KL) soils were L-shaped and for sandy loam (BSL) soil S-shaped, all being well fitted by the Freundlich isotherm. A higher adsorption of carbofuran was observed on FSL followed by ASL, KL and BSL soils as anticipated by the values obtained for the Freundlich constant, KF and partition coefficient, KD. The Frontal Retardation factor (FRf) values obtained from soil TLC studies were inversely proportional to the KF and KD values. The affinity of carbofuran towards organic carbon, organic matter and clay content of the soils was evaluated by calculating the KOC, KOM and KC values. The negative magnitude of the Gibbs'free energy (ΔG0) indicated the spontaneity of the adsorption of carbofuran onto the soils studied. The leaching index (LI) of carbofuran calculated for the soils studied indicated its high potential to leach into shallow aquifers and ground water. Pearson's correlations calculated for KF and KD against the soil properties showed a highly significant correlation with the clay + silt content of the soils. Multiple regression of KF and KD against the soil properties indicated that the mineral content of the soils (clay and clay + silt) is the best predictor of carbofuran adsorption, followed by soil pH. Predicted log KOM values were also evaluated by using the aqueous solubility, the 1-octanol/ water partition coefficient (KOW), the adsorbability index (AI) and the first-order molecular connectivity index (1χ) of carbofuran. Use of the aqueous solubility, and the 1-octanol/water partition coefficient (KOW) to predict the extent of adsorption gave values which displayed a considerable error in comparison to those measured experimentally, whereas the use of the adsorbability index (AI) and the first-order molecular connectivity index (1χ) of carbofuran improved the predictions considerably.

Formulation and evaluation of monolithic matrix polymer films for transdermal delivery of nitrendipine

The objective of the present work was to develop a suitable transdermal drug delivery system for nitrendipine. Polymeric films of nitrendipine were prepared by the film casting technique (glass ring) on mercury substrate. They were evaluated for physicochemical parameters, in vitro release and ex vivo permeation (heat separated human epidermis). Release of the drug from the films followed anomalous transport (0.5 < n < 1).Polymeric combination containing Eudragit RL 100:PVP K 30 in a 4:6 ratio showed the best results. Maximum drug release and skin permeability coefficient in 48 h were 85.8% and 0.0142 cm h(-1), respectively, in formulation C3 (Eudragit RL 100/Plasdone S 630; 4:6) and 88.0% and 0.0155 cm h(-1), respectively, in formulation, D3 (Eudragit RL 100/PVP K 30; 4:6). FTIR and TLC studies indicated no drug and polymer interaction.

TLC and polarimetric investigation of the oscillatory in-vitro chiral inversion ofl-alanine

Summary In recent TLC and polarimetric studies we showed, for the first time, the tendency of profen drugs to undergo spontaneous oscillatory chiral inversion in vitro. Because profen drugs are chiral propionic acid derivatives, we sought other chiral compounds with similar chemical structures and hence a similar tendency to spontaneously change their steric configuration. We have previously demonstrated that L-α-phenylalanine and L-tyrosine also undergo oscillatory in-vitro chiral inversion. We also demonstrated the effect of temperature and mixing on the process, and proposed a detailed model of the oscillator, providing the basis for mechanistic understanding of the oscillatory chiral inversion of these compounds. In this study we focused our attention on L-alanine, another amino acid with a chemical structure formally derived from propionic acid, and, again, by use of TLC and polarimetry, investigated the tendency of L-alanine to undergo oscillatory in-vitro chiral inversion when dissolved in neutral, acidic, and basic solvents. We also studied the effect of temperature and sample mixing. It was confirmed that Lalanine also undergoes chiral inversion. The dynamics of the process are specific to each compound.

Microwave-assisted rapid extraction of red dye from Caesalpinia sappan heartwood

Since ancient times Caesalpinia sappan heartwood dye has been well-known for its medicinal and dyeing properties. Isolation of the red dye using both conventional and newly developed microwave method was carried out. The conventional heating of 2 h provided 0.656 ± 0.049 g of the dye and by microwave heating at 540 W for 20 min, the yield obtained was 0.747 ± 0.047 g. Both the dyes were found to be the same as evidenced by UV, TLC and HPTLC studies. Antioxidant activity of the dyes was also carried out using DPPH and nitric oxide methods to confirm the similarity in their biological activity. The procedure developed can be used for the fast extraction of the red dye of C. sappan without affecting the nature of the product.

