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91.
三褶脉紫菀中的新二萜甙 总被引:1,自引:0,他引:1
三褶脉紫菀(AsterageratoidesTurcz.)系菊科多年生草本植物,遍布全国,是民间常用的中药,有清热解毒、祛痰镇咳的功效[1,2]。化学工作者们曾从其同属植物紫菀(AstertararicusL.f.)中分离到紫菀酮(shionone)、槲皮素(quercetin)、无羁萜(friedelin)、表无羁萜(epifriedelinel)、毛叶醇(lachnophyllol)、乙酸毛叶酯(lachnophyllolacetate)、茴香醚(anethole)以及紫菀三萜皂甙[2—4]… 相似文献
92.
刺果番荔枝中的番荔枝内酯 总被引:4,自引:0,他引:4
从刺果番荔枝(Annona m uricata L.)的种子中分离到3 个单四氢呋喃型番荔枝内酯类化合物,用波谱方法鉴定为海南哥纳香甲素(how iicin A, S13)、乙素(how iicin B, S5)和新化合物4-去氧海南哥纳香乙素(4-desoxyhow iicin B, S2)。 相似文献
93.
94.
L. H. Li Y. S. Dong 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1993,87(3):361-368
Trigeneric hybrids between the (Triticum aestivum ×Agropyron michnoi) F1 (CM, 2n=5x=35; ABDPP) and two winter rye (Secale cereale L., 2n=2x=14; RR) cultivars, Wugong 774 and AR-132, were synthesized. Such trigeneric hybrids could be used to transfer resistance genes for powdery mildew from rye to CM and subsequently to common wheat and to identify (1) the effects of the P genome ofAgropyron on the self-fertility of the hybrids and (2) the differences in genetic background between rye cultivars with marked differences in pollinating habit. The trigeneric hybrids varied widely in morphology and showed a high level of resistance to such diseases as barley yellow dwarf virus (BYDV), stripe rust, leaf rust, stem rust, and powdery mildew. Selfed and many backcross derivatives were obtained from the trigeneric hybrids. The results indicated that rye cvs Wugong 774 and AR132 arose from different gene pools and that the P genome ofAgropyron carries gene(s) responsible for chromosome segregation, leading to functional gamete formation and self-fertility of the hybrids. The F2 and BC1 plants could be obtained in two ways — fusion of the unreduced gametes and the assumed apomixis of unreduced female gametes in the trigeneric hybrid plant II-4 — which indicates that this trigeneric hybrid may be a special genetic stock. Chromosome pairing in the trigeneric hybrids and ways of producing wheat/rye and wheat/Agropyron translocations are discussed. 相似文献
95.
利用染色体配对分析和酯酶及种子醇溶蛋白电泳分析研究了我国育成的11个八倍体小偃麦,结果表明:(a)来源于小麦和中间偃麦草杂交后代的6个部分双二倍体中,中1和中2的偃麦草染色体组不同于中3、中4、中5和小偃78829的偃麦草染色体组;(b)来源于小麦和长穗偃麦草杂交后代的5个部分双二倍体中,小偃784的偃麦草染色体组不同于小偃693和小偃7631中的偃麦草染色体组,表明在长穗偃麦草中有两个互不相同又不同于小麦的染色体组E和F,而小偃7430和小偃68中的偃麦草染色体组很可能是E和F染色体组的重组体;(c)小偃784中的长穗偃麦草染色体组和中5及小偃78829中的中间偃麦草染色体组基本相同,而中2的中间偃麦草染色体组不同于小偃693和小偃7631中的长穗偃麦草染色体组F,这意味着在长穗偃麦草和中间偃麦草中可能只有一个共同的染色体组E。部分双二倍体中酯酶及醇溶蛋白偃麦草染色体特征带的存在和发现,为这些染色体或其片段导入小麦后的鉴定提供了方便。 相似文献
96.
