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Convenient Synthesis of N-Methylpyrrolidine-2-thione and Some Thioamides
Zong, Zhi-Min,Peng, Yao-Li,Liu, Zhi-Gang,Zhou, Shi-Lu,Wu, Lin,Wang, Xiao-Hua,Wei, Xian-Yong,Lee, Chul Wee 한국화학공학회 2003 Korean Journal of Chemical Engineering Vol.20 No.2
The synthesis of thioamides and thiolactams, which are used as important organic intermediates, has attracted great attention. However, expensive reagents, severe reaction conditions and low yields of the target products made conventional methods inconvenient and economically infeasible. To overcome these disadvantages, we investigated a new process for synthesizing thioamides and thiolactams. We examine thermal reactions of CS_2 with N-methyl-2-pyrrolidinones, formylamide, acetamide and N, N-dimethylformylamide, respectively. The results show that under optimum conditions N-methylpyttolidine-2-thione and the corresponding thioamides can be obtained in good to excellent yields by the above thionation reactions.
Xiao-Feng Li,Min-Hua Zong,Guang-Lei Zhao,Yi-Gang Yu,Hui Wu 한국생물공학회 2010 Biotechnology and Bioprocess Engineering Vol.15 No.4
In this paper, enzymatic regioselective acylation of 1-β-D-arabinofuranosylcytosine (ara-C) with vinyl benzoate (VB) using immobilized Candida antarctica lipase B in binary organic solvents was explored. It was found that the lipase showed high regioselectivity (> 99%) towards the 5'-OH of ara-C in the representative organic solvent mixture (hexane-pyridine). To understand the enzymatic processes and provide a fair comparison of hexane-pyridine with C4MIm·PF6-pyridine (the representative ionic liquid-containing system), the effect of each process variable on the reactions in hexane-pyridine was investigated. The results indicate that the optimum hexane content,initial a w, molar ratio of VB to ara-C, and temperature were 28% (v/v), 0.11, 15, and 40°C, respectively. Under optimized conditions, the initial reaction rate in hexanepyridine (44.4 mM/h) was much higher than that in C4MIm·PF6-pyridine (29.4 mM/h) for each case. The maximum conversion yield, however, was increased when the reaction system was shifted from hexane-pyridine to C4MIm·PF6-pyridine. Further study revealed that the presence of an acidic by-product (benzoate acid, released during the acylation process) may cause rapid inactivation of the enzyme in hexane-pyridine, leading to a lower conversion rate, whereas the ionic liquid may have coating and protecting effects on the lipase during the reaction.
Stanniocalcin-1 protects bovine intestinal epithelial cells from oxidative stress-induced damage
Li-ming Wu,Rui Guo,Lin Hui,Yong-gang Ye,Jing-mei Xiang,Chun-yun Wan,Miao Zou,Rui Ma,Xiao-zhuan Sun,Shi-jin Yang,Ding-zong Guo 대한수의학회 2014 Journal of Veterinary Science Vol.15 No.4
Chronic enteritis can produce an excess of reactive oxygenspecies resulting in cellular damage. Stanniocalcin-1(STC-1)reportedly possesses anti-oxidative activity, the aim of thisstudy was to define more clearly the direct contribution ofSTC-1 to anti-oxidative stress in cattle. In this study, primaryintestinal epithelial cells (IECs) were exposed to hydrogenperoxide (H2O2) for different time intervals to mimic chronicenteritis-induced cellular damage. Prior to treatment with 200μM H2O2, the cells were transfected with a recombinantplasmid for 48 h to over-express STC-1. Acridine orange/ethidium bromide (AO/EB) double staining and trypan blueexclusion assays were then performed to measure cell viabilityand apoptosis of the cells, respectively. The expression of STC-1and apoptosis-related proteins in the cells was monitored byreal-time PCR and Western blotting. The results indicated thatboth STC-1 mRNA and protein expression levels positivelycorrelated with the duration of H2O2 treatment. H2O2 damagedthe bovine IECs in a time-dependent manner, and this effectwas attenuated by STC-1 over-expression. Furthermore, overexpressionof STC-1 up-regulated Bcl-2 protein expression andslightly down-regulated caspase-3 production in the damagedcells. Findings from this study suggested that STC-1 plays aprotective role in intestinal cells through an antioxidant mechanism.
