107 resultados para phenolic antioxidants
Resumo:
本论文由三部分共四章组成。第一部分介绍丁香化学成分的研究成果,第二部分为升麻的化学成分研究,第三部分综述了环菠萝蜜烷三萜结构和活性关系的研究现状。 第一部分包括第一和第二章。第一章介绍了丁香(Eugenia caryophyllataThunb.)花蕾的化学成分和结构鉴定。采用正、反相硅胶柱层析等各种分离方法,从其乙醇提取物的乙酸乙酯萃取物和正丁醇萃取物中共分离出34 个化合物,它们的结构类型分属黄酮、三萜、鞣质等。其中1 个为新的酚苷类化合物,其结构经波谱分析鉴定为2-O-(6'-O-没食子酰基)-b-D-葡萄糖基苯甲酸甲酯(24),另外还有12 个化合物为首次从该植物中分离得到。第二章介绍了丁香挥发油的气相色谱- 质谱联用( GC-MS )和正丁醇萃取物的高效液相色谱- 质谱联用(HPLC-MS/MS)分析,尝试简单快速地检测丁香挥发油及极性部分的主要化学成分的方法。 第二部分为第三章。本章介绍了传统中药升麻(Cimicifuga foetida L.)根部乙醇提取物化学成分的分离纯化和结构鉴定。通过正、反相硅胶柱层析等分离纯化方法和MS、NMR 等波谱解析技术,共分离鉴定了20 个化合物,主要为环菠萝蜜烷三萜,其中5 个新三萜化合物分别鉴定为cimicidol-3-one(38)、3'-O-乙酰基升麻苷H-1(41)、2'-O-乙酰基升麻苷H-1(42)、(3b,12b,16b)-12-乙酰氧-16,23-环氧-9,19-环羊毛甾烷-22-烯-24-酮3-O-b-D-吡喃木糖苷(44)和升麻碱(54)。新化合物54 为结构新颖的环菠萝蜜烷三萜皂苷生物碱,这是首个发现的具有环菠萝蜜烷三萜骨架的生物碱,也是从升麻属植物中发现的第一个三萜生物碱,它的结构通过多种波谱解析,特别是2D-NMR 的充分应用,并结合化学降解和反应得到证实。此外,还介绍了分离得到的一种具有明显抑制破骨细胞活性的化合物(QS29)的体外活性研究。 第三部分即第四章,综述了升麻属植物中环菠萝蜜烷三萜与其生物活性的构效关系研究现状。 This dissertation consists of three parts. In the first and the second parts, thechemical constituents from the flower buds of Eugenia caryophyllata and therhizomes of Cimicifuga foetida were reported. The third part is a review on astructure-activity relationship of the cycloartane triterpenoid from Cimicifuga species. The first part is composed of two chapters. The chapter 1 is about the isolationand identification of the chemical constituents from the flower buds of E.caryophyllata. A new phenolic glucoside gallate, methyl 2-O-(6’-O-galloyl)-b-D-glucopyranosylbenzoate (24), together with thirty-three known compounds has beenisolated from the ethanol extract of the flower buds of E. caryophyllata throughrepeated column chromatography on normal and reversed phase silica gel. Thestructure of the new compound was elucidated on the basis of spectral and chemicalevidence. Those kno wn compounds were belonged to flavone, triterpenoid, tannin andsome simple compounds. Among them, 12 compounds were isolated from the titleplant for the first time. The second chapter describes the capillary GC-MS analysis ofthe volatile components and the HPLC-MS/MS analysis of the polar constituents fromthe flower buds of E. caryophyllata, in order to detect the main constituents in thecrude extract rapidly and precisely. The third chapter is about the chemical constituents of the rhizomes C. foetida, atraditional Chinese medicine which was used as anti-inflammatory, analgesic andantipyretic agents. Our investigation of the bioactivities constituents of the rhizomesof C. foetida led to the isolation of five new cycloartane triterpenoids, which werecharacterized as cimicidol-3-one (38), 3'-O-acetyl cimicifugoside H-1 (41),2'-O-acetyl cimicifugoside H-1 (42), (3b,12b,16b)-12-acetoxy-16,23-epoxy-9,19-cyclolanost-22-ene-24-one 3-O-b-D-xylopyranoside (44) and cimicifugadine (54),along with fifteen known compounds through repeated column chromatography onnormal and reversed phase silica gel. Among them, 54 is a novel cycloartanealkaloid and first discovered as a new type alkaoid from nature. The structures ofthese compounds were elucidated on the basis of spectral and chemical evidence, andcimicidol-3-one was confirmed by X-ray crystallography analysis. Moreover, onecompound exhibited strong anti-osteoporosis activity in vitro experiment. The fourth part is a review on a structure-activity relationship analysis of thecycloartane triterpenoid from Cimicifuga species.
