Ru0·Run+/Al2O3 as a Versatile Catalyst in the Isomerization of Allyl Alcohol

This study focuses on examining the isomerization of allyl alcohol using ruthenium (Ru) supported on alumina as a heterogeneous catalyst. The synthesized Ru/Al solids were characterized by various characterization techniques. The content of Ru was estimated by the energy dispersive x-ray technique. The x-ray diffraction (XRD) confirmed the presence of phases in the support and active species in the catalysts. The surface area of the support after Ru impregnation and the pore volume were determined by nitrogen physisorption. The analysis of programmed temperature (TPR and TPO) shows different redox sites which is confirmed by XPS. The catalytic results suggest a dependence on the amount of available metallic Ru, as well as the importance of the continuous regeneration of the metal using H2 to achieve a good conversion of the allyl alcohol. For comparison purposes, the commercial Ru on alumina 5% (CAS 908142) was used. The results show up to 68% alcohol conversion and 27% yield of the isomerization product using Ru(1,5.4h)/Al catalyst in comparison with 86% conversion and 39% yield of the isomerization product using CAS 908142. In contrast, our catalysts always presented higher TOF values (149–160) in comparison with CAS 908142 (101).

Occurrence of the Ochratoxin A Degradation Product 2′R-Ochratoxin A in Coffee and Other Food: An Update

Food raw materials can contain the mycotoxin ochratoxin A (OTA). Thermal processing of these materials may result in decreased OTA levels but also in the formation of the thermal isomerization product 2′R-ochratoxin A (2′R-OTA). So far, only 2′R-OTA levels reported from 15 coffee samples in 2008 are known, which is little when compared to the importance of coffee as a food and trading good. Herein, we present results from a set of model experiments studying the effect of temperatures between 120 °C and 270 °C on the isomerization of OTA to 2′R-OTA. It is shown that isomerization of OTA starts at temperatures as low as 120 °C. At 210 °C and above, the formation of 25% 2′R-OTA is observed in less than one minute. Furthermore, 51 coffee samples from France, Germany, and Guatemala were analyzed by HPLC-MS/MS for the presence of OTA and 2′R-OTA. OTA was quantified in 96% of the samples, while 2′R-OTA was quantifiable in 35% of the samples. The highest OTA and 2′R-OTA levels of 28.4 µg/kg and 3.9 µg/kg, respectively, were detected in coffee from Guatemala. The OTA:2′R-OTA ratio in the samples ranged between 2.5:1 and 10:1 and was on average 5.5:1. Besides coffee, 2′R-OTA was also for the first time detected in a bread sample and malt coffee powder.

Systemic and tumor-targeted delivery of siRNA by cyclic NGR and isoDGR motif-containing peptides

NGR-10R/siRNA complex and its isomerization productisoDGR-10R/siRNA efficiently delivered siRNA into tumor cellsin vitroandin vivo.

Effect of Mo/Al2O3 Catalyst Component on Composition of Residue Hydrocracked Product

Hydrocracking of Venezuelan heavy oil with no catalyst, dispersed Mo catalyst and Mo/Al2O3catalyst were carried out to investigate the effect of Mo/Al2O3catalyst component on the composition of residue hydrocracked product. Experimental data revealed that both dispersed Mo catalyst and Mo/Al2O3catalyst improved the conversion of Venezuelan heavy oil and inhibited the formation of coke, but the two types of catalyst have the opposite effects on generation of light products. Besides, the activity metal suppressed the formation of isomerization product while the acidity support enhanced it.

Simultaneous determination of β-methyl-β-nitrostyrolene and its related substances by PS-DVB chromatographic column and structural analysis of its photo-isomerization product

Determination of MNS and its related substances by RP-HPLC-UV and structural analysis of its photo-isomerization product.

Selective IR Laser Induced Isomerization and Dissociation of BIS (Trifluoromethyl) Ketene Molecules

Multiphoton IR laser induced isomerization and dissociation of (CF3)2C=C=O (FMK) molecules have been studied. The antisymmetric stretch v1 = 2192 cm-1 of C=C=O—and antisymmetric v16 = 991 cm-1 of C—C— bonds were excited by the second- and first harmonics of a pulsed TEA CO2 laser. The dependence of isomerization conversion on laser radiation frequency, fluence, and number of shots was measured. The isomerization channel was predominant compared with dissociation for the conditions of IR multiphoton excitation under study.The isomerization of FMK by the second–harmonic radiation of a CO2 laser was proved to be selective with respect to oxygen isotopes. The isomerization product (FMA molecules) was enriched with 18O with maximum value of selectivity α(18/16) = 3.9 when FMK molecules were excited at 2ωlas = 2143.8 cm-1.

CO2 laser induced decomposition of propylene oxide

The continuous-wave (cw) CO2 laser induced decomposition of propylene oxide yields propanal, propanone and methyl vinyl ether as primary isomerization products. The absence of allylol and great amounts of ethene among products of ensuing fragmentation of primary products make the reaction different from conventional thermal decomposition of propylene oxide. CW CO2 laser induced decomposition of methyl vinyl ether affords propanal as isomerization product and shows thermal interconvertibility of propylene oxide and methyl vinyl ether.