Metabolic engineering for the production of dicarboxylic acids and diamines

Microbial production of chemicals and materials from renewable carbon sources is becoming increasingly important to help establish sustainable chemical industry. In this paper, we review current status of metabolic engineering for the bio-based production of linear and saturated dicarboxylic acids and diamines, important platform chemicals used in various industrial applications, especially as monomers for polymer synthesis. Strategies for the bio-based production of various dicarboxylic acids having different carbon numbers including malonic acid (C3), succinic acid (C4), glutaric acid (C5), adipic acid (C6), pimelic acid (C7), suberic acid (C8), azelaic acid (C9), sebacic acid (C10), undecanedioic acid (C11), dodecanedioic acid (C12), brassylic acid (C13), tetradecanedioic acid (C14), and pentadecanedioic acid (C15) are reviewed. Also, strategies for the bio-based production of diamines of different carbon numbers including 1,3-diaminopropane (C3), putrescine (1,4-diaminobutane; C4), cadaverine (1,5-diaminopentane; C5), 1,6-diaminohexane (C6), 1,8-diaminoctane (C8), 1,10-diaminodecane (C10), 1,12-diaminododecane (C12), and 1,14-diaminotetradecane (C14) are revisited. Finally, future challenges are discussed towards more efficient production and commercialization of bio-based dicarboxylic acids and diamines.     

珍珠荚蒾的化学成分研究

从珍珠荚蒾(Viburnum foetidum var.ceanothoides)的枝叶中分离得到14个化合物,经鉴定分别为:白桦醇(1),熊果醇(2),β-谷甾醇(3),白桦脂酸(4),熊果酸(5),对羟基苯甲酸(6),4,4′-二羟基-a-古柯间二酸(7),反式对香豆酸(8),顺式对香豆酸(9),红花菜豆酸(10),原儿茶酸(11),胡萝卜苷(12),1-O-(6-O-α-L-rhamnopyranosyl-β-D-glucopyranosyl) -4-allylbenzene(13)和apigenin 7-O-α-L-rhamnopyranosyl(1″ ′→2″)-β-D-glucopyranoside (14).其中,化合物1、7、9、10和13为首次从荚蓬属中分离得到;所有化合物均首次从珍珠荚蓬中分离得到.     

Assessment of toxicity of volatile fatty acids to Photobacterium phosphoreum

The toxicity of four volatile fatty acids (VFAs) as anaerobic digestion (AD) intermediates was investigated at pH 7. Photobacterium phosphoreum T3 was used as an indicator organism. Binary, ternary and mixtures of AD intermediates were designated by letters A (acetic acid + propionic acid), B (acetic acid + butyric acid), C (acetic acid + ethanol), D (propionic acid + butyric acid), E (propionic acid + ethanol), F (butyric acid + ethanol), G (acetic acid + propionic acid + butyric acid), H (acetic acid + propionic acid + ethanol), I (acetic acid + butyric acid+ ethanol), J (propionic acid + butyric acid + ethanol) and K (acetic acid + propionic acid + butyric acid + ethanol) to assess the toxicity through equitoxic mixing ratio method. The IC₅₀ values of acetic acid, propionic acid, butyric acid and ethanol were 9.812, 7.76, 6.717 and 17.33 g/L respectively, displaying toxicity order of: butyric acid > propionic acid > acetic acid > ethanol being additive in nature. The toxic effects of four VFAs could be designated as synergistic and one additive in nature.     

发酵无花果香料的挥发性成分分析

利用微生物发酵无花果开发特色香料,并采用同时蒸馏萃取装置收集挥发性成分并用气相色谱一质谱仪对生物技术制备的无花果香料挥发性成分进行分离和鉴定,经毛细管色谱分离出47种组分,确认了其中的45种成分,并用面积归一化法测定了各种成分的百分含量,其主要成分为：9,12-十八碳二烯酸乙酯(27．34％)、十六酸乙酯(23．99％)、邻苯二甲酸二丁酯(6．18％)、邻苯二甲酸二异丁酯(5．52％)、9,12-十八碳二烯酸甲酯(4．72％)、十六酸甲酯(4．67％)、9,12,15-十八碳三烯酸乙酯(4．48％)、9-十八碳烯酸乙酯(3．80％)、糠醛(2．53％)、9,12,15-十八碳三烯酸甲酯(1．85％)、十八酸乙酯(1．42％)、9-十八碳烯酸甲酯(1．26％)等。     

Hydroperoxide-dependent epoxidation of unsaturated fatty acids in the broad bean (Vicia faba L.)