Resumo:
过去十多年,世界手性药物市场需求迅速增长,手性制药工业的发展壮大,已经引起了各国政府、学术界,特别是企业界的高度重视。手性药物中含有大量的手性胺单元,因此研究高效构建手性胺结构单元的方法具有重要的意义和实用价值,而亚胺的不对称还原是合成手性胺最便捷的方法。 手性有机小分子路易斯碱催化三氯氢硅不对称还原亚胺是最近几年才发展起来的一类新的亚胺不对称还原方法。尽管在对映选择性和底物适用范围等方面已经获得了突破性的进展,但是,高性能的路易斯碱催化剂仅局限于N-甲酰氨基酸酰胺一种类型,而且其底物适用范围和催化活性仍不够理想。因此,发展新型催化剂很有必要。 手性硫氧化物作为手性诱导剂的应用已经有数十年的时间,广泛应用在不对称合成及天然产物的全合成中。理论上,硫氧结构单元也可以作为路易斯碱,对硅烷类试剂进行活化,而且硫氧键还有碳氧键难以比拟的先天优势,硫原子自带手性特征,在反应过程中,手性中心离反应位点更近,因此,从手性硫氧化合物出发,极有可能开发出新的高效手性路易斯碱催化剂。最近,Kobayashi和Khiar在亚胺的不对称烯丙基化反应中用手性亚砜活化烯丙基三氯硅烷,获得了较好的ee值,但反应中手性亚砜的用量都需要化学计量以上,因此还不能算做真正意义上的催化剂,进一步的文献调研也未见真正意义上的硫手性有机小分子催化剂。 本文首次成功将硫手性亚磺酰胺衍生物应用于催化三氯氢硅对亚胺的不对称还原,在经过对亚磺酰胺衍生物的多次结构优化,开发出了合成容易,催化活性和立体选择性都很优良,并且有着前所未有的底物普适性的新型手性路易斯碱催化剂。 我们首先尝试将商品化的20mol%叔丁基亚磺酰胺和对甲基亚磺酰胺直接用作催化剂催化三氯氢硅对亚胺的不对称还原,尽管仅获得中等的收率和很低的对映选择性,但证明我们的设计思路是可行的。在此基础上,我们以叔丁基亚磺酰胺为原料和基本骨架,设计合成了一系列的亚磺酰胺类催化剂,通过对催化剂的结构改造,发现当催化剂中存在较强酸性的酚羟基时,催化效果得到大幅提高。随着对催化剂的进一步结构优化,我们找到了一个结构简单,催化效果还不错的催化剂,经过反应条件优化以后,催化反应的收率最高能达到98%,对映选择性最高达93%,并且这个催化剂的底物适应范围比之前报道的催化剂都要广泛。针对酚羟基在催化剂中的重要作用,我们进行了仔细的机理研究后发现,在催化反应中,催化剂极有可能是通过双分子机理去活化三氯氢硅从而实现不对称催化的,而酚羟基的作用就是通过分子间氢键促进双分子催化剂与三氯氢硅的络合。受此启发,我们设计了一系列具有双齿结构的催化剂,通过对双齿催化剂的结构优化,最终筛选出了一个结构更加简单,但催化效果更好的双齿催化剂。10mol%该催化剂催化亚胺还原最高获得95%的收率和96%的ee值。这一结果也进一步验证了我们先前对催化剂机理的推测。 随后,我们还尝试将这些催化剂用于二级胺和芳香酮的直接还原胺化反应中,虽然能获得不错的收率,但对映选择性却很差,我们对反应条件进行了仔细的摸索,仍然没有获得突破。但这些实验为进一步研究二级胺和酮的不对称直接还原胺化反应奠定了良好的基础。 In the past decade, the rapid growth of the global chiral drug market and the significant development of the chiral pharmaceutical industry have attracted a great deal of attention from government, academia and enterprises. Chiral amine is an important structural motif of chiral drugs. Therefore, development of methods for the construction of this motif is of great importance. Catalytic enantioselective reduction of imines represents one of the most straightforward and efficient methods for the preparation of chiral amines. The chiral Lewis base organocatalysts promoted asymmetric reduction of imines by HSiCl3 has recently achieved significant advancements. Although big breakthroughs have been made in terms of substrate generality and enantioselectivity, the highly effective catalysts are limited to N-formyl amino acid amides, of which the efficiency and substrate scope remain unsatisfactory. Therefore, development of novel organocatalysts for this transformation is in great demand. Chiral sulfoxides have been well established as efficient and versatile stereocontrollers and have been extensively used in asymmetric synthesis and total synthesis of natural products. The S=O structural motif of sulfoxide could also behave as Lewis base activator for cholorsilane reagents, which, moreover, could be even better than caboxamide considering that the sulfur atom is chiral and thus the chirality center is closer to the reaction center. There exist great potentials that highly effective novel Lewis base organocatalysts could be developed starting from S-chiral sulfoxides. Recently, several S-chiral sulfoxides were reported by Kobayashi and Khiar to be used as Lewis base catalyst to activate allyltrichlorosilanes in asymmetric allylations and good enantioselectivities were obtained. However, these S-chiral sulfoxides were all used at a more than stoichiometric amount and were thus not authentically catalytic. A careful literature survey further revealed that there has been so far no S-chiral organocatalyst available. In this study, we, for the first time, successfully used S-chiral sulfinamides as Lewis base organocatalysts for the asymmetric reduction of ketimines by HSiCl3. After several rounds of structural optimization, we developed the first example of highly effective S-chiral organocatalysts, which promoted the asymmetric reduction of ketimines with trichlorosilane in high yield and excellent enantioselectivity with unprecedented substrate spectrum. In our initial practice, we examined 20mol% of the commercially available (R)-tert-butanesulfinamide and (S)-toluenesulfinamide as the catalyst in the hydrosilylation of ketimine. Although the product was only furnished in moderate yield and low ee, these results demonstrated that our strategy of catalyst design is on the right way. Next, starting from chiral tert-butanesulfinamide, we prepared a series of tert-butanesulfinamide derivatives via simple reductive amination and examined their catalytic efficiencies in the reduction of ketimine. We found that the catalyst bearing a phenolic hydroxyl group exhibited good reactivity and enantioselectivity. On the basis of which, we obtained a structurally simple and highly effective novel organocatalyst, affording the product in 98% yield and 93% ee under optimal reaction conditions. After careful exploration on the role of phenolic hydroxyl group in the catalyst, we speculated that two molecules of the catalyst be involved in the course of reaction, of which the assembly around the silicon center is facilitated by the intermolecular hydrogen bonding through the phenolic hydroxyl groups. Thus, we incorporated two units of sulfonamide into one molecular and prepared a new type of bissulfinamides organocatalysts and examined their catalytic efficiencies in the reduction of ketimine. After optimizing the structure of these catalysts, we finally obtained a novel organocatalyst which has even simpler molecular structure but showed better efficacies, 10mol% of which afforded up to 97% yield and 96% ee under optimal reaction conditions. These results further proved our speculation about the catalytic mechanism. We also examined the newly developed S-chiral organocatalysts in direct asymmetric reductive amination of secondary amines with aromatic ketone. The product was furnished in good yield but in low ee. No better results could be obtained despite our intense opimization efforts. Nevertheless, these experiments laid excellent foundations for eventual success.
