干旱胁迫对蒙古黄芪和膜荚黄芪不同器官黄酮类成分积累的影响

以一年生蒙古黄芪和膜荚黄芪幼苗为材料,采用盆栽控水试验,研究连续干旱胁迫12 d及恢复浇水对2种黄芪生理状态及其根、茎、叶中毛蕊异黄酮葡萄糖苷和毛蕊异黄酮2种黄酮类成分含量的影响。结果显示:(1)干旱胁迫明显抑制了2种黄芪地上部生长,对其根系生长则无明显影响;土壤相对含水量在连续干旱处理4 d后就下降,但2种黄芪的叶片相对含水量只有在中度干旱胁迫(连续干旱8～12 d)下才下降,且膜荚黄芪的下降幅度大于蒙古黄芪。(2)干旱胁迫下,蒙古黄芪和膜荚黄芪根和叶中的SOD和POD活性均呈先上升后下降的趋势,且蒙古黄芪根和叶中的SOD和POD活性均低于膜荚黄芪。(3)干旱胁迫下,膜荚黄芪不同器官中的毛蕊异黄酮葡萄糖苷含量表现为叶茎根,而蒙古黄芪根、茎和叶之间毛蕊异黄酮葡萄糖苷含量差异不明显;膜荚黄芪中的毛蕊异黄酮含量表现为叶大于茎,在蒙古黄芪中则表现为茎大于叶;而且2种黄芪的黄酮类成分在同一器官中的积累也有一定的差异性。研究认为,蒙古黄芪的抗旱性高于膜荚黄芪,适度的干旱胁迫能够促进黄芪器官中毛蕊异黄酮葡萄糖苷和毛蕊异黄酮的积累。     

蒙古黄芪不同生育期黄酮类成分积累及其根际微生物多样性研究

该研究比较了内蒙古赤峰市翁牛特旗、锡林郭勒盟正蓝旗、包头市固阳县、山西省大同市浑源县和甘肃省定西市陇西县5个不同种源的蒙古黄芪不同生育期生长情况及黄酮类成分含量积累,并采用Illumina MiSeq高通量测序技术分析不同生育期根际土壤微生物多样性。结果显示:(1)随着生育期推进,固阳、浑源和赤峰种源的黄芪生长较快,根干重在9月份达到峰值,其他生物量指标种源间差异不大。(2)陇西和浑源种源的黄芪根中毛蕊异黄酮葡萄糖苷含量较高,并在9月份达到峰值,而其他成分(芒柄花苷、毛蕊异黄酮和芒柄花素)呈波动变化。(3)蒙古黄芪不同生育期内根际土壤微生物群落差异较大,其中根际细菌变化最为明显,9月份多样性更高,而真菌群落差异相对较小,不同种源间根际微生物群落组成相似。研究表明,蒙古黄芪毛蕊异黄酮葡萄糖苷含量随生育期显著上升,故最佳采收期不宜过早,而微生物群落结构的差异可能是蒙古黄芪获得生长优势和有效成分积累的重要因素之一。     

黄芪化学成分与生态因子的相关性

以主成分分析(PCA)和相关性分析(CA)法研究黄芪中主要有效成分与生态因子的相关性,探究影响黄芪主要成分积累的生态因子.结果表明: 山西产地黄芪中的黄芪甲苷、毛蕊异黄酮苷、芒柄花苷、山奈酚和黄芪多糖的含量显著高于内蒙古和甘肃两地.影响黄芪化学成分含量的气候因子主要为年均相对湿度、年日照时数及7月均温.影响黄芪化学成分含量的土壤元素主要为钙,且钙在一定范围内与毛蕊异黄酮苷、山柰酚、芒柄花苷、槲皮素、黄芪多糖的含量呈负相关.     

