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Abstract
In the present communication we report on the radiation induced grafting of methyl methacrylate (MMA) onto irradiated isotactic polypropylene film (IPP) by Peroxidation method to prepared grafted membrane (IPP-g-MMA). The radioactive isotope 60Co was used as the source of gamma radiation. A plausible mechanism of grafting has been proposed. Optimum conditions pertaining to maximum percentage of grafting were evaluated as a function of different reaction parameters such as radiation dose, inhibitor concentration, monomer concentration, reaction time and reaction temperature respectively. Maximum percentage of grafting (85%) was obtained at [radiation dose] = 25 kGy, [inhibitor concentration] = 0.04 wt%, [MMA] = 6 wt%, [Reaction Temperature] = 60 °C in a [Reaction time] of 120 min. The evidence of grafted membrane was characterized by Fourier transform infrared spectroscopy, Atomic force microscopy method, Scanning electron microscopy which indicates that MMA has been grafted onto IPP. Hydrolysis of the grafted membranes in 1 N NaOH transformed ester groups of the grafted membranes to carboxylic acid and hydroxyl groups to form hydrolyzed grafted membranes. Hydrolyzed grafted membranes were investigated for their swelling behavior. Swelling properties of the hydrolyzed grafted membranes were performed in different solvents such as water, N,N-dimethylformamide (DMF) and dimethylsulfoxide (DMSO). Maximum percentage swelling value of IPP-g-MMA was observed in pure DMSO, followed by DMF and water.
Abstract
Stimuli-responsive membranes were prepared by peroxidation radiation-induced grafting of 2-hydroxyethyl methacrylate (2-HEMA) onto IPP. The radioactive isotope 60Co was used as the source of gamma radiation. A plausible mechanism of grafting has been proposed. Using this method, the degree of grafting and morphology could be controlled through the variation of reaction parameters such as total dose, inhibitor concentration, monomer concentration, reaction time, reaction temperature and solvents. Maximum percentage of grafting (210 %) was obtained at total radiation dose of 20 kGy. The graft copolymerization reaction was carried out for 3 h with 20 v/v% of the monomer (2-HEMA) in methanol at 85 °C using 0.06 wt% of FeCl3 as inhibitor. The chemical structures of grafted membranes were characterized by Fourier transform infrared spectroscopy (FTIR) which indicates that HEMA has been grafted onto IPP. The atomic force microscopy (AFM), scanning electron microscopy (SEM) techniques were used to assess the morphological characterization of the membranes, revealing the roughness of the surface. These membranes were investigated for their swelling behavior. pH-sensitivity and the dyeability of the grafted and ungrafted membranes have also been studied.
Abstract
Acrylonitrile (AN)-methyl acrylate (MA), acrylonitrile (AN)-ethyl acrylate (EA), acrylonitrile (AN)-butyl acrylate (BA) copolymers with and without doping with ferric chloride were prepared by free radical polymerization at 70°C. Mössbauer spectrum shows no reduction of ferric species to ferrous during the copolymerization. TGA studies show that the addition of ferric chloride changes the thermal decomposition pattern of the copolymer. TGA analysis shows that the inclusion of ferric chloride stabilizes the copolymers by 20–25°C. Mössbauer studies of the copolymers heated at 300°C and 500°C for 15 min showed that during the thermal degration, Fe3+ species was reduced to Fe2+ and then finally it formed 
-Fe2O3.
Marmelosin is one of the major phytochemical constituents of Aegle marmelos (L.) Corr. (Rutaceae). Till date, there are no methods reported for the estimation of marmelosin in plasma matrix using high-performance thin-layer chromatography (HPTLC) which is a versatile analytical technique promoting shorter analysis time and less consumption of solvents with efficient data acquisition and processing. This study is an attempt to develop a rapid and sensitive HPTLC method for the estimation of marmelosin from rat plasma and its application to evaluate pharmacokinetics of A. marmelos fruit pulp extract and a traditional Unani medicine Sharabat-e-Belgiri. Plasma processing involved liquid-liquid extraction with diethyl ether followed by HPTLC. Separation and determination of marmelosin were performed on silica gel 60 F254 TLC plate using toluene-ethyl acetate-glacial acetic acid as mobile phase. United States Food and Drug Administration (USFDA) guidelines for bioanalytical validation were followed to validate the HPTLC method. R
F of marmelosin was found to be 0.57. The calibration curve was linear over the range of 1.0–150.0 μg mL−1 (r
2 = 0.995) in rat plasma. Limit of detection and limit of quantitation were found to be 0.5 μg mL−1 and 1.0 μg mL−1, respectively. The extraction recovery from plasma was in the range of 90.07–98.22%. The intra-day and inter-day precisions were found to be 90.89–104.12%, and 92.82–104.86%, respectively. The absorption of marmelosin from extract was found significantly higher than the formulation. The results indicated that HPTLC is a suitable technique for the estimation and pharmacokinetic evaluation of marmelosin from plant extract and Unani formulation in rat plasma.
A sensitive, simple, and reliable reversed-phase HPTLC method has been established for quantification of mimosine in Mimosa pudica Linn. whole plant powder. The plant powder was first extracted with methanol. The residue was then extracted with water and the aqueous extract was used for quantification. Chromatography was performed on silica gel RP-18 F254s plates with ethyl acetate-glacial acetic acid-water, 6 + 1 + 1.7 ( v/v ), as mobile phase. Quantification was achieved by densitometric scanning at λ max = 282 nm in reflectance-absorbance mode. The response to mimosine was a linear function of concentration over the range 30 to 100 μg mL −1 in the extract. The amount of mimosine in M. pudica was found to be 20 mg g −1 whole plant powder. The method was validated for linearity, precision, accuracy, and robustness.
A sensitive, simple, and accurate high-performance thin-layer chromatographic method has been established for determination of oleanolic acid in whole-plant powder from Oldenlandia corymbosa L. A methanol extract of the powder was used for the experimental work. The concentration of oleanolic acid in whole plant was found to be 1.892 μg g −1 . Separation was performed on aluminum HPTLC plates coated with silica gel 60 F 254 , with dichloromethane-toluene-acetone-methanol, 3 + 4 + 1.5 + 0.3 ( v/v ), as mobile phase. After development, plates were treated with Liebermann-Burchard reagent and detection and quantification were performed by densitometry at λ = 529 nm. Detection and quantitation limits were 0.1 μg and 0.5 μg, respectively. Oleanolic acid response was linear over the range 1 to 9 μg. The validated HPTLC method can be used for routine quality-control analysis of Oldenlandia corymbosa L. whole-plant powder and for quantitative determination of oleanolic acid.