Resumo:
花椒(Zanthoxylum bungeanum)是川西干旱河谷地区重要的经济作物,化感作用是花椒连作障碍的重要原因之一。花椒凋落物分解是影响花椒林地土壤肥力及花椒产量的重要因素,因此系统研究花椒化感作用是否对花椒凋落物的分解产生影响可以为解决花椒连作障碍导致的产量下降等问题提供科学的理论依据。本文通过室内模拟实验研究了花椒凋落物的四个分解动态以及分解后凋落物浸提液对花椒林地土壤性质的影响;通过野外盆栽实验研究了花椒凋落物浸提液对花椒幼苗的生长、花椒凋落物的质量及土壤性质的影响。最终从生理生化角度揭示了花椒的化感作用对凋落物分解的影响机理,为深入解决花椒连作障碍问题、对花椒凋落物采取有效的人工措施提供了科学的理论依据。主要的研究结果如下: 1. 室内分解实验证明,花椒凋落物在分解的60 d 内分解速率呈现由大到小的变化趋势,并且凋落物分解呈现明显的毒性动态。凋落物在分解的10 d、30 d 时,分解速率较大,30 d 以后分解速率显著降低。凋落物分解的10 d 左右酚酸释放量最大,此时凋落物的毒性最大,凋落物分解到10 d 以后,酚酸释放量逐渐减少,凋落物的毒性也逐渐减小。 2. 四个分解动态的花椒凋落物浸提液对土壤化学性质产生了显著的影响。花椒凋落物在分解的60 d 内,其浸提液使土壤pH值均显著的增加。分解0 d 的凋落物浸提液显著的降低了土壤铵态氮的含量,抑制了纤维素分解菌的生长;分解60 d 的凋落物浸提液显著的降低了土壤酚酸含量,增加了土壤有效磷的含量;分解30 d 和60 d 的凋落物浸提液均显著的促进了好气性纤维素分解菌的生长。这说明花椒凋落物在分解过程中呈现出明显的毒性动态:凋落物分解的初期毒性作用较大,随着分解的继续进行特别是在分解的30 d 以后,其毒性作用慢慢降低。 3. 花椒凋落物浸提液对花椒幼苗表现出明显的化感作用。不同浓度的浸提液对花椒幼苗地上及地下生物量、叶面积均产生了显著的抑制作用,并且随着浸提液浓度的升高抑制作用加强。凋落物浸提液对叶片厚度的影响较小,只有Y1对叶片厚度的生长抑制作用显著。 4. 花椒的化感作用改变了凋落物的质量,并对凋落物分解产生了显著的影响。对花椒幼苗用不同浓度的凋落物浸提液进行处理,Y1使凋落物有机碳含量、木质素含量、C/N、木质素/氮显著降低,纤维素含量显著升高;Y3使凋落物有机碳含量、木质素含量、C/N、木质素/氮显著升高。花椒凋落物质量的改变显著的影响了凋落物的分解,凋落物的分解速率大小依次为:Y1(10.15 a-1)> Y2(8.71 a-1)> CK(6.41 a-1)> Y3(5.08 a-1)。 5. 花椒的化感作用改变了土壤性质,并对凋落物分解产生了显著的影响。对花椒幼苗用不同浓度的凋落物浸提液处理的同时,也改变了土壤性质。不同浓度的凋落物浸提液显著的升高了土壤pH值、有机碳含量。各种浓度的凋落物浸提液对土壤多酚氧化酶的活性均起到了显著的促进作用。凋落物浸提液Y1对土壤纤维素分解酶的活性、细菌和真菌的生长也具有显著的促进作用。土壤性质的改变显著的影响了凋落物的分解,凋落物的分解速率大小依次为:Y1(10.30 a-1)>Y2(9.60 a-1)>CK(6.41 a-1)>Y3(6.29 a-1)。 6. 不论是凋落物质量发生改变还是土壤性质发生改变,在凋落物分解的整个过程中,C元素始终处于单调净释放的状态,并且C释放量与分解速率成显著的正相关,即凋落物分解越快,凋落物C释放量越大。凋落物分解过程中,均出现了酚酸大量释放的情况,并与凋落物分解速率成显著正相关。凋落物分解后的木质素含量、木质素/氮均增加,并且随着浸提液浓度的升高,凋落物木质素含量、木质素/氮升高。 Zanthoxylum bungeanum is an important economic crop in dry valley of the Minjiang river (Sichuan, Southwest China), but allelopathy is one of the important reasons for its continuous cropping. Zanthoxylum bungeanum litter decomposition affects Zanthoxylum bungeanum soil fertility and its output. So systemically investigate if allelopathy affects litter decomposition could provide the scientific methods to solve the problem of output fall caused by the continuous cropping. In this paper, the releasing dynamics of phenolic acid during Zanthoxylum bungeanum litter decomposition (0, 10, 30 and 60 days) and the effects of its aqueous extract on soil chemical properties were investigated via the laboratory study. Effects of Zanthoxylum bungeanum litter aqueous extract on the growth of young Zanthoxylum bungeanum seedlings, litter qualities and the soil qualities were investigated via the field study. Finally, we open out the action manner of Zanthoxylum bungeanum allelopathic effect on the litter decomposition, and provide the theoretical basis to solve the Zanthoxylum bungeanum continuous cropping. The main results showed that: 1. The laboratory litter decomposition experiment showed a trend of decomposition rate from large to small and an occurrence of phytotoxicity with clear dynamic patterns during Zanthoxylum bungeanum litter decomposition. The litter decomposition rate was larger at the tenth and 30th day during 60-day litter decomposition and gradually decreased after 30 days of litter decompostion. The releasing quantity of the litter phenolic acid was the highest at the tenth day, and here, the litter toxicity was the biggest. The releasing quantity of the litter phenolic acid gradually decreased after 10 days of litter decomposition, so the phytotoxicity of litter was gradually decreased with the litter decomposition. 