观察了hFPIL6/2对6.5Gyγ线照射NIH小鼠第10天造血功能恢复的影响。结果表明:照射小鼠连续4d给予hFPIL6/2250μg·kg-1·d-1,其脾重、CFU-8、骨髓有核细胞数及CM-CFU分别比对照组增加59.0%、278.5%、57.9%和138.2%,统计学处理均有显著差异;对此四项指标的改善也明显优于25μg组。另外,250μg剂量组小鼠外周血象30d的动态观察结果表明,hFPIL6/2不但能明显提高红细胞和血红蛋白的最低值,而且能使血小板的恢复提前。提示hFPIL6/2在促进血小板生成和促进红系造血方面可能具有良好的应用前景。 相似文献
97.
天花粉蛋白与FMP复合物的晶体结构 总被引:6,自引:1,他引:5
用浸泡法得到了天花粉蛋白(TCS)与FMP复合物的晶体,在SIMENNSX-200B面探测器系统上收集了一套2.0分辨率的X射线衍射数据。用同晶差值傅立叶法解析了复合物的结构,经X—PLOR程序修正得到了TCS—FMP复合物的分子结构并找出了197个水分子,最后的R因子为0.172,键长和键角的RMS偏差分别为0.015和2.922度。TCS—FMP复合物中,FMP与天花粉蛋白分子有较好的结合,其结合位置正处于根据三维结构和突变体信息推测的N一糖苷酶活性口袋之中。它的类嘌呤环夹在Y70和Y111两个侧链环之间,与Y70环近乎平行,其N7和N6分别与TCS分子的G1094羰基氧和I71的N成氢键,N3靠近R163的侧链,其磷酸根则伸向活性口袋的底部,与E189、E160和R163等残基作用。 相似文献
98.
99.
Three overlapping lct genes involved in L-lactate utilization by Escherichia coli. 总被引:10,自引:7,他引:3
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In Escherichia coli, the lct locus at min 80 on the chromosome map is associated with ability to grow on L-lactate and to synthesize a substrate-inducible flavin-linked dehydrogenase. Similar to that of the glpD-encoded aerobic glycerol-3-phosphate dehydrogenase, the level of induced enzyme activity is elevated by aerobiosis. Both of these controls are mediated by the two-component signal transduction system ArcB/ArcA, although sensitivity to the control is much more striking for L-lactate dehydrogenase. This study disclosed that the lct locus contained three overlapping genes in the clockwise order of lctD (encoding a flavin mononucleotide-dependent dehydrogenase), lctR (encoding a putative regulator), and lctP (encoding a permease) on the chromosomal map. These genes, however, are transcribed in the counterclockwise direction. No homology in amino acid sequence was found between aerobic glycerol-3-phosphate dehydrogenase and L-lactate dehydrogenase. A phi (lctD-lac) mutant was inducible by L-lactate but not D-lactate. Although the mutant lost the ability to grow on L-lactate, growth on D-lactate, known to depend on a different enzyme, remained normal. 相似文献
100.
H.-P. Lipp D. P. Wolfer W. X. Qin C. B. Klee C. W. Heizmann† 《Journal of neurochemistry》1993,60(5):1639-1649
Abstract: The distribution of a novel calcium-binding protein with a molecular mass of 18 kDa (CBP-18) in the rat brain was studied by means of biochemical methods and immunohistochemistry on cryostat-sectioned tissue and compared with staining patterns of parvalbumin on adjacent sections. The biochemical analysis revealed high levels of CPB-18 in cortex and cerebellum, low levels in the lungs, and undetectable levels in all other tissues tested. Immunohistochemically, the polyclonal rabbit-derived antibody for CPB-18 showed selective affinity with periglomerular cells and dendrites in the olfactory bulb. Distinct immunostaining of scattered cells and their proximal dendrites was found in the anterior olfactory nuclei and in the perirhinal and entorhinal cortex. Strong staining of neuropil with recognizable but diffusely outlined cells was observed in the retrosplenial cortex, central amygdala, hippocampal rudiment, septum, area preoptica, hypothalamus, colliculus superior, and parabrachial nuclei. The cerebellum showed strong neuropil staining of both the molecular and the granule cell layer. Less intense neuropil staining and a few scattered cells were found in the neocortex, the remaining basal forebrain, and in the entire brainstem. Immunoreactivity was barely detectable or missing in the striatum, the hippocampus, the thalamus, and in the colliculus inferior. Thus, CPB-18 shows a unique staining pattern in the CNS, different from all other Ca2+ -binding proteins studied so far. 相似文献