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  Citation statistics : Table of Contents
   2016| September-December  | Volume 15 | Issue 3  
    Online since January 5, 2017

 
 
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ORIGINAL ARTICLES
Evaluation of Egyptian pomegranate cultivars for antioxidant activity, phenolic and flavonoid contents
Ahmed M. A. Souleman, Gamil E Ibrahim
September-December 2016, 15(3):143-149
DOI:10.4103/1687-4315.197582  
Aim The aim of the present study was to evaluate total phenolic and flavonoid contents as well as antioxidant activity of the peel, juice and seed extracts of pomegranate fruit from different Egyptian cultivars. The selected cultivar was subjected for evaluation of the effect of peel homogenate on volatile compounds in juice supplemented with this homogenate. Background Pomegranate fruit is a rich source of natural antioxidants; it has wide applications in food and pharmaceutical industry. Materials and methods Five cultivars of Egyptian pomegranate were subjected to a comparative study of phenolic and flavonoid contents as well as its antioxidant activity. The phenolic compounds were determined through high-performance liquid chromatography, and the volatile compounds of selected cultivar peel were added to juice through gas chromatography and gas chromatography–mass spectrometry. Results While the total phenolic content varied between 5.21 mg gallic acid equivalent/g in PG4 fruit juice and 17.24 mg gallic acid equivalent/g in PG1 peel, the total flavonoid content ranged from 9.64 in PG2 juice to 34.28 mg rutin/g in the peel of PG1. All peel, juice and seeds extracts exhibited high antioxidant activities, evaluated using 1,1’-diphenyl-2-picrylhydrazyl and β-carotene assays. Gallic acid, chlorogenic acid and caffeic acid were the predominant phenolic compounds of the pomegranate cultivars. A total of 17 volatile compounds were identified, including six monoterpenes, three monoterpenoids, three aldehydes, three esters, and two alcohols. Conclusion Peel, juice and seed of Egyptian pomegranate cultivars contain significant amounts of phenolics and flavonoids contents. However, the peel contains higher contents compared with juice and seeds. Peel homogenate of the selected cultivar showed a remarkable effect on volatile compounds when used for fortification of the pomegranate juice.
  3 1,841 575
Optimization of the production and characterization of milk-clotting enzyme from Bacillus subtilis isolated from marine sponge
Hala R Wehaidy, Mohamed A Abdel-Naby, Wafaa G Shousha, Mohammed I.Y. El Mallah, Michael M Shawky
September-December 2016, 15(3):158-166
DOI:10.4103/1687-4315.197584  
Background and objectives Milk-clotting enzyme (MCE) has important applications in the dairy industry and in the cheese-manufacturing process. Because of the increase in cheese consumption and the low supply of calf rennets, there is a need for a suitable rennet substitute from an appropriate source. The present investigation aims at microbial production of MCE and medium optimization for maximal enzyme production by the most potent strain. Partial purification and the properties of the partially purified enzyme are also studied. Materials and methods In the present study several microorganisms were tested for production of the MCE. MCE/caseinase ratio was investigated and was used as the key parameter for selection of the most potent strain and for medium optimization. Medium optimization experiments were carried out in an attempt to increase the enzyme productivity by the most potent strain. The produced enzyme was partially purified using ammonium sulfate at 50% concentration and the properties of the partially purified enzyme were investigated. Results and conclusion Among all the tested bacteria the marine sponge Pseudoceratina arabica isolated bacterium (isolate I) showed the highest milk-clotting activity. This isolate was used for MCE production throughout this study and it was identified as Bacillus subtilis KU710517. Maximum enzyme productivity (581.8 U/ml) and maximum MCE/caseinase ratio were obtained using a medium containing 50 g/l wheat bran with xylose and yeast extract as carbon and nitrogen sources. For the partially purified enzyme, the optimal temperature and pH were 85°C and 5.0, respectively. The enzyme was thermally stable at 45°C and retained 100% activity after 90 min. At 50°C for the same period of time it retained about 82% activity. However, at 60°C, the enzyme lost about 70% of its original activity after 30 min. The activation energy (Ea) of the enzyme was calculated as 6.95 kcal/mol. Km and Vmax values were 4.6 mg/ml and 2933 U/mg protein, respectively.