2. The Zanthoxylum bungeanum litter aqueous extract after four decomposition stages had significantly effect on the soil chemical qualities. The pH value in soil was significantly increased in litter aqueous extract of four decomposition stages. The NH+4-N concentration was significantly decreased in soil amended with litter aqueous extract of 10-day decomposition which inhibited the growth of Aerobic cellulose-decomposer. The growth of soil Aerobic cellulose-decomposer was promoted by the litter aqueous extract of 30-day decomposition. Available phosphorus concentration was significantly increased and phenolic acid content was significantly decreased in soil amended with litter aqueous extract of 60-day decomposition which promoted the growth of Aerobic cellulose-decomposer. The study results showed an occurrence of phytotoxicity with clear dynamic patterns during Zanthoxylum bungeanum litter decomposition. The phytotoxicity of litter was the largest at the initial stage, but the phytotoxicity gradually decreased with the litter decomposition, especially after 30 days of decomposition. 3. The field study indicated that the Zanthoxylum bungeanum litter aqueous extract had significant allelopathic effects on the growth of young seedlings.Different concentration aqueous extract had signinficant inhibiting effects on biomass and leaf area of young seedlings. The inhibiting effect on the biomass strengthened with the litter aqueous extract concentration augment. Litter aqueous extracts had less effect on the leaf thickness, and only Y1 had significant inhibiting effect on the leaf thickness. 4. The Zanthoxylum bungeanum allelopathy had significant effect on the litter qualities and the litter decomposition. Treating the young Zanthoxylum bungeanum seedlings with different concentration of litter aqueous extracts, the leaf litter organic C, lignin, C/N and lignin/N all decreased and the cellulose content increased under Y1 treatment. The leaf litter organic C, lignin, C/N and lignin/N all increased under Y3 treatment. So the litter decomposition was significant affectded by the litter qualities, and the litter decomposition rate was Y1(10.15 a-1)> Y2(8.71 a-1) > CK(6.41 a-1) > Y3(5.08 a-1). 5. The Zanthoxylum bungeanum allelopathy had significant effect on the soil qualities and the litter decomposition. Treating the young Zanthoxylum bungeanum seedlings with different concentration of litter aqueous extracts, also changed the soil qualities. Different concentration of litter aqueous extracts had significant effects on the soil pH and organic C content. Every concentration of litter aqueous extracts accelerated the soil Polyphenol Oxidase activity and Y1 accelerated the soil Cellulase activity, the number of soil bacteria and fungi. So the litter decomposition was significant affected by the soil qualities, and the litter decomposition rate was Y1(10.30 a-1) > Y2 (9.60 a-1) >CK(6.41 a-1)>Y3(6.29 a-1)。 6. Whether the litter or soil qualities changed, the litter C element at the state of release at all times during the litter decomposition, and the release quantity increased with the decomposition rate augment. Litter released plentiful total penolics content during decomposition, and the release quantity had the positive correlation with the litter decomposition rate. The litter lignin content and the lignin/N all increased with the litter aqueous extracts concentration augment after litter decomposition.
