Phytochemical Profiling,In Vitro Biological Activities,and In Silico Molecular Docking Studies of Dracaena reflexa

Dracaena reflexa, a traditionally significant medicinal plant, has not been extensively explored before for its phytochemical and biological potential. The present study was conducted to evaluate the bioactive phytochemicals and in vitro biological activities of D. reflexa, and perform in silico molecular docking validation of D. reflexa. The bioactive phytochemicals were assessed by preliminary phytochemical testing, total bioactive contents, and GC-MS analysis. For biological evaluation, the antioxidant (DPPH, ABTS, CUPRAC, and ABTS), antibacterial, thrombolytic, and enzyme inhibition (tyrosinase and cholinesterase enzymes) potential were determined. The highest level of total phenolic contents (92.72 ± 0.79 mg GAE/g extract) was found in the n-butanol fraction while the maximum total flavonoid content (110 ± 0.83 mg QE/g extract) was observed in methanolic extract. The results showed that n-butanol fraction exhibited very significant tyrosinase inhibition activity (73.46 ± 0.80) and acetylcholinesterase inhibition activity (64.06 ± 2.65%) as compared to other fractions and comparable to the standard compounds (kojic acid and galantamine). The methanolic extract was considered to have moderate butyrylcholinesterase inhibition activity (50.97 ± 063) as compared to the standard compound galantamine (53.671 ± 0.97%). The GC-MS analysis of the n-hexane fraction resulted in the tentative identification of 120 bioactive phytochemicals. Furthermore, the major compounds as identified by GC-MS were analyzed using in silico molecular docking studies to determine the binding affinity between the ligands and the enzymes (tyrosinase, acetylcholinesterase, and butyrylcholinesterase enzymes). The results of this study suggest that Dracaena reflexa has unquestionable pharmaceutical importance and it should be further explored for the isolation of secondary metabolites that can be employed for the treatment of different diseases.     

Gas-phase thermolysis of condensed-1,2,4-triazines: interesting routes toward heterocyclic ring systems

Gas-phase thermolysis of thieno[2,3-e][1,2,4]triazines gave benzonitrile, isothiazole, pyridazine, and thieno[2,3-d]thiazole derivatives. Similar transformation of benzo[1,2,4]triazine and phenanthro[9,10-e][1,2,4]triazine derivatives into their corresponding condensed thiazoles has been achieved by heating at 350 °C with sulfur. A mechanism for these pyrolytic transformations was proposed.     

Dynamic behavior in diplatinum metalloreceptors

Diplatinum metalloreceptors anti-4a and anti-4b exhibit dynamic behavior in solution that is modified by anion binding. An X-ray crystal structure determination of anti-4a supports its proposed solution structure.     

Allocation of Marketing Effort Among <Emphasis Type="Italic">P</Emphasis> Substitutional Products in <Emphasis Type="Italic">N</Emphasis> Territories<Superscript>†</Superscript>

Frequently, companies face the problem of allocating a given marketing budget in order to maximize their total returns. In this paper we examine the problem of allocating marketing effort, such as advertising, among P substitutional products, distributed in N different sales territories. Two models are discussed. In the first model it is assumed that at most one product is promoted in each sales territory. It is shown that a simple algorithm leads to at least a local optimum in a finite number of steps. In the second model, the restriction of one product per territory is eliminated. Applying a concept of effective effort, the model is transformed to an equivalent separable programming problem, solvable by a “single-pass” algorithm for various forms of response functions. Furthermore, a concept of successive modifications of the objective function is discussed.     