Incubation of linoleic acid with the 105,000g particle fraction of the homogenate of the broad bean (Vicia faba L.) led to the formation of the following products: 13(S)-hydroxy-9(Z),11(E)-octadecadienoic acid, 9,10-epoxy-12(Z)-octadecenoic acid (9(R),10(S)/9(S)/10(R), 80/20), 12,13-epoxy-9(Z)-octadecenoic acid (12(S),13(R)/12(R)/13(S), 64/36), and 9,10-epoxy-13(S)-hydroxy-11(E)-octadecenoic acid (9(S),10(R)/9(R),10(S), 91/9). Oleic acid incubated with the enzyme preparation in the presence of 13(S)-hydroperoxy-9(Z),11(E)-octadecadienoic acid or cumene hydroperoxide was converted into 9,10-epoxyoctadecanoic acid (9(R),10(S)/9(S),10(R), 79/21). Two enzyme activities were involved in the formation of the products, an omega 6-lipoxygenase and a hydroperoxide-dependent epoxygenase. The lipoxygenase, but not the epoxygenase, was inhibited by low concentrations of 5,8,11,14-eicosatetraynoic acid and nordihydroguaiaretic acid. In contrast, the epoxygenase, but not the lipoxygenase, was readily inactivated in the presence of 13(S)-hydroperoxy-9(Z),11(E)-octadecadienoic acid. Studies with 18O2-labeled 13(S)-hydroperoxy-9(Z),11(E)-octadecadienoic acid showed that the epoxide oxygens of 9,10-epoxyoctadecanoic acid and of 9,10-epoxy-13(S)-hydroxy-11(E)-octadecenoic acid were derived from hydroperoxide and not from molecular oxygen.     

喜光花叶的化学成分研究(Ⅲ)

从喜光花Actephila merrilliana叶中分离得到11个化合物,通过理化方法和波谱数据分别鉴定为5,5’-dimethoxy-alloagerasasin(1)、对羟基苯甲醛(2)、丁香酸(3)、正十八烷酸(4)、反式桂皮酸(5)、对甲氧基苯甲酸(6)、间苯二酚(7)、邻苯二甲酸(8)、邻羟基苯甲酸(9)、对羟基苯甲酸(10)以及戊二酸(11),以上所有化合物均首次从该属植物中分离得到。     

猫儿屎和三叶木通种子油中脂肪酸成分的GC-MS分析

采用索氏提取法提取木通科植物猫儿屎和三叶木通种子的脂溶性成分,甲酯化处理后用气相色谱-质谱联用技术(GC-MS)分离和鉴定其组成和含量。从猫儿屎种子油中鉴定出9种脂肪酸,占检出物总质量分数的94.67%(其中饱和脂肪酸占12.63%,不饱和脂肪酸占82.04%),主要成分为9-十六烯酸(47.22%)、9-油酸(27.13%)、棕榈酸(10.75%)、亚油酸(7.47%)和硬脂酸(1.61%)。从三叶木通种子油中鉴定出10种脂肪酸,占检出物总质量分数的99.75%(其中饱和脂肪酸占23.39%,不饱和脂肪酸占76.36%),主要成分为11-油酸(47.63%)、亚油酸(27.05%)、棕榈酸(20.14%)、16-甲基-十七烷酸(3.03%)和8-油酸(1.07%)。结果表明,猫儿屎和三叶木通种子油中脂肪酸含量丰富,在食用、医疗保健等方面具有较高的应用潜力和综合开发前景。     

珍珠菜的化学成分研究(英文)

从珍珠菜(Lysimachia clethroidesDuby)的70%丙酮提取物中分离得到11个化合物,经理化性质及波谱数据分析分别鉴定为23-羟基乌苏酸(1)、Isotachioside(2)、对羟基苯甲酸(3)、3-甲氧基-4-羟基苯甲酸(4)、原儿茶酸(5)、3,5-二羟基苯甲酸(6)、甲基-α-D-呋喃果糖苷(7)、尿苷(8)、β-谷甾醇(9)、胡萝卜苷(10)和齐墩果酸(11)。化合物1、2、4、7和8为首次从该属植物中分离得到,化合物3、5、6、9~11为首次从该种植物中分离得到。     