Antiulcer Activity of the Root Bark of Oroxylum indicum. Against Experimental Gastric Ulcers

The current study was undertaken to investigate the effect of the root bark of Oroxylum indicum. Vent. (Bignoniaceae) against experimental gastric ulcers. The 50% alcohol extract of root bark of Oroxylum indicum. and its different fractions, viz., petroleum ether, chloroform, ethyl acetate and n.-butanol, were studied (p.o.) against ethanol-induced gastric mucosal damage. The alcohol extract (300 mg/kg) and its different fractions (100 and 300 mg/kg) showed significant reduction in gastric ulceration. Out of all these fractions, the petroleum ether (96%) and n.-butanol (99%) fractions showed maximum inhibition of gastric lesions against ethanol-induced gastric mucosal damage. The results were comparable with omeprazole (reference standard). In the ethanol-induced gastric ulcer model, treatment with both the active fractions and omeprazole showed significant antioxidant activity as evident from the reduction in the extent of lipid peroxidation that was measured in terms of malondialdehyde (MDA), along with significant rise in the superoxide dismutase (SOD), catalase (CAT), and reduced glutathione levels (GSH), when compared with the control group. In 6-h pylorus-ligated animals, active fractions of drug at 100 mg/kg showed significant reduction in the ulcer index. Furthermore, in the pylorus-ligation model, significant reduction (p < 0.05) was observed in total acidity, total acid output, pepsin activity, and pepsin output, along with a significant rise in the total carbohydrate to protein ratio (reflecting mucin activity) when compared with the control group. TLC studies revealed the presence of baicalein in the petroleum ether and hydrosylate in n.-butanol fraction. Fingerprinting of both the active fractions was developed by performing HPLC analysis. Baicalein was found to be a major flavonoid present both in petroleum ether and n.-butanol hydrosylate. The mechanism of its antiulcer activity could be attributed to a decrease in gastric acid secretory and antioxidant activities leading to gastric cytoprotection. This activity could be linked to the presence of baicalein in the root bark of the plant.

New oxorhenium(V) complexes with 2N2S donor sets and radiochemical behavior of their technetium analogs

Oxorhenium(V) complexes of two thioether amines have been synthesized and characterized spectroscopically. The five-coordinated ReO 3+ moiety is satisfied by the amine compounds behaving as dibasic tetradentate (NSSN) ligands and a chloride ion. The radioanalytical studies of their technetium analogs have been carried out at different pH values in the range 3–10. The solvent extraction, TLC, electrophoresis and HPLC studies using 99mTc radiotracer indicate that the labeled complex with the TcO 3+ core is similar to the rhenium complex with the ReO 3+ core.

Selective recognition of neodymium (III) using ion imprinted polymer particles.

Neodymium (III) ion-imprinted polymer (IIP) materials were prepared by the copolymerization of neodymium (III)-5,7-dichloroquinoline-8-ol-4-vinylpyridine ternary complex with styrene(monomer), divinyl benzene (crosslinking monomer) in the presence of 2,2'-azobisisobutyronitrile (initiator). The synthesis was carried out in 2-methoxy ethanol medium (porogen) and the resultant material was filtered, washed, dried and powdered to form unleached IIP particles. The imprint ion was removed by stirring the above particles with 50% (v/v) HCl for 6 h to obtain leached IIP particles with cavities in the polymer particles. Control polymer (CP) particles were similarly prepared without imprint ion, i.e. neodymium (III). CP, unleached and leached IIP particles were characterized by TLC, IR, microanalysis, XRD and UV-visible spectrophotometric studies. The preconcentration of 5-150 microg of neodymium (III) ions present in 500 ml of solution was possible with as little as 40 mg of neodymium (III) IIP particles in the pH range 7.5-8.0 with a detection limit of 50 ng/l. Five replicate determinations of 25 microg of neodymium (III) present in 500 ml of solution gave a mean absorbance of 0.120 with a relative standard deviation of 2.65%. The imprinting effect of IIP particles was noticed in all preconcentration and selectivity studies when compared with CP particles. Furthermore, the selectivity coefficients of neodymium (III) IIP particles were much higher compared with the reported separation factors for the best liquid-liquid extractants, viz. di-2-ethylhexyl phosphoric acid and 2-ethylhexyl-ethylhexyl phosphonate. Kinetic and isotherm studies during rebinding of neodymium (III) onto IIP particles were also carried out.

