结构脂质的合成及应用

结构脂质(SLs)是一类具有营养性和功能性的甘油三酯。对结构脂质的合成方法(酯交换法、酸解法和二步法)和几种常见结构脂质(中碳链甘油三酯、中长碳链甘油三酯、类可可脂、人造母乳、磷酸甘油酯、酚酸甘油酯)的应用进行了综述。     

Chemical Synthesis of Amino Acid Containing Lipids I: Lipids Derived from Monobasic Amino Acids

Long-chain alkyl esters of N-acyl monobasic amino acids were prepared by reacting N-acyl amino acids with long-chain alkyl methane sulfonates in the presence of sodium bicarbonate in dimethylformamide. The necessary N-acyl amino acids were prepared by reacting an amino acid with an active fatty acid ester of p-nitrophenol in ethanol containing sodium bicarbonate. Reaction between a fatty acid and p-nitrophenol in chloroform, in presence of thionyl chloride, yielded the active ester necessary for the N-acylation of an amino acid.     

以酒石酸为骨架的新型阳离子脂质材料的合成

以天然产物L-(+)-酒石酸为骨架,以氨基己酸、辛胺、十二胺或十六胺为原料成功构建了3种新型阳离子脂质材料。所得产物结构经~1HNMR、IR和质谱等进行了表征。结果表明,所得中间体和阳离子脂质材料的结构与目标化合物结构相符,为基因治疗中阳离子脂质体的制备提供了载体材料。     

Comparison of Carotenoids for Their Antifibrogenic Effects in Hepatic Stellate Cells

Hepatic stellate cells (HSC) have an important role in the development of liver fibrosis by producing extracellular matrix proteins when they are activated upon liver injury. We previously demonstrated that astaxanthin (ASTX), a xanthophyll carotenoid, attenuates HSC activation. The objective of this study was to compare the anti-fibrogenic effects of ASTX with those of other common carotenoids. LX-2 cells, a human HSC cell line, were treated with ASTX, lycopene, lutein (LT), zeaxanthin, or canthaxanthin, to measure messenger RNA (mRNA) and protein expression of pro-fibrogenic genes. Pro-fibrogenic gene expressions were also measured in ASTX- or LT-treated primary mouse HSC. To determine the underlying mechanisms of the anti-fibrogenic effect of ASTX and LT, SMA-related and MAD-related protein 3 (SMAD3) pathways and the accumulation of reactive oxygen species (ROS) were measured in LX-2 cells. Among five carotenoids tested, ASTX and LT attenuated HSC activation in LX-2 cells by reducing the mRNA and protein levels of pro-fibrogenic genes, such as smooth muscle α actin and procollagen type I α1 (COL1A1). In addition, both ASTX and LT significantly decreased the expression of pro-fibrogenic genes, including COL1A1, COL3A1, and COL6A1, in activated primary mouse HSC, with ASTX being more potent than LT. The anti-fibrogenic effect of ASTX was mediated by inhibiting the phosphorylation of SMAD3 and cellular ROS accumulation, while LT only prevented the accumulation of ROS in LX-2 cells. In conclusion, ASTX showed the most potent anti-fibrogenic effect among the five carotenoids via inhibition of SMAD3 phosphorylation and cellular ROS accumulation while LT only prevented ROS levels in HSC.     

Effects of Storage Temperature and Water Activity on the Degradation of Carotenoids Contained in Microencapsulated Chili Extract

The aim of this work was to evaluate the effects of storage temperature and water activity on degradation of carotenoids contained in microencapsulates of non-aqueous extracts from chili (NAEC). Total carotenoids content and adsorption isotherms of microencapsulated NAEC in a 1:1 weight ratio with gum Arabic-maltodextrin DE 20 (GA 50%–MD50%) were determined at 25, 35, and 40°C. The isotherms were fitted using the Guggenheim-Anderson-de-Boer model and their enthalpies and entropies, both differential and integral, were estimated by the Clausius-Clapeyron method. The minimum integral entropy was considered as the point of maximum stability at which water less readily participates in degradation reactions. Zones of minimum integral entropy were found between 7.56–8.30, 6.10–6.95, and 5.15–6.04 kg H₂O/100 kg dried solids, corresponding to water activity (a_w) of 0.210–0.239, 0.238–0.277, and 0.262–0.313 at 25, 35, and 40°C, respectively. Total carotenoids content (CT) degraded over time, but degradation of carotenoids was lower in microcapsules stored at 25°C than those stored at 35 or 40°C. The morphology of microcapsules was altered at a_w > 0.6, including swelling of the polysaccharide matrix was presented, and possible subsequent dissolution of the wall material, which indicates a high rate of carotenoid degradation. When microencapsulated NAEC were storage between 0.2–0.6 of water activity, the highest glass transition temperatures were achieved. In this range, the wall materials of the microcapsules suffer less microstructural modifications, associated with the minimum level of degradation of carotenoids. Sometimes, in this water activity range, the zones of minimal entropy were observed.     

