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Biologia Futura
Authors: Muhammad Saad, Helen Mary, Umar Amjid, Ghulam Shabir, Kashif Aslam, Shahid Masood Shah, and Abdul Rehman Khan

Tartary buckwheat, known for its rich source of health beneficial secondary metabolites, is cultivated in many areas of the world. Among different environmental factors, photoperiod strongly influence its growth, flowering time, and ultimately the yield. In this context, epigenetics could contribute significantly in the regulation of plant response against changing environment. Therefore, with the aim to study the involvement of DNA methylation in photoperiod mediated plant response, genome-wide DNA methylation analysis was performed in two accessions (A1 and A2) of Tartary buckwheat using three photoperiodic treatments, i.e., 10-hr light/day (T1), 12-hr light/day (T2), and 14-hr light/day (T3). Flowering time and plant fresh weight data revealed that accessions A1 and A2 prefer T1 and T2 treatments, respectively. Total DNA methylation ratio increased with the increase in photoperiod in accession A1 but decreased under same conditions in accession A2. Full methylation increased significantly while intensive decrease in hemimethylation was noted from T2 to T3 in A1, whereas full methylation strongly increased and hemimethylation strongly decreased from T1 to T2 in A2. Overall, the DNA methylation events appeared more frequently than demethylation events. This study reports for the first time an accession-/genotype specific pattern of shift in the DNA methylation under different photoperiodic treatments that will pave the way toward identification of specific genes involved in the regulation of plant response against photoperiodic stress.

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A sensitive, inexpensive high-performance liquid chromatography–ultraviolet detection (HPLC–UV) method has been developed and validated for the simultaneous monitoring of pantoprazole sodium sesquihydrate (PSS) and domperidone maleate (DM) in rabbit plasma on a C18 column with UV detection at 285 nm. Box–Behnken design was used with 3 independent variables, namely, flow rate (X 1), mobile phase composition (X 2), and phosphate buffer pH (X 3), which were used to design mathematical models. Response surface design was applied to optimize the dependent variables, i.e., retention time (Y 1 and Y 2) and percentage recoveries (Y 3 and Y 4) of PSS and DM. The method was sensitive and reproducible over 1.562 to 25 μg/mL. The effect of the quadratic outcome of flow rate, mobile phase composition, and buffer pH on retention time (p ˂ 0.001) and percentage recoveries of PSS and DM (p = 0.0016) were significant. The regression values obtained from analytical curve of PSS and DM were 0.999 and 0.9994, respectively. The percentage recoveries of PSS and DM were ranged from 94.5 to 100.41% and 94.77 to 100.31%, respectively. The developed method was applied for studying the pharmacokinetics of PSS and DM. The C max of test and reference formulations were 48.06 ± 0.347 μg/mL and 46.31 ± 0.398 μg/mL for PSS, and 15.11 ± 1.608 μg/mL and 12.06 ± 1.234 μg/mL for DM, respectively.

Open access
Acta Chromatographica
Authors: Muhammad Hanif, Shahid Shah, Nasir Rasool, Ghulam Abbas, Malik Saadullah, Sajid Mehmood Khan, Muhammad Masood Ahmed, Nazar Abbas, Mehran Ashfaq, and Omeira Iqbal

Abstract

The high performance liquid chromatographic (HPLC) method was developed for the combined estimation of sodium alginate and pectin in raft forming pharmaceuticals on C18 column ZORBAX ODS (1.5 cm × 4.6 mm, 5 μm) with UV detection at 378 nm. The assay condition comprised of phosphate buffer pH 7.4 and methanol 60:40% v/v at a flow rate of 1.25 mL/min. The separation of sodium alginate and pectin with good resolution and a retention time less than 8 min was attained. The method was linear over a range of 200–800 μg/mL of sodium alginate and pectin. The regression values obtained from linearity curve of sodium alginate and pectin were 0.9993 and 0.9991, respectively. The retention time of sodium alginate and pectin was 3.931 and 7.470 min, respectively. The percent recovery of sodium alginate and pectin ranged from 94.2–98.5% and 92.1–98.4% respectively. The limit of detection (LOD) and limit of quantification (LOQ) of sodium alginate were found to be 2.443 and 3.129 μg/mL and the LOD and LOQ of pectin were 3.126 and 3.785 μg/mL, respectively. The resolution of sodium alginate and pectin was found in the range of 1.03–1.89 and 1.10–1.91, respectively. This method has been successfully applied to analyze the concentrations of sodium alginate and pectin in raft forming drug delivery systems.

Open access