Publications by authors named "Amira Abood"

8 Publications

  • Page 1 of 1

A multi-omics approach to lignocellulolytic enzyme discovery reveals a new ligninase activity from NO1.

Proc Natl Acad Sci U S A 2021 May;118(18)

Centre for Novel Agricultural Products, Department of Biology, University of York, York YO10 5DD, United Kingdom;

Lignocellulose, the structural component of plant cells, is a major agricultural byproduct and the most abundant terrestrial source of biopolymers on Earth. The complex and insoluble nature of lignocellulose limits its conversion into value-added commodities, and currently, efficient transformation requires expensive pretreatments and high loadings of enzymes. Here, we report on a fungus from the genus, isolated from a wheat-straw composting community, that secretes a large and diverse array of carbohydrate-active enzymes (CAZymes) when grown on lignocellulosic substrates. We describe an oxidase activity that cleaves the major β-ether units in lignin, thereby releasing the flavonoid tricin from monocot lignin and enhancing the digestion of lignocellulose by polysaccharidase mixtures. We show that the enzyme, which holds potential for the biorefining industry, is widely distributed among lignocellulose-degrading fungi from the Sordariomycetes phylum.
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http://dx.doi.org/10.1073/pnas.2008888118DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8106297PMC
May 2021

Synthesis, crystal structure, and ADME prediction studies of novel imidazopyrimidines as antibacterial and cytotoxic agents.

Arch Pharm (Weinheim) 2020 Mar 27;353(3):e1900271. Epub 2020 Jan 27.

Department of Chemistry of Natural and Microbial Products, Division of Pharmaceutical and Drug Industries Research, National Research Centre, Cairo, Egypt.

In the present study, a novel series of polyfunctionalized imidazopyrimidines 6a-u and 9a-d were efficiently constructed by a domino reaction between 2-imino-6-substituted-2,3-dihydropyrimidin-4(1H)-ones 4a-d or 8a-c and 2-bromoacetophenones 5a-i under mild basic conditions. The synthesized series were screened for their antibacterial activity against Staphylococcus aureus and Bacillus subtilis as Gram-positive (+) bacteria, as well as against Gram-negative (-) bacteria Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Salmonella typhi. Most of the synthesized derivatives of imidazopyrimidines 6 and 9 showed remarkable selectivity against Gram(-) bacteria over the Gram(+) ones. Compounds 6c, 6f, and 6g displayed potent and broad-spectrum antibacterial activity against all tested strains. Compounds 6f and 6g displayed promising inhibitory activity on GryB ATPase from E. coli with IC  = 1.14 and 0.73 μM, respectively. Simultaneously, some of the synthesized imidazopyrimidines were screened for their antiproliferative activity against 60 cancer cell lines at a concentration of 10 μM. Compound 9d showed potent activity against most of the tested cell lines, with a mean growth inhibition of 37%. The ADME (absorption, distribution, metabolism, and excretion) prediction study demonstrated that the synthesized hits have, in addition to their promising chemotherapeutic activity, acceptable pharmacokinetic properties, and a drug-likeness nature to be further developed.
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http://dx.doi.org/10.1002/ardp.201900271DOI Listing
March 2020

Investigation of a new horizon antifungal activity with enhancing the antimicrobial efficacy of ciprofloxacin and its binary mixture via their encapsulation in nanoassemblies: in vitro and in vivo evaluation.

Drug Dev Res 2020 05 30;81(3):374-388. Epub 2019 Dec 30.

Department of Parasitology and Animal Diseases, National Research centre, Giza, Egypt.

