响应面法优化超声波辅助亚麻木酚素提取工艺及抗氧化性研究

以亚麻籽为原料,对超声波辅助提取亚麻木酚素进行了研究。通过单因素试验,分别考察原料颗粒度、超声功率、液固比、超声温度和超声时间对亚麻木酚素得率的影响。并在单因素试验基础上,采用Box-Behnken中心组合设计和响应面法对超声波提取亚麻木酚素工艺进行优化,建立了二次多项式回归方程的预测模型。研究结果表明,超声波辅助提取亚麻木酚素的最佳工艺条件为:原料颗粒度60目,提取溶剂60%乙醇,超声功率400 W,液固比17:1,超声温度40℃,超声时间15 min,亚麻木酚素得率为7.18 mg/g。抗氧化活性研究表明,亚麻木酚素对DPPH、过氧化氢和超氧阴离子均有良好的清除能力,IC_(50)值分别为145 mg/L、75 mg/L和0.25 mg/L。     

Continuous abrasive method for mechanically fractionating flaxseed

Both the flaxseed hull, which is rich in the lignan secoisolariciresinol diglucoside (SDG), and the embryo, which is rich in oil with high α-linolenic acid content, are of interest for functional food use. A mechanical process for preparing hull-and embryo-rich fractions was developed and characterized. The process consisted of three pearlers, a sifter that yielded fines, and a gravity table that yielded final hull and embryo fractions. The SDG contents of fractions correlated inversely with oil content, showing that oil content indicated purity of both embryo and hull fractions and that the fines were essentially hull particles. Process performance depended on seed variety, moisture content, and feed rate; the best yields were 285 g hull +fines/kg for low-moisture Omega flaxseed, and 470 g embryo/kg seed for low-moisture Neche. Corresponding oil contents of those fractions were 28.8 and 47.4%, respectively. This process appears to be commercially feasible, provided it can be scaled up. A single stage was used to identify features that should be incorporated into a scaled-up unit, for example a 7-mesh screen in the pearler chamber rather than 6- or 8-mesh, and use of an overhead feed inlet to the chamber to direct seed into the disk-plate gap.     

The Role of Polyphenol in Modulating Associated Genes in Diabetes-Induced Vascular Disorders

Diabetes-induced vascular disorder is considered one of the deadly risk factors among diabetic patients that are caused by persistent hyperglycemia that eventually leads to cardiovascular diseases. Elevated reactive oxygen species (ROS) due to high blood glucose levels activate signaling pathways such as AGE/RAGE, PKC, polyol, and hexosamine pathways. The activated signaling pathway triggers oxidative stress, inflammation, and apoptosis which later lead to vascular dysfunction induced by diabetes. Polyphenol is a bioactive compound that can be found abundantly in plants such as vegetables, fruits, whole grains, and nuts. This compound exerts therapeutic effects in alleviating diabetes-induced vascular disorder, mainly due to its potential as an anti-oxidative, anti-inflammatory, and anti-apoptotic agent. In this review, we sought to summarize the recent discovery of polyphenol treatments in modulating associated genes involved in the progression of diabetes-induced vascular disorder.     

Effectiveness of Magnolol,a Lignan from Magnolia Bark,in Diabetes,Its Complications and Comorbidities—A Review

Diabetes mellitus is a chronic metabolic disease characterized by disturbances in carbohydrate, protein, and lipid metabolism, often accompanied by oxidative stress. Diabetes treatment is a complicated process in which, in addition to the standard pharmacological action, it is necessary to append a comprehensive approach. Introducing the aspect of non-pharmacological treatment of diabetes allows one to alleviate its many adverse complications. Therefore, it seems important to look for substances that, when included in the daily diet, can improve diabetic parameters. Magnolol, a polyphenolic compound found in magnolia bark, is known for its health-promoting activities and multidirectional beneficial effects on the body. Accordingly, the goal of this review is to systematize the available scientific literature on its beneficial effects on type 2 diabetes and its complications. Taking the above into consideration, the article collects data on the favorable effects of magnolol on parameters related to glycemia, lipid metabolism, or oxidative stress in the course of diabetes. After careful analysis of many scientific articles, it can be concluded that this lignan is a promising agent supporting the conventional therapies with antidiabetic drugs in order to manage diabetes and diabetes-related diseases.     