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土壤线虫是土壤动物的主要功能类群之一,在土壤养分分解和循环中起到重要的作用。本研究通过施用两种形态氮肥,硝态氮(NO-3–N)和铵态氮(NH+4–N),对黄瓜整个生长期内根际土壤线虫的群落组成、结构及其多样性等的影响进行了比较研究。为增进土壤健康,提高土壤质量以及合理施用氮肥提供科学的理论依据。研究结果如下: 1. 氮肥处理后,不同浓度NO-3–N处理提高了根际土壤线虫数量,而NH+4–N处理(202.5 kg N/ hm2)抑制了线虫数量的增加。线虫群落结构相对较稳定,营养类群变化不大。且少量优势科/属会对土壤线虫群落特征起着至关重要的作用。 2. 在整个生长季节内,非寄生线虫的群体动态变化与寄生线虫的群体的动态变化具有相反的变化趋势。其中,NO-3–N处理和NH+4–N处理后植物寄生线虫出现频率的变化趋势相近,都是由高到低;非植物寄生线虫出现频率的变化趋势则都是由低到高。这说明非植物寄生线虫数量增长和空间占位对植物寄生线虫群体有一定的抑制作用。另外,也反映了适量氮肥在一定程度上能够减轻植物寄生线虫对黄瓜的危害。 3. 由多样性指数变化可知,NO-3–N和NH+4–N在低肥(67.5 kg N/hm2)和高肥(202.5 kg N/hm2)处理较中肥(135.0 kg N/hm2)处理,更不利于提高土壤线虫多样性地提高和线虫群落的稳定性。中肥不同形态氮肥处理与对照相比,H´指数在初花期和结果期显著增加了土壤线虫的H´指数,说明施入两种形态的氮肥能够提高线虫生物多样性程度。NH+4–N处理在初花期和结果期显著降低了土壤线虫种类的丰富性。土壤线虫生物多样性变化中,H´和SR指数在一定程度上能够反映施用无机氮肥对土壤线虫的多样性的影响,而J指数和λ指数效果不明显。NO-3–N和NH+4–N处理相比较,NO-3–N处理对黄瓜土壤线虫的多样性指数影响更大,促进了土壤线虫群体的多样化和种类的丰富度,更有利于提高土壤线虫的多样性,增加其稳定性。这些结果表明适量无机氮肥特别是NO-3–N的施用对黄瓜土壤线虫的生物多样性有一定的维护和提高作用。 4. 线虫数量与土壤质量指标的相关分析表明:线虫数量与有关土壤理化生指标,如土壤NO-3–N、NH+4–N、有机质含量等的正相关程度高,与总酚含量等显著负相关;与根际土壤微生物,细菌、真菌、放线菌数量等呈显著正相关。另外,线虫数量与土壤含水量未表现出显著相关关系。 Nematodes play a major role in decomposition and nutrient cycling in soil. Nematode community analyses are useful in assessing soil ecosystem status and function. The effects of two forms of mineral nitrogenous fertilizers (NO-3–N and NH+4–N) on nematode community composition, structure and diversity in rhizosphere of cucumber were investigated during different growing seasons of cucumber. Systematically research of effects of nitrogenous fertilizers could help to obtain better undstanding of a healthy soil and using nitrogenous fertilizers in reason. The main results are as follows: 1. The total numbers of nematode were more abundant in NH+4–N treatments than other teatments. However, NH+4–N teatment(202.5 kg N/hm2)dramatically inhibited it. All the tropic groups in the soil nematode communities were stable, and the dominant family or genus had an important function in the nematode community structure. 2. There was similar trend of the frequency of plant parasitic nematodes between NO-3–N and NH+4–N treatment, the similar trend of the frequency of non-plant parasitic nematodes was also found. But the frequency of plant parasitic nematodes exhibited a contrary trend to that of plant parasitic nematodes after different nitrogenous fertilizer treatments. The results showed that the increasing trend of the frequency and the niche of non-plant parasitic nematodes inhibited the plant parasitic nematodes, and indicated that right chemical fertilizers dosage could abate plant parasitic nematodes harm to cucumber. 3. The changes of the biodiversity index showed that the nitrogen treatment(135.0 kg N/hm2)promoted the stabilization of soil nematode diversity than other nitrogen treatments(67.5 kg N/hm2 and 202.5 kg N/hm2). In the treatment(135.0 kg N/hm2),The changes in nematode diversity between the control plots and treated plots were compared by the biodiversity index (H´, J, SR, λ). Among these tested index, H´ and SR were effective in reflecting the effects of different nitrogenous fertilizers on the diversity of soil nematodes. In comparison with the NH+4–N treatment, the NO-3–N treatment promoted the stabilization of soil nematode diversity. 4. Correlation coefficients between nematode abundance and soil quality indices indicated that the total numbers of nematode were affected positively by NO-3–N, NH+4–N and the organic matter, and negatively by total phenolic acids; the total num- bers of nematode had positive correlation with bacteria, fungi and actinomycetes nu- mbers. Soil water contents had only a weak negative influence on it.