The main goal of this study was to prepare and evaluate nanosponges containing ciprofloxacin (CIP) or its binary mixture with N-acetyl carnosine (NAC). Nanosponges were prepared by ultrasound-assisted synthesis technique using hydroxypropyl βeta-cyclodextrin (HPβ-CD), as the polymer and diphenyl carbonate (DPC) as the crosslinker. Entrapment efficiency (EE%) of CIP or its binary mixture with NAC in nanosponges was deduced spectrophotometrically. Nanosponges were characterized using several methods. EE% of CIP or its binary mixture with NAC inside nanosponges ranged from 98.63 ± 3.1 to 100 ± 0.07%. Particle size of nanosponges ranged from 66.7 to 90.1 nm. Release of drugs from nanosponges was biphasic and the release pattern followed Korsmeyer-Peppas model. Ex vivo and in vivo studies results showed that the antibacterial effect was enhanced with encapsulation of drugs in the nanosponge system. Furthermore, a potent antifungal activity was obtained from all examined formulae against Candida albicans (10231). The study revealed that successful encapsulation of CIP or its binary mixture with NAC in nanosponge formulations has innovated a new promising therapeutic activity for both drugs.
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http://dx.doi.org/10.1002/ddr.21632DOI Listing
May 2020

A synbiotic multiparticulate microcapsule for enhancing inulin intestinal release and Bifidobacterium gastro-intestinal survivability.

Carbohydr Polym 2018 Aug 20;193:137-143. Epub 2018 Mar 20.

Dairy Science Department, National Research Centre, Dokki, Cairo, Egypt. Electronic address:

A novel synbiotic multiparticulate microparticle was produced in the current study to expand the synbiotic industrial applications. Initially, the inulin was fabricated into PLGA nanoparticles. After the inulin entrapment efficiency was boosted to reach 92.9 ± 8.4% by adjusting the formulation parameters, the developed particles were characterized by different techniques such as particle size analyzer, TEM, and TLC. The obtained data showed that the particle size was 115.8 ± 82.7 nm, the particles had smooth surface and round shape, and the fabrication procedure did not affect the integrity of the inulin. Later, the inulin loaded nanoparticles together with selected Bifidobacterium species were double coated with gum arabic and alginate. The maximum survivability of the encapsulated Bifidobacterium in the simulated gastric solution reached 88.29% of the initial population, which was significantly higher than the survivability of the free bacteria. Finally, the inulin release from the multiparticulate microparticles was studied and found to be sustained over three days.
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http://dx.doi.org/10.1016/j.carbpol.2018.03.068DOI Listing
August 2018

Purification and characterization of a new thermophilic collagenase from Nocardiopsis dassonvillei NRC2aza and its application in wound healing.

Int J Biol Macromol 2018 Sep 8;116:801-810. Epub 2018 May 8.

Chemistry of natural and microbial products, National Research Centre, Dokki, Cairo, Egypt. Electronic address:

A thermostable metallo-collagenase enzyme (150 kDa), recently identified in a newly isolated actinomycestes strain (Nocardiopsis dassonvillei NRC2aza), has been purified from natural source, characterized to have application in wound healing. A simple 3 step purification procedure gave an increase of purity by 6.23 fold with a specific activity of 387.2 U mg. The enzyme activity showed stability across a range of pH (7.0-8.5) and temperature (40-55 °C) with optima at pH 8.0 and 60 °C, respectively. Activators include Mg, Ca, Zn, Na, K and Ba, while Mn, Co, Niand Ag ions gave partial inhibition. Full inhibition was given by other tested ions and metalloproteinase inhibitors. Broad substrate specificity was demonstrated including activity against a native collagen. The K and V of the enzyme using azocollagen were 5.5 mg/ml and 1280 U, respectively. The purified collagenase enhanced wound closure in vitro and in vivo and the repair process was dose dependent. Topical application of the purified collagenase (either of 25 or 50 U) to cutaneous wounds significantly accelerated the rate of wound healing and the formation of granulation tissue. Hence, the purified collagenase has a great potential as a therapeutic agent in wound care and collagen related diseases.
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http://dx.doi.org/10.1016/j.ijbiomac.2018.05.030DOI Listing
September 2018

Modulation of Cyp450, ALS1 and COX-2 signaling pathways induced by infection via novel antifungal agents.

Saudi Pharm J 2018 Mar 1;26(3):349-357. Epub 2018 Feb 1.

Biochemistry, Therapeutic Chemistry Department, National Research Centre-Dokki, Cairo, Egypt.

