琥珀酰化修饰对甘油醛-3-磷酸脱氢酶活性的影响

通过定点突变和生物学分析,研究了赖氨酸琥珀酰化对GAPDH活性的影响。结果表明:发菜GAPDH基因全长为1014 bp,由338个氨基酸组成,其中K264位点在藻类中高度保守。将K264位点的氨基酸K(AAA)突变为R(AGA),野生型和突变型GAPDH在大肠杆菌中表达,获得一个36.61 ku的外源蛋白。纯化后蛋白活性测定发现,发生琥珀酰化修饰比未发生琥珀酰化修饰的GAPDH(K264)活性显著降低,表明琥珀酰化修饰参与发菜GAPDH活性的调节。研究结果为深入研究发菜GAPDH的分子信息和生物学功能提供理论参考。

Membrane Lipids and Their Fatty Acid Composition in Nostoc flagelliforme Cells

Nostoc flagelliforme Born. et Flah is highly adapted to drought stress, cold and light stresses, and suitable for growing in the unfavorable areas. This paper presents the results of the analysis of the membrane (mainly thylakoid membrane) lipids from N. flagelliforme in order to investigate the relationship between membrane lipid composition and stress resistance to this cyanobacteria. The membrane lipids are composed of monogalactosyl diacylglycerol (MGDG), digalactosyl diacylglycerol (DGDG), sulfoquinovosyl diacylglycerol (SQDG) and phosphatidylglycerol (PG). The major fatty acids in these lipids are palmitic (16∶0), palmitoleic (16∶1), stearic (18∶0), oleic (18∶1), linoleic (18∶2) and linolenic (18∶3) acids. In N. flagelliforme , polyunsaturated fatty acids account for 73% of the total fatty acids, much higher than that of the other cyanobacteria reported so far. Among which 16∶1 and 18∶3 are as high as 28.9% and 34.3% respectively. The high resistance of N. flagelliforme to abnormal conditions may be associated with the extent of unsaturation of fatty acids. In addition, the wild N. flagelliforme treated with water for 30 min and cultured for 24 h and the lipid and fatty acid composition were found to be not affected by water_absorption.

ULTRASTRUCTURE OF THE VEGETATIVE CELLS OF NOSTOC FLAGELLIFORME PREPARED WITH HIGH PRESSURE FREEZING AND FREEZE SUBSTITUTION TECHNIQUE

The ultrastructure of the vegetative cells of Nostoc flagelliforme Born. et Flah. was investigated with high pressure freezing and freeze substitution technique and compared with the results obtained by using conventional preparation methods. During the processes of chemical fixation, dehydration and embedding, the cell structures might be more artificially modified than that obtained from high pressure freezing and freeze substitution. With the present method, the sheath of N. flagelliforme could be well penetrated and no extra big space could exist between the cell and the sheath. The cell protoplasm rarely shrinked. Some fine structures of cell inclusions and unit membranes became visualized. Many bacteria were harbored in the sheath. In addition, the presence of big vacuoles in the cell of N. flagelliforme as well as the presence of bacteria in the sheath shown in the present preparation for cyanobacteria has not been described so far in the literature.

发菜(Nostoc flagelliforme)培养条件的研究

研究了光照强度、日供水次数、CO2浓度和培养基成分对发菜生长的影响。结果显示,中度光强(114μmol.m-2.s-1)下发菜生长最快;发菜的生长基本同供水次数成正相关系;CO2浓度的升高并没有显著促进发菜生长,低光条件下(57μmol.m-2.s-1),高浓度的CO2(2800μL/L)抑制了发菜的生长;用BG11培养的发菜生物量的增长显著高于用BG110培养的;BG11培养基中K+和CO32-的缺失并没有显著影响发菜的生长。

Aβ-Carotene Ketolase Gene NfcrtO from Subaerial Cyanobacteria Confers Drought Tolerance in Rice