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花椒(Zanthoxylum piperitum)是川西干旱河谷地区的重要经济作物,化感作用是花椒连作障碍的原因之一。系统研究花椒化感作用有助于深入理解并最终解决花椒连作障碍。本文通过研究花椒叶、林下土壤浸提液及单一纯化感物质对花椒幼苗生长、苜蓿种子萌发及幼苗生长的影响作用,从生理生化角度揭示浸提液及纯化感物质的作用方式。通过室外和室内模拟实验,对浸提液及纯化感物质的化感效应进行比较,为花椒连作障碍的解决和化感作用机制的深入理解提供依据。主要结果如下: 1.花椒叶及林下土壤浸提液对地下生物量影响作用强与对地上生物量的化感效应,两种浸提液的化感效应强度不同,叶浸提液作用表现更显著。其中在Y6、Y8 、T6和T8处理时,花椒幼苗地下生物量分别降低了31.2%、32.1%、31.6%和31.7%。 2.两种浸提液均能显著影响花椒幼苗体内的保护性酶活性,总体说来,在高浓度下抑制各种抗氧化物酶活性,幼苗体内丙二醛含量增加,幼苗受害严重;在较低浓度下,各种保护性酶活性有所增加,丙二醛含量减少,幼苗伤害减轻。同时,不同月份里,各种酶的活性高低显著不同,9月份的活性显著低于7月份的酶活性。对于养分含量的影响,Y8、T8的影响强度最大,分别使碳元素含量降低了27.8%和30.8%,使钾元素含量降低了34.7%和25.6%。 3.花椒叶及林下土壤浸提液对苜蓿种子萌发及幼苗生长有化感作用,表现在最终萌发率、不同物质代谢及保护性酶活性的差异上。两种浸提液对苜蓿种子萌发过程中蛋白质的含量均无显著性影响,对淀粉和可溶性糖的影响作用类似,高浓度处理无明显化感效应,较低浓度处理显著降低二者在萌发苜蓿种子中的含量。Y2、Y4与T4处理分别使可溶性糖含量减少了32.3%、29.1%和18.8%,Y2与T2处理分别使淀粉含量降低了29.3%和26.8%。 4.苜蓿种子在4种单一化感物质最高浓度即10-3 mol•L-1处理下,萌发率显著降低,半数萌发时间推迟,随着处理浓度降低,抑制作用逐渐减弱,当降低到10-6 mol•L-1时,又能够表现出对苜蓿种子萌发的促进作用。 5.纯化感物质在10-6 mol•L-1时使苜蓿幼苗叶片的保护性酶活性显著升高,丙二醛含量显著降低;在10-3 mol•L-1时使苜蓿叶片中保护性酶活性显著降低,丙二醛含量增加,膜脂过氧化程度加重。 Zanthoxylum piperitum is one of the most important cash crops and has been extensively cultivated in Eastern Tibetan Plateau, especially in the fragile dry valley areas. Allelopathic effects could be a reason for Z. piperitum’s continuous cropping impediment. Systemmatically research of the effect of Z. piperitum allelopathy could help to comprehend the continuous cropping impediment. The allelopathic effects on seedlings growth and seed germination of aqueous extracts of Zanthoxylum piperitum and phenolic allelochemicals were studied, and the action mechanism of the two substances was also discussed from physiology. Indoor and outdoor experiments were set to compare the difference between aqueous extracts and pure allelochemicals. The main results showed that: 1. The aqueous extracts of leaf and soil had significant allelopathic effects on aboveground and underground biomass, but the effect on underground biomass was stronger than the effect on underground evidently. Treated with Y6、Y8 、T6 and T8, the underground biomass was reduced 31.2%、32.1%、31.6% and 31.7% respectively. 2. The activity of activities of superoxide dismutase, catalase, peroxidase and ascorbate peroxidase were significantly reduced, while the content of MDA was increased and the seedlings were suffered stronger, when treated by the high concentration; but at the low concentration, these were reversed. And then, at the different month, the activities of antioxidant enzyme were significantly distinct. As for the contents of nutrient element, Y8、T8 had the more intensive effects than other treatments. 3. The results showed that the two types of aqueous extracts had significant allelopathic effects on seed germination, substances metabolize and the activity of antioxidant enzyme. But the aqueous extracts had no effects on the content of protein, while had the similar effects on the content of starch and soluble sugar. At Y2、Y4 and T4, the content of soluble sugar decreased 32.3%、29.1% and 18.8% respectively. 4. Treated with 10-3 mol•L-1 of the four allelochemicals, the seed germination of alfalfa was significantly inhibited. Ferulic acid, coumarin and vanillic acid at 10-3 mol•L-1 significantly reduced the activities of antioxidant enzyme, while the content of MDA in alfalfa seedling was significantly increased. The restrain effects became weakened with the treat concentration falled. However, ferulic acid, coumarin and vanillic acid could increase the activities of antioxidant enzyme at 10-6mol•L-1.
