Abdul Hafeez Laghari

Determination of free phenolic acids and antioxidant activity of methanolic extracts obtained from fruits and leaves of Chenopodium album

In this study, determination of phenolic acids as well as investigation of antioxidant activity of methanolic extracts from the fruits and leaves of Chenopodium album is described. Extracts were subjected to acidic hydrolysis in order to obtain total free phenolic acids. However, some of phenolic acids were identified and quantified by HPLC-DAD. The results were confirmed by LC-MS equipped with MS-ESI. In addition, Folin-Ciocalteu method was applied to determine the total phenolic contents. The antioxidant activity of C. album extracts was examined by using DPPH and hydroxyl radical-scavenging activity assays. Results revealed that the leaves extract exhibits better performance in antioxidant assays and in the higher total phenolic contents (3066mg of GAE/100g) when compared to fruits extract (1385mg of GAE/100g). From these results it has been revealed that the methanolic extracts of C. album from fruits and leaves have great potential as a source for natural health products.

Determination of free phenolic acids and antioxidant capacity of methanolic extracts obtained from leaves and flowers of camel thorn (Alhagi maurorum)

The present study comprises the determination of some phenolic acids from the leaves and flowers of Alhagi maurorum by HPLC-DAD, confirmed by LC-MS-APCI. The antioxidant properties and measurements of the total phenolic contents of the extracts were assessed by 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging and Folin–Ciocalteu methods, respectively. It was found that the leaf extract had higher antioxidant potential (83.5%) than the flower extract (72.3%). The antioxidant properties and total phenolic contents of the leaves were higher than those of the flowers.

Application of attenuated total reflectance Fourier transform infrared spectroscopy for determination of cefixime in oral pharmaceutical formulations

A quick and reliable analytical method for the quantitative assessment of cefixime in orally administered pharmaceutical formulations is developed by using diamond cell attenuated total reflectance (ATR) Fourier transform infrared (FT-IR) spectroscopy as an easy procedure for quality control laboratories. The standards for calibration were prepared in aqueous medium ranging from 350 to 6000mg/kg. The calibration model was developed based on partial least square (PLS) using finger print region of FT-IR spectrum in the range from 1485 to 887cm(-1). Excellent coefficient of determination (R(2)) was achieved as high as 0.99976 with root mean square error of 44.8 for calibration. The application of diamond cell (smart accessory) ATR FT-IR proves a reliable determination of cefixime in pharmaceutical formulations to assess the quality of the final product.

Validated HPLC-RI Method for the Determination of Lactulose and its Process Related Impurities in Syrup

A simple, swift with good sensitivity and reproducibility, HPLC-RI method has been developed for the quantification of lactulose and related compounds (fructose, galactose, epilactose and lactose) in oral suspension formulation. The analysis was carried out by using mobile phase (water and acetonitrile 75:25) at the flow rate of 1.0 ml/min. on isocratic HPLC-RI system. After manipulating mobile phase composition and mobile phase flow rate a good separation of five components was achieved within 15 minutes of run time. This study is beneficial to determine the active ingredient as well as related compounds simultaneously, without using buffer in mobile phase which causes bad resolution and has limitation to analyze on other hyphenated techniques such as LC-MS.

Determination of Volatile Constituents and Antimicrobial Activity of Camel Thorn (Alhagi camelorum) Flowers

A direct analysis headspace method coupled to gas chromatography– mass spectrometry (GC–MS) is reported for the determination of volatile compounds and antimicrobial activity in the flowers of Alhagi camelorum. The method was used for the determination of volatile compounds in dry as well as methanol extracts of the flowers. The highest efficiency of the headspace method was achieved at 140°C and 10 min of incubation time. Forty compounds were identified by this technique. In comparison with generally used hydro-distillation method, the headspace GC–MS method was very simple, required low amount of sample, was convenient to handle without using any solvent, and required shorter analysis time. It also offered high trapping ability for volatile and thermally sensitive compounds. The major components identified by this method were furfuraldehyde derivatives, which indicate the presence of higher carbohydrate content. In addition, methanol extracts of Alhagi camelorum flowers were investigated for their antimicrobial activity with two species Escherichia coli (Gram-negative bacterium) and Staphylococcus aureus (Gram-positive coccal bacterium). The extracts had remarkable antibacterial activity against these species with minimum inhibitory concentration values of 50 and 70 µg · mL−1 for E. coli and S. aureus, respectively.

Antioxidant Activity of Alhagi camelorum Phenolics Extracted by Automated and Standard Extraction Techniques

Two extraction techniques, automatic soxtherm apparatus and conventional ultrasonic extraction, were compared in terms of yield, composition, and with special focus on antioxidant activity. In the DPPH test automated extraction showed higher antioxidant potential with IC50 value of 7.5 mg/mL as compared to that of ultrasonic extraction which is 12.5 mg/L, whereas combining both was found to be relatively better. A similar trend in total phenolic and total flavonoid contents was observed. HPLC analysis of both extracts revealed the presence of gallic acid, p-hydroxybenzoic acid, caffeic acid, syringic acid rutin, and ferrulic acid with significant difference in their profile.

Purification of flavonoid metal complexes from Alhagi camelorum with calix[4]arene based impregnated resin

Calixarenes are well known for their molecular recognition properties. Thus, the present study was carried out to explore their usage in the isolation of flavonoids [i.e. quercetin (I) and catechin (II)] from plant extracts, e.g. Alhagi camelorum through metal complexation. The synthesis of flavonoid metal complexes from plant extracts through direct complexation and their purification by using calix[4]arene based resin (R-1) was carried out simultaneously to ensure the separation efficiency of R-1. It was observed that the direct complexation of flavonoids present in plant extracts and purification using a column loaded with R-1 could be the best choice for industries requiring the isolation and purification of flavonoids or their complexes from plants.