Design of Stacked Self-Healing Rings Using a Genetic Algorithm

Ring structures in telecommunications are taking on increasing importance because of their self-healing properties. We consider a ring design problem in which several stacked self-healing rings (SHRs) follow the same route, and, thus, pass through the same set of nodes. Traffic can be exchanged among these stacked rings at a designated hub node. Each non-hub node may be connected to multiple rings. It is necessary to determine to which rings each node should be connected, and how traffic should be routed on the rings. The objective is to optimize the tradeoff between the costs for connecting nodes to rings and the costs for routing demand on multiple rings. We describe a genetic algorithm that finds heuristic solutions for this problem. The initial generation of solutions includes randomly-generated solutions, complemented by seed solutions obtained by applying a greedy randomized adaptive search procedure (GRASP) to two related problems. Subsequent generations are created by recombining pairs of parent solutions. Computational experiments compare the genetic algorithm with a commercial integer programming package.     

Structural and dynamical properties of iridium surfaces: First principles and molecular dynamics investigations

The structural and dynamical properties of Ir(1 0 0) clean surface are investigated in the temperature range 100-1100 K. We performed molecular dynamics (MD) simulations using the interaction potential energies obtained from the density-functional theory (DFT) and plane-wave pseudopotential (PWPP) method. The obtained contraction of the first interlayer distance, d₁₂ , decreases from −4.94% at 100 K to −4.84% at 1100 K. This decrease deviates by 11.8% at 100 K to 13.6% at 1100 K, from that at 0 K (−5.6%). The expansion of the second interlayer distance, d₂₃, however increases from 0.89% at 100 K to 1% at 1100 K, causing a deviation that ranges from −11% to 0% from that at 0 K (1%). The deviation of the calculated surface vibrational frequencies and surface relaxations over the entire range of temperatures (100-1100 K) is rather modest as a result of small anharmonic effects of the surface.     

Diagnostic value of different antigenic fractions of hydatid cyst fluid from camel and sheep in Kingdom of Saudi Arabia

Hydatid cyst fluids (HCF) crude extracts from camels and sheep slaughtered in Riyadh region, KSA were subjected to Sodium Dodecyl Sulfate–Polyacrylamide Gel Electrophoresis (SDS–PAGE) and Western blot analysis. Sera from 17 confirmed human cases of hydatidosis, 25 patients with other parasitic infections and 10 clinically healthy subjects were used to evaluate the diagnostic value of the different antigenic fractions of these extracts. Immunoblotting results revealed that, at least 11 major discrete protein fractions (110–8 kDa) were recognized by sera from hydatidosis patients, sera from patients with other parasitic diseases showed cross-reactivity with few of these bands. The cluster of bands (38–35 kDa) that may be a breakdown of “Arc 5” antigen (39–38 kDa) was detected by 100% and 94% of sera from hydatidosis cases with HCF extracts from camel and sheep, respectively. This cluster showed also some cross reactivity (20% and 8%) with control sera from patients with other parasitic infections with camel and sheep HCF extracts, respectively. Polypeptides at 24–22, 16 and 8 kDa which may probably correspond to antigen B subunits were also identified by all samples from hydatidosis patients with sheep HCF extracts and by 100%, 65% and 74% with camel HCF extracts respectively. Sera from control subjects did not react with any of these polypeptides (24–22, 16 and 8 kDa). According to our results, the identified molecular weight bands (16 and 8 kDa using HCF crude extracts from sheep and 24–22 kDa using HCF crude extracts either from camel or sheep) represent good candidates for immunodiagnosis of hydatidosis.     

Synthesis of a halo-methylphenylene periphery-functionalized triazine-based dendritic molecule with a 3,3′-dimethyl-biphenyl linker using tris(halo-methylphenylene)triazines as building blocks

A tris(bromo-methylphenylene)triazine and its corresponding phosphine oxide derivative have been synthesized; the latter compound was found to be a potent ligand for the hydroformylation reaction. Suzuki coupling of the mono-pinacolboronate derivative of the former compound with a tris(iodo-methylphenylene)triazine was possible at two of the three iodine atoms, yielding a bromo- and iodo-methylphenylene periphery-functionalized triazine-based dendritic molecule with a 3,3′-dimethyl-biphenyl linker.