长叶竹柏中的化学成分

从罗汉松科罗汉松属植物长叶竹柏(Podocarpus fleuryi Hiekle)中分得11种成分。根据理化性质,波谱方法及化学反应分别鉴定为棕榈酸(1),柳杉酚(2),β-谷甾醇(3),竹柏内酯 A(4),竹柏内酯 B(5),异银杏双黄酮(6),β-谷甾醇硬脂酸酯(7),3β,5α-二羟基-6-豆甾酮(8),5α-羟基-6-豆甾酮-3β-棕榈酸酯(9),胡萝卜甙(10)和丁香甙(11)。所有成分在该植物中均属首次报道,其中化合物9为新化合物。双内酯化合物4及5具有极强的细胞毒作用。     

滇藏杜英化学成分研究

通过有机溶剂提取、色谱等手段从滇藏杜英(Elaeocarpus braceanus)分离到17个化合物,根据氢谱(1H NMR)、碳谱(13C NMR)、质谱(MS)等波谱解鉴定分别为3-氨基4-羟基-苯甲酸-1-O-β-D-吡喃木糖甙(1)、3,5,7-三羟基-4'-甲氧基黄酮(2)、杨梅素(3)、5-O-甲基-杨梅素(4)、4'-O-甲基-杨梅素(5)、二氢山奈酚(6)、二氢杨梅素(7)、杨梅素3-O-α-L-鼠李糖甙(8)、山奈酚-3-O-α-L-鼠李糖甙(9)、4'-O甲基-杨梅素3-O-α-L-鼠李糖甙(10)、7,4'-O–二甲基杨梅素3-O-α-L-鼠李糖甙(11)、4'-O–甲基杨梅素3-O-β-D-葡萄糖甙(12)、山奈酚-3-O-β-D-葡萄糖甙(13)、(3β,9β,10α,16α,23R)-16,23-epoxy-3-(β-D-glucopyranosyloxy)-20-hydroxy-9-methyl-19-norlanosta-5,24-dien-11-one(14)、β-谷甾醇(15)、β-胡萝卜甙(16)和3,5-二羟基4-甲氧基苯甲酸(17),其中1为新化合物,其它16个化合物是首次从滇藏杜英中发现。     

冻地银莲花的化学成分

从冻地银莲花(Anemone Tupestris ssp.Gelida (Max.)Lauener)中分离鉴定了12个化合物.分别为常春藤配基(1).刺楸皂甙A(2),牡丹草皂甙B(3),白头翁皂甙D(4),常春藤皂甙B(5),刺楸皂甙B(6),hederacholichiside E(7),hederacholichiside F(8),槲皮素-7-O-α-L-鼠李糖甙(9)槲皮素-3-O-β-D-半乳糖-7-O-α-L-鼠李糖甙(10).胡萝卜甙(11)和β-谷甾醇(12).以上化合物在本植物中均为首次报道.     

半卧狗娃花中的黄酮类化合物

从半卧狗娃花(Heteropappus semiprost Griers)全草的乙醇提取物中分离并鉴定了7个黄酮类化合物,通过波谱分析及化学方法鉴定其结构为:3′,4′,5,7-四羟基黄酮(1),3′-甲氧基槲皮素(2),槲皮素-3-O-α-L-吡喃鼠李糖甙(3),槲皮素-3-O-β-D-吡喃半乳糖甙(4),异鼠李亭-3-O-β-D-吡喃半乳糖甙(5),槲皮素-3-O-α-L-吡喃鼠李糖(1→6)-β-D-吡喃葡萄糖甙(6),异鼠李亭-3-O-α-L-吡喃鼠李糖(1→6)-β-D-吡喃葡萄糖甙(7),其中化合物1~5为首次从本属植物中分离得到。     

药囊花茎叶的化学成分研究

药囊花（Cyphotheca montana Diels）茎叶的乙醇提取物具有抗菌活性,进一步的活性追踪表明活性成分在乙酸乙酯和正丁醇萃取物中,我们从这两种萃取物中共分离鉴定出9个化合物,其结构通过波谱分析等分别鉴定为：槲皮素-3-O-α-L-鼠李糖甙（1）,杨梅素-3-O-α-L鼠李糖甙（2）,山萘酚-3-（2″,6″-二-O-（E）-p-羟基苯丙烯酰-β-D-吡喃葡萄糖甙（3）,3,3′-O-二甲基逆没食子酸-4-O-β-D-吡喃葡萄糖甙（4）,槲皮素（5）,2α,3β,19α,23-四羧基乌苏-12-烯-28-酸-28-0-β-D吡喃葡萄糖甙（6）,乌苏酸（7）,β-谷甾醇（8）和胡萝卜甙（9）,这些化合物均为首次从我国该特有单种属植物中分离得到。     