Nostoc flagelliforme is a terrestrial cyanobacterium that can resist many types of stressors,including drought,ultraviolet radiation,and extreme temperatures.In this study,we identified the drought tolerance gene NfcrtO,which encodes aβ-carotene ketolase,through screening the transcriptome of N.flagelliforme under water loss stress.Prokaryotic expression of NfcrtO under 0.6 mol/L sorbitol or under 0.3 mol/L NaCl stress significantly increased the growth rate of Escherichia coli.When NfcrtO was heterologously expressed in rice,the seedling height and root length of NfcrtO-overexpressing rice plants were significantly higher than those of the wild type(WT)plants grown on½Murashige and Skoog solid medium with 120 mmol/L mannitol at the seedling stage.Transcriptome analysis revealed that NfcrtO was involved in osmotic stress,antioxidant,and other stress-related pathways.Additionally,the survival rate of the NfcrtO-overexpression lines was significantly higher than that of the WT line under both hydroponic stress(24%PEG and 100 mmol/L H_(2)O_(2))and soil drought treatment at the seedling stage.Physiological traits,including the activity levels of superoxide dismutase,peroxidase,catalase,total antioxidant capacity,and the contents of proline,trehalose,and soluble sugar,were significantly improved in the NfcrtO-overexpression lines relative to those in the WT line under 20%PEG treatment.Furthermore,when water was withheld at the booting stage,the grain yield per plant of NfcrtO-overexpression lines was significantly higher than that of the WT line.Yeast two-hybrid analysis identified interactions between NfcrtO and Dna J protein,E3 ubiquitin-protein ligase,and pyrophosphate-energized vacuolar membrane proton pump.Thus,heterologous expression of NfcrtO in rice could significantly improve the tolerance of rice to osmotic stress,potentially facilitating the development of new rice varieties.

Effects of Lanthanum on Liquid Culture and Contents of Amino Acids ofNostoc Commune Flagelliforme Cells

The effects of La(NO3)(3) on the liquid culture and the contents of amino acids of Nostoc commune flagelliforme cells were studied. It is indicated from the experimental results that the growth of Nostoc commune flagelliforme cells can be stimulated by La(NO3)(3) at the concentrations from 1 to 200 mg.L-1, and among them the treatment of 100 mg.L-1 La(NO3)(3) has the largest A(670) and dry weight which increased by 64.9% and 61.1%, respectively as compared with the control, and La(NO3)(3) can also influence the contents of some kinds of amino acids in Nostoc commune flagelliforme cells. The contents of aspartic acid and glutamic acid decreased by 59.9% and 57.9%, respectively, and that of proline increased by 24.5% with the treatment of 200 mg.L-1 La(NO3)(3).

The inhibition of Typhonium flagelliforme Lodd. Blume leaf extract on COX-2 expression of Wi Dr colon cancer cells

Objective: To determine the inhibition activity of Typhonium flagelliforme Lodd. Blume(T. flagelliforme) leaf extract on cyclooxygenase 2(COX-2) expression of colon cancer cells.Methods: T. flagelliforme leaf extract was prepared to macerate in ethyl acetate. In vitro anticancer activity was assayed by MTT method on Wi Dr colon cancer cells. This study applied apoptosis induction assay to investigate the mechanism of cell death using double staining method. COX-2 expression was stained by immunocytochemistry.Results: T. flagelliforme showed anticancer activity and induced apoptosis on Wi Dr cells through inhibition of COX-2 expression with IC5070 mg/m L.Conclusions: This study showed that T. flagelliforme is a promising chemopreventive agent for colon cancer through COX-2 inhibition.

The effects of different strength of MS media in solid and liquid media on in vitro growth of Typhonium flagelliforme

Objective: To determine the effects of different strength of Murashige and Skoog(MS)media(full,1/2and1/4) in solid and liquid media on in vitro growth of Typhonium flagelliforme(T. flagelliforme), whereby an optimum media composition can be provided for mass propagation of T. flagelliforme.Methods: Rhizome bud of T. flagelliforme was obtained from the axenic in vitro established T. flagelliforme plantlets in Plant Tissue Culture Laboratory, Universiti Teknologi MARA, Shah Alam. Rhizome bud was used as explant and cultured onto shoot proliferation medium under different strength of MS media(full,1/2,1/4) in solid and liquid culture media.Results: After 6 weeks of culture, the number of shoot, number of leaf, number of root,height of shoot, fresh weight, dry weight and chlorophyll content of T. flagelliforme were analyzed. A comparison was made between liquid and solid culture media. The results revealed that the liquid culture media were more effective for all the growth parameters(shoot height, shoot number, leaf number, root number, fresh weight, dry weight, chlorophyll a and chlorophyll b content) compared to solid culture media. Apart from that,this study revealed the positive relationship between strength of MS media and type of culture media(solid and liquid media) to the growth of T. flagelliforme. Growth of T. flagelliforme was improved when MS strength was increased in liquid media. In contrast, growth of T. flagelliforme was improved when MS strength was decreased in solid media.Conclusions: Through this study, an optimum media composition for mass propagation of T. flagelliforme had been established by observing effects of MS media strength and type of culture media(solid and liquid media) on the growth of T. flagelliforme.