  1 1,317 156
Preparation and characterization of oxcarbazepine microemulsion
Tejas B Patel, Tejal G Soni, Bhanubhai N Suhagia
September-December 2016, 15(3):173-180
DOI:10.4103/1687-4315.197586  
Background Oxcarbazepine (OXZ) is an antiepileptic drug used to treat partial seizures. OXZ is available in dosage forms of tablet (150, 300, and 600 mg) and suspension (300 mg in 5 ml) in India. Children and adults complain that the suspension form has a downside in its stability (8 weeks). Aims The aim of the present investigation was to develop a microemulsion (ME) of OXZ for enhanced solubility and stability of drug in product. Materials and methods An ME comprises isopropyl myristate (oil phase), aerosol OT (a bipolar surfactant), and an aqueous phase comprising ethanol and distilled water in a ratio of 2: 8. Various ratios of oil: surfactant (1: 9 to 9: 1) were taken and the amount of aqueous phase titrated was determined using the water titration method. The data were plotted in a pseudoternary phase diagram and an optimized batch was selected. The batch was characterized by droplet size determination, zeta potential, drug content, and in-vitro dissolution studies. Results Size of the globules was found to be 53.65 and 59.15 nm in both ME 1 and ME 2, respectively; thus, it can also be termed as nanoemulsion. Zeta potential shows that the formulation is stable as it has positive zeta, giving 6.13 and 5.21 mV as zeta for ME 1 and ME 2, respectively. pH and conductance were also close to neutral, and hence the system was biocompatible. Conclusion Finally, on the basis of physicochemical characterization and stability studies, it can be concluded that water-in-oil ME for OXZ will serve as a novel drug delivery system with increased solubilization capacity and increased stability.
  1 1,583 171
Assessment the microbiological and molecular aspects of soil isolated bacteria that suppress Pythium ultimum in Abha/KSA
Mona Kilany, Essam H Ibrahim, Saad A Amry, Mohammed Hashem, Mohammad Hamada
September-December 2016, 15(3):181-186
DOI:10.4103/1687-4315.197587  
Background Pythium ultimum is largely threatening many economically important plants by causing seedling damping-off disease. Microbial control approach is considered a new, effective, and safe trend in the eradication of phytopathogens. Aims The current work focused on the isolation and molecular identification of soil isolated bacteria that suppress the damping-off-causing pathogen (P. ultimum). Moreover, optimization of environmental factors and detection of the mode of action of P. ultimum suppression was taken into consideration. Materials and methods Soil bacteria were isolated and screened for their antagonistic potential toward P. ultimum. The most vigorous isolate was characterized and identified. Some environmental factors were optimized using a well-plate assay. The inhibitory effect of bacteria, whether fungistatic or fungicidal, was detected. Mode of action of fungal inhibition was studied as well. Statistical analysis Statistical analysis was carried out using one-way analysis of variance in Excel. Results The bacterial isolate was identified as Enterococcus faecalis. The extracellular filtrate presented higher fungal inhibition (68%) compared with the bacterial cells (53%). The environmental factors for fungal inhibition were optimized to be pH 8, 28°C, 100% inoculum size, and third day of incubation reaching maximal values of 75, 76, 81, and 83%, respectively. Conclusion E. faecalis is a promising fungicidal agent against P ultimum through the production of diffusible metabolites.
  - 1,010 96
Fixed dose combination of targeted release paediatric dry syrup containing ofloxacin and ornidazole using natural polymers: formulation and characterization
Bitupan Bhuyan, Ratna J Das, Hemanta K Sharma
September-December 2016, 15(3):132-142
DOI:10.4103/1687-4315.197581  
Background Tablets and capsules are difficult to swallow for children. Therefore, liquid formulations are preferred for administration to children. Most of the drugs have bitter taste and children do not support oral administration. Aim The aim of this study was to prepare a palatable paediatric dry syrup with ofloxacin and ornidazole as targeted released formulation using natural polymer and to mask the bitter taste of the drugs with suitable natural polymers. Materials and methods Extraction of the mucilaginous substances was carried out as per the method of extraction of pectin, followed by phytochemical examination, and physicochemical characterization was carried out. Lethal dose, 50% of the extracted natural polymer was determined as per OECD/OCDE guidelines 423. Compatibility study of natural polymer with formulation excipient was carried out. Preparation, characterization and evaluation of microspheres were carried out, including drug-release study in simulated gastric fluid and intestinal fluid, followed by preparation of dry syrup using suitable sweetening and flavouring agents. Results The release study states that the polymers released the drugs at the intestine (site of action) only and not (or little) at the stomach. Drug release from the optimum formulation F5 (Dillenia indica) was 99.97% for ofloxacin and 99.12% for ornidazole after 2.5?h in simulated intestinal fluid as compared with 8.3% for ofloxacin and 8.46% for ornidazole after 8?h in simulated gastric fluid. Microspheres of optimum formulation F5 D. indica were used for preparation of dry syrup. Statistical methods were utilized to analyse the results of different tests performed throughout the investigation. Conclusion Palatable dry syrup containing ofloxacin and ornidazole using natural polysaccharides was successfully prepared without any stability problem. It is expected to be effective/suitable for the paediatric patients with high compliance.