黄芪种子萌发及萌发后生长过程中黄酮类化合物合成的动态变化

在对膜荚黄芪和蒙古黄芪种子萌发和萌发后生长时期进行划分的基础上,研究了黄芪中3种主要黄酮类化合物芒柄花素、毛蕊异黄酮和毛蕊异黄酮苷在萌发和萌发后生长过程中含量的变化。为了弄清黄酮含量变化的机制,我们还对黄芪中黄酮生物合成途径酶的转录水平做了研究。结果表明,在种子萌发和萌发后生长阶段,两种黄芪中均出现了明显的黄酮类化合物累积增加的情况。通过检测黄酮类物质生物合成途径酶基因的转录表达水平,我们发现萌发阶段蒙古黄芪中黄酮类物质积累增加主要由上游途径酶基因的表达水平升高引起,而膜荚黄芪中则几乎涉及到所有途径酶。此外,我们还发现萌发后生长阶段中,两种黄芪中合成途径酶基因转录对黄酮类物质含量的调控则选择性地存在时间延迟效应。     

黄芪注射液的化学成分

采用正、反相硅胶柱层析从黄芪注射液原液中分离纯化出 14个化合物 ,经波谱分析鉴定了它们的结构。其中 6个为异黄酮化合物 ,分别是芒柄花素 (1) ,毛蕊异黄酮 (2 ) ,6″ O 乙酰基芒柄花苷 (3) ,芒柄花苷 (7) ,红车轴草异黄酮 7 O β D 吡喃葡萄糖 (12 ) ,毛蕊异黄酮 7 O β D 吡喃葡萄糖 (13) ;1个紫檀烷化合物 ,结构为 9,10 二甲氧基紫檀烷 3 O β D吡喃葡萄糖 (4) ;1个异黄烷化合物 ,结构为 2′ 羟基 3′ ,4′ 二甲氧基异黄烷 7 O β D 吡喃葡萄糖 (6 ) ;另外 6个为黄芪皂苷类化合物 ,分别是乙酰黄芪皂苷Ⅰ(5 ) ,黄芪皂苷Ⅰ (8) ,异黄芪皂苷Ⅰ (9) ,异黄芪皂苷Ⅱ (10 ) ,黄芪皂苷Ⅱ (11)和黄芪甲苷 (14)。其中化合物 3系首次从黄芪属植物中分离得到。     

HPLC-UV-ELSD法同时测定黄芪中黄芪皂苷和黄酮类成分

建立HPLC-UV-ELSD法同时测定黄芪中黄芪皂苷Ⅰ、黄芪皂苷Ⅱ、黄芪皂苷Ⅲ、黄芪甲苷、毛蕊异黄酮葡萄糖苷、刺芒柄花苷、毛蕊异黄酮的含量,并比较四种不同供试液中7种成分的含量差异,实验采用Agilent 5 TC-C_(18)色谱柱(250 mm×4.6 mm,5μm),0.3%甲酸水溶液-乙腈进行梯度洗脱,流速为1.0 mL/min,检测波长254 nm;柱温30℃,漂移管温度70℃。在该色谱条件下,黄芪中7种成分能得到较好的分离,稳定性,重复性及精密度良好。本方法能简便、快捷、有效的测定黄芪药材中多种成分含量。大孔树脂制备供试品中黄芪皂苷和黄酮类成分更高,说明碱化处理对黄芪中的成分含量产生了一定影响。     

引种栽培黄芪药材中主要黄酮类成分含量比较研究

种质资源的筛选和评价对于黄芪的规范化栽培与种植具有重要意义。本研究即分别采用分光光度法、高效液相色谱法测定引种至山西浑源黄芪道地产区不同来源黄芪药材中总黄酮和毛蕊异黄酮、芒柄花素的含量,并进行相关性分析。结果表明:上述成分不仅仅与黄芪栽培方式、产地有关,还与种质来源密切相关;山西、陕西地区黄芪种质适宜在当地栽培和野生种植,而甘肃、内蒙古黄芪引种到山西浑源地区黄酮类物质含量较原产地为高,适宜大面积引种;黄芪药材中毛蕊异黄酮和芒柄花素的含量呈显著的正相关。该研究结果将为黄芪的规范化种植、优良品种选育及质量评价体系的优化提供新的科学依据。     

