Simple, accurate, sensitive and validated UV spectrophotometric and chemometric methods were developed for the determination of imidapril hydrochloride (IMD) in the presence of both its alkaline (AKN) and oxidati...Simple, accurate, sensitive and validated UV spectrophotometric and chemometric methods were developed for the determination of imidapril hydrochloride (IMD) in the presence of both its alkaline (AKN) and oxidative (OXI) degradation products and in its pharmaceutical formulation. Method A is the fourth derivative spectra (D4) which allows the determination of IMD in the presence of both AKN and OXD, in pure form and in tablets by measuring the peak amplitude at 243.0 nm. Methods B, C and D, manipulating ratio spectra, were also developed. Method B is the double divisor-ratio difference spectrophotometric one (DD-RD) by computing the difference between the amplitudes of IMD ratio spectra at 232 and 256.3 nm. Method C is the double divisor-first derivative of ratio spectra method (DD-DR1) at 243.2 nm, while method D is the mean centering of ratio spectra (MCR) at 288.0 nm. Methods A, B, C and D could successfully determine IMD in a concentration range of 4.0-32.0 mg/mL. Methods E and F are principal component regression (PCR) and partial least-squares (PLS), respectively, for the simultaneous determination of IMD in the presence of both AKN and OXI, in pure form and in its tablets. The developed methods have the advantage of simultaneous determination of the cited components without any pre-treatment. The accuracy, precision and linearity ranges of the developed methods were determined. The results obtained were statistically compared with those of a reported HPLC method, and there was no significant difference between the proposed methods and the reported method regarding both accuracy and precision.展开更多
Phytochemicals have been of great interest as a source of natural antioxidants used for health promotion, food preservation, food flavoring and cosmetics. In this research, alcoholic extract from Caralluma arabica and...Phytochemicals have been of great interest as a source of natural antioxidants used for health promotion, food preservation, food flavoring and cosmetics. In this research, alcoholic extract from Caralluma arabica and different solvent fractions were evaluated for their antioxidant, anti-inflammatory and anti-cancer properties as well as their polyphenolic compositions. The total antioxidant property was estimated by the ferric reducing antioxidant power (FRAP), 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2, 2-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS+) and β-carotene bleaching tests. Among the ethanol extract and three fractions, the ethyl acetate fraction showed the highest phenolic content (33.1 mg gallic acid/g) and the best antioxidant activity. The ascorbic acid equivalent antioxidant capacities of the ethyl acetate fraction were 143.64, 381.3, 112.6 μmol/g in FRAP, ABTS and DPPH assays, respectively. This study verified that the ethanol extract and ethyl acetate fraction from Caralluma arabica have strong antioxidant activity that was correlated with their high level of phenolic content. Furthermore, the same extract showed appreciable anti-inflammatory via Lipoxygenase inhibitory activity (LOX), the IC50 values ranged from 11.2 - 30.77 μg/mL. Moreover, Ethyl acetate fraction showed the strongest cytotoxic effect (IC50 = 87.55 μg/mL) against MCF-7 breast cancer cell line. These findings suggest that Caralluma arabica may be considered as an interesting source of antioxidants for nutraceutical industries.展开更多
Three novel amprolium HCl(AMP)-selective electrodes were investigated with 2-nitrophenyl octylether as a plasticiser in a polymeric matrix of polyvinyl chloride(PVC). Sensor I was fabricated using potassium tetra...Three novel amprolium HCl(AMP)-selective electrodes were investigated with 2-nitrophenyl octylether as a plasticiser in a polymeric matrix of polyvinyl chloride(PVC). Sensor I was fabricated using potassium tetrakis(4-chlorophenyl) borate(Tp ClPB) as a cationic exchanger without incorporation of an ionophore.Sensor Ⅱ used 2-hydroxy propyl β-cyclodextrin as an ionophore while sensor Ⅲ used p-tert-butylcalix[8]arene as an ionophore. The three proposed sensors showed Nernestian response slopes of 29.2±0.8,29.3±0.6 and 30.2±0.4 m V/decade over the concentration range from 10–6 to 10–2 mol L_(-1),respectively. The proposed sensors displayed useful analytical characteristics for the determination of AMP in bulk powder, different pharmaceutical formulations, and chicken liver and in the presence of ethopabate. The proposed method was validated according to ICH guidelines for its linearity, accuracy,precision and robustness.展开更多