Qian, Ying-Ying,Liu, Xin-You,Wu, Qian,Song, Xian,Chen, Xiao-Feng,Liu, Yi-Qian,Pei, Dong,Shen, Li-Zong,Shu, Yong-Qian Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.19
Background: Although the predictive value of the excision repair cross-complementing group 1 (ERCC1) C118T polymorphism in clinical outcomes of patients with colorectal cancer (CRC) receiving oxaliplatin-based chemotherapy has been evaluated in numerous published studies, the conclusions are conflicting. Therefore, we performed the present meta-analysis to determine the precise role of the ERCC1 C118T polymorphism in this clinical situation and help optimize individual chemotherapy. Materials and Methods: A multiple search strategy was used to identify eligible studies. Pooled odds ratios (ORs) and their 95% confidence intervals (CIs) were used to estimate objective response and oxaliplatin-induced toxicity, with hazard ratios (HRs) with 95%CIs for progression-free survival (PFS) and overall survival (OS). Results: A total of 22 studies including 2,846 CRC patients were eligible in the analysis. Overall, no significant correlation was found between the ERCC1 C118T polymorphism and objective response to oxaliplatin-based chemotherapy, in all patients or in the Asian and Caucasian subgroups. However, the pooled analysis showed that the PFS and OS were significantly shorter in patients who carried T/T or T/C genotypes of ERCC1 C118T as compared to the C/C genotype. On stratified analysis by ethnicity, the ERCC1 118T allele was associated with a favorable prognosis in Caucasians (PFS, HR=0.58, 95%CI: 0.24-1.44; OS, HR=0.38, 95%CI: 0.22-0.64) but an unfavorable prognosis in Asians (PFS, HR=2.49, 95%CI: 1.87-3.33; OS, HR=2.63, 95%CI: 1.87-3.69) based on a dominant model. In addition, we failed to find a statistically significant impact of ERCC1 C118T polymorphism on oxaliplatin-induced toxicity. Conclusions: The ERCC1 C118T polymorphism may have prognostic value in patients with CRC undergoing oxaliplatin-based chemotherapy.
Direct ethanol production from dextran industrial waste water by Zymomonas mobilis
Ming-xiong He,Han Qin,Xiao-bo Yin,Zhi-yong Ruan,Fu-rong Tan,Bo Wu,Zong-xia Shui,Li-chun Dai,Qi-chun Hu 한국화학공학회 2014 Korean Journal of Chemical Engineering Vol.31 No.11
The direct production of ethanol from dextran industrial waste water was investigated by using Zymomonasmobilis via batch and semi-continuous fermentation mode. In batch fermentation, pretreated waste water (unsterilizedand sterilized), pH value (3.8 and 6.0), and Mg2+(with and without) was compared with OD600, sugar and ethanol con-centration. After 24 h fermentation, sugar in the dextran waste water was almost exhausted, and the amount of ethanolaccumulated reached 24.33-29.92 g/l, which is nearly 99% of the theoretical yield of ethanol. Kinetic parameters ofZ. mobilis in batch fermentation were also investigated. The raw dextran waste water was also used in semi-continuousfermentation. After 48 h fermentation, the production of ethanol was 28.65 g/l. These results indicated that dextranwaste water may be used as a candidate substrate and Z. mobilis could convert the raw material into ethanol directly.
Enhanced β-carotene production by Rhodotorula glutinis using high hydrostatic pressure
Sui-Lou Wang,Jun-She Sun,Bei-Zhong Han,Xiao-Zong Wu 한국화학공학회 2008 Korean Journal of Chemical Engineering Vol.25 No.3
High hydrostatic pressure (HHP) technology was used for improving the ability of β-carotene biosynthesis of Rhodotorula glutinis R68. After the treatments of five repeated cycles at 300MPa for 15 min, the barotolerant mutant PR68 was obtained. After 72 h of culture, the biomass of mutant PR68 was 21.6 g/L, decreased by 8.5% compared to the parent strain R68, but its β-carotene production reached 19.4 mg/L, increased by 52.8% compared to the parent strain R68. The result of restriction fragment length polymorphism analysis suggested that mutant strain PR68 was likely to change in nucleic acid level, and thus enhanced β-carotene production in this strain was a result of gene mutation induced by HHP treatment. HHP technology seems a promising approach for improving industrial microbes
Kai‑Dong Xie,Qiang‑Ming Xia,Jun Peng,Xiao‑Meng Wu,Zong‑Zhou Xie,Chun‑Li Chen,Wen‑Wu Guo 한국식물생명공학회 2019 Plant biotechnology reports Vol.13 No.2
The unreduced (2n) gametes have long been used in triploid breeding of citrus. In lemon, the previously reported mechanisms for 2n megagametophyte formation were controversial, whereas that for 2n pollen production is still unknown. Herein, the frequency of and mechanism underlying 2n megagametophyte and 2n pollen formation in ‘Eureka’ lemon were investigated based on cytological observation and genotyping of the triploid hybrids between ‘Eureka’ lemon and ‘Early gold’ sweet orange. As a result, 4.79% of the viable pollens of ‘Eureka’ lemon were identified as the 2n pollen with a larger diameter (70.16 ± 3.92 μm). The 2n pollen might be resulted from the formation of parallel spindles at meiosis stage II. Among the 204 plantlets regenerated from embryo rescue following the sexual cross, 12 were triploids as identified by flow cytometry. According to the analysis of heterozygosity transmission using 13 pericentromeric single nucleotide polymorphism (SNP) markers and 20 randomly distributed simple sequence repeat (SSR) markers, 11 triploids were identified to be originated from the fertilization of 2n megagametophytes of ‘Eureka’ lemon, with a frequency of 5.39%. Among them, nine 2n megagametophytes were supposed to be arisen from the second division restitution (SDR), whereas the other two were from postmeiotic genome doubling (PMD). These results to understand the mechanism underlying 2n gamete formation in lemon are valuable for its efficient polyploid breeding.