A New Cyclopeptide and Other Constituents from the Leaves of Zanthoxylum rigidum Humb. & Bonpl. ex Willd. (Rutaceae)

A new cyclopeptide, cyclozanthoxylane A ( 1 ), the lignans cis‐ and trans‐methylpluviatolide, the flavonoid isoquercitrin, along with a mixture of benzoic and cinnamic acid derivatives, were isolated from the MeOH extract of the leaves of Zanthoxylum rigidum (Rutaceae). The structures of the compounds were determined on the basis of 1D‐ and 2D‐NMR, and MS analysis. It is the first time that a natural cyclic peptide has been isolated from the genus Zanthoxylum.     

Site‐Selective Approach to β‐Fluorination: Photocatalyzed Ring Opening of Cyclopropanols

To expand upon the recent pioneering reports of catalyzed sp³ C?H fluorination methods, the next rational step is to focus on directing “radical‐based fluorination” more effectively. One potential solution entails selective C?C bond activation as a prelude to selective fluorination. Herein, we report the tandem photocatalyzed ring‐opening/fluorination reactions of cyclopropanols by 1,2,4,5‐tetracyanobenzene (TCB) and Selectfluor to afford a process tantamount to site‐selective β‐fluorination of carbonyl‐containing compounds. This new approach provides a synthetically mild and operationally simple route to otherwise difficult‐to‐prepare β‐fluorinated products in good yields and with good‐to‐excellent regioselectivity. Remarkably, substrates that contain other usually reactive (e.g., benzylic) sites undergo ring‐opening fluorination preferably. The versatility of this method to give cyclic β‐fluorides from tertiary cyclopropanols and γ‐fluoro alcohols is also highlighted.     

Oxidation Reactions of Azines. 10. Synthesis, Structure, and Oxodihydroxylation of 3-Hydroxymethyl-1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine

It has been established that oxidation of a mixture of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine and dicyanomethane or formaldehyde with manganese dioxide gives 3-hydroxymethyl-1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine, the structure of which was confirmed by X-ray structural analysis. Some oxidative conversions by potassium permanganate of the product formed and its esters have been studied. These included lactamization, aromatization, and oxodihydroxylation.     

Determination of the Real Influence of the Addition of Four Thickening Agents in Creams Using Rheological Measurements

This study aimed to characterize different emulsions obtained by the addition of four thickening agents, using rheological measurements, beyond analyzing the emulsions by polarized light microscopy looking for liquid crystals on them. The addition of these four thickening agents did not modify the base emulsion rheology, only an improvement in the sensory of the formulation was verified. The polarized light microscopy showed the formation of liquid crystalline structures in all the formulations, thus, the thickening agents did not influence in this parameter too. However, the emulsions could be considered appropriated for cosmetic purposes, probably being highly physically stable.     

Association of 3-O-methylquercetin with β-cyclodextrin: complex preparation, characterization and ex vivo skin permeation studies

3-O-Methylquercetin (3-MQ) is a poorly soluble flavonoid not commercially available that presents antiviral activity. In this work, 3-MQ was isolated from Achyrocline satureioides and an inclusion complex of the flavonoid with β-cyclodextrin (βCD) was prepared. The complex was characterized by means of IR, ¹H NMR and molecular mechanics calculation, which suggested the insertion of the B ring of 3-MQ into the βCD cavity. In addition, the skin permeation of 3-MQ and its associations with βCD from hydroxypropyl methylcellulose (HPMC) hydrogels was investigated using Franz diffusion cells. For 3-MQ assay in pig ear skin, a LC method was developed and validated in the range 0.05–1.5 μg/mL. The hydrogels presented similar behavior, although in the absence of polymeric matrix, the complexation of 3-MQ with βCD seems to enhance its availability on skin surface, demonstrating the influence of the inclusion phenomena on 3-MQ diffusion through the gel and partition toward the stratum corneum.     

Br2偶宇称里德堡态的转动结构和电子角动量

由（２＋１）多光子电离方法获得溴分子６８８００－６９６００ｃｍ＾－１范围内的［ΠΠ／２］４ｄ偶宇称里德堡态转动激发光谱，通过对转动光谱的分析，确定了转动常数，Ｂ８１－８１＝０．０８６８８。并对电子角动量进行了标定，角动量Ω＝１。     

A new quinoxaline and isoindigo based polymer as donor material for solar cells: Role of ecofriendly processing solvents on the device efficiency and stability

A new semiconducting polymer based on two different electron deficient (quinoxaline and isoindigo) and electron rich (benzodithiophene) moieties is synthesized, characterized and used as donor material for photovoltaic devices. Blade‐coated bulk heterojunction solar cells are fabricated in air by using chlorinated (o‐dichlorobenzene) and nonchlorinated (o‐xylene) solvents for the deposition of the active layer. The use of o‐xylene allows a ～10% improvement of the device efficiency in comparison to the analogous system processed from o‐dichlorobenzene. In addition, the evolution of the photovoltaic parameters of the resulting devices during thermal stress is monitored and compared, demonstrating a nearly identical resistance against temperature. The reported results not only highlight the promising properties of the new polymer in terms of environmental stability and compatibility with nonhalogenated solvents, but also show an easy and ecofriendly way to further improve the device performance without altering the corresponding thermal stability. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 234–242     

Ruthenium(II) complexes of 2-benzoylpyridine-derived thiosemicarbazones with cytotoxic activity against human tumor cell lines

Reaction of [RuCl(3)(dppb)H(2)O] (dppb=1,4 bis(diphenylphospine)butane) with 2-benzoylpyridine thiosemicarbazone (H2Bz4DH) and its N(4)-methyl (H2Bz4M) and N(4)-phehyl (H2Bz4Ph) derivatives gave [RuCl(dppb)(H2Bz4DH)]Cl (1), [RuCl(dppb)(H2Bz4M)]Cl (2) and [RuCl(dppb)(H2Bz4Ph)]Cl (3). The cytotoxic activity of the studied compounds was tested against the MCF-7, TK-10 and UACC-62 human tumor cell lines. The precursor [RuCl(3)(dppb)H(2)O] exhibits cytocidal activity against the tree cell lines. H2BzDH, H2Bz4M, and [RuCl(dppb)(H2Bz4M)]Cl (2) show a selective cytocidal effect against the UACC-62 cell line which makes them the most promising compounds.     

1,4-Dihydropyridine/BF3OEt2 for the reduction of imines: Influences of the amount of added BF3OEt2 and the substitution at N-1 and C-4 of the dihydropyridine ring

We have evaluated four 1,4-dihydropyridines (DHPs 1a, 1b, 1c and 1d) as reducing agents, which presented free (hydrogenated) or phenyl-substituted N-1 and C-4 positions of the DHP ring. Reactions combining each of the DHP and different amounts of BF₃OEt₂ were evaluated for the reduction of imine 2a (N-benzylideneaniline). DHP simultaneously substituted at N-1 and C-4 (1a), and DHP substituted at C-4 (1b) gave lower yields for reduction of 2a in comparison with DHPs 1c and 1d (both unsubstituted at the C-4 position). By evaluating the amount of added BF₃OEt₂ to the reaction mixture, we have found that DHP 1c (substituted at N-1) provided its best yield for amine 3a (82%) when associated with stoichiometric amounts BF₃OEt₂, while DHP 1d (N-1- and C-4-unsubstituted derivative) was more effective (90% yield) with catalytic quantities of the Lewis acid. The reaction system using DHP 1c under stoichiometric BF₃OEt₂ could also be successfully applied with additional imine examples and under reductive amination conditions.