北山羊角化学成分解析

本文以北山羊角为主要研究对象,利用傅里叶变换红外光谱仪、气相色谱仪和全自动氨基酸分析仪检测分析其红外光谱、脂肪酸和氨基酸成分.结果表明:北山羊角红外光谱主要体现角蛋白组分的特征峰,其中1 540 cm-1、l 653 cm-1、3 061 cm-1归属于角蛋白分子中酰胺类成分;1 454 cm-1、2 875 cm-1、2 963 cm-1归属于角蛋白分子中脂类成分;北山羊角共检测出10种脂肪酸组分,主要成分包括棕榈酸、油酸、山俞酸,它们占脂肪酸总量的53.9％;17种氨基酸组分,总量为976.62 mg/g.     

红树植物木榄胚轴中的挥发性成分和脂肪酸成分分析

应用毛细管气相色谱-质谱联用技术对红树植物木榄胚轴中挥发性成分和脂肪酸成分进行了分析检测,检测到挥发性成分30个,鉴定了其中的27种成分,占所检测挥发性成分总量的97.01%,以烷烃类为主,占鉴定成分的67.43%,还有酸、酯及萜类化合物等;检测到脂肪酸组分23种,确定了其中的19种,脂肪酸检出量为97.81%,其中饱和脂肪酸占64.87%,不饱和脂肪酸占35.13%。     

野生露珠杜鹃林不同分解层的土壤化感潜力

探明野生杜鹃群落不同层次土壤浸提物的化学成分及其含量差异,为阐明杜鹃群落天然更新障碍与化感作用之间的关系提供基础数据,从化学生态学角度解释群落天然更新障碍的原因。通过种子发芽试验,比较凋落物层(L层)、腐殖质层(H层)和土壤表层(S层)浸提液对自身种子萌发的化感效应,采用内标法结合气相色谱-质谱(GC/MS)联用等技术鉴定土壤浸提液所含的有机化合物。(1)种子发芽试验显示,露珠杜鹃不同土壤层浸提液的化感效应不同。L层的抑制作用最为强烈,其浸提液显著抑制自身种子的萌发。H层和S层对自身具有一定的抑制作用,与对照相比不显著;(2)鉴定了不同层次土壤浸提液中所含的有机化合物,L层、H层和S层均检测出31种组分,其中相对含量大于5%的组分分别有6、8和8种。L层浸提液主要化感成分为丙三醇和棕榈酸,分别达到总量的19.56%和19.17%;H层主要化感成分为2-羟基丙酸和棕榈酸,分别达到总量的14.05%和12.48%;S层土壤浸提物的主要化感成分为棕榈酸和2-羟基乙酸,分别达到总量的14.91%和12.79%。野生露珠杜鹃不同土壤浸提物的化感物质含量以L层最高,L层作为群落土壤化感物质的主要来源;从化感物质组分来分,长链脂肪酸和有机酸类是H层和S层主要的化感物质种类,长链脂肪酸类和醇类是L层主要的化感物质种类。杜鹃群落林下土壤中存在的化感物质可能是其天然更新障碍的重要原因之一。     

麦红吸浆虫幼虫脂肪酸变化的分析测定(英文)

采用气相色谱法测定了不同时期麦红吸浆虫Sitodiplosismosellana (Gehin)幼虫脂肪酸的变化。结果表明 :幼虫脂肪酸组分有 1 0～ 1 6种 ,其中主要以棕榈酸 (C1 6:0 )、油酸 (C1 8:1 )和亚油酸 (C1 8:2 ) 3种组分为主 ,占全部脂肪酸总量的 95 %以上 ;其次是硬脂酸 (C1 8:0 )含量较高 ,约占 2 %～ 3 .5 % ;其它组分脂肪酸含量很少 ,均在 1 %以下。从 5月中下旬麦红吸浆虫幼虫离穗入土进入越夏至翌年 4月化蛹羽化前 ,脂肪酸组分表现了由少到多的变化趋势。越夏、越冬幼虫及越冬后未进入活动状态的圆茧其脂肪酸组分中不含花生酸 (C2 0 :0 ) ,而且饱和脂肪酸含量明显少于越冬后进入活动状态的幼虫和麦穗幼虫 ;而越冬后进入活动状态的幼虫和麦穗幼虫脂肪酸组分中含有一定量的花生酸 ,不饱和脂肪酸含量明显少于越夏、越冬幼虫及越冬后未进入活动状态的圆茧 ,故花生酸的有无及饱和脂肪酸与不饱和脂肪酸含量的比例变化可作为判断麦红吸浆虫幼虫活动状态 ,特别是滞育不同深度的生化指标之一     

