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1.
油蒿和籽蒿种子化学组成的研究   总被引:1,自引:0,他引:1  
油蒿和籽蒿种子化学组成的研究鲁作民(中国科学院兰州沙漠研究所,兰州730000)STUDIESONCHEMICALCOMPOSITIONSINSEEDSOFARTEMISIAORDOSICAANDA.SPHAEROCEPHALA¥LuZuo-min(...  相似文献   

2.
二种不同抗冷性水稻品种剑叶5’-核苷酸酶的细胞化学定位陈善娜邹晓菊梁斌(云南大学生物系,昆明650091)THECYTOCHEMICALLOCATIONOF5’-NUCLEOTIDASEINSWORDSHARPEDLEAVESOFTWODIFFER...  相似文献   

3.
半纤维素的化学结构和生理功能   总被引:6,自引:1,他引:5  
半纤维素的化学结构和生理功能李雄彪,张金忠(北京大学生物学系北京100871)(南开大学生物系天津300071)CHEMICALSTRUCTUREANDPHYSIOLOGICALFUNCTIONOFHEMICELLULOSE¥LiXiong-biao...  相似文献   

4.
山豆根木葡聚糖的研究   总被引:5,自引:0,他引:5  
研究了山豆根中一种木葡聚糖的结构.用1mol/LNaOH提取,DEAE-SephadexA-25离子交换柱层析,Fehling试剂分级得到山豆根木葡聚糖组分SSb-1FA,用完全酸水解,甲基化分析,部分酸水解,三氧化铬氧化和1H,13CNMR等方法对其结构进行研究.结果表明:SSb-1FA的分子量为2.6×104,比旋光度[α]20D=+10.9°(c0.22,H2O),由L-Fuc,D-Xyl,D-Gal和D-Glc组成,摩尔比为:2.929.97.559.8.SSb-1FA由1→4连接的β-D-Glc残基构成主链,分枝有α-D-Xyl(1→,β-D-Gal(1→2)α-D-Xyl(1→等类型,部分非还原末端由L-Fuc(1→构成.  相似文献   

5.
DDPH[1-(2.6-二甲基苯乙氧基)-2-(3.4二甲氧基苯乙胺基)丙烷盐酸盐]是南京药科大学合成的降压新化合物,也具有降低肺动脉高压和抑制肺动脉平滑肌细胞增殖作用。本实验用细胞培养、免疫细胞化学、图像分析、3H-TdR、细胞周期测定等方法,进一步探讨DDPH对缺氧性肺动脉平滑肌细胞(PASMCS)增殖的抑制机制。结果:缺氧促进肺动脉内皮细胞(PAECs)的PDGF·BB和bFGF两种生长因子的表达(积分光密度OD值)增高。缺氧内皮细胞条件培养液(HECCM)能促进PASMCS的PDGF·BB的OD值增高,bFGF的OD值无明显改变。加药组(HEC-CM+DDPH)的PDGF·BB和bFGF的OD值均显著降低,尤以PDGF·BB的OD值减少最多.提示:DDPH能抑制HECCM引起PASMCS的PDGF·BB和bFGF表达增多和细胞增殖。结果与大鼠实验观察相符。  相似文献   

6.
植物非蛋白氨基酸的化学结构   总被引:1,自引:0,他引:1  
植物非蛋白氨基酸的化学结构吴晓东杨兴洪张连忠(中国农业大学生物学院,北京100094)CHEMICALSTRUCTUREOFPLANTNONPROTEINAMINOACIDSWuXiao-dongYangXing-hongZhangLian-zho...  相似文献   

7.
高密度脂蛋白体外氧化修饰动力学研究   总被引:6,自引:1,他引:5  
在体外HDL在Cu^2+诱导下可发生氧化修饰,为了探讨体外务浆高密度脂蛋白(HDL)氧化修饰中几种产物的动力学改变,用Cu^2+与HDL保温2 ̄24h,分别观察了HDL氧化修饰过程中硫代巴比妥酸反应物质(TBARS),脂氢过氧化物(LOOH)、共轭二烯(CD)及相对电泳迁移率(REM)等的变化。结果显示,LOOH和CD两个指标动力学变化相似,呈现延滞期,扩增期和下降期三个时相,而TBARS和REM  相似文献   

8.
用HNMR法测定TDK肽在H2O(HODK),50%六氟丙醇(FPDK)和2mol/LGu.HCl(GUDK)溶液构象。在HODK和FPDK中,TDK肽的两段序列Asp0-Ile4,Ser9-Ili17分别具有较稳定的α-螺旋含量;而GUDK的SALS序列仍能检测到有序残存结构。并假设SALS序列是肽链形成二级结构的原始核心。  相似文献   

9.
植物抗寒剂CR_9应用于提高柑桔抗寒力的研究刘庚峰,张映南,唐赛文(湖南省园艺研究所。长沙410125)(常德市农科所,常德415000)STUDIESONTHECOLD-RESISTERCR-9FORINCREASINGTHECOLDRESISTA...  相似文献   