Effects of PCSK-9 Inhibition by Alirocumab Treatments on Biliary Cirrhotic Rats

Hyperlipidemia and oxidative stress with elevated oxidized low-density lipoprotein (ox-LDL) exacerbate hepatic inflammation and fibrosis. The plasma level of low-density lipoprotein (LDL) is controlled by proprotein convertase subtilisin/kexin 9 (PCSK9). Alirocumab is a monoclonal antibody that decreases LDL via inhibiting PCSK9 function. Apart from lipid-lowering effects, alirocumab exerts anti-inflammation, anti-angiogenesis and anti-oxidant effects. This study aims to investigate the impact of alirocumab treatment on common bile duct ligation (BDL)-induced biliary cirrhotic rats. After a 4-week treatment of alirocumab, the hemodynamic data, blood biochemistry, ox-LDL level, oxidative stress markers, severity of hepatic encephalopathy and abnormal angiogenesis of BDL rats were measured and compared to the control group. BDL rats presented cirrhotic pictures and elevated ammonia, total cholesterol, LDL and ox-LDL levels compared to the control group. Alirocumab decreased plasma levels of total cholesterol, LDL, and oxidative stress markers; however, it did not affect the hemodynamics, liver and renal biochemistry, and the plasma levels of ammonia and ox-LDL. The motor activities, portal-systemic collaterals and mesenteric vascular density were not significantly different between alirocumab-treated and control groups. In addition, it did not affect hepatic inflammation, intrahepatic angiogenesis, liver fibrosis and free cholesterol accumulation in the liver of BDL rats. In conclusion, PCSK9 inhibition by alirocumab treatment ameliorates hyperlipidemia and systemic oxidative stress in biliary cirrhotic rats. However, it does not affect the plasma level of ox-LDL, intrahepatic inflammation and fibrosis. In addition, PCSK9 inhibition has a neutral effect on abnormal angiogenesis and hepatic encephalopathy in biliary cirrhotic rats.     

柑橘皮中类胡萝卜素的提取研究

文章采用有机溶剂浸提法,用常见的有机溶剂对柑橘果皮中类胡萝卜素进行浸提、过滤并进行条件优化.通过单因素试验和正交试验,确定最佳提取条件为：采用提取剂乙醇、乙酸乙酯、正己烷（v/v/v=3∶1∶1）,温度为40℃、提取时间为150 min、投料比为1∶10 g/mL为最佳提取条件.     

Lipase-Catalyzed Synthesis of Fatty Acid Pyridylcarbinol Ester for the Analysis of Seed Lipids

Numerous derivatives of fatty acids (FA), including esters of methanol/3‐hydroxymethylpyridine or dimethyloxazoline, are used for the analysis of FAs in biological specimens. Picolinyl derivatives are frequently prepared for structural determination by gas chromatography–mass spectrometry (GC‐MS) since they provide characteristic fragments. The ester can be prepared by chemical methods‐multistep methodologies or basic transesterification. Microbial lipases catalyze a number of transesterification reactions, and their catalytic activities are often stable at extreme conditions. Although these characteristic features may be useful in the application of typical FA structure analysis by picolinyl ester, detailed studies have not been reported. To address the problems, a simple and quantitative methodology for the synthesis of picolinyl esters from lipids has been developed. It involves the transesterification with Novozym 435 (Novozymes Biopharma US Inc., Franklinton, USA), resin‐immobilized lipase from Candida antartica in toluene. Mild reaction conditions allow for complete derivatization of perilla seed oil in 30 min at 50 °C. The procedure was further studied with various TAGs and fatty wax from 17 plants. The optimized procedure was as follows; 1 mg lipid and 20 mg catalyst in 2 mL toluene at 50 °C for 1 h. Quantitative analysis of marker FAs was performed with the proposed method. The results coincided well with those from potassium t‐butoxide‐catalyzed reaction. The optimized method, however, was not applicable for the determination of some epoxy FAs, fatty wax, and parinaric acid.     