三七花蕾中黄酮类成分的分离与结构鉴定(英文)

通过硅胶柱层析,制备性薄层色谱分离,从三七花蕾中分离得到2个黄酮化合物,依据理化性质及光谱数据鉴定为山奈酚-3-O-α-L-鼠李糖甙(1)和山奈酚-3-O-(2’’,3’’-二反式对羟基桂皮酰基)-α-L-鼠李糖甙(2)。这两个黄酮均首次从该植物中分离得到。     

红背山麻杆化学成分的研究

采用柱色谱技术从红背山麻杆叶子的60％乙醇提取物中分离得到4个黄酮苷和2个其他类化合物.根据理化性质及波谱方法分别鉴定为:芹菜素-6-C-D-葡萄糖苷(1)、芹菜素-7-O-芸香糖苷(2)、芹菜素-7-O-β-(2″-O-α-鼠李糖基)葡萄糖醛酸苷(3)、木犀草素-7-O-α-L-鼠李糖(1→6)-β-D-葡萄糖苷(4)、没食子酸乙酯(5)、β-胡萝卜苷(6).以上化合物均为首次从该植物中分离得到,其中化合物1～4为首次从山麻杆属中分离得到的黄酮苷.     

狗脊化学成分研究

从狗脊（Woodwardia japonica(L.f.)Sm)中分离得到五个化合物,经解析,分别鉴定为：山柰素-3-O-α-L-（4-O-乙酰基）鼠李糖基-7-O-α-L-鼠李糖甙（kaempferol3-O-α-L-（4-O-acetyl)rhamnopyranoside-7-O-β-L-rhamnopyranoside)(Ⅰ）,山柰素-3-O-α-L-鼠李糖基-7-O-α-L-鼠李糖甙（kaempferol3-O-α-L-rhamnopyranoside-7-O-α-L-rhamnopyanoside)（Ⅱ）,狗脊蕨酸（woodwardinic acid)(Ⅲ）,β-谷甾醇（β-sitosterol)(Ⅳ）,胡萝卜甙（daucosterol)(Ⅴ）,这五个化合物均系首次从该植物中获得。     

结香化学成分的研究

从结香(Edgeworthia chrysantha)的花蕾中分离得出3个香豆索,2个黄酮。用波谱等方法确定其结构为伞形花内酯(umbelliferone,1),6-甲氧基-7-羟基双香豆素-3,7’-醚(daphnoretin,2),7,7’-二羟基双香豆素-8,8’-醚-7-α-L-鼠李糖甙(edgeworoside c,5),4’,5,7-三羟基黄酮醇-3-O-β-D-(6′′-对羟基桂皮酰基)-葡萄糖甙(tiliroside,3),山萘酚-3-O-β-D-葡萄糖甙(kaempferol-3-O-β-D-glucoside,4),以上化合物均为首次从结香花蕾中得到。     

香薷中的化学成分

从香[Eltholtzia ciliata(Thund.)Hyland]中分出14个化合物,用波谱和化学等方法确定为6-甲基三十三烷(Ⅰ),13-环己基二十六烷(Ⅱ),β-谷甾醇(Ⅲ),棕榈酸(Ⅳ_a),亚油酸(Ⅳ_b),亚麻酸(Ⅳ_c),熊果酸(Ⅴ),5-羟基-6、7-二甲氧基黄酮(Ⅵ),5-羟基-7、8-二甲氧基黄酮(Ⅶ),5、7-二羟基-4′-甲氧基黄酮(Ⅷ),5-羟基-7、4′-二甲氧基双氢黄酮醇(Ⅸ),β-谷甾醇-3-β-D-葡萄糖甙(Ⅹ),5-羟基-6-甲基-7-O-α-D-半乳吡喃糖双氢黄酮甙(Ⅺ),刺槐素-7-O-β-D-葡萄糖甙(Ⅻ)。其中化合物Ⅺ为新化合物,除(Ⅳ_b)和(Ⅳ_c)外,其余为首次从该属植物中得到。     

