Current organic synthesis最新文献

Aims: In order to study on structure-activity relationships of benzofurans.

Background: Benzofuran is a kind of natural compound widely existing in nature with pharmacological effects. The development of new anticancer benzofuran derivatives has attracted more and more attention.

Methods: We have introduced an active quinazoline unit into piperazine-substituted benzofuran, prepared a series of quinazoline-benzofuran compounds, and evaluated cytotoxic activity against a panel of human tumor cell lines by MTT assay.

Results: 48 novel quinazoline-substituted benzofuran derivatives have been prepared, and in vitro, cytotoxic activity against five human tumor cell lines was evaluated. The results indicated that some quinazoline-benzofuran conjugates showed selective inhibitory activity against tumor cell lines.

Conclusion: We have found that compound 14x displayed excellent cytotoxic activity, which could be considered a potential anticancer agent.

Background: Isocyanide is an intriguing one-carbon synthon that is frequently employed in a variety of carbon-carbon and carbon-heteroatom bond-forming reactions. Isocyanide-based multicomponent reactions (IMCRs) are effective synthetic tools in organic synthesis for the preparation of complex heterocyclic molecules. The IMCRs in water have become an attractive research direction, enabling simultaneous growth of both IMCRs and green solvents towards ideal organic synthesis.

Objective: The goal of this review is to provide a general overview of IMCRs in water or biphasic aqueous systems for accessing various organic molecules, as well as an examination of their benefits and mechanistic insights.

Conclusion: High atom economies, mild reaction conditions, high yields, and catalyst-free processes are crucial features of these IMCRs in water or biphasic aqueous systems.

Among the many reports published on strategies applicable to synthesizing pyrazolines and its analogs, The 1,3-dipolar cycloaddition offers a remarkably wide range of utility. Many 1,3-dipolar cycloaddition reactions used for the synthesis of pyrazolines provide better selectivity, eco-friendly, and less expensive chemical processes. In the presented study, we have reviewed various recently adopted strategies for the synthesis of pyrazoline, which followed the 1,3-dipolar cycloaddition reactions mechanism and classified them based on starting materials such as nitrile imines, diazo compounds, different zwitter ions, chalcones, and isoprene units. The manuscript also focused on the synthesis of pyrazolines starting from Seyferth-Gilbert reagents (SGR) and Psilostachyin (PSH) reagents. We hope this work will help those engaged or have plans to research pyrazoline or its analogs, as synthetic protocols based on starting material are rarely available for pyrazolines. Thus, this article holds a valuable complement to the development of newer pyrazoline and its derivatives.

Aims: The aims of this study are to synthesize new derivatives of sodium alginate that improve the inherent properties, such as hydrogel strengthening, and create environmental sensitivity, such as pH sensitivity, for use in drug delivery.

Background: Today, hydrogels, due to outstanding properties such as biodegradability, biocompatibility, mechanical properties, and response to stimuli properties, are widely used as harmless biomaterials in various fields in drug delivery, wound dressing, and tissue engineering. Stimulus-sensitive polymers significantly respond to slight changes in their environment. Different types of stimuli are used to influence the properties of polymers, the most important of which are temperature and pH because these are two vital factors in the human body; hence, temperature-sensitive and pHsensitive hydrogels have been extensively studied. The ability to absorb water and swell the hydrogel is due to hydrophilic chains in the hydrogel network, and water absorption by hydrogel can be controlled by response to the stimuli. Since hydrogels mimic human tissue, the ability to retain water in them is essential. As a result, it is considered in many biomedical drug delivery systems. Stimulusresponsive swelling can control diffusion out of and into the hydrogel network, which allows temporal and spatial control of drug release. When a drug is loaded onto a biodegradable and stimulisensitive hydrogel, the drug delivery system has the added advantage of sustained release of the drug, which reduces side effects.

Methods: In this study, two different hydrocarbons, [1,3-diaminopropane (DAP)] as a short-chain hydrocarbon, and [1,7-diaminoheptane (DAH)] as a long-chain hydrocarbon were grafted onto three types ofsodium alginate (SA), through amide bond linkages. The hydrogel copolymer matrices were compared with sodium alginate (SA) beads. The graft copolymers were characterized using FTIR, 1HNMR, XRD spectroscopy, elemental analysis (CHNS) and thermal analysis (TGA, DTA and DSC). An environmental scanning electron microscope (ESEM) was used to investigate the surface morphology of hydrogels.

Results: Effects of variables such as the length of hydrocarbon chains cross-linked to alginate, temperature, pH, and cross-linkers on the properties of hydrogels investigated in the temperature range of 2-70 ˚C and two different pH values (4.4 and 7.4). The results showed that when the hydrocarbon chain length of diamines decreases, the extent of cross-linking and strength of the hydrogels are increased. Other results suggest that the hydrogels obtained from high-viscosity alginate derivatives had positive pH sensitivity. Hydrogels prepared in this study demonstrated good mechanical and swelling ratios that are necessary for wound dressing.