  - 3,697 1,548
Biotransformation of progesterone to valuable steroids by isolated strain of Streptomyces
Abeer A El-Hadi, Sayeda S Mohamed, Khadiga M Abu-Zied
September-December 2016, 15(3):167-172
DOI:10.4103/1687-4315.197585  
Introduction and purpose The possibility of using of novel marine actinomycetes as a source of production of some industrially important hydroxyl steroid derivatives in one-step biotransformation process of progesterone was investigated in this study. Materials and methods Genomic DNA of the actinomycetes isolate was extracted using GeneJET Genomic DNA purification kit. The actinomycetes isolate was identified by 16S rDNA. The molecular sizes of amplified regions were confirmed using agarose gel electrophoresis. The identified Streptomyces strain was inoculated into the transformation medium, which was supplemented with progesterone as a substrate (5 mg/50 ml medium). The transformation products were separated and characterized on the basis of their infrared/nuclear magnetic resonance/mass spectrometry analysis as pregnenolone (1), 3β-hydroxyandrost-4-ene-17-one (2), and testosterone (3). Results and conclusion Because of the excellent track record of actinomycetes in this regard, new actinomycetes strain isolated from marine sources was used in this investigation. The isolated strain was identified by 16S rDNA. The 16S rDNA region was amplified using PCR (about 500 bp) using universal primers. According to sequencing similarities and multiple alignments, the isolate was found to be closely related to Streptomyces tunisiensis strain CN-207 with 98% identity. The infrared spectrum, 1H-nuclear magnetic resonance, and mass spectral database was used in the identification of the three isolated compounds 1, 2, and 3. The isolated steroid molecules from the total extract (0.3 g) are pregnenolone (1), 3β-hydroxyandrost-4-ene-17-one (2), and testosterone (3).
  - 1,145 110
Dissolution rate enhancement of irbesartan and development of fast-dissolving tablets
Vidyadhara Suryadevara, Sasidhar R Lankapalli, Sivaprasad Sunkara, Vikas Sakhamuri, Harika Danda
September-December 2016, 15(3):150-157
DOI:10.4103/1687-4315.197583  
Objective The objective of the present investigation was to enhance the solubility and dissolution rate of poorly soluble drug irbesartan by preparing it as solid dispersions and formulating it as fast-dissolving tablets (FDTs) using various excipients. Background Irbesartan is poorly soluble in water, and this low aqueous solubility in addition to its poor wettability leads to poor bioavailability of the drug. Materials and methods Solid dispersions were prepared using Soluplus, PEG 6000, and Kollidon as carriers. The dispersions were prepared using the solvent evaporation and kneading methods in a 1:1 ratio of drug and carrier. These formulations were characterized for solid state properties using X-ray powder diffraction and Fourier transform infrared spectroscopy spectral studies. Formulations were further evaluated for dissolution. Results The aqueous solubility of irbesartan in solid dispersions was improved by the presence of polymer Soluplus when compared with other carriers. Solid state characterization indicated that irbesartan was present as amorphous material in the formulation with carrier. This was due to efficient entrapment of the drug in polymer matrix. Thus, the solid dispersion prepared with Soluplus would be useful for delivering poorly soluble irbesartan with enhanced solubility and dissolution rate. Furthermore, the solid dispersions that were formulated as FDTs using superdisintegrants showed faster drug release with increased dissolution rate. Conclusion FDTs containing irbesartan solid dispersions prepared using the solvent evaporation method and croscarmellose sodium as superdisintegrant showed faster disintegration and increased dissolution rate.
  - 2,004 248
REVIEW ARTICLE
Synthetic approaches and potential bioactivity of different functionalized quinazoline and quinazolinone scaffolds
Mohsen M Kamel, Wafaa A Zaghary, Reem I Al-Wabli, Manal M Anwar
September-December 2016, 15(3):98-131
DOI:10.4103/1687-4315.197580  
Drug discovery and optimization constitutes one of the most important targets in medicinal chemistry. Because of their wide bioactivity spectra, nitrogen-containing heterocycles have received significant attention in many bio(organic) studies. The current review is a simple summary of different environmentally benign synthetic procedures that afford a variety of quinazoline and quinazolinone scaffolds with promising biological potential. The molecular modeling of various classes has also been discussed to elucidate the molecular reasons that led to the observed inhibition profile of different protein kinases, including which amino acids in their active sites would be involved in the anticipated bonding interactions. Furthermore, this article aims to investigate which classes deserve further development to get more specific and more potent quinazoline and quinazolinone candidates in various biological targets.
  - 5,162 4,382
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