人外周血单核细胞来源的树突状细胞的体外“2＋2”快速法培养及其鉴定

以人浓缩白细胞来源的CD14 单核细胞为前体,建立体外快速培养树突状细胞(dendritic cell,DC)的方法.采用密度梯度离心和MACS磁珠分选系统,收集高纯度的CD14 单核细胞;以rGM-CSF、rIL-4联合分化2天诱导不成熟DC,再将分化后的细胞以rTNF-α、IL-1β、IL-6、PGE2共同活化2天得到成熟DC.流式细胞仪检测结果表明,分化2天的不成熟DC具有吞噬能力,且表型HLA-DR、CD40、CD80表达在80%以上,CD83、CD86基本小表达,成熟后的DC能够激活T细胞增殖,HLA-DR表达增高,CD83、CD86表达占85%.     

Identification of a Novel <i>OsCYP2</i> Allele that Was Involved in Rice Response to Low Temperature Stress

Cyclophilin (CYP) plays an important role in plant response to stress, and OsCYP2, one gene of cyclophlilin family, is involved in auxin signal transduction and stress signaling in rice. However, the mechanism that OsCYP2 is involved in rice response to low temperature is still unclear. We identified a new OsCYP2 allelic mutant, lrl3, with fewer lateral roots, and the differences in shoot height, primary root length and adventitious root length increased with the growth process compared to the wild-type plant. Auxin signaling pathway was also affected and became insensitive to gravity. The transgenic rice plants with over-expression of OsCYP2 were more tolerant to low temperature than the wild-type plants, suggesting that OsCYP2 was involved in the low temperature response in rice. In addition, OsCYP2 negatively regulated the expression of OsTPS38, a terpene synthase gene, and was dependent on the OsCDPK7-mediated pathway in response to low temperature stress. OsTPS38- overexpressed transgenic line ox-2 was more sensitive to low temperature. Therefore, OsCYP2 may negatively regulate OsTPS38 through an OsCDPK7-dependent pathway to mediate the response to low temperature in rice. These results provide a new basis for auxin signaling genes to regulate rice response to low temperature stress.     

Nanosilver-Promoted Lateral Root Development in Rice is Mediated through Hydrogen Peroxide

Nanosilver (10⁻⁹ m) refers to particles comprising 20–15,000 silver atoms, exhibiting high stability and specific surface area. At present, nanosilver has been used in agricultural cultivation and production. This study examined the effects of nanosilver on growth and development of rice root systems. Study results showed that fresh weight of rice belowground organs and root length both increased significantly by 5% and 25%, respectively, after rice radicles were treated with 2 ppm of nanosilver for three days. However, the H₂O₂ level reached its peak at 2 days from treatment, but the activities of the antioxidant enzymes CAT, APX, and GR were inhibited by 2 ppm of nanosilver treatment. The results showed that nanosilver treatment inhibited the antioxidant enzyme activity of rice roots. The treatment of rice radicles with 5 μM H₂O₂ promoted root development and the same was observed when nanosilver was used for treatment. Moreover, ascorbic acid (AsA) is a H₂O₂ scavenger and therefore rice root development was inhibited when AsA was added to rice radicles together with either treatment of nanosilver or H₂O₂. In summary, nanosilver treatment of rice radicles promoted root growth and development via the regulation of H₂O₂ and not the O₂^•− pathway.     

Effects of Nano-Cerium Oxide on Seed Germination and Seedling Growth of <i>Vitex negundo</i>

Cerium oxide nanoparticles (CeO₂NPs) are likely to have dramatic impacts on plant performances, yet the effects of CeO₂NPs on seed germination and seedling growth have not been fully explored. In this study, the seed germination and seedling growth of subshrub species Vitex negundo under different concentrations of CeO₂NPs (low-1 mg/L, medium-100 mg/L, high-500 mg/L) have been discussed. Results showed that: (1) The seed germination rate reduces by 11.25% and 2.5% under the low and medium concentrations of CeO₂NPs, respectively, but increased by 7.08% under the high concentration; (2) CeO₂NPs had significant effects on the growth traits (root length, shoot height and biomass) of seedlings, being the highest under the medium concentration and the lowest under the highest concentration; (3) The superoxide dismutase activity was the maximum (355.91 U/g), but the protein concentration was the minimum (3.85 ug/mL) under the high concentration of CeO₂NPs. Our results indicated that the effects of CeO₂NPs on seed germination and seedling growth are concentrationdependency, i.e., low and medium concentrations inhibited while high concentration promoted seed germination, however, seedling growth showed opposite responses. Therefore, appropriate CeO₂NPs concentrations are beneficial to the seed germination and seedling growth of Vitex negundo and improve the physiological performance of seedlings and enhance their adaptability to environmental adversity.     

