Phenolic compounds,essential oil composition,and antioxidant activity of Angelica purpurascens (Avé-Lall.) Gill

In this study, methanol extracts (MEs) and essential oil (EO) of Angelica purpurascens (Avé-Lall.) Gill obtained from different parts (root, stem, leaf, and seed) were evaluated in terms of antioxidant activity, total phenolics, compositions of phenolic compound, and essential oil with the methods of 2,2-azino-bis(3ethylbenzo-thiazoline-6-sulfonic acid (ABTS•⁺), 2,2-diphenyl-1-picrylhydrazil (DPPH•) radical scavenging activities, and ferric reducing/antioxidant power (FRAP), the Folin–Ciocalteu, liquid chromatography−tandem mass spectrometry (LC−MS/MS), and gas chromatography-mass spectrometry (GC−MS), respectively. The root extract of A. purpurascens exhibited the highest ABTS•⁺, DPPH•, and FRAP activities (IC₅₀: 0.05 ± 0.0001 mg/mL, IC₅₀: 0.06 ± 0.002 mg/mL, 821.04 ± 15.96 µM TEAC (Trolox equivalent antioxidant capacity), respectively). Moreover, EO of A. purpurascens root displayed DPPH• scavenging activity (IC₅₀: 2.95 ± 0.084 mg/mL). The root extract had the highest total phenolic content (438.75 ± 16.39 GAE (gallic acid equivalent), µg/mL)). Twenty compounds were identified by LC−MS/MS. The most abundant phenolics were ferulic acid (244.39 ± 15.64 μg/g extract), benzoic acid (138.18 ± 8.84 μg/g extract), oleuropein (78.04 ± 4.99 μg/g extract), and rutin (31.21 ± 2.00 μg/g extract) in seed, stem, root, and leaf extracts, respectively. According to the GC−MS analysis, the major components were determined as α-bisabolol (22.93%), cubebol (14.39%), α-pinene (11.63%), and α-limonene (9.41%) among 29 compounds. Consequently, the MEs and EO of A. purpurascens can be used as a natural antioxidant source.     

Purification and Properties of a Thermostable Xylanase GH 11 from Penicillium occitanis Pol6

An extracellular, endo-??-1,4-xylanase was purified to homogeneity from the culture filtrate of the filamentous fungus Penicillium occitanis Pol6, grown on oat spelt xylan. The purified enzyme (PoXyn2) showed a single band on SDS?CPAGE with an apparent molecular weight of 30?kDa. The xylanase activity was optimal at pH?3.0 and 65?°C. The specific activity measured for oat spelt xylan was 2,368?U?mg^?1. The apparent K _m and V _max values were 8.33?mg?ml^?1 and 58.82???mol?min^?1?ml^?1, respectively, as measured on oat spelt xylan. Thin-layer chromatography experiments revealed that purified PoXyn2 degrades xylan in an endo-fashion releasing xylobiose as main end product. The genomic DNA and cDNA encoding this protein were cloned and sequenced. This PoXyn2 presents an open reading frame of 962?bp, not interrupted by any introns and encoding for a mature protein of 320 amino acids and 29.88?kDa.     

Synthesis of vicinal perfluoroalkyl enol ethers

A convenient preparation of vicinal perfluoroalkyl enol ethers, by the action of alcohols on 1-bromo-1-perfluoroalkylethylenes in the presence of potassium hydroxide, is described. Some aspects of their reactivity are reported.     

Crystal structure of tris (phenylammonium) chloride pentachloroantimonate (III) monohydrate

The tris (phenylammonium) chloride pentachloroantimonate (III) monohydrate salt is triclinic with the following cell parameters: a = 9.4283(3), b = 11.4482(3), c = 13.1748(3)Å, = 113.493(2), = 90.381(2), = 97.331(1)°, V = 1290.86(6)ų, with Z = 2 formula units. The structure consists of [C₆H₅NH₃]⁺ cations, water molecules, Cl^– anions, and SbCl₅ square pyramids. Hydrogen bonds, established through water molecule, link the anions [SbCl₅]^2– and Cl^– and make an infinite chain in the [011] direction. Chains are linked together via another hydrogen bond network originating from the ammonium groups. A distortion of the SbCl₅ square pyramid can be attributed to the stereo activity of the Sb(III) lone electron pair.     

Crystal structure of di(N-benzyl piperidinium) pentachloroantimonate(III) dihydrate

The salt di(N-benzyl piperidinium) pentachloroantimonate(III) dihydrate crystallizes in the orthorhombic system with space group Cmc2₁, the unit cell dimensions are: a = 29.383(1), b = 10.509(2), c = 9.941(1) Å, with Z = 8. The structure shows a layer arrangement perpendicular to the a axis: planes of SbCl₆ octahedra alternate with planes of [C₁₂H₁₇N]⁺ cations. The SbCl₆ octahedra are connected through a O(W)–HCl hydrogen bonds and a chlorine bridge, so that infinite unidimensional chains of composition [SbCl₅(H₂O)₂]^2n– _n are formed in the structure along the c direction. These chains are connected to [C₁₂H₁₇N]⁺ entities by N–HCl and N–HO(W) hydrogen bonds, forming a three-dimensional network. It was found that lengths of Sb–Cl bonds may differ from each other. The differences shown as a distortion of the SbCl₆ octahedra were attributed to the Sb(III) lone electron pair stereoactivity.     

Synthese et proprietes d'ethers β-monofluores

Two methods have been used for the synthesis of β-monofluorinated ethers. One is the methylation of α-fluorinated alcoholates obtained from corresponding 2-fluoroalcohols by action of NaH in T.H.F. The second method is the nucleophilic substitution of tosyl group by fluorine in 2-methoxy-tosylates. Spectral properties of these β-fluorinated ethers have been studied. Furthermore ¹⁹F N.M.R. spectrum of the E 2-methoxyfluorocyclohexane has been investigated at low temperatures.     

Synthesis of β,β‘-Difluorinated and β,β’-F-Dialkylated Acetals

Using the phase transfer catalysis technique, a series of fluorinated acetals has been prepared, in basic medium, by action of dicholromethane on 2-mononfluorinated alcohols or 1-F-alkyl 2-fluoroethanols. The identification of these new acetals has been achived by the study cf their ¹H, 19F NMR and their mass spectra.     

Synthese d'une Serie de 2-(F-alkyl) Thioenol Ethers

2-(F-alkyl) enol ethers react easily with thiols. With one equivalent of the thiol, the corresponding 2-(F-alkyl) thioenol ethers were formed via an addition-elimination mechanism. With two equivalents of thiol or with one equivalent of 1,2-ethanedithiol, 2-(F-alkyl) thioacetals or 2-(F-alkyl) dithiolanes were obtained in good yields.