Characterization of Corrinoid Compounds in the Edible Cyanobacterium <i>Nostoc flagelliforme</i>the Hair Vegetable

Vitamin B12 contents in the edible cyanobacterium Nostoc flagelliforme, also known as hair vegetable, were assayed using a microbiological method. We detected high vitamin B12 contents in samples of naturally grown cells (109.2 ± 18.5 μg/100g dry weight) and cultured cells (120.2 ± 53.6 μg/100g dry weight). However, commercially available hair vegetable samples, which comprised fake substitutes and Nostoc, had variable contents (4.8 - 101.6 μg/100g dry weight) because concomitant fake items contain very low vitamin B12 contents. To evaluate whether natural and cultured N. flagelliforme samples contained vitamin B12 or pseudovitamin B12, corrinoid compounds were purified and identified as pseudovitamin B12 (approximately 72%) and vitamin B12 (approximately 28%) using silica gel 60 TLC bioautography and LC/MS. The results suggested that N. flagelliforme contains substantial amounts of pseudovitamin B12, which is inactive in humans.

发菜伴生细菌的分离鉴定及其对发菜生理代谢的影响

为了探究发菜(Nostoc flagelliforme)伴生菌对其生理代谢的影响,进一步了解发菜的生长体系以及发菜与伴生菌的相互作用,本文采用平板划线法从发菜固体培养基上分离出11株伴生菌,利用高效液相色谱-四极杆飞行时间质谱(LC-qToF-MS)鉴定伴生菌产生的N-酰基高丝氨酸内酯类分子(AHLs)种类.通过质谱图可知微杆菌属(Microbacterium sp.)ABNF-1产生C_(12)-HSL,根瘤菌属(Rhizobium sp.)ABNF-4产生C_(6)-HSL、C10-HSL、C_(12)-HSL,戈登氏菌属(Gordonia sp.)ABNF-9产生C_(6)-HSL、C10-HSL,假单胞菌属(Pseudomonas balearica sp.)ABNF-10产生C10-HSL、C_(12)-HSL.对发菜AHLs产生菌共培养的代谢产物分析表明,主成分分析(PCA-X)和正交偏最小二乘法判别分析(OPLS-DA)的评分都呈现明显的离散现象,表明共培养组的代谢产物发生了变化,发菜的脂肪酸代谢和碳代谢发生了显著变化.通过外源添加AHLs发现,当群体感应信号分子AHLs浓度为5μmol/L以上时,AHLs能够促进荚膜多糖的积累,提高细胞总糖含量,对发菜多糖含量影响显著,这进一步说明AHLs能够影响发菜细胞的生长代谢.

水半夏水煎液化学成分研究

目的:研究水半夏水煎液的化学成分。方法:利用中压反相柱、Sephadex LH-20葡聚糖凝胶柱、半制备高效液相等色谱方法对水半夏水煎液进行分离纯化,并根据理化性质及核磁共振波谱、质谱等数据分析鉴定化合物结构。结果:从水半夏水煎液中分离得到24个化合物,分别鉴定为:腺苷(1)、原儿茶酸(2)、苯乙胺(3)、(S)-2-羟基-3-(4′-羟基苯)丙酸(4)、2,5-二羟基苯甲酸(5)、L-色氨酸(6)、(3S)-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid(7)、环(天冬酰胺-苯丙氨酸)(8)、(-)-(1S,3S)-1-methyl-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid(9)、(S)-3-苯基乳酸(10)、烟酰胺(11)、(+)-异落叶松树脂醇(12)、松脂素(13)、stagonoculiazin(14)、1-棕榈酰基-3-O-β-D-半乳糖基甘油酯(15)、亚麻酸(16)、1-亚油酰甘油酯(17)、1-linoleoylglycerol(18)、benzenetridecanoic acid(19)、亚油酸甲酯(20)、(E)-9-十八碳烯酸甲酯(21)、亚油酸(22)、10,13-octadecadienoic acid(23)、(8-hydroxymethylen)-trieicosanyl acetate(24)。结论:其中,化合物2~5、8~11、14、15、17、18、21、23、24为首次从该植物中分离得到。

