New ursane triterpenoids from Ficus pandurata and their binding affinity for human cannabinoid and opioid receptors

Amgad I. M. Khedr,Sabrin R. M. Ibrahim,Gamal A. Mohamed,Hany E. A. Ahmed,Amany S. Ahmad,Mahmoud A. Ramadan,Atef E. Abd El-Baky,Koji Yamada,Samir A. Ross 대한약학회 2016 Archives of Pharmacal Research Vol.39 No.7

Phytochemical investigation of Ficus pandurataHance (Moraceae) fruits has led to the isolation of two newtriterpenoids, ficupanduratin A [1b-hydroxy-3b-acetoxy-11a-methoxy-urs-12-ene] (11) and ficupanduratin B [21ahydroxy-3b-acetoxy-11a-methoxy-urs-12-ene] (17), alongwith 20 known compounds: a-amyrin acetate (1), a-amyrin(2), 3b-acetoxy-20-taraxasten-22-one (3), 3b-acetoxy-11amethoxy-olean-12-ene (4), 3b-acetoxy-11a-methoxy-12-ursene (5), 11-oxo-a-amyrin acetate (6), 11-oxo-b-amyrinacetate (7), palmitic acid (8), stigmast-4,22-diene-3,6-dione(9), stigmast-4-ene-3,6-dione (10), stigmasterol (12), b-sitosterol(13), stigmast-22-ene-3,6-dione (14), stigmastane-3,6-dione (15), 3b,21b-dihydroxy-11a-methoxy-olean-12-ene (16), 3b-hydroxy-11a-methoxyurs-12-ene (18), 6-hydroxystigmast-4,22-diene-3-one (19), 6-hydroxystigmast-4-ene-3-one (20), 11a,21a-dihydroxy-3b-acetoxy-urs-12-ene(21), and b-sitosterol-3-O-b-D-glucopyranoside (22). Compound21 is reported for the first time from a natural source. The structures of the 20 compounds were elucidated on thebasis of IR, 1D (1H and 13C), 2D (1H–1H COSY, HSQC,HMBC and NOESY) NMR and MS spectroscopic data, inaddition to comparison with literature data. The isolatedcompounds were evaluated for their anti-microbial, antimalarial,anti-leishmanial, and cytotoxic activities. In addition,their radioligand displacement affinity on opioid andcannabinoid receptors was assessed. Compounds 4, 11, and15 exhibited good affinity towards the CB2 receptor, withdisplacement values of 69.7, 62.5 and 86.5 %, respectively. Furthermore, the binding mode of the active compounds inthe active site of the CB2 cannabinoid receptors was investigatedthrough molecular modelling.

Cobalt/Chromium Nanoparticles-Incorporated Carbon Nanofibers as Effective Nonprecious Catalyst for Methanol Electrooxidation in Alkaline Medium

Ibrahim M. A. Mohamed,Moaaed Motlak,H. Fouad,나지르 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2016 NANO Vol.11 No.5

Cobalt-Chrome nanoparticles-incorporated carbon nanofibers (CNFs) are proposed as an effective nonprecious electrocatalyst for methanol oxidation in the alkaline media. The introduced nanofibers were prepared by simple technique, electrospinning. Carbonization of as-spun mat composed of chromium acetate, cobalt acetate and poly(vinyl alcohol) (PVA) at high temperature (900℃) leads to production of the introduced nanofibers. The physicochemical characteristics were investigated by X-ray diffractometer (XRD), scanning electron microscope (SEM), field emission scanning electron microscope (FESEM), transmission electron microscope (TEM) equipped with EDX and TEM mapping. The exploited analyses confirmed that the final product is in the form of CNFs decorated by Co/Cr nanoparticles. Based on the results obtained from the cyclic voltammetry (CV) measurements, the proposed Co/Cr-incorporated CNFs possess high electrocatalytic activity toward methanol electrooxidation as a clear peak of methanol oxidation appeared with corresponding current density of 56 mA/cm2 . Moreover, the current density increased by increasing methanol concentration up to 4.0 M. Overall, the proposed nanofibers open new avenue for platinum-free and stable nanostructural catalysts for fuel cell technology.