Extraction of Lignan Compounds from Roasted Sesame Oil and their Effects on the Autoxidation of Methyl Linoleate

ABSTRACT:  Lignan compounds were extracted from roasted sesame oil and their effects on the autoxidation of methyl linoleate (ML) were studied. Lignan compounds extracted from roasted sesame oil, sesamol, sesamin, and sesamolin, were added to ML, which was then oxidized at 60 ^oC for 18 h in the dark. Alpha-tocopherol was separately added to ML for a reference antioxidant. Degree of ML oxidation was monitored by conjugated dienoic acid (CDA) contents and p -anisidine value (PAV) by AOCS methods, and ML retention by gas chromatography. CDA contents and PAV of samples increased with the oxidation time at 60 ^oC in the dark, and ML decreased. Sesamol-, sesamin-, or sesamolin-added samples showed lower CDA contents, PAV, and ML loss than the samples without lignans during oxidation in the dark, which indicated that lignan compounds lowered the ML autoxidation. The antioxidant activity of sesamol was significantly higher ( P < 0.05) than that of sesamin, sesamolin, or α-tocopherol. Lignan compounds added to ML were degraded during the autoxidation of ML, and the degradation rate was higher in sesamol- than in sesamin-, or sesamolin-added ML, but was lower than in tocopherol-added samples. As the lignan compounds concentration in ML increased, the degradation rate of lignans decreased, and the inhibition of the ML autoxidation by lignan compounds increased. The results strongly suggested that the autoxidative stability of ML could be improved by the addition of sesamol, sesamin, or sesamolin extracted from the roasted sesame oil.     

芝麻中芝麻素提取工艺研究进展

芝麻素是一种具有良好生理功能和药理价值活性成分,具有广阔开发前景和市场需求。该文综述芝麻的芝麻素性质、应用及提取方法,重点介绍国内外从芝麻中提取芝麻素工艺。     

Short communication: The mammalian lignan enterolactone is absorbed by newborn dairy calves fed enterolactone-enriched milk

Flaxseed is the richest source of the plant lignan secoisolariciresinol diglucoside, which is converted to the mammalian lignans enterolactone (EL) and enterodiol by the gut microbiota of ruminants and humans. Enterolactone has been associated with improved animal and human health due to its antioxidant and anticarcinogenic properties. The objective of this study was to determine the pharmacokinetics of EL in newborn dairy calves fed milk replacer or EL-enriched milk. We hypothesized that newborn Holstein calves fed EL-enriched milk would have greater area under the curve and plasma concentration of EL compared with those fed milk replacer. On d 5 of life, calves were administered 2 L of milk replacer (n = 10; low-EL treatment: 123 nmol/L of EL) or 2 L of EL-enriched milk (n = 10; high-EL treatment: 481 nmol/L of EL) during the morning feeding (0700 h). Blood samples were taken from the jugular vein before (0 h) and at 0.5, 1, 1.5, 2, 2.5, 3, 4, 6, 8, 10, 12, 24, and 48 h after oral administration of treatments. The area under the curve for the plasma concentration of EL was analyzed according to the trapezoidal rule between 0 and 12 h after treatment administration, and it was greater in high- (26 nmol/L × h) than low-EL calves (4.30 nmol/L × h). Similarly, the maximum concentration of EL in plasma was greater in high- (5.06 nmol/L) versus low-EL calves (1.95 nmol/L). Furthermore, the time after treatment intake to reach maximum plasma concentration of EL was faster in high- (4.31 h) compared with low-EL (4.44 h) treatment. Calves were able to absorb EL, indicating that EL-enriched milk can potentially be used as source of EL to pre-weaned ruminants.     

A new antioxidant from wild nutmeg

Nutmeg (Myristica fragans and Myristica argentea) is a spice widely used in food. Argenteane is a dilignan which has been isolated from nutmeg mace (the lace-like seed membrane of nutmeg). On the basis of the experimental measurements of the lipid peroxidation inhibition, argenteane appeared to be an antioxidant as powerful as vitamin E. The present joint experimental and theoretical study helped to understand the mechanism of action of this compound. The density functional theory (DFT) calculations of the O–H bond dissociation enthalpies (BDEs) correlated with the capacity to scavenge free radicals. We demonstrated that the central moiety is able to release one or two H atom(s) to the free radicals. This mechanism was confirmed by (i) the BDE calculations and (ii) the free radical-scavenging capacity measurements of two lignans and 3,3′-dimethoxy-1,1′-biphenyl-4,4′-diol (i.e., the argenteane central moiety). In addition to this active part, two lipophilic chains participate in the molecule’s capacity to react with the oxidative species generated in the membrane vicinity.     