米邦塔仙人掌化学成分研究

从米邦塔仙人掌正丁醇部分分离到10个化合物。应用色谱和光谱分析方法分别鉴定为对羟基苯甲酸(1)、β-羟基-3-甲氧基-4-羟基苯乙酮(2)、2,3,4-三羟基戊酸(3)、4-甲氧基桂皮酸(4)、3-羟基-4-甲氧基肉桂酸(5)、5-羟基阿魏酸(6)、4-羟基肉桂酸(7)、原儿茶酸(8)、n-butyl eucomate(9)和eucomic acid(10)。化合物2～10为首次从该植物分离得到。     

Survival, fecundity and fertility of Bactrocera oleae, as affected by amino acid analogues

The effect of twenty five amino acid analogues at various concentrations upon the adult olive fruit fly Bactrocera oleae Gmelin (Diptera: Tephritidae), was tested. Insect survival was significantly shortened by the following amino acid analogues: (in parentheses are indicated the antagonized amino acids) D-cycloserine (alanine), L-glutamic acid--hydrazide (glutamine), DL-allyl-glycine (cysteine), L-canavanine (arginine), L-methionine-DL-sulfoximine (methionine) and 3,4-dehydro-DL-proline (proline). Fecundity was significantly reduced by the same analogues plus aminoethanesulfonic acid (glycine), taurine (alanine), L-norvaline (leucine), a-methyl-DL-serine (serine), DL-hydroxyglutamic acid (glutamic acid), (S)-2-(aminoethyl)-L-cysteine (lysine), a-methyl-DL-methionine (methionine) and a-methyl-DL-histidine (histidine). All the above amino acid analogues also depressed egg-hatching with the exception of taurine, DL-hydroxyglutamic acid, DL-allyl glycine, a-methyl-DL-methionine and a-methyl-DL-histidine. Finally, y-glutamyl-p-nitroanilide (glutamic acid), crotyl-glycine (methionine), DL-7-azatryptophan and 5-methyl-DL-tryptophan (tryptophan), DL-1,2,4 triazole-3-alanine (histidine) and DL-pipecolic acid (proline) did not affect any of the parameters tested.     

一种无孢灵芝菌丝体的活性成分

利用制备型高效液相、凝胶层析、制备型薄层色谱等方法对无孢灵芝龙芝2号的固体发酵菌丝体进行分离纯化,通过波谱分析,化合物分别鉴定为灵芝酸P（1）,灵芝酸T1（2）,灵芝酸Mk（3）,灵芝酸S（4）,灵芝酸T（5）,ganodermanondiol（6）,灵芝酸Me（7）,5α, 8α-epidioxyergosta-6, 22-dien-3β-ol（8）,灵芝酸R（9）,lanosta-7, 9(11), 24-trien-3α-hydroxy-26-oic acid（10）,ganodermenonol（11）。其中灵芝酸T1为首次发现的天然产物。体外细胞实验证实,11种化合物对肿瘤细胞L1210的增殖均有很强的抑制作用,其增殖抑制的IC₅₀值均在39.69μmol/L以下。     

绿僵菌SC0924酚酸类代谢产物及其抗荔枝霜疫霉活性

从绿僵菌SC0924固体发酵物中分离得到8个酚酸类化合物,通过波谱分析,分别鉴定为香草酸(1)、丁香酸(2)、邻氨基苯甲酸(3)、苯乙酸(4)、阿魏酸(5)、二氢阿魏酸(6)、2-羟基-3-苯丙酸(7)和2-羟基-3-对羟基苯丙酸丁酯(8).以滤纸片琼脂扩散法对以上化合物进行抗荔枝霜疫霉活性试验,结果表明除化合物2和6外,其余化合物均有抑菌活性.     

藏药翁布的酚性成分研究

从藏药翁布(Myricaria germanica)的60％丙酮提取物中进行了进一步研究,从中共分离得到了11个化合物.利用光谱和波谱分析法,分别鉴定为阿魏酸(1),松柏醇(2),阿魏酸葡糖苷(3),异落叶松脂醇(4),咖啡酸(5),对羟基桂皮酸(6),没食子酸(7),3,5-二羟基-4-甲氧基苯甲酸(8),杜鹃醇(9),3-甲氧基-4-羟基-苯甲酸(10)和3,4,5-三羟基肉桂酸(11).化合物1～11均为首次从该植物中分得,其中1～6和8～11为首次从水柏枝属植物中分离得到.     