First Measurements of Carbonaceous Aerosol across Urban, Rural and Residential Areas in Jeddah City, Saudi Arabia

Iqbal M. Ismail,Ahmad S. Summan,Jalal M. Basahi,Essam Hammam,Mohamed F. Yassin,Ibrahim A. Hassan 한국대기환경학회 2021 Asian Journal of Atmospheric Environment (AJAE) Vol.15 No.2

Concentrations of black carbon (BC), organic carbon (OC), and total suspended particulate matter (TSP) were simultaneously assessed in urban, rural and residential areas in Jeddah city for one year from January to December 2017. It was aimed in the present study to provide information about the spatial and seasonal variability of these aerosol species in Jeddah, and insight into sources, processes and effects of meteorological conditions. To the best of our knowledge, this is the first study investigating the variability of carbonaceous aerosols (OC and BC) in Saudi Arabia. The average concentrations of OC, BC, and TSP varied spatially and temporally. The annual average concentrations of OC, BC, and TSP were 134.05, 7.16, and 569.41 μg m-3 and 34.32, 5.14, and 240.64 μg m-3 and 10.67, 4.39 and 101.31 μg m-3 in the urban, residential and rural areas, respectively. Moreover, there was a clear seasonal variation in the concentration of carbonaceous aerosols; the highest concentrations were recorded in February and September, while the lowest concentrations of OC were recorded during April, May and August in the urban, residential and rural sites, respectively. Nevertheless, the lowest concentrations of BC were recorded during March in the urban and residential sites and during November in the rural site. The relative concentrations of OC and BC to the TSP were relatively high, and they have a significant correlation with prevalent wind speed (-0.636, and -0.581 in the urban area), (-0.539 and -0.511 in the residential area), and (-0.508 and -0.501 in the rural area), respectively. The marked differences in the concentrations of BC and OC were reflected on OC/BC ratio, which is a good representative of different source types. This preliminary study showed that the potential local sources were emissions from traffic (fossil fuel), biomass burning, anthropogenic activities (e.g. car drifting and outdoor cooking), and industrial activities. The present study suggest the presence of highly inefficient combustion sources and highlight the need for the regulation of such emissions.

Chrysanthemum extract and extract prepared silver nanoparticles as biocides to control Aedes aegypti (L.), the vector of dengue fever

Hamed A. Ghramh,Kh.M. Al-Ghamdi,Jazem A. Mahyoub,Essam H. Ibrahim 한국응용곤충학회 2018 Journal of Asia-Pacific Entomology Vol.21 No.1

Mosquitoes play a key role in the transmission of some important diseases. The need for controlling these insectsis critical to reduce their risks to human and domesticated animals. Recently the trend to explore effectivechemical compounds from local plants has begun as a safe means of control. The present study aimed to evaluatethe anti-larval activity of Chrysanthemum extract and the prepared silver nanoparticle (AgNPs) against the Aedesaegypti mosquito, the dengue vector in Saudi Arabia. A series of different concentrations of ethanol extract andextract prepared AgNPs against the fourth-life larvae was tested. The effective concentrations of crude extractand AgNPs ranged from 50 to 250 and 10 to 30 ppm respectively, and the death percentages corresponding tothese concentrations ranged from 18 to 92 and 36 to 96% respectively. According to the LC50 values of treatedlarvae, AgNPs (12.754 ppm) is more effective against A. aegypti mosquito larvae than the crude extract(228.345 ppm) at about 17.9 times. The mixing of the plant extract with the silver nitrate has led to potentiation. This is due to the synergy that occurs between the extract and the silver particles during the reduction process. The compounds in the extract are related to the surface of the particles, increasing the strength of their effects. Itis recommend to separate the active elements in the Chrysanthemum plant and its preparation in the form ofnanoparticles as a promising compound in mosquito control programs with least damage to human kind and theenvironment.

