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21.
Mostafa El Khomsi Hamada Imtara Mohammed Kara Anouar Hmamou Amine Assouguem Brahim Bourkhiss Mahmoud Tarayrah Mashail N. AlZain Nurah M. Alzamel Omar Noman Driss Hmouni 《Molecules (Basel, Switzerland)》2022,27(2)
Anchusa italica Retz has been used for a long time in phytotherapy. The aim of the present study was to determine the antioxidant and antibacterial activities of extracts from the leaves and roots of Anchusa italica Retz. We first determined the content of phenolic compounds and flavonoids using Folin–Ciocalteu reagents and aluminum chloride (AlCl3). The antioxidant activity was determined using three methods: reducing power (FRAP), 2.2-diphenyl-1-picrylhydrazyl (DPPH), total antioxidant capacity (TAC). The antimicrobial activity was investigated against four strains of Escherichia coli, two strains of Klebsiella pneumoniae and coagulase-negative Staphylococcus, and one fungal strain of Candida albicans. The results showed that the root extract was rich in polyphenols (43.29 mg GAE/g extract), while the leave extract was rich in flavonoids (28.88 mg QE/g extract). The FRAP assay showed a strong iron reduction capacity for the root extract (IC50 of 0.11 µg/mL) in comparison to ascorbic acid (IC50 of 0.121 µg/mL). The DPPH test determined an IC50 of 0.11 µg/mL for the root extract and an IC50 of 0.14 µg/mL for the leaf extract. These values are low compared to those for ascorbic acid (IC50 of 0.16 µg/mL) and BHT (IC50 0.20 µg/mL). The TAC values of the leaf and root extracts were 0.51 and 0.98 mg AAE/g extract, respectively. In vitro, the extract showed inhibitory activity against all strains studied, with diameters of zones of inhibition in the range of 11.00–16.00 mm for the root extract and 11.67–14.33 mm for the leaf extract. The minimum inhibitory concentration was recorded for the leaf extract against E. coli (ATB:57), corresponding to 5 mg/mL. Overall, this research indicates that the extracts of Anchusa italica Retz roots and leaves exert significant antioxidant and antibacterial activities, probably because of the high content of flavonoids and polyphenols. 相似文献
22.
Lidia Matesic Julie M. Locke Kara L. Vine Marie Ranson John B. Bremner Danielle Skropeta 《Tetrahedron》2012,68(34):6810-6819
To further expand the structure–cytotoxic activity relationships of isatin derivatives and to reduce flexibility in substituent groups at nitrogen, 20 analogues incorporating a ring system between the N1 and C7 atoms of isatin were prepared using a variety of synthetic strategies. This yielded pyrroloindole-, pyrroloquinoline-, pyrroloacridine-, pyrrolophenanthridine- and benzopyrrolophenanthridine-based systems with embedded isatin moieties, the latter possessing a novel carbon skeleton. These compounds were subsequently assessed for their in vitro cytotoxicity against human U937 lymphoma cells, with the brominated pyrroloacridine dione 27 showing the most promising activity (IC50 3.01 μM) after 24 h. 相似文献
23.
24.
The energy and structural changes of lithium microclusters based on temperature has been investigated by using Molecular-Dynamic simulation Method. Two and three-body interacted semi-empiric potential energy formula that characterized the interaction has been used. It has been calculated that the dissociation of atoms from cluster has started after 1300 K for Li3 and 1350 K for Li4, respectively. Dissociations at the fixed temperatures are very close to the expected values of the lithium metal. Additionally, it has been observed that Li4 microclusters above 1000 K and Li3 clusters above 700 K temperatures have steady structures in two different energy values. 相似文献
25.
Two-center nuclear attraction integrals over Slater type orbitals with integer and noninteger principal quantum numbers in nonlined up coordinate systems have been calculated by means of formulas in our previous work (T. Özdoan and M. Orbay, Int. J. Quant. Chem. 87 (2002) 15). The computer results for integer case are in best agreement with the prior literature. On the other hand, the results for noninteger case are not compared with the literature due to the scarcity of the literature, but also compared with the limit of integer case and good agreements are obtained. The proposed algorithm for the calculation of two-center nuclear attraction integrals over Slater type orbitals with noninteger principal quantum numbers in nonlined-up coordinate systems permits to avoid the interpolation procedure used to overcome the difficulty introduced by the presence of noninteger principal quantum numbers. Finally, numerical aspects of the presented formulae are analyzed under wide range of quantum numbers, orbital exponents and internuclear distances. 相似文献
26.
D. N. Khan Marwat A. H. Kara F. M. Mahomed 《International Journal of Theoretical Physics》2007,46(12):3022-3029
We show how one can construct conservation laws of equations that are not variational but are Euler–Lagrange in part using Noether-type symmetries associated with partial Lagrangians. These Noether-type symmetries are, usually, not symmetries
of the system. The resultant construction of the conservation law resorts to a formula equivalent to Noether’s theorem. A variety
of examples are given. 相似文献
27.
A. H. Kara 《Acta Appl Math》2014,132(1):371-376
We study the invariance, reduction, exact solutions and conservation laws of the dispersionless Kadomtsev-Petviashivili and the heavenly equation. The existence of nontrivial conservation laws lead to repeated reductions paving the way for determining exact solutions. A variety of such solutions exist dependent on the subalgebra of Lie point symmetries that is chosen in the reduction procedure. 相似文献
28.
Symmetries of linear iterative equations and new conditions on the infinitesimals are obtained. Regarding the expressions of the solutions in terms of the parameters of the source equation, an ansatz is made on the original parameters. We have also obtained an expression for the source parameters of the transformed equation under equivalence transformations. We conducted this work with a special emphasis on second-, third- and fourth-order equations, although some of our results are valid for equations of a general order. 相似文献
29.
The fundamental relation between Lie-Bäcklund symmetry generators andconservation laws of an arbitrary differential equation is derived without regardto a Lagrangian formulation of the differential equation. This relation is used inthe construction of conservation laws for partial differential equations irrespectiveof the knowledge or existence of a Lagrangian. The relation enables one toassociate symmetries to a given conservation law of a differential equation.Applications of these results are illustrated for a range of examples. 相似文献
30.
Felix Weinberg Fred Carleton Dhiren Kara Agatha Xavier Derek Dunn-Rankin Matthew Rickard 《Experiments in fluids》2006,40(2):231-237
Air induction and rotation about the axis of a vertical tube is generated by an assembly of corona discharges between pinpoints
and earthed electrodes, which induces a swirling ionic wind. The mechanism is elucidated and the geometrical configuration
of the electric field lines of force is optimised by studying the deposition of charged particles on the earth electrodes,
by numerical modelling of a simplified geometry and ultimately by maximising the measured tangential velocities. Upward convective
flows of up to a litre per second are provided by an additional ionic wind pump at the base of the tube. With assemblies of
up to three layers of six points each, tangential velocities of up to 3.3 m/s (≈900 rpm) are attained at the periphery, as
recorded by small Pitot tubes. The concept, developed particularly for microgravity environments, appears suitable for adding
a substantial centrifugal contribution to the operation of electrostatic precipitators and as a basis for further progress
on electrical field-controlled burners. 相似文献