10.
应用脱氧核糖降解法研究了CuZn-SOD对几种·OH产生系统的作用机理.结果证明:SOD对Fe(3+)·O·H2O2系统中·OH的产生有明显的抑制作用,而失活SOD或BSA对它的抑制作用不大;在Fe(2+)·H2O2和CU(2+)·H2O2系统中,SOD、失活SOD和BAS均能抑制·OH的产生;在Fe(2+)·O系统中,SOD对·OH产生作用不大,而失活SOD或BSA对它有明显的抑制作用.由此推测SOD对·OH形成可能有三方面的影响:1.对O的清除作用,阻断Haber-Weiss反应;2.对金属离子的络合作用,降低·OH的产额;3.促进H2O2的积累,加快Fenton反应.  相似文献   

11.
The aerial parts of Chromolaena pulchella biosynthesize two groups of diterpenes belonging to opposite enantiomeric series, specifically, the furanoid ent-clerodanes (5R,8R,9S,10R)-(-)-hardwikiic acid (1), methyl (5R,8R,9S,10R)-(-)-hardwikiate (2), (5S,8R,9S,10R)-(-)-hautriwaic acid lactone (3), methyl (5R,8R,9S,10R)-(-)-nidoresedate (4) and methyl (8R,9R)-(-)-strictate (5), as well as the labdanes (5S,8R,9R,10S)-(+)-(13E)-labd-13-ene-8,15-diol (6) and (5S,8R,9R,10S)-(+)-isoabienol (7). The absolute configuration of the two groups of diterpenes was unambiguously assigned by comparison of the vibrational circular dichroism spectra of 3 for ent-clerodanes, and of 7 for labdanes with their theoretical spectra obtained by density functional theory calculations. The results support a biogenetic proposal to diterpenes found in the studied botanical species.  相似文献   

12.
Ichikawa A  Ono H  Harada N 《Chirality》2004,16(8):559-567
The stereoselective Grignard reaction of (1R,2S,5R)-(-)-2-isopropyl-5-methylcyclohexyl pyruvate (menthyl pyruvate) with 9-phenanthrylmagnesium bromide yielded diastereomeric hydroxy-esters, where intramolecular OH em leader O=C hydrogen bond was observed in IR and (1)H NMR spectra. The alkaline hydrolysis of the major product gave (+)-2-hydroxy-2-(9-phenanthryl)propionic acid (H9PP acid (3)), whose absolute configuration was assigned as S based on the chemical correlation with (1R,2S,5R)-2-isopropyl-5-methylcyclohexyl ester of (S)-2-methoxy-2-(9-phenanthryl)propionic acid (M9PP acid (2)); the absolute configuration of 2 had been previously established by X-ray crystallography. The enantioresolution of (+/-)-6-methyl-5-hepten-2-ol, sulcatol, an insect pheromone, was carried out using (S)-(+)-M9PP acid 2.  相似文献   

13.
The structure of a new hydroxy terpenoid acid, 6(S)-isopropyl-3ξ-methyl-3ξ-hydroxy-9-oxo-4E-decenoic acid (1a), isolated from a solvent-extract of Turkish tobacco, was elucidated by the spectroscopic properties and chemical evidence. This compound was suggested to be derived from thunberganoid diterpenoids and be a precursor of two dienoic acids, 6(S)-sopropyl-3-methyl-9-oxo-2E,4E-decadienoic acid (3a) and 6(S)-isopropyl-3-methyl-9-oxo-2Z,4E-decadienoic acid (4a) in Turkish tobacco.  相似文献   

14.
8-Hydroxyoctadeca-9Z,12Z-dienoic acid (8-HODE) and 10-hydroxyoctadeca-8E,12Z-octadecadienoic acid (10-HODE) are produced by fungi, e.g., 8R-HODE by Gaeumannomyces graminis (take-all of wheat) and Aspergillus nidulans, 10S-HODE by Lentinula edodes, and 10R-HODE by Epichloe typhina. Racemic [8-(2)H]8-HODE and [10-(2)H]10-HODE were prepared by oxidation of 8- and 10-HODE to keto fatty acids by Dess-Martin periodinane followed by reduction to hydroxy fatty acids with NaB(2)H(4). The hydroxy fatty acids were analyzed by chiral phase high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) with 8R-HODE and 10S-HODE as standards. 8R-HODE eluted after 8S-HODE on silica with cellulose tribenzoate (Chiralcel OB-H), and 10S-HODE eluted before 10R-HODE on silica with an aromatic chiral selector (Reprosil Chiral-NR). 5S,8R-Dihydroxyoctadeca-9Z,12Z-dienoic acid (5S,8R-DiHODE) is formed from 18:2n-6 by A. nidulans and 8R,11S-dihydroxyoctadeca-9Z,12Z-dienoic acid (8R,11S-DiHODE) by Agaricus bisporus. 8R-Hydroperoxylinoleic acid (8R-HPODE) can be transformed to 5S,8R-DiHODE and 8R,11-DiHODE by Aspergillus spp., and 8R,13-dihydroxy-9Z,11E-dienoic acid (8R,13-DiHODE) can also be detected. We prepared racemic [5,8-(2)H(2)]5,8- and [8,11-(2)H(2)]8,11-DiHODE by oxidation and reduction as above and 8R,13S- and 8R,13R-DiHODE by oxidation of 8R-HODE by S and R lipoxygenases. The diastereoisomers were separated and identified by normal phase HPLC-MS/MS analysis. We used the methods for steric analysis of fungal oxylipins. Aspergillus spp. produced 8R-HODE (>95% R), 10R-HODE (>70% R), and 5S,8R- and 8R,11S-DiHODE with high stereoselectivity (>95%), whereas 8R,13-DiHODE was likely formed by nonenzymatic hydrolysis of 8R,11S-DiHODE.  相似文献   