Synthesis and Properties of Modified Oligodeoxyribonucleotides Containing 2"-O-(2,3-Dihydroxypropyl)uridine and 2"-O-(2-Oxoethyl)uridine

A new uridine derivative, 2"-O-(2,3-dihydroxypropyl)uridine, and its 3"-phosphoramidite were obtained for direct introduction into oligonucleotides during automated chemical synthesis. Oligonucleotides 10 to 15 nt long harboring 2"-O-(2,3-dihydroxypropyl)uridine residues were synthesized; periodate oxidation of these oligomers gave oligonucleotides containing 2"-O-(2-oxoethyl)uridine residues. The presence of a reactive aldehyde group in 2" position of the carbohydrate moiety was confirmed by the interaction withp-nitrophenylhydrazine and methionine methyl ester. The thermostability of DNA duplexes containing modified units does not practically differ from that of the natural analogues.     

Titanium Dioxide Nanoparticles Promote Root Growth by Interfering with Auxin Pathways in <i>Arabidopsis thaliana</i>

TiO₂ nanoparticles (nano-TiO₂) are widely used in the world, and a considerable amount of nano-TiO₂ is released into the environment, with toxic effects on organisms. In the various species of higher plants, growth, including seed germination, root elongation, and biomass accumulation, is affected by nano-TiO₂. However, the underlying molecular mechanisms remain to be elucidated. In this study, we observed that nano-TiO₂ promoted root elongation in a dose-dependent manner. Furthermore, we found that nano-TiO₂ elevated auxin accumulation in the root tips of the auxin marker lines DII-VENUS and DR5:: GUS, and, correspondingly, quantitative real-time PCR analysis revealed that nano-TiO₂ increased the expression levels of auxin biosynthesis- and transportrelated genes. GFP fluorescence observation using transgenic PIN2-GFP indicated that nano-TiO₂ promoted root growth by inducing PIN2 accumulation. Thus, we propose that nano-TiO₂ promote root growth in Arabidopsis thaliana by altering the expression levels of auxin biosynthesis- and transport-related genes.     

Sub-Surface Drip Irrigation in Associated with H₂O₂ Improved the Productivity of Maize under Clay-Rich Soil of Adana,Turkey

Maize being sub-tropical crop is sensitive to water deficit during the early growth stages; particularly clay-rich soil, due to the compaction of the soil. It is well-documented that potential sub-surface drip irrigation (SDI) (Full irrigation; SDIFull (100% field capacity (FC)), Deficit irrigation; SDIDeficit (70% FC)) improves water use efficiency, which leads to increased crop productivity; since it has a constraint that SDI excludes soil air around the root-zone during irrigation events, which alter the root function and crop performance. Additionally, in clayrich soils, the root system of plants generally suffers the limitation of oxygen, particularly the temporal hypoxia, and occasionally from root anoxia; while SDI system accomplishes with the aerating stream of irrigation in the rhizosphere could provide oxygen root environment. The oxygen can be introduced into the irrigation stream of SDI through two ways: the venturi principle, or by using solutions of hydrogen peroxide through the air injection system. Therefore, the application of hydrogen peroxide (H₂O₂; HP) can mitigate the adverse effect of soil compactness and also lead to improving the growth, yield and yield attributes of maize in clay-rich soil. Considering the burning issue, a field study was conducted in consecutive two seasons of 2017 and 2018; where hybrid maize was cultivated as a second crop, to evaluate the effect of liquid-injection of H₂O₂ (HP) into the irrigation stream of SDI on the performance of maize in a clay-rich soil field of Adana, Turkey. When soil water content decreased in 50% of available water, irrigation was performed. The amount of water applied to reach the soil water content to the field capacity is SDIFull (100% FC) and 70% FC of this water is SDIDeficit (70% FC). In the irrigation program, hydrogen peroxide (HP) was applied at intervals of 7 days on average according to available water with and without HP: SDIFull (100% FC) + 0 ppm HP with full SDI irrigation; SDIFull (100% FC) + 250 ppm HP with deficit SDI irrigation; SDIDeficit (70% FC) + 0 ppm HP, SDIDeficit (70% FC) + 250 ppm HP and SDIDeficit (70% FC) + 500 ppm HP. Deficit irrigation (SDIDeficit (70% FC)) program was started from tasseling stage and continued up to the physiological maturity stage with sub-soil drip irrigation. H₂O₂ was applied 3 times during the growing season. Two years’ results revealed that the liquid-injection of H₂O₂ into the irrigation stream of SDI improved the growth and yield-related attributes and grain yield of maize. Based on the obtained results, during the extreme climatic condition in the year 2017, SDIFull (100% FC) + 250 ppm HP was more effective than SDIFull (100% FC) + 0 ppm HP on all traits for relative to full irrigation. While, during the favourable climatic condition in the 2018 season, SDIFull (100% FC) + 250 ppm HP was more effective than full irrigation with SDIFull (100% FC) + 0 ppm HP for the grain yield, grains, and SPAD value. Accordingly, the most effective treatment was SDIFull (100% FC) + 250 ppm HP, as it gave the highest growth and yield-related attributes and grain yield of maize followed by SDIDeficit (70% FC) + 250 ppm HP. Therefore, SDIFull with 250 ppm H₂O₂ using as liquid-injection may be recommended to mitigate the adverse effect of soil compactness particularly water-deficit stress in clay-rich soil for the sustainability of maize production.     