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雌雄异株植物对环境的不同响应一直是一个有趣而新颖的研究领域,由于雌雄个体不同的繁殖成本及不同的生存策略,使得雌雄植株在生长、存活、生殖格局、空间分布、资源配置等方面已经表现出明显的不同,在生理和分子水平上也表现出明显的性别间差异。干旱是制约农林业发展的环境因子之一,叶锈病是对杨树危害最严重的病害之一,由于长期进化的结果,不同性别的植物必然对生物和非生物胁迫有着不同的响应。本文以雌雄异株的青杨为模式植物,研究雌雄间在生理、生化、亚细胞结构和蛋白质水平上对生物和非生物胁迫的差异响应。主要研究结果如下: (1) 青杨雌雄植株对锈病胁迫的生理生化差异响应 在正常的对照组中,雄株叶片比雌株叶片有着较高的活性氧自由基产生速率、较高的SOD、POD、PPO 和较低的CAT 活性;在锈病感染的早期阶段, SOD、POD、CAT 活性、活性氧自由基产生速率、H2O2 含量、膜脂过氧化程度和细胞膜的电渗率在雌雄株中都增加,而PPO 仅在雄株中增加明显,APX 仅在雌株中增加明显,并且雌株比雄株有着更严重的锈病感染程度、细胞膜的伤害程度和光合系统II 的破坏程度,雌株有更多的净光合速率、气孔导度和叶绿素a 含量的降低,在同工酶变化上,雌雄间对锈病也显示出不同的表达模式。结果显示,雄株比雌株对锈病有着更好的抗性和更有效的ROS 清除系统。 (2) 青杨雌雄植株对干旱胁迫的生理生化及亚细胞结构的差异响应 与较好水分条件相比,干旱下雄株比雌株有着更高的A-Ci 响应参数,如Rubisco 最大羧化速率、光呼吸速率、暗呼吸速率和最大电子传递速率等。干旱显著地增加了膜脂过氧化程度和游离脯氨酸含量,并且雄株比雌株表现出较低的膜脂过氧化程度,较高的总蛋白和游离脯氨酸含量。无论是中度干旱还是极度干旱,除了CAT 外,雄株比雌株表现为较强的抗氧化酶活性,在同工酶谱带上,雌雄间表现出不同的变化模式,并且有些条带是干旱影响应的,而有些条带是性别特异性的,这些性别特异性条带能够作为鉴定性别快速而准确的标记。干旱显著地影响了线粒体、叶绿体和细胞壁的结构,尤其在中度干旱胁迫下,雄株线粒体和叶绿体比雌株呈现出较好的完整性,并且雄株细胞壁要比雌株更厚。因此, 雄株比雌株表现出更强的干旱忍耐性和更高效的抗氧化酶系统。 (3) 青杨雌雄植株对干旱胁迫的蛋白质组差异响应 用双相电泳检测到雌雄间近1000 个蛋白点,通过对比发现对照组雌雄间有54 个差异蛋白点,干旱下雌雄间有108 个差异点,其中102 个被质谱成功鉴定。对照组雌雄间的差异蛋白主要集中在与光合作用相关蛋白、抗氧化酶、胁迫防御蛋白和一些调节基因表达的蛋白;干旱胁迫下雌雄间差异蛋白明显增多,主要有参与信号转导、调节基因表达、蛋白质加工、转录产物的转录翻译后修饰的调节性蛋白蛋白和参与氧化还原平衡、抗胁迫、细胞壁合成、光合作用、能量代谢、氨基酸代谢和脂肪酸代谢等的功能性蛋白。干旱下这些蛋白的表达量在雌雄中有的表现出相同的表达模式,如干旱下雌雄株中Rubisco 激活酶、小热激蛋白等表达都增加,而有的表现出相反的表达模式,如Rubisco 大亚基的降解片段、羰酸酯酶等在雄株中表达量上调而在雌株中却是下调。因此,雌雄间在蛋白质水平上对干旱胁迫响应的差异是显著的,也是复杂的。 It is an interesting and novel topic that dioecious plants possess different responses to environmental stress. As for the different productive cost and different survive strategy, different sexual plants have shown obviously morphological, physiological and molecular differences. Drought is one of the most worldwidely important environmental stress factors that limit plant growth and ecosystem productivity. Rust disease is one of the economically important diseases in many trees. As a result of the long evolutionary process, male and female plants should show different responses to abiotic and biotic stress. In this paper, using a dioeious tree of Populus cathayana Rehd as a model, we study the sexual differences to drought and rust disease stress in physiological, biochemical, sub-cellular and proteomics levels. The main results are follows: (1) The sexual differences in physiology and biochemistry of poplar to rust disease In controls, males showed higher production of superoxide radicals, higher activities of SOD, POD, PPO and lower CAT activity. Under rust disease, the activities of antioxidant, the content of ROS and the degree of cellular member destroyed were increased in both sexes, except for PPO in diseased males and APX in diseased females. However, females showed more seriously disease severity and cellular member and PS II destroyed degrees. Net photosynthesis rate, transpiration rate and chlorophyll a content were decreased more in diseased females than in males. There were also some different changes inantioxidant isozymes under rust disease. The results suggested that male poplar possessed a more effectively antioxidant system and were more resistant to rut disease than females. (2) The sexual differences in physiology and biochemistry of poplar to drought stress Under drought stress, there were higher rates of RuBP-saturated CO2 assimilation, dark respiration, photorespiratory release of oxygen, the max electron transportrate in CO2-saturated and carboxylation efficiency in males than in females. And males showed lower TBARS and higher proline content. Except for CAT, the activities of other antioxidants were higher in males than in females. Meanwhile, there were obviously differences in isozyme changes between teo sexes. Drought stress obviously destroyed the integralities of chloroplasts and mitochondria and the sexual differences in sub-cellular level were obviously under the moderate water stress. Male cell walls were more sensitive to drought stress than did female. The results suggested males were more resistant to drought stress. (3) The sexual differences in proteomics of poplar to drought stress By 2-D and MS analysis, we identified 102 different protein spots between males and females. Under control conditions, the different proteins were mainly in photosynthesis related proteins, antioxidants, stress response proteins and some gene expression related proteins. Under drought stress, the different proteins were focused on (i) regulated proteins such as signaling conduction, kinase, HSP, gene expressional regulation and protein modification, (ii) functional proteins such as photosynthesis, energy metabolism, antioxidant, redox, stress response, lipid metabolism and amino acid metabolism. Some protein showed the same expressional pattern, while some showed contrary expressional pattern. Thus, the results suggested that sexual differences in proteomics were significant and complex.
