Acylation of 3,4-Diaminofurazan

An acylation method of 3,4-diaminofurazan was developed. Under the catalysts of p-Tolu- enesulfonic acid, 3-amino-4-formylaminofurazan, 3-amino-4-acetylaminofurazan, 3-amino-4-propio- nylaminofurazan, 3-amino-4-butylramino-furazan and 3-amino-4-benzoylaminofurazan were synthe- sized by acylation of 3,4-diaminofurazan with formic acid, acetic acid, propionic acid, butyric acid and benzoic acid respectively. Also, 3,4-diacetylaminofurazan and 3,4-dipropionylaminofurazan were synthesized by acylation of 3,4-diaminofurazan with acetic anhydride and propionic anhydride re- spectively. Compared with the traditional method which uses acyl halogen as reagent, our method reduced the reaction time and increased the yield and purify. The 3-amino-4-acylaminofurazan could be hydrolyzed to 3,4-diaminofurazan in ethanol with acid catalyst.

Acyldesilylation of 5-Trimethylsilyl-2-furancarboxaldehyde

Acyldesilylation of 5-trimethylsilyl-2-furancarboxaldehyde with acyl chlorides was investigated and the unexpected 5-acyl-2-dichloromethylfuran were obtained as main products. The expected 5-acyl-2-furancarboxaldehydes were also found after hydrolyzing of the corresponding dichloro-compounds.

椰子Acyl-ACP硫酯酶相关基因的克隆及其表达分析

椰子是一种重要的热带油料作物,椰子果成熟后,椰子果肉脂肪酸的主要成分为C12的月桂酸。应用椰子转录组测序的结果,从中挖掘了11个脂酰-ACP硫脂酶基因,分别是2个FatA基因、4个FatB1基因、3个FatB2以及2个FatB3基因。应用荧光定量PCR检测了Unigene9211、Unigene19303、Unigene45926、Unigene27250以及Unigene22278在果肉形成的3个阶段的表达变化,结果显示,这些基因在果肉形成的3个阶段持续表达。同时,对3个时期的果肉的脂肪酸成分也进行了测定,结果显示,在椰果发育7个月时,中低碳链的脂肪酸含量较低,但随着椰果的发育,中低碳链的脂肪酸逐步增加。

ACYL RADICAL CYCLISATIONS

Several phenylselenyl esters were selected as precursors of acyl radicals and synthesised by our established method. Treatment of these phenylselenyl esters with tributyltinhydride and AIBN generated the corresponding acyl radicals, which were found to proceed in 5 exo trig or 6 endo trig cyclisations to afford high yields of cyclopentanones and cyclohexanones, The substitution groups on the substrates have played an important role on the regioselectivity of cyclisations.

An Efficient Method for the Synthesis of Acyl-diazenes Using NaNO_2/NaHSO_4·H_2O

An efficient and convenient method for the synthesis of acyl-diazenes is reported. Ten acyl-diazenes have been synthesized from acylhydrazines in excellent yields under mild conditions. There are eight new substances among these compounds.

ZEOLITE－CATALYZED FRIEDEL－CRAFTS ACYLATION OF AROMATICS：I》．SYNTHESIS OF 4－ACYL ANISOLE WITH A HY CATALYST

A series of aromatic ketones 4-acyl anisole were synthesized with high yield by using carboxylic acids as acylating agents and a HY zeolite as catalyst.

Pharmacological inhibition of diacylglycerol acyltransferase-1 and insights into postprandial gut peptide secretion