Estimation of Growth and Photosynthetic Performance of Two C₄ Species (<i>Pennisetum spicatum</i> (L.) Körn. and <i>Zea mays</i> L.) under a Low Temperature Treatment

Pearl millet (Pennisetum spicatum (L.) Körn.) and maize (Zea mays L.) are C₄ grass species grown for feeding humans and animals in Almadinah Almunawwarah, which is in the western part of Saudi Arabia. During the winter, the mean temperature, which drops to 14°C, represents a major problem for the growth of these species in this region. Therefore, the objectives of this research were to investigate the growth response and the photosynthetic performance of P. spicatum and Z. mays under a low temperature stress. The treatments involved daytime and nighttime temperatures of 14/12°C (low temperature) and 24/22°C (optimum temperature). The results indicated that low temperature significantly reduced all growth and physiological parameters, including seed germination, leaf expansion, leaf area, shoot length and root length of the two species compared to those of the control. Additionally, the low temperature significantly decreased the light-saturated assimilation rate (A_sat), quantum yield (ϕ), saturated rate of carbon dioxide uptake (A_max) and efficiency of carboxylation on both species compared to those of the control. Moreover, the values of Fv/Fm and the chlorophyll contents of both species were significantly reduced by low temperature compared to those of the control. It can be concluded that both species had little tolerance to low temperatures.     

Residues required for phosphorylation of translation initiation factor eIF2α under diverse stress conditions are divergent between yeast and human

PERK, PKR, HRI and GCN2 are the four mammalian kinases that phosphorylate the α subunit of the eukaryotic translation initiation factor 2 (eIF2α) on Ser51. This phosphorylation event is conserved among many species and attenuates protein synthesis in response to diverse stress conditions. In contrast, Saccharmyces cerevisiae expresses only the GCN2 kinase. It was demonstrated previously in S. cerevisiae that single point mutations in eIF2α’s N-terminus severely impaired phosphorylation at Ser51. To assess whether similar recognition patterns are present in mammalian eIF2α, we expressed human eIF2α’s with these mutations in mouse embryonic fibroblasts and assessed their phosphorylation under diverse stress conditions. Some of the mutations prevented the stress-induced phosphorylation of eIF2α by all mammalian kinases, thus defining amino acid residues in eIF2α (Gly 30, Leu 50, and Asp 83) that are required for substrate recognition. We also identified residues that were less critical or not required for recognition by the mammalian kinases (Ala 31, Met 44, Lys 79, and Tyr 81), even though they were essential for recognition of the yeast eIF2α by GCN2. We propose that mammalian eIF2α kinases evolved to maximize their interactions with the evolutionarily conserved Ser51 residue of eIF2α in response to diverse stress conditions, thus adding to the complex signaling pathways that mammalian cells have over simpler organisms.