Environmentally benign Scouring of Cotton Knits Using Locally Produced Acid Pectinase Enzyme

Nabil A. Ibrahim,Basma M. Eid,Mohamed S. Abdel Aziz,Soha M. Hamdy,Safaa E. AbdAllah 한국섬유공학회 2019 Fibers and polymers Vol.20 No.4

The main task of the present study is to pre-screen selected fungal strain (Fusarium oxysporum M1-EGY) isolatedfrom local agriculture soil and optimize cultivation conditions for an acid pectinase production. Experimental resultsdemonstrated the optimum conditions for achieving the highest enzyme activity (14.80 U/ml) were found to be: incubationperiod (8 days) at pH (5), temperature (30 oC), and shaking rate (150 rpm), apple pectin carbon source (2 %), and ammoniumphosphate as nitrogen source (0.2 gN/l). The positive impacts of utilizing the produced crude acid-pectinase in eco-friendlyscouring of various cotton knits as well as their subsequent bleaching and reactive dyeing have been confirmed. Additionally,the use of local resources for an acid pectinase production would encourage and promote local production of textile enzymesand their potential applications in Egyptian textile sector, taking in consideration efficiency, textile quality, environmental andeconomy concerns.

Temporal analysis of 16 STR loci in human blood drawn from two culicid mosquitoes cultured at different temperatures

Ahmed M.A. Ibrahim,Lamia A. ALRAKAN,Saleh Ahmed ALAIFAN 한국곤충학회 2015 Entomological Research Vol.45 No.5

Female mosquitoes feed on human blood, which can be collected to analyze human short tandem repeat (STR) sequences; these are specific to each human individual. Analysis of STRs might help in identification of a person found near a crime scene. Aedes aegypti and Culex pipiens mosquitoes fed on human blood were cultured at 18°C or 40°C (median temperature for summer and winter time in Riyadh governorate, Saudi Arabia) for 3, 6, 12, 24, 48 and 72 h. In A. aegypti, human DNA concentration was reduced with time at both temperatures. At 18°C, we obtained full STR profiles up to 48 h post feeding on human blood while none of the 16 loci were obtained at 72 h. At 40°C, we missed six sites at 12 h after blood sucking, 12 at 24 h, and 15 at 48 h and 72 h. In C. pipiens cultured at 18°C, full profiles were developed up to 48 h following blood feeding while we could not amplify five sites at 72 h. At 40°C, mortality among females was 50% at 24 h and 100% at both 48 h and 72 h; however, we had full profiles in all samples including dead insects. This research addressed the possibility of using mosquitoes in forensic research by DNA genotyping by changing the mosquito culturing temperature and mosquito genus. Our findings proved that different types of mosquito change the temporal pattern of STR analysis and showed that the mosquito culturing temperature affects the integrity of DNA for STR analysis.

Magnetic Properties of La3+-ion-doped Polycrystalline Z-type Hexaferrite Powders Synthesized via the Co-precipitation Method

M. M. Rashad,M. Rasly,I. A. Ibrahim,H. M. El-Sayed,A. A. Sattar 한국물리학회 2013 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.63 No.3

Co2Z-type hexagonal ferrite powders doped with La3+ ions (Ba3−XLaxCo2Fe24O41 where x =0.0, 0.05, 0.10 and 0.15) were prepared using a co-precipitation method. The results revealed thatsingle-phase Co2Z-type ferrite was formed from the precipitated precursor in the presence of sodiumdodecyl sulfate (SDS) as an anionic surfactant. The obtained precursor was preheated at 600 ℃ for4 h then post annealed at 1300 ℃ for 6 h. The crystallite size increased with increasing of La3+-ion molar ratio. The microstructure of the formed powders appeared to be a hexagonal-plateletlikestructure. The DC resistivity of the obtained Co2Z decreased with increasing La3+ content. The saturation magnetization (Ms = 53.7 - 55.5 emu/g) was slightly increased with increasingsubstitution of La3+ ion. Moreover, two resonance frequency peaks were observed through theimaginary part of complex magnetic permeability; meanwhile, a decrease in the real part of thecomplex magnetic permeability was observed through the X-band frequencies.