水半夏与半夏镇咳祛痰作用分析

目的:比较水半夏、半夏及其炮制品的镇咳祛痰作用。方法:采用小鼠浓氨水引咳法和小鼠气管酚红分泌量法,以咳嗽潜伏期、咳嗽次数、咳嗽抑制率和酚红分泌量、祛痰指数为指标,比较水半夏、半夏的镇咳祛痰作用,比较姜水半夏、姜半夏在复方半夏片中的镇咳祛痰作用。结果:与对照组相比,水半夏、半夏均能显著延长小鼠咳嗽的潜伏期(P<0.05),减少咳嗽次数(P<0.001),增加小鼠气管的酚红分泌量(P<0.05);水半夏、半夏在镇咳祛痰方面,无显著差异(P>0.05),但水半夏的咳嗽抑制率和祛痰指数优于半夏。与对照组相比,姜半夏方及姜水半夏方均能显著延长小鼠咳嗽的潜伏期(P<0.001),减少咳嗽次数(P<0.001),增加小鼠气管的酚红分泌量(P<0.001);姜水半夏方的镇咳祛痰活性与姜半夏方相比无显著差异(P>0.05),但姜水半夏方的咳嗽抑制率和祛痰指数优于姜半夏方。结论:水半夏在镇咳祛痰作用方面具有替代半夏的潜力,值得进一步深入研究。

鞭檐犁头尖抗癌活性及其潜在机制临床前研究的系统综述

目的:评价一种中药植物鞭檐犁头尖(T.flagelliforme)作为抗癌药物的临床前研究的系统综述。方法:对Scopus、PubMed、Web of Science、ScienceDirect、LILACS、EBSCO Medline、Mendeley等7个数据库进行全面检索,检索时间截止到2023年9月8日。排除了临床试验和非原创的同行评议报告后,鞭檐犁头尖的提取物,组成,或分离化合物的体内外研究且经过同行评审的英文文献均被纳入。本研究定性评估了鞭檐犁头尖对不同肿瘤细胞、肿瘤大小和作用机制的有效性。证据质量由三名独立评估人员使用ToxRTool进行评估,并验证其一致性。结果:检索后共纳入27项研究:22项体外研究,4项体内研究,1项体内外研究。结果发现鞭檐犁头尖对白血病、乳腺癌、结直肠癌和肺癌有效。大多数研究的评估为“有限制的可靠”。鞭檐犁头尖通过阻断细胞周期、活化caspase-3/-9、分解PARP、裂解DNA、减少生存素含量、降低ROS表达、抑制COX-2和HSP70表达和抑制NF-kB通路等来诱导细胞凋亡。当与干扰素联合使用时,其能阻碍血管生成。结论:尽管鞭檐犁头尖具有良好的抗癌活性,但其作为单独抗癌药物的疗效尚不确定。它似乎更适合用于癌症的补充或联合治疗。研究设计不理想,报告不完整,以及在多篇文章中没有纳入适当的阳性对照和统计分析可能是本研究缺乏结论性证据的原因。

发状念珠藻对盐胁迫的响应

探讨了发状念珠藻 (NostocflagelliformeBorn etFlah )对盐胁迫的耐受适应机制 ,采用含不同浓度NaCl(0、0 1、0 2、0 4、0 6、0 8、1 0mol/L)的BG110 培养液处理具有正常生理活性的丝状体 ,2 5± 0 5℃ ,4 0 μmol/m2 /s下照光培养12h ,测定藻体光合作用、呼吸作用等生理活性以及体内一些物质的含量 ,结果表明 :随培养液中NaCl浓度的升高藻体光合作用、呼吸作用以及PSⅡ活性 (Fv/Fm)降低 ;质膜透性不断增大 ,丙二醛含量升高 ,自由水含量、自由水 /束缚水比值下降 ,类胡萝卜素、可溶性糖含量增加 ,脯氨酸含量变化不大。由此可知 ,盐胁迫下发状念珠藻正常生理活性受到抑制而表现出一定的抗逆能力 ;该藻对盐胁迫具有一定的耐受能力 ,类胡萝卜素的增加有助于清除藻体内的氧自由基 ,可溶性糖可能是其主要渗透调节物质之一 ,脯氨酸在盐胁迫中的渗透调节作用不大。