AIM To examine the role that enzyme Acyl-CoA:diacylglycerol acyltransferase-1(DGAT1) plays in postprandial gut peptide secretion and signaling.METHODS The standard experimental paradigm utilized to evaluate the incretin response was a lipid challenge.Following a lipid challenge,plasma was collected via cardiac puncture at each time point from a cohort of 5-8 mice per group from baseline at time zero to 10 h.Incretin hormones [glucagon like peptide-1(GLP-1),peptide tyrosine-tyrosine(PYY) and glucose dependent insulinotropic polypeptide(GIP)] were then quantitated.The impact of pharmacological inhibition of DGAT1 on the incretin effect was evaluated in WT mice.Additionally,a comparison of loss of DGAT1 function either by genetic ablation or pharmacological inhibition.To further elucidate the pathways and mechanisms involved in the incretin response to DGAT1 inhibition,other interventions [inhibitors of dipeptidyl peptidase-IV(sitagliptin),pancreatic lipase(Orlistat),GPR119 knockout mice] were evaluated.RESULTS DGAT1 deficient mice and wildtype C57/BL6J mice werelipid challenged and levels of both active and total GLP-1 in the plasma were increased.This response was further augmented with DGAT1 inhibitor PF-04620110 treated wildtype mice.Furthermore,PF-04620110 was able to dose responsively increase GLP-1 and PYY,but blunt GIP at all doses of PF-04620110 during lipid challenge.Combination treatment of PF-04620110 and Sitagliptin in wildtype mice during a lipid challenge synergistically enhanced postprandial levels of active GLP-1.In contrast,in a combination study with Orlistat,the ability of PF-04620110 to elicit an enhanced incretin response was abrogated.To further explore this observation,GPR119 knockout mice were evaluated.In response to a lipid challenge,GPR119 knockout mice exhibited no increase in active or total GLP-1 and PYY.However,PF-04620110 was able to increase total GLP-1 and PYY in GPR119 knockout mice as compared to vehicle treated wildtype mice.CONCLUSION Collectively,these data provide some insight into the mechanism by which inhibition of DGAT1 enhances intestinal hormone release.

Studies on O-,N-Acylation of 3-Hydroxyisoxazole and Their Regioselective Synthesis(Ⅰ)——O-,N-acylation of 5-Methyl-3-hydroxyisoxazole with 2,2-Dimethyl 3-Substituted Cyclopropanecarboxylic Chlorides

The reactions of 5-methyl-3-hydroxyisoxazole with 2, 2-dimethyl, 3-substituted cyclopropanecarboxylic chlorides give O-acyl-5-methyl-3-hydroxyisoxazole and N-acyl-5-methylisoxazolin-3-one derivatives. The ratio of O-acyl to N-acyl product depends upon the acylation reagents. O-acyl derivatives can be converted to the N-acyl compounds by isomerization under acidic conditions or heating.

Synthesis of Chiral 3-Acylcamphors

3-Acylcamphors were synthesized in moderate yields by the condensation of camphor with esters using sodium hydride as a base.

A magnetic biocatalyst based on mussel-inspired polydopamine and its acylation of dihydromyricetin

A support made of mussel-inspired polydopamine-coated magnetic iron oxide nanoparticles （PD-MNPs） was prepared and characterized. The widely used Aspetyillus niger lipase （ANL） was immobilized on the PD-MNPs （ANL@PD-MNPs） with a protein loading of 138 mg/g and an activity recovery of 83.6% under optimized conditions. For the immobilization, the pH and immobilization time were investigated. The pH and thermal and storage stability of the ANL@PD-MNPs significant- ly surpassed those of free ANL. The ANL@PD-MNPs had better solvent tolerance than free ANL. The secondary structure of free ANL and ANL@PD-MNPs was analyzed by infrared spectroscopy, A kinetic study demonstrated that the ANL@PD-MNPs had enhanced enzyme-substrate affinity and high catalytic efficiency. The ANL@PD-MNPs was applied as a biocatalyst for the regioselective acylation of dihydromyricetin （DMY） in DMSO and gave a conversion of 79.3%, which was higher than that of previous reports. The ANL@PD-MNPs retained over 55% of its initial activity after 10 cycles of reuse. The ANL@PD-MNPs were readily separated from the reaction system by a magnet. The PD-MNPs is an excellent support for ANL and the resulting ANL@PD-MNPs displayed good potential for the efficient synthesis of dihydromyricetin-3-acetate by enzymatic regioselective acylation.

ZEOLITE－CATALYZED FRIEDEL－CRAFTS ACYLATION OF AROMATICS∶Ⅲ．SYNTHESIS OF 4－ACYL ANISOLE WITH USY CATALYST

The synthesis with high yield of a series of4-acyl anisole was performed through the Friedel-Crafts reaction of anisole with alkanoic or substituted benzoic acids in thepresence of an ultrastable Y zeolite (USY) catalyst.

