Mössbauer spectra of alkali tris(maleato) ferrates(III), i.e., M3[Fe(C2H2C2O4)3]·nH2O [M=Li, Na, K, Cs] at 300 K display a doublet. The Mössbauer parameters indicate these complexes to be high spin with octahedral
symmetry. The isomer shift shows a decreasing trend with the increase in electronegativity/polarizing power of the substituent
cation (Li+, Na+, K+, Cs+). A linear correlation between isomer shift values and the (Fe−O) stretching frequencies has also been observed.
Authors:Prawez Alam, Y.T. Kamal, Mohammed H. Alqarni, Hala H. Zaatout, and Maged S. Abdel-Kader
A new rapid, simple, economical, and environment-friendly reversed- phase high-performance thin-layer chromatography (RPHPTLC) method has been established for the simultaneous determination of glycyrrhizin and glabridin in Glycyrrhiza glabra roots, rhizomes and selected herbal formulations. The method was carried out using RP-18 silica gel 60 F254S HPTLC glass plates and methanol–water (7:3 v/v) as the mobile phase. The developed plates were scanned and quantified densitometrically at 256 and 233 nm for glycyrrhizin and glabridin, respectively. Glycyrrhizin and glabridin peaks from G. glabra roots and rhizomes and herbal formulations were identified by comparing their single spots at RF = 0.63 ± 0.02 and RF = 0.28 ± 0.01, respectively. Linear regression analysis revealed a good linear relationship between the peak areas and the amounts of glycyrrhizin and glabridin in the ranges of 1000–7000 and 100–700 ng band−1, respectively. The method was validated, in accordance with the International Conference on Harmonization (ICH) guidelines for precision, accuracy, and robustness. The proposed method will be useful to determine the therapeutic doses of glycyrrhizin and glabridin in herbal formulations as well as in bulk drug.
Authors:Mhaveer Singh, Yunus Kamal, Ennus Tamboli, Rabea Parveen, Shahid Ansari, and Sayeed Ahmad
A novel HPTLC method has been developed for the estimation of glabridin in Licorice rhizome and its Unani polyherbal formulation (Qurs-e-Gul). Separation was achieved on silica using toluene, dichloromethane, and ethyl acetate in equal ratios. A compact, well resolved peak of glabridin with RF value 0.56 ± 0.02 was observed. Calibration curve revealed a good linear relationship with r2 value of 0.993 between the peak area and concentration in the range of 25–500 ng spot−1. The proposed method was validated as per the International Conference on Harmonization (ICH) guidelines. The stability assessment was carried out by studying degradation of glabridin stressed by acid, base, oxidation, thermal, and humidity. Photodegradation was also carried out after keeping the drug in sunlight, dark, and in UV lights. The method proposed can be used for routine determination of glabridin in crude drugs and in herbal formulations containing Licorice as one of the ingredients, for quality control as well as for stability testing with high precision, accuracy and a wide range of linearity.
Authors:Y.T. Kamal, Mhaveer Singh, Shahana Salam, and Sayeed Ahmad
The alternative system of medicines like Unani and Ayurveda is preferred worldwide nowadays due to its therapeutic efficacy, lower side effects, holistic approach, psychological dimensions, and qualitative action of weather and seasonal requirement. A simple procedure is described for the simultaneous extraction and estimation of piperlongumine and piperine in a well-known Unani polyherbal formulation using reversed-phase high-performance liquid chromatography (HPLC). The chromatography was carried out on reversed-phase C18 (250 × 4.6 mm) column with a mobile phase containing acetonitrile—water (50:50 v/v). Detection was accomplished with ultraviolet (UV) detection at λ = 325 nm. The flow rate was kept as 1.0 mL−1. The proposed method was validated according to International Conference on Harmonization (ICH) guidelines for accuracy (94.4–105.0%), precision (0.37–2.17% RSD), and robustness (0.14–2.11% RSD). The limit of detection (LOD) values were found as 30 and 10 ng mL−1, while limit of quantification (LOQ) was 100 and 30 ng mL−1 for piperlongumine and piperine, respectively, which proved the sensitivity of the method satisfactory enough for accurate analysis of the both piperlongumine and piperine.
Authors:Y. T. Kamal, Hasan Soliman Yusufoglu, Prawez Alam, and Ahmed Ibrahim Fouda
In this research, a novel method was developed for the matrix solid phase dispersion (MSPD) followed by high-performance liquid chromatography (HPLC) quantification of four marker constituents (vitamin C, gallic acid, rutin, and ellagic acid) in the freeze-dried pomegranate fruit juice. Various MSPD parameters like type of dispersant, sample–dispersant ratio, solvents, its volume, and time of extraction have been optimized after many trials. Furthermore, HPLC method has been developed and optimized for the analysis of all four components. The HPLC separation was achieved using a 250 × 4.6 mm column, particle size of 5 μm, C18 reverse phase column, with a mobile phase consisting of acetonitrile and 0.05% H3PO4, in gradient elution mode with a mobile phase flow rate of 1 mL/min, using ultraviolet (UV)–visible detection at 254 nm. All calibration curves showed good linear regression (r2 ≥ 0.9925) within test ranges. The extraction recoveries of the marker constituents analyzed by MSPD methods were found as ranging from 97.5% to 103.5%. From comparing the chromatograms, validation data and other parameters like time, labor, and feasibility, we found that MSPD technique was most suitable for the analysis as compared to conventional liquid–liquid extraction technique.