Fractionation of Lipids by Countercurrent distribution

The application of countercurrent distribution to the fractionation of lipids both for analytical and preparative purposes, is presented. The method has been applied to the separation of a wide variety of lipids including: fatty acids, methylesters of fatty acids, glycerides, phospholipids, derivatives of phospholipids, complex lipid mixtures and non-lipid contaminants.     

Biodegradation of wood-pulp black liquor hydroxyacids by Micrococcus lylae

When Micrococcus lylae grew on the black liquor from wood pulping, glucoisosaccharinic and acetic acids were completely used in 48 h, 2-hydro-xybutanoic acid decreased by 67%, lactic acid by 45% and glycolic acid by 38%. Conditions of the utilization of glucoisosaccharinic acid were optimized.     

Free Fatty Acids Reduction in Waste Cooking Oil by Rhodosporidium toruloides and Simultaneous Carotenoids,Lipids, and PAL Enzyme Production in a Two-Phase Culture System

Waste cooking oil (WCO) is a problematic waste product that contains free fatty acids (FFAs), preventing it from being valorized easily as biodiesel and poses an environmental hazard if incorrectly disposed. The use of WCO as a carbon source for Rhodosporidium toruloides (R. toruloides) using a two-phase culture system is developed. The normal growth of R. toruloides when cultured in WCO (OD₆₀₀ 52) reveals its ability to use a hydrophobic substrate as the carbon source compared to glucose (OD₆₀₀ 51.9). Interestingly, the extracellular lipase activity when R. toruloides is grown on WCO is 14.4 U mL⁻¹ compared to when grown on glucose (2.4 U mL⁻¹). Additionally, FFA levels in WCO are reduced from 2% to 0.2% at end of fermentation, suggesting that R. toruloides can consume FFA. Furthermore, higher yield of beneficial products: β-carotene (4.57 µg mL⁻¹), torularhodin (4.2 µg mL⁻¹), fatty acids (1 mg mL⁻¹), and phenylalanine ammonia-lyase (PAL) enzyme (0.12 µmol mg⁻¹) are produced when WCO is the carbon source, compared to glucose (4.1 µg mL⁻¹ β-carotene, 3.0 µg mL⁻¹ torularhodin, 1 mg mL⁻¹ of fatty acids, and 0.096 µmol mg⁻¹ PAL enzyme). This is a first study that shows R. toruloides can grow on hydrophobic carbon source.     

Carotenoids and tocols of corn grain determined by HPLC

A high performance liquid chromatographic (HPLC) procedure has been developed that permits determinationof carotenoids and tocols in the same sample preparation of corn grain. For 15 inbreds, the total carotenoids ranged from 16 to 77 μg/g dry wt and the total tocols from 30 to 128 μg/g dry wt. For four inbreds, total carotenoids were concentrated in the horny endosperm (83±2%) and total tocols in the germ (77±6%). After six months storage at room temperature, the mean loss of total carotenoids for four inbreds was 42±4%, while the tocols had a mean loss of 5%. Presented at the AOCS meeting in Honolulu, HI in May 1986.     

三元共聚物的合成及阻垢分散性能研究

以过硫酸铵为引发剂,采用水溶液聚合法,合成马来酸酐(MA)、丙烯酰胺(AM)和甲基丙烯酸甲酯(MMA)三元共聚物。经红外分析测试证实所得产品为三元共聚物。选择两种共聚物和AA/AMPS对常见无机垢进行阻垢分散实验,聚合物具有低剂量效应,对抑制碳酸钙、硫酸钙和磷酸钙垢沉积效果显著,同时分散氧化铁性能较好。     

Synthesis and Characterization of Novel Cationic Lipids Derived from Thio Galactose

Two double chain cationic lipids QAS C _n -2-S (n = 12, 14) derived from thio galactose and carbamate-linkage tertiary amine were synthesized and their structures were confirmed by MS, TOF-MS, ¹H NMR and ¹³C NMR. The QAS C₁₂-2-S revealed superior surface activity compared with QAS C₁₄-2-S with lower CMC and γ_CMC. Though Lipo C₁₂-2-S displayed large average particle-size with high polydispersity, positive charged Lipo C _n -2-S can be combined with the negative charged DNA, also negatively stained TEM images confirmed the formation of vesicles. All the above prove that the Lipo C _n -2-S is helpful for gene transfection.     