超临界CO_2萃取韭菜籽油成分的GC-MS分析

以索氏提取法为对照,采用超临界二氧化碳(SC-CO_2)萃取韭菜籽油,气相色谱-质谱联用技术(GC-MS)对韭菜籽油成分进行分析,NIST 02质谱数据库对其进行分析和鉴定.结果表明,SC-CO_2萃取压力为22.25 MPa、温度为40.40℃条件下萃取86.7 min时,萃取得率为17.52%,共分离鉴定出17种物质,其中,饱和脂肪酸以棕榈酸(6.25%)为主,占脂肪酸总量的 9.05%;不饱和脂肪酸主要是亚油酸(69.71%)和油酸(19.53%),占脂肪酸总量的90.50%.采用索氏提取得率为16.50%,共鉴定出10种物质,饱和脂肪酸以棕榈酸(7.22%)为主,占总脂肪酸量的9.84%;不饱和脂肪酸主要是亚油酸(69.34%)和油酸(20.12%),不饱和脂肪酸占脂肪酸总量的90.16%.另外SC-CO_2萃取韭菜籽油还检出单不饱和脂肪酸7-棕榈烯酸、角鲨烯和β-谷甾醇.     

灵芝孢子油脂肪酸组分的分析

采用气相色谱与质谱(GC-MS)联用分析,从超临界CO2萃取孢子油中鉴定出18种脂肪酸成分,包括6种不饱和脂肪酸、7种饱和脂肪酸、2种环链脂肪酸,以及己酸、辛酸、壬酸等短链脂肪酸。GC定量分析结果表明:灵芝孢子油中检出9种已知脂肪酸,不饱和脂肪酸总量为73.6%;其中,主体成分油酸(C18∶1)、亚油酸(C18∶2)和棕榈酸(C16∶0)等含量分别为57.5%、13.4%、19.6%;此外,不饱和脂肪酸十六碳烯酸(C16∶1)、亚麻酸(C18∶3)等不饱和脂肪酸含量为2.2%、0.5%。     

辣椒籽中脂肪酸和微量元素的测定

分析和测定辣椒籽中微量元素和脂肪酸的含量。用石油醚作溶剂在索氏提取器中提取辣椒籽的脂肪酸,用气相色谱-质谱联用法(GC-MS)进行分析,按峰面积归一化法并通过数据库处理,求出脂肪酸成分的百分含量。经硝酸-高氯酸体系消解,应用火焰原子吸收光谱法测定辣椒籽中5种微量元素的含量。结果表明:辣椒籽中脂肪酸中主要成分为12-甲基-十三烷酸(0.93%)、棕榈酸(13.01%)、亚麻酸(10.42%)、亚油酸(43.80%)和油酸(18.66%),占检出总量的89.52%;对辣椒皮和辣椒籽中Zn、Cu、Ca、Fe、Mn 5种元素进行检测,得出5种微量元素在辣椒籽中的含量均高于辣椒皮中的含量,辣椒籽中含有丰富的微量元素。因此,辣椒籽是一种值得综合利用的副产品资源。     

椰子脂肪酸积累及与FatB基因表达关系研究

为筛选控制椰子果实中低碳链脂肪酸积累的关键FatB基因,本研究以海南本地高种绿椰四个发育时期的果实为试验材料,参考国家标准GB/T2906-1982谷类、油料作物种子粗脂肪测定方法,用索氏提取法提取果肉脂肪酸,应用气质联用检测技术测定各发育时期脂肪酸含量及组分,同时应用qRT-PCR对椰子脂肪酸合成相关基因FatB1、FatB2及FatB3进行相对定量分析,明确各发育时期椰子果实脂肪酸积累与FatB基因表达量变化之间的关系。结果表明:(1)椰子油含9种脂肪酸成分,在椰子果实发育的早期(第6和第7个月),棕榈酸、硬脂酸和油酸的含量较高,月桂酸和肉豆蔻酸相对含量较低,通过实时荧光定量PCR发现,此时FatB1基因的相对表达量较高。(2)而在椰子果实发育的后期(第8和第9个月),棕榈酸、硬脂酸和油酸的相对含量迅速降低,月桂酸和肉豆蔻酸相对含量迅速升高,FatB2和FatB3基因的相对表达量较高,FatB1的表达量略有降低。该研究初步掌握了椰果各发育时期FatB基因表达量与脂肪酸成分间的变化趋势,该结果为将来筛选控制椰子果实中低碳链脂肪酸积累的关键FatB基因奠定基础,同时为椰子脂肪酸成分的分子改良提供理论依据。     