Cloning and Enzymatic Activity Analysis of the Malonyl-CoA:acyl Carrier Protein Transacylase in <i>Brassica napus</i>Cultivars with Different Oil Content

The full-length genomic DNA of MCAT (Malonyl-CoA:acyl carrier protein transacylase) in Brassica napus was cloned. BnMCAT shares very high identity with AtMCAT in gene sequence and gene structure. A multiple alignment of the protein sequence showed that BnMCAT shares high identity with other MCATs from E. coli and plants. BnMCAT was expressed in all tissues, such as roots, stems, leaves, flowers, and seeds, and no significant differences in the expression level were found in different embryo stages after pollination. According to an in vitro relative activity analysis, purified recombinant BnMCAT expressed in E. coli had transacylase activity. Although the relative activities of BnMCAT in crude extracts isolated from different staged embryos were similar and showed little variation, a higher relative activity was found in a crude extract isolated from embryos in comparison to leaves. Different relative activities of BnMCAT in crude extracts isolated from cultivars with different oil content were also found, suggesting that the activity of BnMCAT might be a decisive factor for a high oil content. Together, these results showed that BnMCAT is an important enzyme in the FAS system and indicate that BnMCAT might be a new target enzyme for future crop improvement through genetic engineering.

Ghrelin基因衍生肽Des-acyl ghrelin和Obestatin主要功能及其分泌调节

除胃饥饿素(Ghrelin)外,Ghrelin基因还能衍生出多种具有活性的产物。本文对Ghrelin基因衍生肽进行了介绍,并对2种主要的产物去酰化胃饥饿素(Des-acyl ghrelin)和肥胖抑制素(Obestatin)的分布、主要功能及其分泌调节等内容进行了综述,旨在为开展其在动物生产领域中的研究提供理论基础。

Long-chain acyl-CoA synthetase in fatty acid metabolism involved in liver and other diseases:An update

Long-chain acyl-Co A synthetase(ACSL) family members include five different ACSL isoforms, each encoded by a separate gene and have multiple spliced variants. ACSLs on endoplasmic reticulum and mitochondrial outer membrance catalyze fatty acids with chain lengths from 12 to 20 carbon atoms to form acyl-Co As, which are lipid metabolic intermediates and involved in fatty acid metabolism, membrane modifications and various physiological processes. Gain- or lossof-function studies have shown that the expression of individual ACSL isoforms can alter the distribution and amount of intracellular fatty acids. Changes in the types and amounts of fatty acids, in turn, can alter the expression of intracellular ACSLs. ACSL family members affect not only the proliferation of normal cells, but the proliferation of malignant tumor cells. They also regulate cell apoptosis through different signaling pathways and molecular mechanisms. ACSL members have individual functions in fatty acid metabolism in different types of cells depending on substrate preferences, subcellular location and tissue specificity, thus contributing to liver diseases and metabolic diseases, such as fatty liver disease, obesity, atherosclerosis and diabetes. They are also linked to neurological disorders and other diseases. However, the mechanisms are unclear. This review addresses new findings in the classification and properties of ACSLs and the fatty acid metabolismassociated effects of ACSLs in diseases.

Silica gel supported AlCl_3 catalyzed Friedel-Crafts acylation of aromatic compounds

Silica gel supported aluminium trichloride（SiO2-AlCl3） has been shown to be a mild,efficient,and chemoseiective heterogeneous Lewis acid catalyst for the acylation of aromatic compounds with acid chlorides.The catalyst can be reused up to five times after simple washing with ether and is stable（as a bench top catalyst）.

Synthesis, Crystal Structure, Docking and Antifungal Activity of a New Pyrazole Acylurea Compound

The title compound N-（（3,5-dimethylphenyl）carbamoyl）-1-methyl-3-（trifluoromethyl）-1 H-pyrazole-4-carboxamide（C（15）H（15）F3N4O2） was synthesized, and its structure was confirmed by 1 H NMR, H RMS and X-ray diffraction. It crystallizes in the triclinic system, space group P1 with a = 11.7147（5）, b = 11.7935（5）, c = 13.6620（5） A, α = 69.755（7）°, β = 66.182（6）°, γ = 72.100（7）°, Dc = 1.423 g/cm^3, Z = 4, V = 1588.88（11） A^3, the final R = 0.0347 and wR = 0.1005 for 7171 observed reflections with I 〉 2σ（I）. The preliminary biological test showed that the title compound has antifungal activities against Fusarium oxysporum, Pseudomonas syringae, Corynespora mazei and Botrytis cinerea at 100 μg/mL as 5.19%, 53.50%, 88.55% and 70.62%, respectively. The docking results indicated the hydrogen bonds formed between the compound and SHD.

