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151.
Mohamed Shaaban Mohammad Magdy El-Metwally Ahmed Adel Abdel-Razek Hartmut Laatsch 《Natural product research》2018,32(20):2437-2446
Terretonin M (1), a new highly oxygenated tetracyclic meroterpenoid, was isolated from the thermophilic fungus Aspergillus terreus TM8 together with 10 known metabolites: terrelumamide A, asterrelenin, 7-prenyl-indolyl-3-carbaldehyde, (3β,5α,6β)-3,5,6-trihydroxy-ergosta-7,22-diene, sitostenone, linoleic acid, ergosterol, uracil, p-hydroxy-benzoic acid, and indole-3-carboxylic acid. The chemical structure of the new compound was elucidated by extensive 1D, 2D NMR, and ESI HR mass measurements, and by comparison with literature data. The absolute configuration of 1 was resolved by analysis of its NOESY spectrum and comparison of its experimental ECD spectrum with DFT calculations. In parallel to this work, revision of the absolute configuration of penisimplicins 3a and 3b is proposed on the basis of their ECD and ORD data. The isolation and taxonomic characterisation of A. terreus TM8 is reported, and the antimicrobial activity of the crude extract and the isolated compounds was studied as well. 相似文献
152.
Recently, indoles are considered interesting heterocyclic compounds due to their wide range of biological activities such as antimicrobial activity. Herein, some new indole derivatives containing heterocyclic moieties were synthesized using 3-chloro-1H-Indole-2-carbaldehyde (1) as a starting material, then allowed to react with compounds containing active methylene under Knoevenagel condensation and afforded the corresponding compounds (2, 3, 9). Also, the compound (1) when allowed to react with hydrazine derivatives gave the corresponding thiosemiccarbazone, semicarbazone, and hydrazone derivatives (4, 5, 6). Reaction of thiosemicarbazone derivatives with α-halognated carbonyl compounds gave the thiazolyl indole derivatives (10, 12a–b). Cyclic chalcones (11a–c) were obtained when compound (10) reacted with different aromatic aldehydes. The structures of all new synthesized compounds were confirmed on the basis of spectral analysis, IR, 1H NMR, 13C NMR, and MS spectroscopy. All synthesized compounds were evaluated for their antimicrobial activity. Compounds (2, 5, 7, 8, 11a, 12a) showed high antibacterial activity and compounds (3, 6, 9, 10, 11a, 12a) showed high antifungal activity. 相似文献
153.
Nesma A. Abd El-Fatah Ahmed F. Darweesh Adel A. Mohamed Ismail A. Abdelhamid Ahmed H.M. Elwahy 《Tetrahedron》2017,73(11):1436-1450
The synthetic utility of 2-mercaptonicotinonitriles 3 and 4, as well as 2-mercapto-4-oxo-6-phenyl-1,4-dihydropyrimidine-5-carbonitrile 20 as building blocks for novel bis- and poly(pyridines), along with poly(pyrimidines) via alkylation with the corresponding bis- and poy(halo) compounds was investigated. Spectroscopic and theoretical studies confirmed the S-alkylation rather than the N-alkylation. 相似文献
154.
Adel A.-H. Abdel-Rahman Ahmed E.-S. Abdel-Megied Mohamed A. M. Hawata Eman R. Kasem Mohamed T. Shabaan 《Monatshefte für Chemie / Chemical Monthly》2007,16(6):889-897
Chalcones were synthesized by a base catalyzed Claisen-Schmidt condensation reaction. Bromination of chalcones afforded the dibromo derivatives. Monobromo derivatives could be obtained
by treating the corresponding dibromochalcones with dry benzene in the presence of triethylamine. Pyrazole derivatives were
obtained by refluxing of dibromochalcones with phenylhydrazine or 2,4-dinitrophenylhydrazine in dry pyridine. Chalcones were
treated with hydrazine hydrate or phenyl hydrazine in ethanol to afford Δ
2-pyrazolines and N-phenyl-Δ
2-pyrazolines. Condensation of chalcones with hydroxylamine hydrochloride or thiourea in ethanolic sodium hydroxide solution
gave 4,5-dihydroisoxazoles and 5,6-dihydropyrimidine-2-(1H)-thiones. The prepared compounds were tested for antimicrobial activity against four different bacterial species displaying
different degrees of antibacterial activities or inhibitory actions. 相似文献
155.