Enzymatic Synthesis of Novel Feruloylated Lipids and Their Evaluation as Antioxidants

Concerns about the use of chemical synthetic antioxidants that promote carcinogenesis has led to the development of natural antioxidants. Ferulic acid (4-hydroxy-3-methoxy cinnamic acid, FA) is a monophenolic phenylpropanoid present in the plant kingdom. It has shown a high antioxidant capacity and biological activities, including antiviral, anticarcinogenic and antimicrobial ones. However, due to poor solubility in hydrophobic media, FA can only be used in aqueous environments and this is a key factor that to a certain extent limits its application and bioavailability. In the present study, novel feruloylated lipids 1(3)-feruloyl-monobutyryl-glycerol (FMB) and 1(3)-feruloyl-dibutyryl-glycerol (FDB) were prepared by lipase-catalysed transesterification between FA and tributyrin. The structure of FMB and FDB was confirmed by NMR and ESI-MS, respectively. The radical scavenging and antioxidant properties of FA, FMB and FDB were evaluated using several different antioxidant assays, including hydroxyl radical scavenging, superoxide anion radical scavenging, 1,1-diphenyl-2-picrylhydrazyl (DPPH·) radical scavenging, inhibition of peroxidation of linoleic acid and reducing power. The antioxidant activities decreased in the following order: BHT ≥ FMB > FDB > FA. The results suggested that FMB and FDB exhibited a strong effect against oxidation in lipophilic systems making them promising antioxidants.     

降解黑荆树栲胶抑菌性能的研究

将黑荆树栲胶用过氧化氢进行氧化降解,GPC测得降解产物数均相对分子质量为 980,红外光谱表明该产物含有酚羟基、酯基以及甲基。该降解产物对大肠杆菌、枯草芽孢杆菌、金黄色葡萄球菌、巨大芽孢杆菌、志贺氏痢疾杆菌的最低抑菌浓度分别为0.05%、0.03%、0.03%、0.03%、0.05%,抑菌性能与原黑荆树栲胶相比有较大的提高。     

Dose-Dependent Effects of Docosahexaenoic Acid Supplementation on Blood Lipids in Statin-Treated Hyperlipidaemic Subjects

The objective of the study was to evaluate potential benefits of docosahexaenoic acid (DHA) rich fish oil supplementation as an adjunct to statin therapy for hyperlipidaemia. A total of 45 hyperlipidaemic patients on stable statin therapy with persistent elevation of plasma triglycerides (averaging 2.2 mmol/L) were randomised to take 4 g/day (n = 15) or 8 g/day (n = 15) of tuna oil or olive oil (placebo, n = 15) for 6 months. Plasma lipids, blood pressure and arterial compliance were assessed initially and after 3 and 6 months in 40 subjects who completed the trial. Plasma triglycerides were reduced 27% by 8 g/day DHA-rich fish oil (P < 0.05) but not by 4 g/day when compared with the placebo and this reduction was achieved by 3 months and was sustained at 6 months. Even though total cholesterol was already well controlled by the statin treatment (mean initial level 4.5 mmol/L), there was a further dose-dependent reduction with fish oil supplementation (r = −0.344, P < 0.05). The extent of total cholesterol reduction correlated (r = −0.44) with the initial total cholesterol levels (P < 0.005). In the subset with initial plasma cholesterol above 3.8 mmol/L, plasma very low density lipoprotein (VLDL), intermediate-density lipoprotein (IDL) and low-density lipoprotein (LDL) were isolated and assayed for cholesterol and apolipoprotein B (apoB) at the commencement of the trial and at 3 months of intervention. Fish oil tended to lower cholesterol and apoB in VLDL and raise both in LDL. There were no changes in IDL cholesterol, IDL apoB and high-density lipoprotein cholesterol. The results demonstrate that DHA-rich fish oil supplementation (2.16 g DHA/day) can improve plasma lipids in a dose-dependent manner in patients taking statins and these changes were achieved by 3 months. Fish oil in addition to statin therapy may be preferable to drug combinations for the treatment of combined hyperlipidaemia.