膜荚黄芪中的异黄酮化合物

从上海崇明产膜荚黄芪(Astragalus membranaceus(Fisch.)Bunge)根的乙醇提取物中分离鉴定了6个异黄酮化合物:8,3＇-二羟基-7,4＇-二甲氧基异黄酮、奥刀拉亭-7-O-β-D-葡萄吡喃糖甙、芒柄花素、7,3＇-二羟基-8,4＇-二甲氧基异黄酮、毛蕊异黄酮和毛蕊异黄酮-7-O-β-D葡萄吡喃糖甙。其中,前两个为新化合物。     

健脾益肺膏主要活性成分的分离鉴定及其含量测定

健脾益肺膏是基于中医"五脏相关学说",结合几十年治疗各种慢性肺病的临床经验总结制作而成的中药制剂。其主要功效药材为黄芪,其他的药材为辅药,起到增强黄芪药效的作用。本文使用各种柱色谱将该药配方中主要成分进行了系统的分离,确定了主要成分的结构。从中分离得到5个主要化合物,通过NMR数据比对,确定了其结构分别为为黄芪甲苷(化合物1)、毛蕊异黄酮葡萄糖苷(化合物2)、β-谷甾醇(化合物3)、果糖(化合物4)和葡萄糖(化合物5);首次测定了其中黄芪甲苷和毛蕊异黄酮葡萄糖苷的含量,分别为0. 014%和0. 008 3%。为后续健脾益肺膏的配方改进及剂型优化提供参考依据。     

宁夏地产黄芪药材MIR定量分析模型构建及产区相关性研究

研究宁夏地产黄芪药材快速质量评价方法。本实验采用HPLC法测定宁夏地产黄芪药材中黄芪甲苷和毛蕊异黄酮葡萄糖苷含量,同时采集黄芪药材的MIR光谱,结合偏最小二乘法(PLS),建立宁夏地产黄芪中黄芪甲苷和毛蕊异黄酮葡萄糖苷的MIR定量分析模型,并进行验证;对宁夏地产黄芪药材红外光谱、二阶导数谱进行分析评价,并对其红外光谱分别进行聚类分析和主成分分析。黄芪甲苷中红外光谱经二阶导数处理后模型最优,模型参数:R~2为99.72,SEE为0.003 7,SEP为0.004 2;毛蕊异黄酮葡萄糖苷中红外光谱经二阶导数处理后模型最优,模型参数:R~2为99.33,SEE为0.000 6,SEP为0.000 7。不同产区黄芪药材相似系数均在0.90以上;二阶导数谱中不同产区黄芪药材酯类、纤维素类和淀粉类成分存在差异;聚类分析和主成分分析发现同心产区和其他产区药材有明显区分。所建的MIR模型有一定的可靠性和预测能力,可用于宁夏地产黄芪药材中黄芪甲苷和毛蕊异黄酮葡萄糖苷含量的定量分析,红外光谱技术可快速评价宁夏产区黄芪药材质量。     

The role of the genesnrf EFG andccmFH in cytochromec biosynthesis inEscherichia coli