Oxidative CO_2 reforming of CH4 over Ni/a-Al_2O_3 catalyst

A.S.A. Al-Fatesh,A.A. Ibrahim,A.H. Fakeeha,A.E. Abasaeed,M.R.H. Siddiqui 한국공업화학회 2011 Journal of Industrial and Engineering Chemistry Vol.17 No.3

Oxidative carbon dioxide reforming of methane to synthesis gas over alumina-supported Ni catalysts was investigated at atmospheric pressure. The reforming reactions were carried out using a CO_2 to CH_4feed ratio of one and reaction temperatures in the range 600–800℃The activity and stability of the catalyst, carbon deposition, and synthesis gas (H_2/CO) ratio were determined. Catalyst deactivation was primarily due to coke formation. energy dispersive spectroscopy (EDS), scanning electron microscopy (SEM) and thermo-gravimetric/differential analyzer (TG/DTA) techniques were used to confirm carbon deposition. It was observed that increasing the oxygen feed concentration and/or reaction temperatures,enhanced methane conversion and reduced coke formation. When 20% O_2 feed was used at 800℃,catalyst stability test revealed a 99.7% CH_4 conversion, 1.0% CH_4 conversion drop and 1% carbon formation.

New issue of GaN nanoparticles solar cell

M.A. Qaeed,K. Ibrahim,K.M.A. Saron,M.S. Mukhlif,A. Ismail,Nezar G. Elfadill,Khaled M. Chahrour,Q.N. Abdullah,K.S.A. Aldroobi 한국물리학회 2015 Current Applied Physics Vol.15 No.4

This study involves the synthesis of gallium nitride (GaN) nanoparticles (NPs) under different low temperatures using a simple chemical method. The nanoparticles are spin coated on Si substrate to fabricate the solar cell. The FESEM images obtained indicate the presence of cubic GaN nanoparticle with average diameter of 50 nm synthesized at 90 ℃. The spin coating technique deposited n-GaN NPs/Si(111) produced a heterojunction solar cell with fill factor of 0.56 and conversion efficiency of 2.06%. Based on these results, this study proposes a novel low cost technique for the fabrication of GaN NPs solar cells.

Protein tyrosine phosphatases encoded in Cotesia plutellae bracovirus: Sequence analysis, expression profile, and a possible biological role in host immunosuppression

Ibrahim, A.M.A.,Choi, J.Y.,Je, Y.H.,Kim, Y. Pergamon Press ; Elsevier Science Ltd ; Pergamon 2007 DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY Vol.31 No.10

A genome project has been launched and aims to sequence total genome of Cotesia plutellae bracovirus (CpBV). On this process, several putative open reading frames have been proposed, among which there was a large gene family coding for protein tyrosine phosphatases (PTPs). This study analyzed the deduced amino acid sequences of 14 CpBV-PTPs in terms of conserved domains with other known polydnaviral PTPs and determined their expression patterns in diamondback moth, Plutella xylostella, parasitized by C. plutellae. The analyzed CpBV-PTPs share the common 10 motifs with classical type of PTPs. However, there are variations among CpBV-PTPs in active site sequence and phosphorylation sites. Quantitative real-time polymerase chain reaction (PCR) indicated that most PTPs in the parasitized P. xylostella were expressed from the first day of parasitization and increased the expression levels during parasitization. All 14 PTPs were expressed in both immune-associated tissues of fat body and hemocytes in the parasitized host. During last instar, the PTP enzyme activity of the parasitized P. xylostella was significantly lower than that of the nonparasitized. The reduction of the PTP activity was observed in cytosolic fraction, but not in membrane fraction. The hemocytes of parasitized P. xylostella markedly lost their spreading ability in response to a cytokine (PSP1: plasmatocyte-spreading peptide 1). The functional link between the reduced PTP activity and the suppressed hemocytic behavior was evidenced by the inhibitory effect of sodium orthovanadate (a specific PTP inhibitor) on hemocyte-spreading behavior of nonparasitized P. xylostella. These results suggest that CpBV-PTPs are expressed in the parasitized P. xylostella and affect cellular PTP activity, which may be associated with host immunosuppression.