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991.
992.
Nine new triterpenoid saponins (1–9) have been isolated from the roots of Gypsophila perfoliata Linn. Their structures were established on the basis of extensive NMR (1H, 13C, HSQC and HMBC) and ESIMS studies. 相似文献
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995.
Three monoterpenoids and two triterpenoids were isolated from Abiesnephrolepis together with 53 known terpenoids. The structures of the compounds were established by 1D and 2D NMR spectroscopy. The absolute configuration of 3-hydroxycamphane-2-carboxylic acid was established as (1S,2R,3S,4R) by Cu-Kα X-ray crystallography. All 58 isolates were tested for cytotoxic activity against four tumor cells viz. A549 (human lung adenocarcinoma), Colo205 (colon adenocarcinoma), QGY-7703 (human hepatoma) and THP-1 (human monocytic leukemia). α-Cadinol exhibited the best effects on A549, Colo205 and QGY-7703 with IC50 values of 8.6, 8.1 and 4.6 μg/mL, respectively. 相似文献
996.
By analyzing the steroidal content of fresh whole plants of Tacca subflabellata (Taccaceae), we isolated one sapogenin and eight glycosides with four kinds of steroidal skeletons including four new glycosides, named taccasubosides A-D (1-4), together with five known compounds. Among them, compound 1 is the first pentacyclic sterol glycoside with 6-6-6-5-6 fused rings. The structures of 1-4 were elucidated on the basis of extensive spectroscopic analysis, including that of 2D NMR data, and the results of acidic hydrolysis. The cytotoxicity of the selected steroidal glycosides (1-4, 8, and 9) was evaluated in vitro against five human cancer cell lines. Compound 9 showed significant inhibitory activity against all five cell lines. 相似文献
997.
998.
Identification and mapping of a new powdery mildew resistance gene on chromosome 6D of common wheat 总被引:1,自引:0,他引:1
Ma H Kong Z Fu B Li N Zhang L Jia H Ma Z 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2011,123(7):1099-1106
Powdery mildew, caused by Blumeria graminis f. sp. tritici, is one of the most serious wheat diseases. The rapid evolution of the pathogen's virulence, due to the heavy use of resistance genes, necessitates the expansion of resistance gene diversity. The common wheat line D57 is highly resistant to powdery mildew. A genetic analysis using an F(2) population derived from the cross of D57 with the susceptible cultivar Yangmai 158 and the derived F(2:3) lines indicated that D57 carries two dominant powdery mildew resistance genes. Based on mapping information of polymorphic markers identified by bulk segregant analysis, these two genes were assigned to chromosomes 5DS and 6DS. Using the F(2:3) lines that segregated in a single-gene mode, closely linked PCR-based markers were identified for both genes, and their chromosome assignments were confirmed through linkage mapping. The gene on chromosome 5DS was flanked by Xgwm205 and Xmag6176, with a genetic distance of 8.3 cM and 2.8 cM, respectively. This gene was 3.3 cM from a locus mapped by the STS marker MAG6137, converted from the RFLP marker BCD1871, which was 3.5 cM from Pm2. An evaluation with 15 pathogen isolates indicated that this gene and Pm2 were similar in their resistance spectra. The gene on chromosome 6DS was flanked by co-segregating Xcfd80 and Xmag6139 on one side and Xmag6140 on the other, with a genetic distance of 0.7 cM and 2.7 cM, respectively. This is the first powdery mildew resistance gene identified on chromosome 6DS, and plants that carried this gene were highly resistant to all of the 15 tested pathogen isolates. This gene was designated Pm45. The new resistance gene in D57 could easily be transferred to elite cultivars due to its common wheat origin and the availability of closely linked molecular markers. 相似文献
999.
The phosphorylation of glutamate receptor 1 (GluR1) has been increasingly implicated in the formation and maintenance of plastic
responses. To investigate molecular mechanisms that underlie the persisting alterations in motor response occurring with levodopa
treatment of parkinsonian patients, we evaluated the time course of these changes in relation to the phosphorylation of GluR1
in 6-hydroxydopamine (6-OHDA) lesioned animals. Three weeks of twice-daily levodopa administration to rats shortened the duration
of the rotational responses and increased the peak turning responses, which lasted at least 7 days after withdrawal of chronic
levodopa treatment. The shortened response duration and increased peak turning, resembling human wearing-off fluctuations
and dyskinesia, were associated with a marked increase in Ser-845 phosphorylated GluR1 (pGluR1S845) immunoreactivity in lesioned
striatum in response to levodopa treatment. The time course of changes in GluR1 phosphorylation correlated with the time course
of changes in motor behavior after withdrawal of chronic levodopa therapy. Our immunostaining data showed that these changes
were confined to parvalbumin-positive neurons where GluR1 are exclusively expressed. Both the altered motor response and the
degree of pGluR1S845 were attenuated by the intrastriatal administration of protein kinase A (PKA) inhibitor Rp-cAMPS or GluR1
antisense oligonucleotides. The results suggest that Ser-845 GluR1 phosphorylation within parvalbumin-positive neurons contributes
to the persistence of the motor response alterations produced by chronic intermittent dopaminergic stimulation. 相似文献
1000.
Ariffin N Abdullah R Rashdan Muad M Lourdes J Emran NA Ismail MR Ismail I Fadzil MF Ling KL Siddiqui Y Amir AA Berahim Z Husni Omar M 《Plasmid》2011,66(3):136-143
Polyhydroxybutyrate-co-hydroxyvalerate (PHBV) is a polyhydroxyalkanoate (PHA) bioplastic group with thermoplastic properties is thus high in quality and can be degradable. PHBV can be produced by bacteria, but the process is not economically competitive with polymers produced from petrochemicals. To overcome this problem, research on transgenic plants has been carried out as one of the solutions to produce PHBV in economically sound alternative manner. Four different genes encoded with the enzymes necessary to catalyze PHBV are bktB, phaB, phaC and tdcB. All the genes came with modified CaMV 35S promoters (except for the tdcB gene, which was promoted by the native CaMV 35S promoter), nos terminator sequences and plastid sequences in order to target the genes into the plastids. Subcloning resulted in the generation of two different orientations of the tdcB, pLMIN (left) and pRMIN (right), both 17.557 and 19.967 kb in sizes. Both plasmids were transformed in immature embryos (IE) of oil palm via Agrobacterium tumefaciens. Assays of GUS were performed on one-week-old calli and 90% of the calli turned completely blue. This preliminary test showed positive results of integration. Six-months-old calli were harvested and RNA of the calli were isolated. RT-PCR was used to confirm the transient expression of PHBV transgenes in the calli. The bands were 258, 260, 315 and 200 bp in size for bktB, phaB, phaC and tdcB transgenes respectively. The data obtained showed that the bktB, phaB, phaC and tdcB genes were successfully integrated and expressed in the oil palm genome. 相似文献