Gastrointestinal metabolism of phytoestrogens in lactating dairy cows fed silages with different botanical composition

Dietary phytoestrogens are metabolized or converted in the gastrointestinal tract of ruminants, only limited knowledge exists on the extent and location of this conversion in vivo. The objective of this study was to quantify the gastro-intestinal metabolism of phytoestrogens in lactating dairy cows fed silages with different botanical composition. Four lactating rumen cannulated Norwegian Red cattle were assigned to a 4 × 4 Latin square with 1 cow per treatment period of 3 wk. The 4 treatment silages were prepared from grasslands with different botanical compositions: organically managed short-term timothy (Phleum pratense L.) and red clover (Trifolium pratense L.) ley (2 yr old: ORG-SG); organically managed long-term grassland with a high proportion of unsown species (6 yr old; ORG-LG); conventionally managed perennial ryegrass (Lolium perenne L.) ley (CON-PR); and conventionally managed timothy ley (CON-TI). The herbages were cut, wilted, and preserved with additive in round bales, fed as a mix of the first and third cut at 90% of ad libitum intake, and contributed to 70% of the total dry matter intake. Milk, feed, omasal digesta, urine, and feces were collected at the end of each period and analyzed for the concentrations of phytoestrogens by using a liquid chromatography–tandem mass spectrometry technique. Concentration of total isoflavones was highest in ORG-SG and lowest in CON-TI silage, whereas the content of total lignans was highest in the grass silages. The isoflavones were extensively metabolized in the rumen on all diets, and the recovery of formononetin and daidzein in omasum, mainly as equol, averaged 0.11 mg/mg. The apparent intestinal metabolism was less severe as, on average, 0.29 mg/mg of the omasal flow was recovered in feces. The plant lignans were also strongly degraded in the rumen. However, the flow of lignans to omasum and excretion in feces were, on average, 7.2- and 5.2-fold higher, respectively, than the intake of the plant lignans matairesinol and secoisolariciresinol, known as precursors of mammalian lignans. Thus, excretion to milk could not be directly related to intake, implying that plant lignans other than matairesinol and secoisolariciresinol in forage are precursors for enterolactone production in the rumen and for its content in milk. Equol followed mainly the flow of large particles out of the rumen, whereas the mammalian lignans were distributed between phases proportional to dry matter flow. The main metabolism of phytoestrogens occurred in the rumen and the main route of excretion was through feces and urine, with only a small part being excreted in milk. The concentration of phytoestrogens in milk can be manipulated through intake but the intermediate transfer capacity to milk appears to be limited by saturation.     

昆明山海棠的非萜类化学成分及其抗肿瘤活性研究

利用硅胶柱色谱、羟丙基葡聚糖凝胶柱色谱(Sephadex LH-20)、MCI柱色谱、中压ODS柱色谱及高效液相色谱(HPLC)等分离手段,并借助核磁共振等多种波谱学方法,从昆明山海棠(Tripterygium hypoglaucum)茎叶中共分离鉴定了11个化合物,结构类型包括木脂素、甾体以及酚性成分,分别为杜仲树脂酚(1),(7R,7'R,7″R,8S,8'S,8″S)-4,4″,7″,9″-四羟基-3,3',3″,5,5',5″-六甲氧基-7,9';7',9;4',8″-氧代-8,8'-倍半木脂素(2),(7R,7'R,7″S,8S,8'S,8″S)-4,4″,7″,9″-四羟基-3,3',3″,5,5',5″-六甲氧基-7,9';7',9;4',8″-氧代-8,8'-倍半木脂素(3),(7R,7'R,8S,8'S)-4,4″,7″,9″-四羟基-3',5,5',5″-四甲氧基-7,9';7',9;4',8″-氧代-8,8'-倍半木脂素(4),(7R,7'R,8S,8'S)-4,4″,7″,9″-四羟基-3',3″,5,5',5″-五甲氧基-7,9';7',9;4',8″-氧代-8,8'-倍半木脂素(5),20β-β-D-葡萄糖-3-羰基孕甾-4-烯(6),20α-β-D-葡萄糖-3-羰基孕甾-4-烯(7),β-谷甾醇(8),邻羟基苯甲醇-1-O-β-D(3'-苯甲酰基)葡萄糖苷(9),邻羟基苯甲醇(10),和4-羟基-2-甲氧基苯甲醇(11),其中化合物2-7和9为首次从该植物中分离得到.此外,体外抗肿瘤活性实验表明,化合物1和6显示出弱的抗肿瘤活性.