内蒙古藜麦的营养成分分析及评价

以内蒙古种植的藜麦为试验原料,对其主要营养成分、氨基酸、脂肪酸、矿物质及维生素进行分析与评价。结果表明：藜麦中蛋白质含量为13-1%、粗脂肪为7-7%、淀粉为49-0%、灰分为2-2%、粗纤维为2-0%。藜麦含有17种氨基酸,其中有7种必需氨基酸,赖氨酸含量丰富。根据氨基酸评分（AAS）和化学评分（CS）,藜麦第一限制性氨基酸是蛋氨酸+胱氨酸。藜麦含有13种脂肪酸,不饱和脂肪酸含量丰富,占脂肪酸总量的85-25%,饱和脂肪酸占14-75%,其中棕榈酸含量最高,占脂肪酸总量的7-92%。矿物质和维生素含量丰富,其中钾、钙、镁、磷、铁、维生素B1和维生素B2含量均很高。因此,内蒙古种植的藜麦具有较高的营养价值。     

卷丝苣苔和勐醒芒毛苣苔脂肪酸成分的研究

用索氏提取法提取,甲酯化处理后采用气相色谱-质谱联用技术首次对卷丝苣苔(Corallodiscus kingianus)和勐醒芒毛苣苔(Aeschynanthus mengxingensis)中脂肪酸成分进行了分析.从卷丝苣苔的脂肪酸成分中鉴定出33个化合物,占检出物总质量分数的95.44%,主要成分为9,12-十八碳二烯酸、(Z,Z,Z)-9,12,15-十八碳三烯酸、十六烷酸.从勐醒芒毛苣苔的脂肪酸成分中鉴定出30个化合物,占检出物总质量分数的94.23%,主要成分为14-甲基-十五烷酸、(E)-9-十八碳烯酸、10,13-十八碳二烯酸.二者有15个组分是相同的.     

Fatty acid composition of lipids from mushrooms belonging to the family Boletaceae

The non-polar lipid content and fatty acid (FA) composition of 11 mushroom species of the family Boletaceae were determined. The non-polar lipid content ranged from 2.0 (Leccinum aurantiacum and Boletus erythropus) to 5.4 % (w/w) d.w. (Suillus grevillei) with an average value of 2.9 %. More than 25 different FAs were found in the mushroom lipids. Unsaturated FAs, mainly linoleic and oleic acids, accounted for about 83 % of the total FAs, while palmitic acid was the main saturated FA. Some FAs are identified for the first time in Boletaceae and in higher Basidiomycetes (cis-11,12-methyleneoctadecanoic acid, 7-cis,10-cis hexadecadienoic) or in fungi (cis-11,12-methyleneoctadecanoic acid). There were significant differences (P < 0.05) in the contents of specific FAs between mushroom species.     

Importance of high-performance liquid chromatographic analysis of serum N-acylneuraminic acids in evaluating surgical treatment in patients with early endometrial cancer

The objectives of this study were the quantification of the two major sialic acid (Sia) forms – N-acetylneuraminic (Neu5Ac) and N-glycolylneuraminic acids (Neu5Gc) – in serum before and after surgical treatment of early endometrial cancer and the relation of their levels with the progress of surgical therapy. The major Sia forms were liberated from sera glycoconjugates by mild acid hydrolysis, separated as per-O-benzoylated derivatives by a highly sensitive reversed-phase HPLC method and detected at 231 nm. Total Sia content in sera of healthy women was not related to age and body weight. Neu5Ac was identified as the major Sia in sera from both cancer patients, healthy individuals as well as in tissue specimens (≥94% of total Sia). In patients with endometrial cancer the total Sia level before surgical treatment (709.5±306.5 mg/l) was significantly higher (p≤0.0001) than that of the control group (213.5±88.7 mg/l). The elevation in Sia level was exclusively due to Neu5Ac. Following surgical therapy, serum Neu5Ac levels (699.4±305.6 mg/l) were significantly decreased (305.9±114.5 mg/l). In one case, where Neu5Ac level was increased 15 days and eight months after surgery (1.8 and 2.5 times as compared to control, respectively), a metastasis not detected during surgery was recorded. The obtained results suggest that Neu5Ac level in serum may be used as a tumor marker in evaluating the suitability of surgical treatment in early endometrial cancer.     

