排序方式: 共有103条查询结果,搜索用时 15 毫秒
51.
Abeer H. Elmaidomy Eman Maher Zahran Raya Soltane Ahlam Alasiri Hani Saber Che Julius Ngwa Gabriele Pradel Faisal Alsenani Ahmed M. Sayed Usama Ramadan Abdelmohsen 《Molecules (Basel, Switzerland)》2022,27(17)
Malaria is one of the most important infectious diseases worldwide. The causative of the most severe forms of malaria, Plasmodium falciparum, has developed resistances against all the available antimalarial drugs. In the present study, the phytochemical investigation of the green seaweed Halimeda macroloba has afforded two new compounds 1–2, along with 4 known ones 3–6. The structures of the compounds had been confirmed using 1& 2D-NMR and HRESIMS analyses. Extensive machine-learning-supported virtual-screening suggested cytochrome-C enzyme as a potential target for compound 2. Docking, absolute-binding-free-energy (ΔGbinding) and molecular-dynamics-simulation (MDS) of compound 2 revealed the strong binding interaction of this compound with cytochrome-C. In vitro testing for crude extract and isolated compounds revealed the potential in vitro inhibitory activity of both extract and compound 2 against P. falciparum. The crude extract was able to inhibit the parasite growth with an IC50 value of 1.8 ± 0.35 µg/mL. Compound 2 also showed good inhibitory activity with an IC50 value of 3.2 ± 0.23 µg/mL. Meanwhile, compound 6 showed moderate inhibitory activity with an IC50 value of 19.3 ± 0.51 µg/mL. Accordingly, the scaffold of compound 2 can be considered as a good lead compound for the future development of new antimalarial agents. 相似文献
52.
Rate constants are reported for substitution at vanadium(IV) in bis-cyclopentadienylvanadium dichloride by a range of anionic and uncharged nucleophiles in acetonitrile solution. Rate constants have been determined for replacement of the first and of the second chloride. The reactivity of V(cp)2Cl2 is compared with that of Ti(cp)2Cl2. © 1997 John Wiley & Sons, Inc. Int J Chem Kinet 29: 835–838, 1997 相似文献
53.
Faiyaz Shakeel Moad M. Alamer Prawez Alam Abdullah Alshetaili Nazrul Haq Fars K. Alanazi Sultan Alshehri Mohammed M. Ghoneim Ibrahim A. Alsarra 《Molecules (Basel, Switzerland)》2021,26(24)
Luteolin (LUT) is a natural pharmaceutical compound that is weakly water soluble and has low bioavailability when taken orally. As a result, the goal of this research was to create self-nanoemulsifying drug delivery systems (SNEDDS) for LUT in an attempt to improve its in vitro dissolution and hepatoprotective effects, resulting in increased oral bioavailability. Using the aqueous phase titration approach and the creation of pseudo-ternary phase diagrams with Capryol-PGMC (oil phase), Tween-80 (surfactant), and Transcutol-HP (co-emulsifier), various SNEDDS of LUT were generated. SNEDDS were assessed for droplet size, polydispersity index (PDI), zeta potential (ZP), refractive index (RI), and percent of transmittance (percent T) after undergoing several thermodynamic stability and self-nanoemulsification experiments. When compared to LUT suspension, the developed SNEDDS revealed considerable LUT release from all SNEDDS. Droplet size was 40 nm, PDI was <0.3, ZP was −30.58 mV, RI was 1.40, percent T was >98 percent, and drug release profile was >96 percent in optimized SNEDDS of LUT. For in vivo hepatoprotective testing in rats, optimized SNEDDS was chosen. When compared to LUT suspension, hepatoprotective tests showed that optimized LUT SNEDDS had a substantial hepatoprotective impact. The findings of this investigation suggested that SNEDDS could improve bioflavonoid LUT dissolution rate and therapeutic efficacy. 相似文献
54.
Alshehri Saad Burgess John Fawcett John Russell David R. Shaker Ali M. 《Transition Metal Chemistry》2000,25(6):691-694
Crystals obtained in the course of preparing the tris-Schiff base iron(II) complex from 2-acetylpyridine and benzylamine have been shown by an X-ray diffraction structure determination to contain an iron(II) complex cation containing two molecules of the target Schiff base and one molecule of 2-acetylpyridine coordinated to the metal. The mechanistic implications of this fact are discussed. 相似文献
55.
Thiourea formaldehyde resin (TFR) has been synthesized by condensation of thiourea and formaldehyde in acidic medium and its thermal degradation has been investigated using TG-FTIR-MS technique during pyrolysis and combustion. The results revealed that the thermal decomposition of TFR occurs in three steps assigned to drying of the sample, fast thermal decomposition of polymers, and further cracking. The similar TG and DTG characteristics were found for the first two stages during pyrolysis and combustion. The combustion process was almost finished at 680?°C, while during pyrolysis a total mass loss of 93 wt% is found at 950?°C. The release of volatile products during pyrolysis are NH3, CS2, CO, HCN, HNCS, and NH2CN. The main products in the second stage are NH3 CO2, CS2, SO2, and H2O during combustion. In the next stage, the combustion products mentioned above keep on increasing, but some new volatiles such as HCN, COS etc., are identified. Among the above volatiles, CO2 is the dominant gaseous product in the whole combustion process. It is found that the thermal degradation during pyrolysis of TFR produced more hazardous gases like HCN, NH3, and CO when compared with combustion in similar conditions. 相似文献
56.