文摘Simple, accurate, sensitive and validated UV spectrophotometric and chemometric methods were developed for the determination of imidapril hydrochloride (IMD) in the presence of both its alkaline (AKN) and oxidative (OXI) degradation products and in its pharmaceutical formulation. Method A is the fourth derivative spectra (D4) which allows the determination of IMD in the presence of both AKN and OXD, in pure form and in tablets by measuring the peak amplitude at 243.0 nm. Methods B, C and D, manipulating ratio spectra, were also developed. Method B is the double divisor-ratio difference spectrophotometric one (DD-RD) by computing the difference between the amplitudes of IMD ratio spectra at 232 and 256.3 nm. Method C is the double divisor-first derivative of ratio spectra method (DD-DR1) at 243.2 nm, while method D is the mean centering of ratio spectra (MCR) at 288.0 nm. Methods A, B, C and D could successfully determine IMD in a concentration range of 4.0-32.0 mg/mL. Methods E and F are principal component regression (PCR) and partial least-squares (PLS), respectively, for the simultaneous determination of IMD in the presence of both AKN and OXI, in pure form and in its tablets. The developed methods have the advantage of simultaneous determination of the cited components without any pre-treatment. The accuracy, precision and linearity ranges of the developed methods were determined. The results obtained were statistically compared with those of a reported HPLC method, and there was no significant difference between the proposed methods and the reported method regarding both accuracy and precision.
文摘Phytochemicals have been of great interest as a source of natural antioxidants used for health promotion, food preservation, food flavoring and cosmetics. In this research, alcoholic extract from Caralluma arabica and different solvent fractions were evaluated for their antioxidant, anti-inflammatory and anti-cancer properties as well as their polyphenolic compositions. The total antioxidant property was estimated by the ferric reducing antioxidant power (FRAP), 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2, 2-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS+) and β-carotene bleaching tests. Among the ethanol extract and three fractions, the ethyl acetate fraction showed the highest phenolic content (33.1 mg gallic acid/g) and the best antioxidant activity. The ascorbic acid equivalent antioxidant capacities of the ethyl acetate fraction were 143.64, 381.3, 112.6 μmol/g in FRAP, ABTS and DPPH assays, respectively. This study verified that the ethanol extract and ethyl acetate fraction from Caralluma arabica have strong antioxidant activity that was correlated with their high level of phenolic content. Furthermore, the same extract showed appreciable anti-inflammatory via Lipoxygenase inhibitory activity (LOX), the IC50 values ranged from 11.2 - 30.77 μg/mL. Moreover, Ethyl acetate fraction showed the strongest cytotoxic effect (IC50 = 87.55 μg/mL) against MCF-7 breast cancer cell line. These findings suggest that Caralluma arabica may be considered as an interesting source of antioxidants for nutraceutical industries.
文摘Three novel amprolium HCl(AMP)-selective electrodes were investigated with 2-nitrophenyl octylether as a plasticiser in a polymeric matrix of polyvinyl chloride(PVC). Sensor I was fabricated using potassium tetrakis(4-chlorophenyl) borate(Tp ClPB) as a cationic exchanger without incorporation of an ionophore.Sensor Ⅱ used 2-hydroxy propyl β-cyclodextrin as an ionophore while sensor Ⅲ used p-tert-butylcalix[8]arene as an ionophore. The three proposed sensors showed Nernestian response slopes of 29.2±0.8,29.3±0.6 and 30.2±0.4 m V/decade over the concentration range from 10–6 to 10–2 mol L_(-1),respectively. The proposed sensors displayed useful analytical characteristics for the determination of AMP in bulk powder, different pharmaceutical formulations, and chicken liver and in the presence of ethopabate. The proposed method was validated according to ICH guidelines for its linearity, accuracy,precision and robustness.