Conclusion: DAP-g-SA and DAH-g-SA pH-sensitive hydrogels were successfully synthesized through am

The study aimed to obtain relationships between the omega invariants of a graph and its complement. We used some graph parameters, including the cyclomatic numbers, number of components, maximum number of components, order, and size of both graphs G and G. Also, we used triangular numbers to obtain our results related to the cyclomatic numbers and omega invariants of G and G. Several bounds for the above graph parameters have been obtained by the direct application of the omega invariant. We used combinatorial and graph theoretical methods to study formulae, relations, and bounds on the omega invariant, the number of faces, and the number of compo-nents of all realizations of a given degree sequence. Especially so-called Nordhaus-Gaddum type resulted in our calculations. In these calculations, the triangular numbers less than a given number play an important role. Quadratic equations and inequalities are intensively used. Several relations between the size and order of the graph have been utilized in this study. In this paper, we have obtained relationships between the omega invariants of a graph and its complement in terms of several graph parameters, such as the cyclomatic numbers, number of components, maximum number of components, order, and size of G and G, and triangular numbers. Some relationships between the omega invariants of a graph and its complement have been obtained.

This study aimed to prepare three imine derivatives (1, 2, and 3) via a condensation reaction of phenyl hydrazine, 2-hydrazino pyridine, and 4-methoxy aniline with 4-formyl pyridine. Electron impact mass spectrometry (EIMS), proton nuclear magnetic resonance (1H-NMR), ultraviolet-visible (UV-Vis) and Fourier transform infrared (FTIR) spectroscopy were utilized for the characterization. The chemosensing properties of [4((2-phenyl hydrazono)methyl) pyridine] (1), [2-(2-(pyridin-4-ylmethylene)hydrazinyl) pyridine] (2), and [4-methoxy-N-yl methylene) aniline] (3) imino bases have been explored for the first time in aqueous media. The photophysical properties of chemosensors (1, 2, and 3) were examined by various cations (Na+, NH4+, Ba+2, Ni+2, Ca+2, Hg+2, Cu+2, Mg+2, Mn+2, and Pd+2). The chemosensor (1) showed very selective binding capability with copper ions at low concentrations (20 μM) without the influence of any other mentioned ions. The maximum complexation was noted with Cu+2 and 1 at pH between 7 to 7.5. The stoichiometry binding ratio between chemosensor (1) and Cu+2 was determined by Job's plot and it was found to be 1:2. The current study explored the use of these Schiff bases for the first time as heterocyclic chemosensors. DPPH radical scavenging, urease enzyme inhibition activities, molecular docking simulation, and density functional theory (DFT) analysis of compounds 1, 2, and 3 were also conducted.

Background: Cheminformatics is a fascinating emerging subfield of chemical graph theory that studies quantitative structure-activity and property relationships of molecules and, in turn, uses these to predict the physical and chemical properties, which are extremely useful in drug discovery and optimization. Knowledge discovery can be put to use in pharmaceutical data matching to help in finding promising lead compounds.

Method: Topological descriptors are numerical quantities corresponding to the chemical structures that are used in the study of these phenomena.

Result: This paper is concerned with developing the generalized analytical expression of topological descriptors for zeolite ACO structures with underlying degree and degree-sum parameters.

Conclusion: To demonstrate improved discrimination power between the topological descriptors, we have further modified Shannon's entropy approach and used it to calculate the entropy measures of zeolite ACO structures.

Background: Topological indices (TIs) are mathematical formulas that are applied in mathematical chemistry to predict the physical and chemical properties of various chemical structures. In this study, three different types of polycyclic aromatic hydrocarbon structures (PAHs) (i.e., Hexa-peri-hexabenzocoronene, Dodeca-benzo-circumcoronene, and Hexa-cata- hexabenzocoronene) are studied with the help of the different connection number-based Zagreb indices.

Method: ϑ = (V(ϑ),E(ϑ)) is used as a graph, where V(ϑ) is a collection of vertices and E(ϑ) is a collection of edges. For a vertex y, ∈V(ϑ), the degree d_ϑ (y), is the number of those vertices that are at a distance of 1 from y and the connection number ρ_ϑ (y) is the number of such vertices that are at a distance of 2 from vertex y.

Results: Theoretical applications of topological indices were described in detail.

Conclusion: Finally, we obtained the first and second Zagreb connections as well as the modified first, second, third, and fourth Zagreb connection indices, which were calculated for three different types (Hexa-peri-hexabenzocorone, Dodeca-benzo-circumcoronene, and Hexa-cata-hexabenzocoronene) of polycyclic aromatic hydrocarbon structures.