Likun Zhou

Selective Production of 1,2‐Propylene Glycol from Jerusalem Artichoke Tuber using Ni–W2C/AC Catalysts

A series of Ni-promoted W(2) C/activated carbon (AC) catalysts were investigated for the catalytic conversion of Jerusalem artichoke tuber (JAT) under hydrothermal conditions and hydrogen pressure. Even a small amount of Ni could greatly promote the conversion of JAT to 1,2-propylene glycol (1,2-PG), whereas the pure W(2) C/AC catalyst resulted in the selective formation of acetol. The product distribution profiles involving the reaction temperature, time, and H(2) pressure indicated that 1,2-PG formed as a result of acetol hydrogenation, which was catalyzed by Ni. Thus, there was a synergy between W(2) C and Ni, and the best performance yielded 38.5% of 1,2-PG over a 4%Ni-20%W(2) C/AC catalyst at 245°C, 6 MPa H(2) , and 80 min. To understand the reaction process, some important intermediates, such as inulin, fructose, acetol, glyceraldehyde, and 1,3-dihydroxyacetone, were used as the feedstock. Based on the product distributions derived from these intermediates, a reaction pathway was proposed, where JAT was first hydrolyzed into a mixture of fructose and glucose under the catalysis of H(+) , then the sugars underwent a retro-aldol reaction followed by hydrogenation catalyzed by Ni-W(2) C.

Molecular cloning and expression characterization of ApoC-I in the orange-spotted grouper

Endogenous yolk nutrients are crucial for embryo and larval development in fish, but developmental behavior of the genes that control yolk utilization remains unknown. Apolipoproteins have been shown to play important roles in lipid transport and uptake through the circulation system. In this study, EcApoC-I, the first cloned ApoC-I in teleosts, has been screened from pituitary cDNA library of female orange-spotted grouper (Epinephelus coioides), and the deduced amino acid sequence shows 43.5% identity to one zebrafish (Danio rerio) hypothetical protein similar to ApoC-I, and 21.2%, 21.7%, 22.5%, 20%, and 22.5% identities to Apo C-I of human (Homo sapiens), house mouse (Mus musculus), common tree shrew (Tupaia glis), dog (Canis lupus familiaris) and hamadryas baboon (Papio hamadryas), respectively. Although the sequence identity is low, amphipathic α-helices with the potential to bind to lipid were predicted to exist in the EcApoC-I. RT-PCR analysis revealed that it was first transcribed in gastrula embryos and maintained a relatively stable expression level during the following embryogenesis. During embryonic and early larval development, a very high level of EcApoC-I expression was in the yolk syncytial layer, indicating that it plays a significant role in yolk degradation and transfers nutrition to the embryo and early larva. By the day 7 after hatching, EcApoC-I transcripts were observed in brain. In adult, EcApoC-I mRNA was detected abundantly in brain and gonad. In transitional gonads, the EcApoC-I expression is restricted to the germ cells. The data suggested that EcApoC-I might play an important role in brain and gonad morphogenesis and growth.

Catalytic conversion of Jerusalem artichoke stalk to ethylene glycol over a combined catalyst of WO3 and Raney Ni

Jerusalem artichoke stalk (JAS) was employed as the feedstock for the production of ethylene glycol (EG) with a combined catalyst comprising commercial WO3 and Raney Ni. The raw JAS contains 51.6 wt% cellulose, 10.3 wt% hemicellulose, 17.2 wt% lignin, 1.7 wt% ash, and 19.2 wt% water-soluble substances. It was found that the lignin component in the JAS had little effect on the conversion of hemicellulose while the water-soluble substances caused a negative effect, which led to an EG yield of only 29.9%. After a simple hot water pretreatment, most of the water-soluble substances were removed, and the EG yield was increased to 37.6%. Moreover, the hot water pretreatment also led to an improvement in the durability of the catalyst. The effects of reaction temperature and reaction duration were also investigated

Catalytic conversion of Jerusalem artichoke tuber into hexitols using the bifunctional catalyst Ru/(AC-SO3H)

Jerusalem artichoke tuber OAT) was employed as a feedstock for production of hexitols under mild conditions over a sulfonated activated carbon supported Ru catalyst (Ru/(AC-SO3H)). In comparison with conventional Ru/AC catalyst, the sulfonation process of the carbon support was observed to create abundant surface acid groups, which in turn function as the anchoring sites for Ru nanoparticles, thus increasing the dispersion of Ru. Consequently, the bifunctional Ru/(AC-SO3H) catalyst displayed significantly enhanced activity in one-pot production of hexitols from JAT; the hexitols yield achieved 92.6% over the 3%Ru/(AC-SO3H) catalyst when the reaction was conducted at 373 K and 6 MPa H-2 for 3 h. The stability of the catalyst was also investigated, which showed a decreasing trend in the yield of sorbitol with the run number due to poisoning of Ru surface by the impurity in the JAT feedstock. In contrast, when pure inulin was used as the feedstock, the catalyst presented excellent stability in the successive four runs