Modifications of cell surface sialic acids modulate cell adhesion mediated by sialoadhesin and CD22

An increasing number of mammalian cell adhesion molecules, including sialoadhesion, CD22 and the family of selectins, have been found to bind cell surface glycoconjugates containing sialic acids. Here we describe how the structural diversity of this sugar influences cell adhesion mediated by the related molecules sialoadhesin and CD22 in murine macrophages and B-cells respectively. We show that the 9-O-acetyl group of Neu5,9Ac₂ and theN-glycoloyl residue of Neu5Gc interfere with sialoadhesin binding. In contrast, CD22 binds more strongly to Neu5Gc compared to Neu5Ac. Of two synthetic sialic acids tested, only CD22 bound theN-formyl derivative, whereas aN-trifluoroacetyl residue was accepted by sialoadhesin. The potential significance for the regulation of sialic acid dependent cell adhesion phenomena is discussed.Dedicated to Professor Dr Gerhard Uhlenbruck on the occasion of his 65th birthday.     

Biodegradation of mixture containing monohydroxybenzoate isomers by <Emphasis Type="Italic">Acinetobacter calcoaceticus</Emphasis>

A bacterial strain capable of utilizing a mixture containing 2-hydroxybenzoic acid (2-HBA), 3-hydroxybenzoic acid (3-HBA) and 4-hydroxybenzoic (4-HBA) acid was isolated through enrichment from a soil sample. Based on 16SrDNA sequencing, the microorganism was identified as Acinetobacter calcoaceticus. The sequence of biodegradation of the three isomers when provided as a mixture (0.025%, w/v each) was elucidated. The dihydroxylated metabolites formed from the degradation of 2-HBA, 3-HBA and 4-HBA were identified as catechol, gentisate and protocatechuate, respectively, using the cell-free supernatant and cell-free crude extracts. Monooxygenases and dioxygenases that were induced in the cells of Acinetobacter calcoaceticus in response to growth on mixture containing 2-HBA, 3-HBA and 4-HBA could be detected in cell-free extracts. These data revealed the pathways operating in Acinetobacter calcoaceticus for the sequential metabolism of monohydroxybenzoate isomers when presented as a mixture.     

Development of high oleic and low linoleic acid transgenics in a zero erucic acid Brassica juncea L. (Indian mustard) line by antisense suppression of the fad2 gene

A zero erucic acid (C22:1) line of Brassica juncea (VH486), adapted to the agronomic conditions of Northern India, has been modified for its fatty acid composition in the seed oil with antisense constructs using the sequence of fad2 gene of B. rapa. The full-length B. rapa fad2 cDNA sequence was determined by 5 and 3 RACE of a partial sequence available in the EST database. Construct pASfad2.1 contained 315 to 1251 bp and construct pASfad2.2 contained 1 to 1251 bp fragment of the fad2 gene, both in antisense orientation, driven by a truncated napin promoter. Analysis of the levels of linoleic acid (C18:2) in the BC1 seeds of single-copy transgenics showed that the construct pASfad2.2 gave better suppression of the fad2 gene as compared to the construct pASfad2.1. The BC1 transgenic seeds containing the pASfad2.2 construct segregated into two distinct classes of C18:2>20% (putative null homozygotes) and C18:2<20% (putative heterozygotes) in a 1:1 ratio, while the T1 seeds segregated into three classes, C18:2>20%, C18:2 between 12% and 20%) and C18:2<12% (putative homozygotes) in a 1:2:1 ratio. Putative homozygous T1 seeds (C18:2<12% analyzed by the half-seed method) of four of the transgenic lines were grown to establish T2 homozygous lines. These had ca. 73% C18:1 and 8 to 9% each of C18:2 and C18:3 (-linolenic acid) fractions in comparison to ca. 53% C18:1, 24% C18:2 and 16% C18:3 in the parental line VH486.     