Tribological Performances of Fatty Acyl Amino Acids Used as Green Additives in Lubricating Oil

The friction and wear characteristics of lauroyl glutamine, lauroyl glycine and lauroyl alanine, used as green additives in HVI 350 mineral lubricating oil, were evaluated on a four-ball tribotester. The morphologies and chemical species of the worn surfaces were analyzed by scanning electron microscope （SEM） and X-ray photoelectron spectroscope （XPS）, respectively. The test results indicated that the three fatty acyl amino acids could effectively improve the anti-wear and friction-reducing abilities of the HVI 350 mineral oil. The improvement in anti-wear and friction-reducing abilities of the mineral oil by the related amino acids was mainly ascribed to the formation of a composite boundary lubrication film due to the adsorption of amino acids on the friction surfaces.

Regioselective enzymatic acylation of troxerutin in nonaqueous medium

A series of monosubstituted troxerutin esters have been synthesized by enzyme-catalyzed regioselective acylation of troxerutin in nonaqueous medium.Using divinyl dicarboxylates(CH_2=CH-OOC-(CH_2)_n-COO-CH=CH_2,n = 2,3,4,7,8,11) featuring different chain length as acyl donors and alkaline protease from Bacillus subtilis as catalyst,troxerutin was regioselective acylated at B ethoxyl group.The results indicated that the regioselectivity of the enzyme-catalyzed acylation was not affected by the chain length o...

Ghrelin-ghrelin O-acyltransferase system in the pathogenesis of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease(NAFLD) is currently considered as the most common liver disease in Western countries,and is rapidly becoming a serious threat to public health worldwide.However,the underlying mechanisms leading to the development of NAFLD are still not fully understood.The ghrelin-ghrelin O-acyltransferase(GOAT) system has recently been found to play a crucial role in both the development of steatosis and its progression to nonalcoholic steatohepatitis.Ghrelin,the natural ligand of the growth hormone secretagogue receptor,is a 28-amino acid peptide possessing a unique acylation on the serine in position 3 catalyzed by GOAT.The ghrelin-GOAT system is involved in insulin resistance,lipid metabolism dysfunction,and inflammation,all of which play important roles in the pathogenesis of NAFLD.A better understanding of ghrelin-GOAT system biology led to the identification of its potential roles in NAFLD.Molecular targets modulating ghrelin-GOAT levels and the biologic effects are being studied,which provide a new insight into the pathogenesis of NAFLD.This review probes into the possible relationship between the ghrelin-GOAT system and NAFLD,and considers the potential mechanisms by which the ghrelin-GOAT system brings about insulin resistance and other aspects concerning NAFLD.

大肠杆菌holo-ACP突变体的表达纯化及相应acyl-ACP的性质初探

酰基酰基载体蛋白(acyl-acyl carrier protein,acyl-ACP)作为酰基供体,在脂肪酸、聚酮等天然产物合成途径中具有重要作用.目前,常以酰基-辅酶A(acyl-CoA)来代替尚未商品化的acyl-ACP进行相关酶的体外活性研究.由于底物蛋白acyl-ACP的ACP部分与相关酶发生相互作用,影响酶的催化特性,这种替代无法真实认识相关酶的酰基转移特性.本文以大肠杆菌pET-28a(+)-ACP为模板,构建12株单点突变体,表达纯化出相应holo-ACP,并进一步合成C16:0-ACP和C18:1-ACP.高效液相色谱的结果表明,ACP单点突变会影响acyl-ACP整体的性质,其中T40残基的改变对acyl-ACP的疏水性、紫外吸收响应和稳定性均产生了显著影响.ACP突变体的性质表征为acyl-ACP与相关酶的互作机制研究奠定了基础.