Probing osmotic effects on invertase with l-(−)-sucrose
作者:Seung-kee Seo、Alexander Wei
DOI:10.1039/b810158b
日期:——
L-(â)-Sucrose was efficiently synthesized using intramolecular aglycon delivery and used to elucidate osmotic effects on the activity of invertase, which catalyzes the hydrolysis of D-(+)-sucrose. The osmotic effect imposed by L-sucrose was responsible for more than 30% of the activity loss ascribed otherwise to âsubstrate inhibition.â
Iron Oxide Encapsulated by Ruthenium Hydroxyapatite as Heterogeneous Catalyst for the Synthesis of 2,5-Diformylfuran
作者:Zehui Zhang、Ziliang Yuan、Dingguo Tang、Yongshen Ren、Kangle Lv、Bing Liu
DOI:10.1002/cssc.201402402
日期:2014.12
Magnetic γ‐Fe2O3 nanocrystallites encapsulated by hydroxyapatite (HAP), HAP@γ‐Fe2O3, were prepared followed by cation exchange of Ca2+ on the external HAP surface with Ru3+ to give the γ‐Fe2O3@HAP‐Ru catalyst. The structure of the as‐prepared catalyst was characterized, and its catalytic activity was studied in the aerobic oxidation of 5‐hydroxymethylfurfural (HMF). γ‐Fe2O3@HAP‐Ru showed a high catalytic
synthesis of 5‐hydroxymethylfurfural (HMF) from a variety of sugars (simple to complex) using phosphatedTiO2 as a catalyst. Fructose and glucose were selectively converted to HMF resulting in 98 % and 90 % yield, respectively, at 175 °C. Cellobiose and sucrose also gave rise to high HMF yields of 94 % and 98 %, respectively, at 180 °C. Other sugar variants such as starch (potato and rice) and cellulose
Efficient conversion of glucose into 5-hydroxymethylfurfural catalyzed by a common Lewis acid SnCl4 in an ionic liquid
作者:Suqin Hu、Zhaofu Zhang、Jinliang Song、Yinxi Zhou、Buxing Han
DOI:10.1039/b914601f
日期:——
The common Lewis acid SnCl4 could efficiently convert glucose into 5-hydroxymethylfurfural in 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMim]BF4). New evidence indicated that the formation of the five-membered-ring chelate complex of the Sn atom and glucose may play a key role for the formation of HMF, and the mechanism for the reaction was proposed. In addition, the [EMim]BF4/SnCl4 system was also suitable for the conversion of fructose, sucrose, inulin, cellobiose and starch.
Efficient catalytic conversion of the fructose into 5-hydroxymethylfurfural by heteropolyacids in the ionic liquid of 1-butyl-3-methyl imidazolium chloride
作者:Yaping Xiao、Yu-Fei Song
DOI:10.1016/j.apcata.2014.07.014
日期:2014.8
Moreover, the used ionicliquid of [BMIM]Cl and HPAs could be recycled and reused with only slight decrease of reactivity for at least ten times. Compared with those systems reported so far, the [BMIM]Cl/PW12 and [BMIM]Cl/SiW12 exhibit higher yield, shorter reaction time, lower temperature for catalyticconversion of the fructose to 5-HMF, and they are environmental-friendly green systems.
H 3 PW 12 O 40(PW 12)和H 4 SiW 12 O 40(SiW 12)的杂多酸(HPA)已被证明是促进果糖脱水成5-羟甲基糠醛(5-HMF)的有效催化剂。存在作为绿色溶剂的1-丁基-3-甲基咪唑鎓氯化物([BMIM] Cl)离子液体。在80°C下仅5分钟即可获得5-HMF,收率和选择性都达到99%。通过施加[BMIM] Cl / PW 12的活化能为31.88 kJ mol -1果糖脱水的系统远低于文献报道的系统。此外,用过的[BMIM] Cl和HPA离子液体可以循环再用,但反应活性仅略微降低至少十倍。与迄今报道的那些系统相比,[BMIM] Cl / PW 12和[BMIM] Cl / SiW 12具有更高的收率,更短的反应时间,更低的将果糖催化转化为5-HMF的温度,而且在环境方面友好的绿色系统。