Synthesis of Neu5Ac- and Neu5Gc-α-(2→6′)-lactosamine 3-aminopropyl glycosides

In order to prepare 3-aminopropyl glycosides of Neu5Ac-α-(2→6′)-lactosamine trisaccharide 1, and its N-glycolyl containing analogue Neu5Gc-α-(2→6′)-lactosamine 2, a series of lactosamine acceptors with two, three, and four free OH groups in the galactose residue was studied in glycosylations with a conventional sialyl donor phenyl [methyl 5-acetamido-4,7,8,9-tetra-O-acetyl-3,5-dideoxy-2-thio- -glycero-α- and β- -galacto-2-nonulopyranosid]onates (3) and a new donor phenyl [methyl 4,7,8,9-tetra-O-acetyl-5-(N-tert-butoxycarbonylacetamido)-3,5-dideoxy-2-thio- -glycero-α- and β- -galacto-2-nonulopyranosid]onates (4), respectively. The lactosamine 4′,6′-diol acceptor was found to be the most efficient in glycosylation with both 3 and 4, while imide-type donor 4 gave slightly higher yields with all acceptors, and isolation of the reaction products was more convenient. In the trisaccharides, obtained by glycosylation with donor 4, the 5-(N-tert-butoxycarbonylacetamido) moiety in the neuraminic acid could be efficiently transformed into the desired N-glycolyl fragment, indicating that such protected oligosaccharide derivatives are valuable precursors of sialo-oligosaccharides containing N-modified analogues of Neu5Ac.     

Quantification of ABA and its metabolites in sweet cherries usingdeuterium-labeled internal standards

Abscisic acid (ABA), phaseic acid (PA), dihydrophaseic acid (DPA), and epi-dihydrophaseic acid (epi-DPA) were quantified in developing fruit and seeds of sweet cherry using each deuterium-labeled internal standard. ABA concentrations in the pulp were low at the early stage of fruit development, reached to the maximum before maturation, and subsequently declined during maturation. The significant increase of ABA after 29 days after full bloom (DAFB) coincides with the softening suggests that ABA may play a role to induce fruit maturation in sweet cherries. ABA metabolite levels were high at the immature stage and decreased with fruit maturation. This fact suggests that fruit may not need ABA in the early stage of fruit development. It was considered that DPA may be the major metabolite of ABA since the concentrations were higher than PA and epi-DPA at all stages of fruit development. ABA concentrations increased at the beginning of seed maturation and then decreased toward harvest. This decrease may be necessary to end seed dormancy. DPA in seeds changed similarly with ABA but its concentrations were always higher than those of ABA.     

分离自苏云金芽胞杆菌的首例细菌乌头酸异构酶TbrA的酶学性质研究

【目的】乌头酸异构酶(aconitate isomerase,AI)可介导具有多重生物学活性及应用潜力的小分子物质反式乌头酸(trans-aconiticacid,TAA)的合成。本文通过表征来自苏云金芽胞杆菌的生物体首条AI基因(tbrA)的产物——TbrA蛋白的催化性质,填补人们对于AI酶学特性的认识。【方法】我们利用大肠杆菌Rosetta菌株和Ni²⁺柱亲和纯化获得了His6-TbrA蛋白,并在体外通过HPLC检测了产物生成及对应酶活。【结果】TbrA蛋白的最适pH、温度与离子强度分别为8.0,37°C和25 mmol/L。TbrA在10°C时仍保留约60%的活性,展现了较好的耐低温特性。金属离子Mg²⁺、Ca²⁺与还原剂DTT可显著增强TbrA活性,而Fe²⁺、Cu²⁺、Zn²⁺、Mn²⁺则强烈抑制TbrA活性。TbrA将顺式乌头酸(cis-aconitic acid,CAA)异构为TAA的正反应Km、Vmax、kcat、kcat/Km值分别为6.25mmol/L、1.39μmol/(L·s)、4.081/s、0.65L/(mmol·s),将TAA异构为CAA的逆反应的上述数值分别为71.50mmol/L、4.17μmol/(L·s)、12.25 1/s、0.17 L/(mmol·s)。【结论】AI酶蛋白TbrA可以在温和的理化条件下表现出最高活性,且更倾向于合成TAA。本研究定量描述了TbrA催化特性,为其今后应用于TAA工业生物合成奠定基础。     

Metabolism of o-phthalic acid by different gram-negative and gram-positive soil bacteria

Different bacteria, isolated from soil by the enrichment method, were able to grow on phthalic acid as carbon source. Protocatechuate was identified as intermediate in phthalate metabolism. All phthalategrown bacteria oxidized phthalate and protocatechuate rapidly without having a lag-period. Benzoic acid, terephthalic acid, protocatechuic acid, salicylic acid, di- and mono-butyl phthalate were also metabolized by some of the organisms, benzoic acid being degraded via catechol and terephthalic acid via protocatechuate as intermediate. All organisms tested cleaved protocatechuate or catechol, respectively, by the ortho fission, when grown on phthalate, terephthalate, or benzoate as carbon source. A characterization and tentative identification of the organisms is given.