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The sorption on humic acid (HA) of metals from an aqueous solution containing Hg(II). Fe(III), Pb, Cu, Al, Ni, Cr(III), Cd, Zn, Co and Mn, was investigated with special emphasis on effects of pH, metal concentration and HA concentration. The sorption efficiency tended to increase with rise in pH, decrease in metal concentration and increase in HA concentration of the equilibrating solution. At pH 2.4. the order of sorption was: Hg Fe Pb Cu=Al Ni Cr=Zn=Cd=Co=Mn. At pH 3.7. the order was: Hg and Fe were always most readily removed, while Co and Mn were sorbed least readily. There were indications of competition for active sites (CO2H and phenolic OH groups) on the HA between the different metals. We were unable to find correlations between the affinities of the eleven metals to sorb on HA and their atomic weights, atomic numbers, valencies, and crystal and hydrated ionic radii. The sorption of the eleven metals on the HA could be described by the equation Full-size image (1K), where Y = % metal removed by HA; X = mgHA; and A and B are empirical constants
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The ecological interaction of brown algae are important as these macroalgae are common and often keystone members in many benthic marine communities.This review highlights their chemical interactions,particularly with potential herbivores,but also with fouling oranganisms,with potential pathogens,with each other as gametes,and with their microenvironments when they are spores.Phlorotannins,which are phenolic compounds unique to brown algae,have been studied hesvily in many of these respects and sre highlightes here.This includes recent controversy about their roles as defences against herbivory,as well as new understanding of their roles in primary cellular functions that may,in many instances,be more important than ,and which at least have to be considered in convert with,any possible ecological functions.Brown algae have also been useful models for testing theoties about the evolution of and ecological constraints on chemical defence.Furthermore,their mocroscopic motile gametes and spores have the ability to react to their chemical environments behavirourally.
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用蘸根和叶面喷施不同浓度油菜素内酯(BRs)的方法,在人工控制土壤水分条件下,对黄土高原重要造林树种文冠果苗木重要的抗氧化酶活性和抗氧化剂含量变化进行研究。结果表明,用0.05~0.4 mg/L BRs处理文冠果苗木,超氧化物歧化酶(SOD)活性在中度干旱胁迫下较清水对照增加,但差异不显著,重度胁迫下增加显著;在中度和重度胁迫下,各处理文冠果苗木过氧化氢酶(CAT)、过氧化物酶(POD)和抗坏血酸过氧化物酶(APX)活性均较清水对照升高,且差异显著;在中度和重度胁迫下,5个浓度BRs处理对抗坏血酸(ASA)和还原型谷光甘肽(GSH)含量均具显著的增加效应。轻度和重度胁迫下,0.2 mg/L BRs处理对文冠果苗木抗氧化酶活性和抗氧化剂含量的增加效应均最为显著。
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Laccase has been immobilized on the carbon nanotubes modified glassy carbon electrode surface by adsorption. As-prepared laccase retains good electrocatalytic activity to oxygen reduction by using 2,2'-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) as the mediator. It can be used as a biosensor for the determination of catechol with broad linear range.
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Four aromatic tetraamine monomers possessing flexible ether linkages were successfully synthesized by nucleophilic aromatic substitution of hydroquinone, 4,4'-dihydroxybiphenyl, 2,2'-bis(4-hydroxyphenyl)propane, and 2,7-dihydroxynaphthalene with 5-chloro-2-nitroaniline, followed by reduction, respectively. With these monomers, a new class of soluble poly[ bis(benzimidazobenzisoquinolinones)] was prepared by a one-step, high-temperature solution polycondensation. The resulting polymers were completely soluble in phenolic solvents and had high inherent viscosities ranging from 1.2 to 1.5 g dL(-1). These polymers had glass transition temperatures in the range of 427-449 degrees C. Thermogravimetric analysis showed that all polymers were thermally stable, with 5% weight loss recorded above 510 degrees C in nitrogen.
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Antioxidant amperometric sensors based on iron-containing complexes and protein modified electrodes were developed. Indium tin oxide glass was printed with TiO2 nanoparticles, onto which iron-containing compounds and protein were adsorbed. When applied with negative potentials, the dissolved oxygen is reduced to H2O2 at the electrode surface, and the H2O2 generated in situ oxidizes Fe-II to Fe-III, and then electrochemical reduction of Fe-III therefore gives rise to a catalytic current. In the presence of antioxidants, H2O2 was scavenged, the catalytic current was reduced, and the decreased current signal was proportional to the quantity of existing antioxidants. A kinetic model was proposed to quantify the H2O2 scavenging capacities of the antioxidants. With the use of the sensor developed here, antioxidant measurements can be done quite simply: put the sensor into the sample solutions (in aerobic atmosphere), perform a cathodic polarization scan, and then read the antioxidant activity values. The present work can be complementary to the previous studies of antioxidant sensor techniques based on OH radicals and superoxide ions scavenging methods, but the sensor developed here is much easier to fabricate and use.