Novel plastoquinone analogs containing benzocaine and its analogs: structure‐based design,synthesis, and structural characterization

Introducing new biologically active organic molecules or their analogs into the pharmaceutically important molecules significantly enables the discovery and development of the medicines that improve the health of patients. Chemical synthesis has a key role in pharmaceutical research and development, aiming to design and build molecules with the essential biological activity needed in drugs. For that reason, herein, three series of novel PQ analogs (the nonhalogenated (PQ1-6) and the halogenated PQ analogs (BrPQ1-6 and ClPQ1-6)) containing benzocaine and its analogs were designed and synthesized starting from the commercially available dimethylhydroquinone (1) with benzocaine and its analogs. The structures of all synthesized analogs were characterized by using spectroscopic methods. The in vitro antibacterial and antifungal activities were evaluated for the PQ analogs.

     

Synthesis of Two Natural Furan‐Cyclized Diarylheptanoids via 2‐Furaldehyde

Two natural diarylheptanoids, 2‐benzyl‐5‐(2‐phenylethyl)furan ( 1 ) and 2‐methoxy‐4‐{[5‐(2‐phenylethyl)furan‐2‐yl]methyl}phenol ( 2 ), were synthesized starting from 2‐furaldehyde. A Wittig reaction of 2‐furaldehyde with benzyltriphenylphosphonium bromide followed by reduction of the alkene C?C bond with Mg gave 2‐(2‐phenylethyl)furan ( 5 ). Lithiation of 5 with BuLi at ?78° followed by alkylation with benzyl bromide gave natural product 1 . In another approach, Friedel? Crafts acylation of compound 5 with benzoyl chloride followed by deoxygenation of the C?O group afforded 1 . The natural product 2 was also synthesized by acylation of 5 with 4‐acetoxy‐3‐methoxybenzoyl chloride ( 16 ) followed by deoxygenation and deacetylation.     

Development and Analysis of the Novel Hybridization of a Single-Flash Geothermal Power Plant with Biomass Driven sCO2-Steam Rankine Combined Cycle

This study investigates the hybridization scenario of a single-flash geothermal power plant with a biomass-driven sCO₂-steam Rankine combined cycle, where a solid local biomass source, olive residue, is used as a fuel. The hybrid power plant is modeled using the simulation software EBSILON^®Professional. A topping sCO₂ cycle is chosen due to its potential for flexible electricity generation. A synergy between the topping sCO₂ and bottoming steam Rankine cycles is achieved by a good temperature match between the coupling heat exchanger, where the waste heat from the topping cycle is utilized in the bottoming cycle. The high-temperature heat addition problem, common in sCO₂ cycles, is also eliminated by utilizing the heat in the flue gas in the bottoming cycle. Combined cycle thermal efficiency and a biomass-to-electricity conversion efficiency of 24.9% and 22.4% are achieved, respectively. The corresponding fuel consumption of the hybridized plant is found to be 2.2 kg/s.     

Modeling of particle–resin suspension impregnation in compression resin transfer molding of particle-filled,continuous fiber reinforced composites

A particle–resin suspension impregnation model is used for analyzing the mold filling process in compression resin transfer molding (CRTM) of particle-filled, continuous fiber composites. The model is based on Darcy flow coupled with particle filtration and is applicable to two-dimensional impregnation through isotropic/anisotropic fiber preforms. Comparisons with simple analytical solutions and experimental results from the literature were made to validate the numerical solution. Simulations showed that CRTM was advantageous over resin transfer molding (RTM) for smaller non-homogeneity in composite microstructure, when particle filtration was high. Limits on certain process parameters were observed beyond which molding pressures in CRTM became comparable with those in RTM. The preform anisotropy was effective in the particle distribution profile. The choice of inlet gate configuration in CRTM was found influential in the particle distribution homogeneity and molding pressures. The developed modeling tool can be extended to analyze any composite liquid molding process involving particle fillers.     

Ostrowski Type Inequality for Double Integrals on Time Scales

We prove the Ostrowski type inequality for double integrals on time scales and thus unify corresponding continuous and discrete versions from the literature. We also apply the Ostrowski inequality for double integrals to the quantum time scales.     