Authors:Alireza Khorami-Moghadam, Amir Jalilian, Kamal Yavari, Bahram Bolouri, Ali Bahrami-Samani, and Mohammad Ghannadi-Maragheh
Antiangiogenic monoclonal antibodies in combination with therapeutic radionuclides are potential targeted therapy agents in
cancer. In this study, bevacizumab was successively labeled with [166Ho]HoCl3 after conjugation with DOTA-NHS-ester with a radiochemical purity of higher than 95% (RTLC). The conjugates were purified
by molecular filtration, the average number of DOTA conjugated per mAb was calculated and total concentration was determined
by spectrophotometric method and the average chelate to antibody ratio (c/a) for the conjugate used in this study was 5.8:1
and protein integrity experiments (SDS-PAGE). The biodistribution studies in wild-type rats demonstrate a similar pattern
to the other radiolabeled anti-vascular endothelial growth factor A (VEGF-A) immunoconjugates. 166Ho-DOTA-bevacizumab is a potential compound for therapy/imaging of VEGF-A expression in oncology.
Authors:R. Parveen, F. J. Ahmad, Z. Iqbal, M. Singh, Y. T. Kamal, and S. Ahmad
Andrographolide and betulinic acid are the terpenoids having potential anti-cancer activity. The cytotoxicity activity of both the drugs was carried out separately and in combination on liver cancer HepG2 cell lines. High-performance liquid chromatography (HPLC) and high-performance thin-layer chromatography (HPTLC) methods were developed and validated for simultaneous estimation of these two terpenoids as per the International Conference on Harmonization (ICH) guidelines, which was applied for quantification in nanoformulation. The retention time by HPLC and retardation factor by HPTLC for andrographolide and betulinic acid were found to be 2.2 and 6.6 min, and 0.24 ± 0.01 and 0.66 ± 0.01, respectively. Both the methods were validated for accuracy, precision, repeatability, robustness, limit of detection (LOD), and limit of quantitation (LOQ). The content of andrographolide and betulinic acid in nanoformulation was found to be 96.0% and 98.0% by HPLC and 96.59% and 98.33% by HPTLC, respectively, of labelled claim.
Authors:Y. T. Kamal, M. Singh, E. T. Tamboli, R. Parveen, and S. Ahmad
A validated reversed-phase HPLC method has been developed for quantitative analysis of berberine in Berberis aristata fruits and in a polyherbal formulation. Separation of berberine was achieved on a C18 column with a mobile phase consisting of a 10–80% acetonitrile gradient in 0.05% aqueous orthophosphoric acid. The flow rate was 1 mL min−1. Detection was at 266 nm. A sharp, well defined peak was obtained at a retention time of 10.0 ± 0.4 min. The method was validated in accordance with ICH guidelines for accuracy, precision, robustness, and the limits of detection (LOD) and quantification (LOQ). Results from linear regression analysis were indicative of a good linear relationship (r2 = 0.998 ± 0.0011) in a wide concentration range (5–500 μ g mL−1). LOD and LOQ were 1.5 and 5.3 μg mL−1, respectively. Satisfactory recovery results (94.6–103.1%) were obtained by the method of standard addition. Intra-day, inter-day, and intersystem precision was satisfactory, with relative standard deviation in the range 0.7–1.8%. The berberine content of fruit of Berberis aristata and the herbal formulation were 0.033% and 0.0089% (w/w), respectively. This HPLC method for quantification of berberine can be used for quality control and standardization of several crude drugs and different herbal formulations in which berberine is present as a phyto constituent.
Authors:S. Mohamed Musthaba, M. T. Athar, Y. T. Kamal, S. Ahmad, J. Ali, and S. Baboota
In this chapter, an isocratic reverse phase HPLC determination of mimosine was developed and validated in an anti-psoriatic topically applied formulation “Lajjalu”. The chromatography was performed on a C18 column with water-orthophosphoric acid (98.8:0.2, υ/υ) as a mobile phase with a pH of 3.0 at a flow rate of 1.0 mL min−1. Detection was performed at 284 nm, and a sharp peak was obtained for mimosine at a retention time of 2.62 ± 0.01 min. Linear regression analysis data for the calibration plot showed a good linear relationship between response curve and concentration in the range of 0.050–5000 ng mL−1 and the regression coefficient was 0.9998 with the linear regression equation y = 4766.8x−17726. The detection (LOD) and quantification (LOQ) limits were 10.3 and 35.6 ng mL−1, respectively. The wide linearity range, sensitivity, accuracy, short retention time, and simple mobile phase imply the method is suitable for routine quantification of mimosine with high precision and accuracy.