Fe(TSPc)-Catalysed Benzylic Oxidation and Subsequent Dealkylation of a Non-Phenolic Lignin Model

Abstract

The mechanism by which the phthalocyanine complex trisodium tetra-4-sulfonatophthalocyanineiron(JJJ) (Fe(TSPc)) promotes oxidation and dealkylation of non-phenolic benzyl alcohol units in lignin under alkaline conditions was investigated using simple lignin model compounds. The iron complex effectively oxidised benzylic hydroxyl groups in 2-hydroxyethyl apocynol (5), with the extent of oxidation increasing with the amount of Fe(TSPc) added. To a limited extent, Fe(TSPc) also catalysed the oxidation of 5 by small amounts of oxygen in the reaction mixture. However, the extent of oxidation did not increase on adding excess air or oxygen, as greater amounts of oxygen also increased complex degradation. Phenolic products were formed in these reactions in the presence of Fe(TSPc), but at a rate slower than that of the benzylic oxidation. Further experiments indicated that the phenolic products were formed by base-promoted loss of the ether group at C4 and that such dealkylation occurred more readily in oxidised products.     

ENHANCEMENT OF AMINO ACID PRODUCTION BY TWO-STEP AUTOLYSIS OF SPENT BREWER'S YEAST

A two-step autolysis process was proposed to enhance amino acid production from spent brewer's yeast. The technique was developed based on comparative study of the dynamics of production and release of proteins and amino acids during the autolysis of a concentrated suspension (22 wt.%) and a dilute yeast cell suspension (11.25 wt.%). The results suggest that, in the concentrated yeast suspension, proteins are more effectively broken down into amino acids, but the product release rate was lower due to a lower concentration gradient across the cell membrane. Thus, a two-step process, in which a high protein conversion occurred in a concentrated cell suspension during the first 13 h period, followed by a 26 h autolysis process within a dilute cell suspension, provided a higher overall yield of amino acids compared than the single-step process. The two-step process was found to result in a 25% higher amino acid yield with a weight fraction increase from 0.4 to 0.5 g/g dry wt. Other than these findings, the effect of adding NaCl to the suspension during autolysis was also investigated. It was found that, for the autolysis conditions employed in this study, the addition of NaCl did not significantly affect the production of protein but inhibited the production of amino acids.     

超临界CO2萃取灵香草精油及其化学成分研究

用超临界CO2萃取技术(SFE-CO2),对灵香草(Lysimachia foenum-graecum Hance)进行了萃取,得到灵香草萃取物。探讨了萃取压力、时间及温度等因素对萃取收率的影响,较佳的工艺为:压力25 MPa、温度40℃、时间4 h。超临界CO2法得到的灵香草萃取物收率为4.5%,高于水蒸气法的收率,且香气纯正。采用GC-MS技术对SFE-CO2法得到的灵香草萃取物化学组成进行了分析鉴定,共鉴定出37个化学成分,总质量分数为91.91%,其中主要成分为:苯乙酮、(Z,Z,Z)-9,12,15-十八碳三烯酸甲酯、(Z,Z)-9,12-十八碳二烯酸、9-十六碳烯酸、十七酸、十七酸乙酯、(Z,Z,Z)-9,12,15-十八碳三烯酸乙酯等化合物。     

紫外分光光度法测定脱硫液中栲胶含量

在实验室用紫外分光光度法测定了脱硫液中栲胶的含量,在pH值8-10范围时,由吸收光谱图可以看 出,该物质在320nm有最大吸收。利用分光光度法在该波长下进行比色测定,栲胶含量在0-30mg·L-1范围内 符合比尔定律,其线性回归方程为C=0．058 1A-0．013(R=0．999 80),回收率99．6％-100．3％,相对偏差小 于0．32％。该方法测定脱硫液中栲胶快速、准确、重现性好、试样无需特殊处理。     

甘肃竹叶椒乙醇提取物化学成分研究

应用GC—MS联用技术分离鉴定甘肃竹叶椒果皮、叶和种子乙醇提取物的化学成分。从竹叶椒果皮、叶和种子乙醇提取物中分别鉴定出30、39和34个峰,被鉴定出化学成分的相对含量分别占总量的90.3%、89.8%和93.9%。竹叶椒果皮、叶和种子中含量较高的化学成分分别是:4-甲基-1-异丙基-3-环己烯醇(8.9%)、4-亚甲基-1-异丙基二环[3.1.0]己-3-醇(8.8%);烷烃类(19.0%)、邻苯二甲酸二丁酯(12.2%)、反-9-十八碳烯酸(11.4%);5-烯丙基-1,3-苯并二(?)茂(12.9%)、3,7-二甲基-1,6- 辛二烯-3-醇(12.6%)、烷烃类(11.8%)、4-甲氧基-6-烯丙基-1,3-苯并二(?)茂(10.5%)。     

Antifeedants against <Emphasis Type="Italic">Hylobius abietis</Emphasis> Pine Weevils: An Active Compound In Extract of Bark of <Emphasis Type="Italic">Tilia cordata</Emphasis> Linden

Linden (Tilia cordata) bark was shown to contain an antifeedant effective against the large pine weevil, Hylobius abietis. Soxhlet extraction of inner and outer bark resulted in an extract that showed antifeedant activity in a microfeeding assay. The extract was fractionated by chromatography on silica gel using gradient elution with solvents of increasing polarity. The content of the fractions obtained was monitored by thin layer- and gas chromatography. Fractions of similar chemical composition were merged. Two of the 17 fractions showed antifeedant activity in the microfeeding assay. Nonanoic acid was identified in both of these fractions. Subsequent testing in the microfeeding assay showed that nonanoic acid possessed strong antifeedant activity against H. abietis adults.     