Electrochemical studies on patent blue VF : a triphenylmethane dye

Electrochemical study of patent blue VF (4[4(N-diethylphenyl)-4,6-disulfenylphenyl]-methylene-2,5-cyclohexadlene-1-(N-diethylimine), triphenylmethane dye, shows a single cathodic peak at 0.626 V for the dye solution (2 x 10 - 4 M), indicating a negative shift with increasing scan rate indicating the irreversible nature of the electrode process. After cpe negligible current (ip, c) was observed and peak nearly gets diminished alongwith disappearence of colour. TLC and coulometric studies support the proposed reduction mechanism.

MOLECULAR WEIGHT STUDIES ON THE GAMMA IRRADIATION DEGRADATION OF POLY(METHYLMETHACRYLATE) IN THE ABSENCE AND PRESENCE OF SULFANILAMIDE DERIVATIVES, PART I: TETRAOXALYLSULFANILAMIDE AND ITS COBALT (II) COMPLEX

Protection of some poly (methylmethacrylate) samples against gamma rays has been investigated in the absence and presence of Tetraoxalylsulfanilamide and its Cobalt (II) complex. The pure PMMA (without additives), PMMA-Ligand and PMMA - Cobalt (II) complex composite samples were irradiated with gamma rays for different exposure doses (5, 15, 25, 35, 50, 75 and 100 KGy). Viscosity average molecular weight (Mv-values) and thin layer chromatographic measurements were carried out after each irradiation dose.The maximum protection against gamma ray is found when 3% of the organic ligand or its Cobalt (II) complex is used in the polymer matrix.The radiation chemical yield for chain scission (Gs) is calculated and has its lower values in the case of the organic ligand, which means that the protection is stronger in the case of the organic ligand than its Cobalt (II) complex. From TLC studies, it is noticed that both the Rf-values and polydispersity of the PMMA samples increase with increasing exposure dose.

Adsorption, Desorption And Mobility of Fomesafen in Chinese Soils

Fomesafen, 5-[2-chloro-4-(trifluoromethyl)phenoxy]-N-(methylsulfonyl)-2-nitrobenzamide, is used widely for weed control in soybeans since its introduction to China. Little information is available on its adsorption, desorption and movement in Chinese soils. The adsorption, desorption and mobility of fomesafen in six Chinese soils was studied. Adsorption isotherms agreed with the Freundlich equation very well. The results of regressionanalysis indicated that soil pH was more important than organic matter for fomesafen adsorption. Fomesafen was more readily desorbed from soils with 0.01 M CaSO4 solution. Soil TLC and column leaching studies showed that fomesafen and its metabolites was less mobile in Chinese soils. About 89.82% of applied fomesafen and its metabolites still remained in upper 5 cm layer 60 days after treatment under field conditions.

Chemotaxis of a Ralstonia sp. SJ98 toward Different Nitroaromatic Compounds and Their Degradation

A Ralstonia sp. SJ98, isolated by a chemotactic enrichment technique, was capable of utilizing different nitroaromatic compounds (NACs). It utilized p-nitrophenol, 4-nitrocatechol, o-nitrobenzoic acid, and p-nitrobenzoic acid as the sole source of carbon and energy. It was observed that Ralstonia sp. SJ98 was chemotactic to the above-mentioned NACs as tested by the drop assay, swarm plate assay, and capillary assay. However, it failed to show chemotactic behavior toward those compounds which were not degraded by the microorganism. This is the first report which shows the chemotaxis of a microorganism toward different NACs and their subsequent degradation. Some of the intermediates of the NACs' degradative pathways have been identified using TLC, GC, and GC-MS studies. The results presented here indicate a correlation between chemotaxis and biodegradation of NACs.

Syntheses and radiochemical studies of99mTc-complexes of polydentate tris-amineoxime ligands

Two new polydentate amineoxime ligands, Tris[1',1'-dimethyl-2'-oximino propyl)-2-aminoethyl]amine (I) and Tris[(1'-methyl-2'-oximinopropyl)-2-aminoethyl]amine (II) possessing trisubstituted nitrogen atoms which would possibly provide an inherent capping as well as ensure stereochemical rigidity, were synthesised. The radiochemical studies of these ligands with 99m Tc were carried out and complexation yields were optimised by varying the reaction conditions. The 99m Tc complexes were characterised by TLC, paper electrophoresis and solvent extraction studies. Radiochemical purity of these complexes were improved considerably on extraction of the complexes in chloroform, evaporation and reconstitution in saline containing stannous ions. The uptake of the 99m Tc complexes with the two ligands prepared under optimised conditions were tested in biodistribution studies using Swiss mice.