发状念珠藻藻殖段的分化及其光合特性的研究

发状念珠藻 (NostocflagelliformeBorn .etFlah .)存在着两个重要而明显的个体发育阶段 ,即营养藻丝体和藻殖段。采用弱光 (铺垫砂粒遮光 ) ,红光或在白光下向培养基中加入DCMU (3,4_dichlorophenyl_1,1_dimethylurea)等方法 ,可促进营养藻丝体转变成藻殖段。用可见光吸收光谱、低温荧光发射光谱和光合放氧活性表示发状念珠藻藻丝体与藻殖段的光合特性 ,表明营养藻丝体和藻殖段的可见光吸收光谱和色素含量差别不大。而两者在不同光强范围 (110～ 12 0 0 μmol·m-2 ·s-1)和不同温度 (15～ 45℃ )下的光合放氧活性 ,表明发状念珠藻的藻殖段比营养藻丝体可能更适合在低光强下和较高的温度下生长。从荧光发射光谱可以看出 ,在光合能量传递中营养藻丝体比藻殖段在两个光系统之间的光能分配上更加均衡 ;但是藻殖段中藻胆体吸收光能向两个光系统的传递比营养藻丝体的更加有效。可以认为藻殖段的形成对光合作用的结构与功能产生影响。

发菜胞外多糖硫酸化条件的优化及红外光谱分析

液体培养发菜细胞,发菜细胞经去藻体、浓缩、透析、脱蛋白、醇沉、DEAE-52离子交换柱层析分级、Sephadex-100葡聚糖凝胶柱分级处理得到发菜胞外精多糖。以硫酸根的取代度为指标,在单因素试验的基础上,利用Box-Behnken设计进行响应面试验,建立因素与响应值之间的数学模型,确定适宜的发菜胞外多糖硫酸化条件。结果表明,发菜胞外多糖硫酸化修饰最佳条件为反应温度71℃、反应时间3 h、氯磺酸-吡啶体积比1∶7,在此条件下,硫酸化取代度为5.05。红外光谱检测表明,硫酸基团已与多糖分子结合。

发状念珠藻胞外多糖的抑菌与抗炎作用

采用BG-11培养液,悬浮培养发状念珠藻,提取发状念珠藻胞外多糖。通过测滤纸片周围抑菌圈直径大小,研究发状念珠藻胞外多糖抑菌作用;通过研究发状念珠藻胞外多糖对二甲苯致小鼠耳肿胀的影响及对角叉菜胶致小鼠足跖肿胀的影响,探究它的抗炎性能。结果表明,发状念珠藻多糖在一定的质量浓度范围内对研究的几种细菌及青霉和红曲霉都有一定的抑菌作用,而对根霉无抑制作用;其能够有效缓解二甲苯和角叉菜胶引起的小鼠耳部与足部炎症。发状念珠藻胞外多糖具有一定的抑菌抗炎性。

发菜细胞培养物对盐胁迫的响应

用不同浓度(0、0.1、0.2、0.4 m o l.L-1)的N aC l处理BG 110培养的发菜细胞,结果显示,发菜光合速率与叶绿素荧光强度随N aC l浓度的升高先增加后降低,当N aC l浓度为0.1 m o l.L-1时光合速率与叶绿素荧光具有最大值,表明发菜细胞培养物能耐受一定浓度的盐胁迫.以BG 110+0.4 m o l.L-1N aC l为对照,在BG 11+0.4m o l.L-1N aC l的胁迫实验中,光合速率与叶绿素荧光强度下降较慢;丙二醛、脯氨酸含量较低;类胡萝卜素含量较高,表明在培养液中添加外源硝酸盐后可以缓解N aC l对发菜细胞培养物的生理胁迫效应,增强其抗盐性.

念珠藻发菜的水分生理特性

对野生风干发菜水分生理指标进行了测定与分析,结果表明:风干含水量为7.3%～11.2%,饱和含水量为616.0%～1258.4%,相对含水量1%左右,水分饱和亏为99%左右,水势为-8.2MPa;最大吸水速率为8.029gH2O·g-1·min-1,饱和吸水后其体积膨大10～14倍,平均吸胀率为1286.9%,其中伸长率为23.5%,增粗率为235.0%;导水力极弱;干燥发菜具有超强的吸水力,能在相对湿度>28.4%的空气中吸取水分;发菜的保水力随环境而变,在阴暗或弱光照的环境中具有较强的保水力.另外,探讨了不同种源发菜的水分生理指标与环境因子的关系.

发菜多糖的提取、纯化鉴定及理化特性研究

对发菜胞外多糖和发菜荚膜多糖分别进行提取研究,获得了2种多糖的理想提取工艺。分别将胞外粗多糖和荚膜粗多糖采用Sevag法脱蛋白,透析去除小分子杂质,DEAE-52柱层析分离纯化后,前者得到1种酸性糖(EPS),后者得到1种中性糖和2种酸性糖(CPSA、CPSB和CPSC),最后通过Sephadex G-100柱层析和紫外扫描检测,EPS、CPSA和CPSB均为单一多糖。