15.
The absolute configuration of the alpha-methylbutyryl residue in (4R,5S,7S,8S,9S,10R,11R,2'S)-7-angeloyloxy-9-hydroxy-8-(alpha-methylbutyryloxy)-longipin-2-en-L-one and (4R,5S,7S,8R,10R,11R,2'S)-7-angeloyloxy-8-(alpha-methylbutyryloxy)- longipin-2-en-L-one was determined by chemical correlation with (S)-(+)-benzyl alpha-methylbutyrate prepared from authentic (S)-(+)-alpha-methylbutyric acid. Both compounds were isolated from the hexane extracts of roots of Stevia pilosa Lag. together with four other longipinene derivatives. The developed correlation method is useful to ascertain the chirality of natural alpha-methylbutyryl esters found in nature and to reinforce the hypotheses on the biogenetic origin of these residues.  相似文献   

16.
蜜蜂蜂王信息素研究进展   总被引:8,自引:2,他引:6  
胡福良  玄红专 《昆虫知识》2004,41(3):208-211
综述了蜂王信息素的化学组成、特性、作用 ,以及与幼虫信息相互关系的研究进展 ,对蜂王信息素在养蜂和植物授粉中的应用做了介绍。西方蜜蜂的蜂王上颚腺信息素 (queen’smandibularglandpheromone,QMP)。QMP包含了 5种成分 :(E) -9-氧 -2 -癸烯酸 ( 9 ODA)、(R ,E) ( ) 和 (S,E) ( +) 9 羟基 -2 -癸烯酸 ( -9 HDA和 +9 HDA)、甲基p -羟基安息香酸盐 (HOB)、4-羟基 -3 -甲氧苯乙醇 (也称香草醇 ,HVA) ,9 ODA是其中最重要的成分 ;QMP的组分与蜜蜂的进化程度有关 ,进化程度越高则组分越复杂 ;QMP通过抑制保幼激素的产生来调节青年工蜂的个体发育。  相似文献   

17.
蓝柄丽齿菌的化学成分   总被引:3,自引:0,他引:3  
从担子菌亚门蓝柄丽齿菌(Calodon suaveolens)中首次分离得到8个化合物,通过波谱学技术并借助必要的化学方法最终确定结构,它们是:(22E,24R)-麦角甾-7,22-二烯-3β-醇(1),(22E,24R)-5α,8α-过氧麦角甾-6,22-二烯.3β-醇(2),(22E,24R)-麦角甾.5,7,22-三烯-3β-醇(3),(22E,24R)-3β-羟基麦角甾-5,22-二烯-7-酮(4),对羟基苯甲酸(5),尿嘧啶(6),polyozellin(7),(4E,BE)-2-N-(2’-羟基棕榈酰)-1-O-β-D-吡喃葡萄糖基-9-甲基-4,8-sphingadienine(8)。  相似文献   

18.
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.  相似文献   

19.
根霉3078的代谢产物的研究   总被引:2,自引:1,他引:1  
从根霉3078菌丝体的甲醇提取物中分离得到9个化合物,通过波谱分析,鉴定为5α,8α-表二氧-(20S,22E,24R)-麦角甾-6,22-二烯-3β-醇(1)、甘油醇-1-单油酸酯(2)、4-羟基苯乙酮(3)、4-羟基苯乙酸(4)、(20S,22E,24R)-麦角甾-7,22-二烯-3β,5α,6β三醇(5)、(S)-3-羟基-3-苯基丙酸(6)、胸腺嘧啶(7)、尿嘧啶(8)和腺苷(9)。  相似文献   

20.
Akita H  Nakamura H  Ono M 《Chirality》2003,15(4):352-359
The total synthesis of (+)-macrosphelide A (1) (18.5% overall yield in 11 steps), (+)-macrosphelide C (2) (25% overall yield in 9 steps), (+)-macrosphelide E (3) (23.9% overall yield in 11 steps), (+)-macrosphelide F (4) (20% overall yield in 9 steps), and (+)-macrosphelide G (5) (22% overall yield in 9 steps) was achieved from a chemoenzymatic reaction product (4R,5S)-4-benzyloxy-5-hydroxy-2(E)-hexenoate 10.  相似文献   

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