Simultaneous spectrophotometric and volumetric determinations of amoxycillin, ampicillin and cloxacillin in drug formulations: reaction mechanism in the base catalysed hydrolysis followed by oxidation with iodate in dilute acid solution

A method for the analysis of degraded products of amoxycillin, ampicillin and cloxacillin in drug formulations, obtained as a result of their base hydrolysis is described. Simultaneous spectrophotometric and volumetric determinations of the antibiotic is based on the neutralization of the degraded product by dilute hydrochloric acid to get a pH ∼2 to be conducive for redox titration using potassium iodate as titrant. A red purple colour is developed in carbon tetrachloride at the end point. Spectrophotometry is done after separating the organic layer and measuring the absorbance of red-purple colour at λ max 520 nm. The pathways of different degraded products and their oxidation mechanism is described on IR, TLC and UV spectroscopic studies.

Multiple shoot regeneration and tissue culture studies on Bacopa monnieri (L.) Pennell

Adventitious shoot buds were induced from leaf and stem explants of Bacopa monnieri on Murashige and Skoog medium supplemented with benzyladenine or kinetin. The source of the explants as well as different gelling agents in the medium were found to influence shoot induction and eventual shoot growth. The best response was obtained in leaf explants taken from shoot cultures grown in medium supplemented with 2 μM benzyladenine and gelled with 0.2% gelrite. A transverse section of the leaf explant incubated in this medium showed several shoot primordia emerging from the leaf surface. This system exhibited a potential for repeated harvesting of the shoots from the original leaf explant as the latter continued to expand and regenerate new shoots, upon repeated periodical subculturing onto fresh medium. However, the callusing response of the plant was very low. Qualitative TLC studies of the regenerated shoots revealed a phytochemical profile similar to that of the field grown-plants.

Antioxidant response of soybean cotyledons (Glycine max) to ultraviolet irradiation

After 24 h of UV-B + UV-C irradiation the homogenates of superficial layers of soybean cotyledons (Glycine max var. Hood) contained significantly more tocopherol (133%) and ascorbic acid (20%) than the control. However, UV-B irradiation alone did not affect the content of these antioxidants. Neither β-carotene nor thiol content was significantly affected after UV-B or UV-B + UV-C irradiation. Pigmentation of cotyledons from control and UV-B-exposed plants did not differ visibly, but cotyledons from plants exposed to UV-B + UV-C accumulated a red pigment in the epidermis 15 h after receiving the UV radiation. Spectral analysis indicated a substantial increase in absorbance between 250 and 340 nm after UV-B + UV-C exposure, compared with controls. Ethanolic extracts from UV-B + UV-C-irradiated cotyledons showed a significant peak at 532 nm at pH 10, which was not seen at pH 6. Successive changes in pH were accompanied by reversible changes in the spectra. TLC studies indicated that Rf values for the pigment were 0.75 and 0.63 in Forestal and formic solvents, respectively. By comparison with literature values, these results are consistent with the features of apigeninidin. The results suggest that UV-B irradiation and UV-C irradiation affect different mechanisms at the cellular level. Key words: Antioxidants, colored pigment induction, cotyledon, ultraviolet irradiation, UV-B + UV-C

Molecular weight and TLC studies on the gamma degradation of some poly(methyl methacrylate) in the absence and presence of N,N-dioxalyl p-aminobenzene sulphonic acid and its iron (II) complex

Protection of some poly(methyl methacrylate) samples against gamma rays has been investigated in the absence and presence of N,N-dioxalyl p-aminobenzene sulphonic acid and its iron (II)-complex. The pure PMMA (without additives), PMMA-ligand and PMMA-iron complex composite samples were irradiated with gamma rays for different exposure doses (5, 15, 25, 35, 50, 75 and 100 KGy). Viscosity average molecular weights ( M v -values) and thin layer Chromatographic measurements were carried out after each irradiation dose. The maximum protection against gamma ray is found when 7% of the organic ligand or its iron complex is used in the polymer matrix. The radiation chemical yield for main chain scission ( Gs) is calculated and has its lower values in the case of the organic ligand which means that the protection is stronger in the case of the organic ligand than its iron complex. From TLC studies, it is noticed that both the R f -values and polydispersity of the PMMA samples increase with increasing exposure dose.