乳酸菌发酵提取物保护皮肤氧化损伤的作用与机理

为筛选出能够保护皮肤细胞减缓氧化应激损伤的乳酸菌,对植物乳杆菌、类干酪乳杆菌、嗜酸乳杆菌、高加索酸奶乳杆菌、瑞士乳杆菌五种不同乳酸菌进行发酵培养获得发酵提取物,从生化、细胞、分子三种水平对所得提取物的抗氧化功效和保护细胞氧化应激损伤的效果和机制进行检测。结果表明五种乳酸菌发酵提取物均具有良好的清除羟自由基和超氧阴离子的能力,植物乳杆菌发酵提取物(Lactobacillus plantarum fermented extract 1,FE1)对两种自由基的清除作用最强,10g/L的FE1能够清除49.14%的羟自由基和73.99%的超氧阴离子。五种乳酸菌发酵提取物中植物乳杆菌发酵提取物、类干酪乳杆菌发酵提取物（Lactobacillus paracasei fermented extract 2, FE2）和嗜酸乳杆菌发酵提取物（Lactobacillus acidophilus fermented extract 3 ,FE3）能够显著提高氧化应激损伤条件下皮肤细胞的存活率（ p<0.05）以及细胞中谷胱甘肽过氧化物酶的活力（p<0.05）,同时降低细胞内活性氧含量（p<0.05）。特别的是,植物乳杆菌发酵提取物还可以显著提升细胞内过氧化氢酶、超氧化物歧化酶活力水平及细胞的总抗氧化能力水平（p<0.05）。分子水平实验结果显示植物乳杆菌发酵提取物可促进Sirt1上调表达,并激活Wnt/β-catenin通路中关键调控基因β-catenin,从而上调了MP30、FoxO3a、Tbx3抗氧化基因表达从而提升其抗氧化能力。因此植物乳杆菌发酵提取物良好的抗氧化性效果具有减缓H2O2刺激引起皮肤细胞氧化损伤的作用。     

Effect of Ligusticum wallichii Aqueous Extract on Oxidative Injury and Immunity Activity in Myocardial Ischemic Reperfusion Rats

We investigated the efficacy of Ligusticum wallichi aqueous extract (LWE) for myocardial protection against ischemia-reperfusion injury. Rats were fed for five weeks with either a control diet (sham and ischemia reperfusion (IR) model control groups) or a diet mixed with 0.2%, 0.4% or 0.6% Ligusticum wallichi extract. At the end of the five week period, hearts were excised and subjected to global ischemia for 30 min followed by reperfusion for 2 h. The hearts were compared for indices of oxidative stress and immunity activities. Administration of Ligusticum wallichi extract significantly decreased serum TNF-α, IL-6, IL-8, NO, MIP-1α, CRP and myocardium MDA levels, and serum CK, LDH and AST activities, and increased myocardium Na(+)-K(+)-ATPase, Ca(2+)-Mg(2+)-ATPase, NOS, SOD, CAT, GSH-Px and TAOC activities. The results indicate that Ligusticum wallichii extract treatment can enhance myocardial antioxidant status and improve the immunity profile in ischemic-reperfusion rats.     

Simultaneous Structural Identification of Natural Products in Fractions of Crude Extract of the Rare Endangered Plant Anoectochilus roxburghii Using H NMR/RRLC-MS Parallel Dynamic Spectroscopy

Nuclear magnetic resonance/liquid chromatography-mass spectroscopy parallel dynamic spectroscopy (NMR/LC-MS PDS) is a method aimed at the simultaneous structural identification of natural products in complex mixtures. In this study, the method is illustrated with respect to (1)H NMR and rapid resolution liquid chromatography-mass spectroscopy (RRLC-MS) data, acquired from the crude extract of Anoectochilus roxburghii, which was separated into a series of fractions with the concentration of constituent dynamic variation using reversed-phase preparative chromatography. Through fraction ranges and intensity changing profiles in (1)H NMR/RRLC-MS PDS spectrum, (1)H NMR and the extracted ion chromatogram (XIC) signals deriving from the same individual constituent, were correlated due to the signal amplitude co-variation resulting from the concentration variation of constituents in a series of incompletely separated fractions. 1H NMR/RRLC-MS PDS was then successfully used to identify three types of natural products, including eight flavonoids, four organic acids and p-hydroxybenzaldehyde, five of which have not previously been reported in Anoectochilus roxburghii. In addition, two groups of co-eluted compounds were successfully identified. The results prove that this approach should be of benefit in the unequivocal structural determination of a variety of classes of compounds from extremely complex mixtures, such as herbs and biological samples, which will lead to improved efficiency in the identification of new potential lead compounds.