Although, fluconazole is widely used in clinical treatment as an antifungal drug, it recorded potential problems as resistance and intracellular accumulation. Female albino mice were injected with single dose of (1.5 × 10 CFU) Three weeks post treatment with fluconazole and two novel synthesized compounds [(2-(4-(Pyridin-2-yl) aminosulfonylphenylamino)-6-(naphthalen-2-yl)-4-(pyridin-2-yl) pyridine-3carbonitrile) and (2-(4-(Pyrimidin-2-yl) aminosulfonylphenylamino)-6-(naphthalen-2-yl)-4-(pyridine-2-yl)pyridine-3-carbonitrile) (13b & 14b, respectively)] in both low and high doses (50 mg/kg & 200 mg/kg), liver function and vaginal inflammation were assessed. significantly elevated serum alanine aminotransferase (ALT) and butrylcholinesterase (BCHE) as well as hepatic malondialdehyde (MDA). Molecular analysis confirmed a significant up-regulation in mRNA gene expression of Agglutinin-like sequence (ALS1), hepatic cytochrome p450 (Cyp450). Vaginal COX-2 gene expression was also elevated. Nevertheless, a significant down-regulation was apparent in mice treated with the aforementioned compounds. Meanwhile, administration of 14b in a high dose noticeably down-regulated the altered parameters expression showing a significant effect in comparison to animals treated with the variable doses of the tested compounds. Histopathological finding confirmed the obtained results. The current work investigated the efficiency of new synthetic pyrimidine derivatives 14bas anti-microbial agents and recommended to be improved and evaluated as a novel antifungal drug to overcome the emergence of resistance problem.
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http://dx.doi.org/10.1016/j.jsps.2018.01.007DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5856942PMC
March 2018

Oxidative dearomatisation: the key step of sorbicillinoid biosynthesis†Electronic supplementary information (ESI) available: Containing all experimental details. See DOI: 10.1039/c3sc52911hClick here for additional data file.

Chem Sci 2014 Feb 26;5(2):523-527. Epub 2013 Nov 26.

School of Chemistry , University of Bristol , Cantock's Close , Bristol BS8 1TS , UK . Email: ; ; Tel: +44 (0) 117 928 9184 ; Institut für Organische Chemie , Leibniz Universität Hannover , Schneiderberg 1B , 30167 Hannover , Germany . Email:

An FAD-dependent monooxygenase encoding gene (SorbC) was cloned from E01-10/3 and expressed as a soluble protein in . The enzyme efficiently performed the oxidative dearomatisation of sorbicillin and dihydrosorbicillin to give sorbicillinol and dihydrosorbicillinol respectively. Bioinformatic examination of the gene cluster surrounding SorbC indicated the presence of two polyketide synthase (PKS) encoding genes designated and . The gene -encodes a highly reducing iterative PKS while SorbB encodes a non-reducing iterative PKS which features a reductive release domain usually involved in the production of polyketide aldehydes. Using these observations and previously reported results from isotopic feeding experiments a new and simpler biosynthetic route to the sorbicillin class of secondary metabolites is proposed which is consistent with all reported experimental results.
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http://dx.doi.org/10.1039/c3sc52911hDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4285102PMC
February 2014

The biosynthesis and catabolism of the maleic anhydride moiety of stipitatonic acid.

Angew Chem Int Ed Engl 2014 Jul 26;53(29):7519-23. Epub 2014 May 26.

School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS (UK).

A series of directed knockout experiments, combined with an in vitro assay of pathway components, has elucidated for the first time the chemical steps involved in the biosynthesis of the tropolone class of fungal maleic anhydrides. The pathway involves the stepwise oxidation of aldehyde and methyl carbon atoms to form a 1,2-dicarboxylate. A hydrolase-catalyzed interconversion of this and the corresponding maleic anhydride, followed by decarboxylation of the diacid leads to the pathway's final product of stipitatic acid.
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http://dx.doi.org/10.1002/anie.201403450DOI Listing
July 2014
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