Aldose-reductase- and protein-glycation-inhibitory principles from the whole plant of Duchesnea chrysantha

Ellagic acid (1), 3,3'-di-O-methylellagic acid (2), 3,3',4-tri-O-methylellagic acid (3), isovitexin (4), kaempferol 3-O-beta-D-glucuronide methyl ester (5), quercetin 3-O-alpha-L-arabinopyranosyl-(1-->6)-beta-D-galactopyranoside (6), ursolic acid, pomolic acid, tormentic acid, euscaphic acid, euscaphic acid 28-O-beta-D-glucopyranoside, and maslinic acid were isolated from the AcOEt- and BuOH-soluble MeOH extract of Duchesnea chrysantha (whole plant). The isolates were subjected to in vitro bioassays to evaluate their inhibitory activity on rat-lens aldose reductase (RLAR) and formation of advanced glycation end products (AGEs). The ellagic acids and flavonoids, compounds 1-6, exhibited moderate inhibitory effects on RLAR. However, compounds 1 and 4-6 showed excellent inhibitory activities towards the formation of AGEs. This is the first report that 4 and 6 exhibit inhibitory activity towards AR and AGEs formation.     

The effects of unsaturated fatty acids on lipid metabolism in HepG2 cells

We investigated the effects of stearic acid (saturated), oleic acid (monounsaturated), linoleic acid (n-6 polyunsaturated), and alpha-linolenic acid (n-3 polyunsaturated) on lipid metabolism in a hepatocyte-derived cell line, HepG2. HepG2 cells were cultured in medium supplemented with either stearic acid (0.1% w/v), oleic acid (0.1% v/v), linoleic acid (0.1% v/v), or alpha-linolenic acid (0.1% v/v). After 24 h, expression of lipid metabolism-associated genes was evaluated by real-time PCR. Alpha-linolenic acid showed a suppressive effect on the hepatic fatty acid de novo synthesis and fatty acid oxidation pathways, while linoleic acid also showed a tendency to suppress these pathways although the effect was weaker. Moreover, alpha-linolenic acid enhanced the expression of enzymes associated with reactive oxygen species (ROS) elimination. In contrast, oleic acid tended to promote fatty acid synthesis and oxidation. In conclusion, alpha-linolenic acid and linoleic acid may be expected to ameliorate hepatic steatosis by downregulating fatty acid de novo synthesis and fatty acid oxidation, and by upregulating ROS elimination enzymes. Oleic acid had no distinct effects for improving steatosis or oxidative stress.     

Quantitative Detection of 15 Serum Bile Acid Metabolic Products by LC/MS/MS in the Diagnosis of Primary Biliary Cholangitis

To determine 15 bile acid metabolic products in human serum by liquid chromatography-tandem mass spectrometry (LC/MS/MS) and value their diagnostic outcome in primary biliary cholangitis (PBC). Serum from 20 healthy controls and 26 patients with PBC were collected and went LC/MS/MS analysis of 15 bile acid metabolic products. The test results were analyzed by bile acid metabolomics, and the potential biomarkers were screened and their diagnostic performance was judged by statistical methods such as principal component and partial least squares discriminant analysis and area under curve (AUC). 8 differential metabolites can be screened out: Deoxycholic acid (DCA), Glycine deoxycholic acid (GDCA), Lithocholic acid (LCA), Glycine ursodeoxycholic acid (GUDCA), Taurolithocholic acid (TLCA), Tauroursodeoxycholic acid (TUDCA), Taurodeoxycholic acid (TDCA), Glycine chenodeoxycholic acid (GCDCA). The performance of the biomarkers was evaluated by the AUC, specificity and sensitivity. In conclusion, DCA, GDCA, LCA, GUDCA, TLCA, TUDCA, TDCA and GCDCA were identified as eight potential biomarkers to distinguish between healthy people and PBC patients by multivariate statistical analysis, which provided reliable experimental basis for clinical practice.     