Mansoor H. Alshehri Barry J. Cox James M. Hill 《Journal of mathematical chemistry》2012,50(9):2512-2526
Deoxyribonucleic acid (DNA) is the genetic material for all living organisms, and as a nanostructure offers the means to create novel nanoscale devices. In this paper, we investigate the interaction of deoxyribonucleic acid inside single-walled carbon nanotubes. Using classical applied mathematical modeling, we derive explicit analytical expressions for the encapsulation of DNA inside single-walled carbon nanotubes. We adopt the 6–12 Lennard–Jones potential function together with the continuous approach to determine the preferred minimum energy position of the dsDNA molecule inside a single-walled carbon nanotube, so as to predict its location with reference to the cross-section of the carbon nanotube. An analytical expression is obtained in terms of hypergeometric functions which provides a computationally rapid procedure to determine critical numerical values. We observe that the double-strand DNA can be encapsulated inside a single-walled carbon nanotube with a radius larger than 12.30 ?, and we show that the optimal single-walled carbon nanotube to enclose a double-stranded DNA has radius 12.8 ?. 相似文献
57.
Rate constants are reported for substitution at the pentacyanoferrate(II) ions [Fe(CN)5L]3−, where L=3,5-dimethylpyridine
or 3-cyanopyridine, in binary aqueous mixed solvents containing up to 60vol% 1,2-ethanediol, 1,2-butanediol, methanol or ethanol.
Trends for diol-containing mixtures are compared with those for monohydroxylic alcohols, and the reactivity pattern for these
complexes is compared with those established earlier for base hydrolysis of tris(1,10-phenanthroline)iron(II) and for the
aquation of cis-dichloro-bis- (1,2-ethanediamine)cobalt(III). The solvatochromic behaviour of several pentacyanoferrate(II)
ions has been established in binary aqueous mixtures containing 1,2-ethanediol, 1,2-butanediol, 1,4-butanediol and 1,2-pentanediol.
A correlation between reactivity and solvatochromism is presented.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
58.
Zayed Elsayed M. E. Alngar Mohamed E. M. Biswas Anjan Ekici Mehmet Guggilla Padmaja Khan Salam Alshehri Hashim M. Belic Milivoj R. 《Optics and Spectroscopy》2022,130(1):28-34
Optics and Spectroscopy - Optical solitons with fiber Bragg gratings and polynomial law of nonlinear refractive index are addressed in the paper. The auxiliary equation approach together with an... 相似文献
59.
Yuanfang Li Tingshuai Li Xiaojuan Zhu Abdulmohsen Ali Alshehri Khalid Ahmed Alzahrani Siyu Lu Xuping Sun 《化学:亚洲杂志》2020,15(4):487-489
NH3 synthesis by the Haber–Bosch method is regarded as the dominant method in industry. Such a process is energy‐intensive, accompanied by a large amount of CO2 emission. Electrocatalytic N2 reduction is a sustainable avenue for NH3 production at ambient conditions. However, it needs a catalyst to boost the N2 reduction reaction. Here, we demonstrate that DyF3 is an efficient electrocatalyst. In 0.1 m Na2SO4, DyF3 attains a large NH3 yield of 10.9 μg h?1 mg?1cat. at ?0.45 V vs. the reversible hydrogen electrode, with the corresponding Faradaic efficiency of 8.8 %. Furthermore, this catalyst exhibits high electrochemical stability. 相似文献
60.
Sabrin R. M. Ibrahim Abdelsattar M. Omar Yosra A. Muhammad Ali A. Alqarni Abdullah M. Alshehri Shaimaa G. A. Mohamed Hossam M. Abdallah Mahmoud A. Elfaky Gamal A. Mohamed Jianbo Xiao 《Molecules (Basel, Switzerland)》2022,27(20)
Phenaloenones are structurally unique aromatic polyketides that have been reported in both microbial and plant sources. They possess a hydroxy perinaphthenone three-fused-ring system and exhibit diverse bioactivities, such as cytotoxic, antimicrobial, antioxidant, and anti-HIV properties, and tyrosinase, α-glucosidase, lipase, AchE (acetylcholinesterase), indoleamine 2,3-dioxygenase 1, angiotensin-I-converting enzyme, and tyrosine phosphatase inhibition. Moreover, they have a rich nucleophilic nucleus that has inspired many chemists and biologists to synthesize more of these related derivatives. The current review provides an overview of the reported phenalenones with a fungal origin, including their structures, sources, biosynthesis, and bioactivities. Moreover, more than 135 metabolites have been listed, and 71 references have been cited. SuperPred, an artificial intelligence (AI) webserver, was used to predict the potential targets for selected phenalenones. Among these targets, we chose human glucose transporter 1 (hGLUT1) for an extensive in silico study, as it shows high probability and model accuracy. Among them, aspergillussanones C (60) and G (60) possessed the highest negative docking scores of −15.082 and −14.829 kcal/mol, respectively, compared to the native inhibitor of 5RE (score: −11.206 kcal/mol). The MD (molecular dynamics) simulation revealed their stability in complexes with GLUT1 at 100 ns. The virtual screening study results open up a new therapeutic approach by using some phenalenones as hGLUT1 inhibitors, which might be a potential target for cancer therapy. 相似文献