It has been suggested that two groups ofEscherichia coli genes, theccm genes located in the 47-min region and thenrfEFG genes in the 92-min region of the chromosome, are involved in cytochromec biosynthesis during anaerobic growth. The involvement of the products of these genes in cytochromec synthesis, assembly and secretion has now been investigated. Despite their similarity to other bacterial cytochromec assembly proteins, NrfE, F and G were found not to be required for the biosynthesis of any of thec-type cytochromes inE. coli. Furthermore, these proteins were not required for the secretion of the periplasmic cytochromes, cytochromec ₅₅₀ and cytochromec ₅₅₂, or for the correct targeting of the NapC and NrfB cytochromes to the cytoplasmic membrane. NrfE and NrfG are required for formate-dependent nitrite reduction (the Nrf pathway), which involves at least twoc-type cytochromes, cytochromec ₅₅₂ and NrfB, but NrfF is not essential for this pathway. Genes similar tonrfE, nrfF andnrfG are present in theE. coli nap-ccm locus at minute 47. CcmF is similar to NrfE, the N-terminal region of CcmH is similar to NrfF and the C-terminal portion of CcmH is similar to NrfG. In contrast to NrfF, the N-terminal, NrfF-like portion of CcmH is essential for the synthesis of allc-type cytochromes. Conversely, the NrfG-like C-terminal region of CcmH is not essential for cytochromec biosynthesis. The data are consistent with proposals from this and other laboratories that CcmF and CcmH form part of a haem lyase complex required to attach haemc to C-X-X-C-H haem-binding domains. In contrast, NrfE and NrfG are proposed to fulfill a more specialised role in the assembly of the formate-dependent nitrite reductase.     

Functional substitution of the recE gene of Bacillus subtilis by the recA gene of Proteus mirabilis

Summary Rec mutants of Bacillus subtilis have been tested for complementation by the recA gene of Proteus mirabilis (recApm) which was introduced into B. subtilis via the plasmid pHP334. In the recE4 mutant of B. subtilis the plasmid pHP334 restored significantly the defects in RecE functions tested: UV-sensitivity, homologous recombination (transduction and transformation) and prophage induction.Although serological methods to detect the presence of RecApm protein in B. subtilis have been unsuccessful, our results strongly indicate that the recE function of B. subtilis is analogous to the recA function of P. mirabilis.Abbreviations Cm^r resistance to chloramphenicol - Em^r resistance to erythromycin - Tc^r resistance to tetracycline - SDS sodium dodecyl sulfate - UV ultraviolet - AS ammonium sulfate     

Multiple invasions of Gypsy and Micropia retroelements in genus Zaprionus and melanogaster subgroup of the genus Drosophila

Background  

The Zaprionus genus shares evolutionary features with the melanogaster subgroup, such as space and time of origin. Although little information about the transposable element content in the Zaprionus genus had been accumulated, some of their elements appear to be more closely related with those of the melanogaster subgroup, indicating that these two groups of species were involved in horizontal transfer events during their evolution. Among these elements, the Gypsy and the Micropia retroelements were chosen for screening in seven species of the two Zaprionus subgenera, Anaprionus and Zaprionus.     

On the identity of dnaP and dnaF genes of Bacillus subtilis

Summary The dnaP strains of Bacillus subtilis are altered in the initiation of DNA replication at high temperature (Riva et al., 1975). Fine mapping of the gene shows that it is located very close to the dnaF gene, described by Karamata and Gross (1970) and mapped by Love et al. (1976) in the polC region. The phenotype of both mutants is indistinguishable: the DNA synthesis stops at non permissive temperature after synthesizing an amount of DNA equivalent to the completion of the rounds of replication already initiated; at permissive temperature they are abnormally sensitive to MMS and are reduced in the ability to be transformed. Both mutants are to be considered as belonging to the dnaF locus.The dnaF gene is very close to the polC gene, which specifies the DNA polymerase III of B. subtilis. The DNA polymerase III of the dnaF mutants is not temperature sensitive in vitro, however, the level of this enzyme is lower by a factor of 4 or 5 in the dnaF mutants, at the permissive temperature. Following shift of dnaF cultures to the non permissive temperature, the level of DNA polymerase III activity specifically decreases further by a factor of at least 10 in the mutant, whereas the DNA polymerase I level is unaffected.The possible roles of the dnaF gene in the control of the cellular level of the DNA polymerase III, and the possibility of a regulatory role of DNA polymerase III in the initiation of DNA replication in bacteria are discussed.Abbreviations and symbols HPUra 6-(p-hydroxyphenylazo)-uracil; mic, minimum inhibitory concentration - MMS methyl-methanesufonate - Pol I Pol II and Pol III: DNA polymerase I, II and III respectively - PCMB parachloro-mercuri-benzoate     