咖啡酸苯乙酯衍生物抑制红细胞溶血和HL-60细胞增殖活性的构效关系研究

蜂胶中的主要成分咖啡酸苯乙酯作为重要的抗氧化剂和癌预防试剂分子,引起了人们相当的兴趣。为了研究其构效关系,作者通过酰基化反应合成了6个咖啡酸苯乙酯衍生物,即:咖啡酸苯乙酯(caffeic acid phenethyl ester,CAPE)、芥子酸苯乙酯(sinapic acid phenethyl ester,SAPE)、阿魏酸苯乙酯(ferulic acid phenethyl ester,FAPE)、4-羟基肉桂酸苯乙酯(4-hydroxycinnamicacid phenethyl ester,4-HCAPE)、3,5-二羟基肉桂酸苯乙酯(3,5-dihydroxycinnamic acidphenethyl ester,3,5-DHCAPE)和3-羟基肉桂酸苯乙酯(3-hydroxycinnamic acid phenethyl este,3-HCAPE)。以水溶性偶氮引发剂2,2'-偶氮二(2-脒基丙烷)二盐酸盐诱导的红细胞溶血为模型,研究了它们的抗氧化活性。根据实验测得的有效抑制溶血时间,其活性顺序为:CAPE≈4-HCAPE>SAPE>FAPE>3,5-DHCAPE>3-HCAPE。其活性显著...     

Determination of underivatised sterols and bile acid trimethyl silyl ether methyl esters by gas chromatography-mass spectrometry-single ion monitoring in faeces

A method for quantification of total faecal sterols and bile acids (BAs) in human stool by using gas chromatography-mass spectrometry-single ion monitoring (GC-MS-SIM) is described. Cholesterol, coprostanol, coprostanone, cholestanol, iso-lithocholic acid (iso-LCA), lithocholic acid (LCA), iso-deoxycholic acid (iso-DCA), deoxycholic acid (DCA), chenodeoxycholic acid (CDCA), cholic acid (CA), and 12-oxo-deoxycholic acid (12-oxo-DCA) in faeces of 86 healthy subjects were determined. The sample preparation for sterol analysis requires hydrolysis and liquid extraction from matrix, but no derivatisation. The GC-flame ionisation detection (FID) and total ion current (TIC) in GC-MS were not sufficient for sterol and BA determination, whereas selectivity and specificity of the GC-MS-SIM ensured the analysis of sterols and BAs in faeces.     

Inhibition of wound ethylene in Lycopersicum esculentum fruit discs by 1-amino cyclopropane-1-carboxylic acid oxidase inhibitors

Inhibition of wound-ethylene by eight structural analogues of 1-aminocyclopropane-1-carboxylic acid (ACC) studied seperately was investigated in unripe tomato fruit discs (Lycopersicum esculentum). The compounds tested were: trans-2-phenylcyclopropane-1-carboxylic acid (PCCA), cyclopropane-1,1-dicarboxylic acid (CDA), cyclopropylamine (CPA), cyclopropyl methyl ketone (CMK), chrysanthemyl alcohol (CHRA), 2-methyl cyclopropanecarboxylic acid (MCA), cyclopropanecarboxylic acid (CCA), 2-methyl-cyclopropane-methanol (2-MCM). The level of inhibition was a function of treatment concentration and time. Differential inhibition induced by the tested compounds was related to their structure.     

Triterpenes from the fungus Poria cocos and their inhibitory activity on nitric oxide production in mouse macrophages via blockade of activating protein-1 pathway

Two new triterpenes, 29-hydroxydehydrotumulosic acid (1) and 29-hydroxydehydropachymic acid (2), together with six known compounds, dehydropachymic acid (3), dehydrotumulosic acid (4), 29-hydroxypolyporenic acid C (5), polyporenic acid C (6), tumulosic acid (7), and pachymic acid (8), were isolated from the dried sclerotia of Poria cocos. In the in vitro bioassays, these isolated compounds reduced, in a dose-dependent manner, nitric oxide (NO) production from lipopolysaccharide (LPS)-induced RAW 264.7 cells, with compounds 5 and 6, the IC(50) values of which were 16.8±2.7 and 18.2±3.3 μM, respectively, exhibiting the greatest inhibition activity. Further Western blot analysis conducted on cells pre-treated with compounds 5 and 6, and luciferase assays on activator protein 1-dependent gene expression revealed that the inhibited NO release was attributed to the reduced expression of iNOs (=inducible NO synthase) enzymes, which might be regulated via the blockade of activator protein-1 signaling pathway.