Apolar constituents of some biologically active <Emphasis Type="Italic">Dianthus</Emphasis> species from Western Anatolia

The apolar constituents of four Dianthus (Caryophyllaceae) species were determined by GC-MS. Palmitic, linoleic, and oleic acids were detected as dominant components in all species. D. elegans d’Urv. var. elegans had the highest antioxidant activity. All four species also showed considerable antimicrobial activity against S. epidermidis and C. albicans.     

Determination of Hg on poly(vinylferrocenium) (PVF)-modified platinum electrode

A new surface based on poly(vinylferrocenium) (PVF⁺)-modified platinum electrode was developed for determination of Hg²⁺ ions in aqueous solutions. The polymer was electrodeposited on platinum electrode by constant potential electrolysis as PVF⁺ClO₄⁻. Cl⁻ ions were then attached to the polymer matrix by anion exchange and the modified electrode was dipped into Hg²⁺ solution. Hg²⁺ was preconcentrated at the polymer matrix by adsorption and also complexation reaction with Cl⁻. Detection of Hg²⁺ was carried out by differential pulse anodic stripping voltammetry (DPASV) after reduction of Hg²⁺. Mercury ions as low as 5 × 10⁻¹⁰ M could be detected with the prepared electrode and the relative standard deviation was calculated as 6.35% at 1 × 10⁻⁶ M concentration (n = 6). Interferences of Ag⁺, Pb²⁺ and Fe³⁺ ions were also studied at two different concentration ratios with respect to Hg²⁺. The developed electrode was applied to the determination of Hg²⁺ in water samples.     

4-Vinylbenzenesulfonic acid adduct of epoxidized soybean oil: Synthesis, free radical and ADMET polymerizations

In this work new radically polymerizable triglyceride based monomers were synthesized by the reaction of epoxidized methyl oleate (EMO) and epoxidized soybean oil (ESO) with 4-vinyl benzene sulfonic acid (4VBSA). The products are 1-(4-vinylbenzene sulfonyl)oxy-2-alkonols of epoxidized soybean oil (SESO) and 1-(4-vinylbenzene sulfonyl)oxy-2-alkonols of epoxidized methyl oleate (SEMO). These adducts were characterized by ¹H NMR, ¹³C NMR, IR and CHNS elemental analysis. SESO was found to contain, on the average, 2.47 4VBSA units per triglyceride. SESO was free radically polymerized and co-polymerized with styrene and the mechanical and thermal properties of the resulting thermosets were determined by DMA, DSC and TGA. SEMO was used as a model compound to determine the efficiency of metathesis catalysts for these fatty acid derivatives. The second generation Hoveyda–Grubbs catalyst was found to give best yields. ADMET polymerization of SESO with this catalyst with and without solvent gave ∼80% yield of a thermoset polymer. Polymers obtained by free radical route swelled in water at room temperature, and hydrolyzed in water at 60 °C.     

Insights into the isomerization of photochromic oxazines from the excitation dynamics of BODIPY-oxazine dyads

We synthesized five BODIPY-oxazine dyads in one to four synthetic steps from known precursors. They differ in the nature of the unsaturated spacer linking the oxazine photochrome to either the conjugated framework or the boron center of the BODIPY fluorophore. Despite the π-character of the linkers, the two functional components are electronically isolated in the ground state and the BODIPY fluorophore maintains its absorption and, with one exception, emission properties unaltered. Instead, the photochemical response of the photochromic component is completely suppressed within all dyads. Rather than the expected opening of the oxazine ring, the laser excitation of these molecular assemblies results in the effective population of the BODIPY triplet in four of the five dyads. Control experiments with appropriate model compounds indicate that the local excitation of the oxazine component results first in intersystem crossing and then energy transfer to the BODIPY component. In fact, the transfer of energy from the triplet state of the former to the triplet state of the latter competes successfully with the opening of the oxazine ring and prevents the isomerization of the photochromic component. These observations demonstrate, for the very first time, that the photoinduced opening of these photochromic oxazines occurs along the potential energy surface of their triplet state. Such valuable mechanistic insights into their excitation dynamics can guide the design of novel members of this family of photochromic compounds with improved photochemical properties.