Adel Almoslh Babak Aghel Falah Alobaid Christian Heinze Bernd Epple 《Entropy (Basel, Switzerland)》2022,24(9)
An experimental study was conducted in a sieve tray column. This study used a simulated flue gas consisting of 30% CO2 and 70%. A 10% mass fraction of methyl diethanolamine (MDEA) aqueous solution was used as a solvent. Three ramp-up tests were performed to investigate the effect of different load changes in inlet gas and solvent flow rate on CO2 absorption. The rate of change in gas flow rate was 0.1 Nm3/h/s, and the rate of change in MDEA aqueous solution was about 0.7 NL/h/s. It was found that different load changes in inlet gas and solvent flow rate significantly affect the CO2 volume fraction at the outlet during the transient state. The CO2 volume fraction reaches a peak value during the transient state. The effect of different load changes in inlet gas and solvent flow rate on the hydrodynamic properties of the sieve tray were also investigated. The authors studied the correlation between the performance of the absorber column for CO2 capture during the transient state and the hydrodynamic properties of the sieve tray. In addition, this paper presents an experimental investigation of the bubble-liquid interaction as a contributor to entropy generation on a sieve tray in the absorption column used for CO2 absorption during the transient state of different load changes. 相似文献
156.
Minar Mahmoud M. Hassanein Adel Gabr Abdel-Razek Sherine Mohamed Affifi Ying Qian Elbieta Radziejewska-Kubzdela Aleksander Siger Magdalena Rudziska Ghada Ahmed Abo-Elwafa Anna Grygier 《Molecules (Basel, Switzerland)》2022,27(23)
The purpose of this study was to explore the effects of roasting linseeds on the pigment, lipid profile, bioactive components, and oxidative stability of the extracted oils. The linseed varieties Giza 11, Giza 12, Sakha 3, and Sakha 6 were roasted at 180 °C for 10 min, and the oils were extracted by cold pressing. The results showed that, after roasting, there was an increase in oil percentage and peroxide value, as well as small increases in p-anisidine and acid values. Roasting also caused an increase in chlorophyll content, while lutein and β-carotene tend to slightly decrease, except in the Giza 11 variety. The total phenolics content was markedly enhanced after roasting. Omega-3 fatty acids were not affected by the roasting process. The total amounts of tocochromanol were found to decrease in the Giza 12 and Sakha 6 varieties after roasting. Plastochromanol-8 increased in all varieties after roasting. The phytosterol composition was minimally affected by roasting. Roasting enhanced the stability of the extracted oils, increasing the induction period and decreasing EC50 values. These results may thus help to discriminate between the different linseed varieties and serve to recommend the use of roasting to enhance the oxidative stability of extracted oil. 相似文献
157.
Mirza Nadeem Ahmad Sohail Nadeem Mohsin Javed Shahid Iqbal Sadaf ul Hassan Samar O. Aljazzar Eslam B. Elkaeed Rami Adel Pashameah Eman Alzahrani Abd-ElAziem Farouk Mohammed T. Alotaibi Hisham S. M. Abd-Rabboh 《Molecules (Basel, Switzerland)》2022,27(17)
The synthesis of MMT and poly(o-anisidine) (MMT/POA) clay nanocomposites was carried out by using the chemical oxidative polymerization of POA and MMT clay with POA, respectively. By maintaining the constant concentration of POA, different percentage loads of MMT clay were used to determine the effect of MMT clay on the properties of POA. The interaction between POA and MMT clay was investigated by FTIR spectroscopy, and, to reveal the complete compactness and homogeneous distribution of MMT clay in POA, were assessed by using scanning-electron-microscope (SEM) analysis. The UV–visible spectrum was studied for the optical and absorbance properties of MMT/POA ceramic nanocomposites. Furthermore, the horizontal burning test (HBT) demonstrated that clay nanofillers inhibit POA combustion. 相似文献
158.
159.
Abdel-Hafez Gehan A. Aboraia Ahmed S. Mohammad Abdel-Mabood I. Youssef Adel F. 《平面色谱法杂志一现代薄层色谱法》2022,35(4):349-362
JPC – Journal of Planar Chromatography – Modern TLC - High-performance thin-layer chromatographic (HPTLC) method provides a simple, sensitive, and accurate analytical method for the... 相似文献
160.
Mohamed A. Ramadan Heba S. Osheba Adel R. Hadhoud 《Numerical Methods for Partial Differential Equations》2023,39(1):268-280
This paper deals with the numerical solution of the integral equations of linear second kind Volterra–Fredholm. These integral equations are commonly used in engineering and mathematical physics to solve many of the problems. A hybrid of Bernstein and improved block-pulse functions method is introduced and used where the key point is to transform linear second-type Volterra–Fredholm integral equations into an algebraic equation structure that can be solved using classical methods. Numeric examples are given which demonstrate the related features of the process. 相似文献