Genetic analysis of the bchC and bchA genes of Rhodobacter sphaeroides

Summary This study has identified by sequence analysis a single gene in the bchC locus of Rhodobacter sphaeroides and three genes, designated bchX, Y and Z, in the bchA locus, which was previously thought to contain only a single gene. All four genes may reside within the same operon and are transcribed in the order bchC-X-Y-Z. Complementation analysis of eight transposon insertion mutants within these genes suggests that bchX, Y and Z are essential for the reduction of 2-devinyl-2hydroxyethyl chlorophyllide a and that bchC encodes the 2-desacetyl-2-hydroxyethyl bacteriochlorophyllide a dehydrogenase. Similarity between the putative BchX protein and dinitrogenase reductase proteins suggests that BchX may also be a reductase, supplying electrons for reduction of 2-devinyl-2-hydroxyethyl chlorophyllide a.     

Primary structure of the tms and prs genes of Bacillus subtilis

Summary The nucleotide sequence was determined of a 3211 nucleotide pair EcoRI-PvuII DNA fragment containing the tms and prs genes as well as a part of the ctc gene of Bacillus subtilis. The prs gene encodes phosphoribosylpyrophosphate (PRPP) synthetase, whereas the functioning of the tms and ctc gene products remains to be established. The prs gene contains an open reading frame of 317 codons resulting in a subunit M_r of 34828. An open reading frame comprising the tms gene contained 456 codons resulting in a putative translation product with an M_r of 49554. Comparison of the deduced B. subtilis PRPP synthetase amino acid sequence with PRPP synthetases from Escherichia coli and rat liver showed extensive similarity. The deduced Tms amino acid sequence was found to be 43% similar to the deduced amino acid sequence of ecourfl, a gene of E. coli with unknown function.     

Chemical composition, in situ ruminal degradability and post-ruminal disappearance of dry matter and crude protein from the halophytic plants Kochia scoparia, Atriplex dimorphostegia, Suaeda arcuata and Gamanthus gamacarpus

Samples of Kochia (K. scoparia), Atriplex (A. dimorphostegia), Suaeda (S. arcuata) and Gamanthus (G. gamacarpus) were collected and analyzed for chemical composition including crude protein (CP), ether extract (EE), ash, neutral detergent fiber (NDFom), acid detergent fiber (ADFom), non-protein N (NPN), Ca, P, Na, K, Cl, Mg, Fe, Cu and Se. In addition, in situ ruminal degradability and post-ruminal disappearance of dry matter (DM) and CP of the samples using a mobile bag technique were determined. Results indicate that the chemical composition of Kochia and Atriplex was notably different from those of Suaeda and Gamanthus. All of these halophytic plants had high concentrations of Na, K, Cl, Cu and Se, and low levels of Ca, P and Mg. The rapidly degradable fractions of DM and CP (g/g) of Kochia (0.31 and 0.35, respectively) and Atriplex (0.39 and 0.50, respectively) were lower than for Suaeda (0.53 and 0.55, respectively) and Gamanthus (0.56 and 0.66, respectively). Ruminal DM and CP disappearance of Kochia (444 and 517 g/kg, respectively) and Atriplex (472 and 529 g/kg, respectively) were lower (P<0.05) than those of Suaeda (553 and 577 g/kg, respectively) and Gamanthus (663 and 677 g/kg, respectively) (P<0.05) using the mobile bag technique. Suaeda had the lowest (P<0.05) NDFom and ADFom disappearance (214 and 232 g/kg, respectively) in the rumen. Kochia scoparia and Atriplex dimorphostegia have more beneficial chemical nutritive components and digestible values versus Suaeda arcuata and Gamanthus gamacarpus.