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351.
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Catharanthus roseus is still the only source for the powerful antitumour drugs vinblastine and vincristine. Some other pharmaceutical compounds
from this plant, ajmalicine and serpentine are also of economical importance. Although C. roseus has been studied extensively and was subject of numerous publications, a full characterization of its alkaloid pathway is
not yet achieved. Here we review some of the recent work done on this plant. Most of the work focussed on early steps of the
pathway, particularly the discovery of the 2-C-methyl-d-erythritol 4-phosphate (MEP)-pathway leading to terpenoids. Both mevalonate and MEP pathways are utilized by plants with
apparent cross-talk between them across different compartments. Many genes of the early steps in Catharanthus alkaloid pathway have been cloned and overexpressed to improve the biosynthesis. Research on the late steps in the pathway
resulted in cloning of several genes. Enzymes and genes involved in indole alkaloid biosynthesis and various aspects of their
localization and regulation are discussed. Much progress has been made at alkaloid regulatory level. Feeding precursors, growth
regulators treatments and metabolic engineering are good tools to increase productivity of terpenoid indole alkaloids. But
still our knowledge of the late steps in the Catharanthus alkaloid pathway and the genes involved is limited. 相似文献
354.
Plasma Physics Reports - The plasma current sheath (PCS) shape and trapping efficiency η are investigated experimentally. The experiments are carried out at the 2.2-kJ Egyptian Atomic Energy... 相似文献
355.
Hegazy Maha A. Abdelmonsif Doaa A. Zeitoun Teshreen M. El-Sayed Norhan S. Samy Doaa M. 《Journal of physiology and biochemistry》2022,78(1):109-124
Journal of Physiology and Biochemistry - Recent studies have suggested that irisin may act as a potential neurokine. Exercise and L-carnosine supplementation showed neuroprotective effects in... 相似文献
356.
Abdel-Hameed el-SS El-Nahas HA El-Wakil EA Ahmed WS 《Zeitschrift für Naturforschung. C, Journal of biosciences》2007,62(5-6):319-325
The methanol extract of the whole parts of Tribulus macropterus Boiss. (family Zygophyllaceae) showed cytotoxic activity against a human tumour cell line (hepatocyte generation 2, HepG2) (IC50 = 2.9 microg/ml). The n-butanolic fraction obtained from successive fractionation of the methanolic extract exhibited activity against HepG2 (IC50 = 2.6 microg/ml). Therefore, this fraction was subjected to separation using different chromatographic techniques. Five compounds, 1-5, were isolated and identified as: (22S,25S)-16beta,22,26-trihydroxy-cholest-4-en-3-one-16-O-beta-D-glucopyranosyl-(1-->3)-beta-D-xylopyranoside (1), (22S,25S)-16beta,22,26-trihydroxy-cholest-4-en-3-one-16-O-beta-D-glucopyranosyl-(1-->3)-beta-D-glucopyranoside (2), sucrose (3), D-pinitol (4) and 3beta-hydroxy-5a-pregn-16(17)en-20-one-3-O-beta-D-xylopyranosyl-(1-->2)-[beta-D-xylopyranosyl-(1-->3)]-beta-D-glucopyranosyl-(1-->4)-[alpha-L-rhamnopyranosyl-(1-->2)]-beta-D-ga-lactopyranoside (5) on the basis of spectroscopic and chemical data. The three steroidal compounds 1, 2 and 5 were also tested against the same cell line HepG2 and their IC50 values were 2.4, 2.2 and 1.1 microg/ml, respectively. 相似文献
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358.
Reham R. Khattab Asma K. Alshamari Allam A. Hassan Hussein H. Elganzory Wael A. El-Sayed Hanem M. Awad Eman S. Nossier Nasser A. Hassan 《Journal of enzyme inhibition and medicinal chemistry》2021,36(1):504
In the current study, new thienopyrimidine conjugates bearing 1,2,3-triazole core and different sugar moieties have been designed and synthesized by Cu(I)-catalysed click dipolar cycloaddition. The cytotoxic activity of the synthesised conjugates 2, 5, 7, and 13–18 was studied against HCT-116 and MCF-7 cell lines by the MTT assay. The triazole glycosides 16 and 18 provided significant cytotoxic activities against HCT-116 cell lines comparable to that of doxorubicin and other studied compounds. The cytotoxic behaviour against MCF-7 exhibited that all the investigated compounds were more potent than doxorubicin. Moreover, all screened targets were evaluated against mutant EGFR kinase type L858R and the results revealed that the acetylated 1,2,3-triazole glycosides 13–18 exhibited excellent EGFR inhibitory activity in comparison with gefitinib. Furthermore, molecular modelling studies were performed to investigate the binding affinity of the most active compounds to EGFR enzyme. 相似文献
359.
Éric HFF Frederico Ailton A Santos Danúbia C Sá-Caputo Rosane F Neves Carlos AS Guimarães Shyang Chang Mario Bernardo-Filho 《Journal of biosciences》2016,41(1):63-68
Laser used to stimulate acupoints is called laser acupuncture (LA). It is generally believed that similar clinical responses to manual acupuncture can be achieved. Here we analysed the effects of the laser (904 nm) at the ‘Zusanli’ acupoint (ST.36) of the stomach meridian on the biodistribution of the radiopharmaceutical Na99mTcO4. Wistar rats were divided into control (CG) and experimental groups (EG). The EG were exposed daily to the laser (904 nm) at ST.36 with 1 joule/min (40 mW/cm2) for 1 min. The animals of the CG were not exposed to laser at all. On the 8th day after LA, the animals were sedated and Na99mTcO4 was administered. After 10 min, the animals were all sacrificed and the organs removed. The radioactivity was counted in each organ to calculate the percentage of radioactivity of the injected dose per gram (%ATI/g). Comparison of the %ATI/g in EG and CG was performed by Mann-Whitney test. The %ATI/g was significantly increased in the thyroid due to the stimulation of the ST.36 by laser. It is possible to conclude that the stimulation of ST.36 does lead to biological phenomena that interfere with the metabolism of the thyroid. 相似文献
360.
El-Sayed R. El-Sayed Shaimaa A. Mousa Dalia A.M. Abdou Mohamed A. Abo El-Seoud Adel A. Elmehlawy Samar S. Mohamed 《Saudi Journal of Biological Sciences》2022,29(4):2463-2474
Developing a suitable applicative process and scaling up the microbial synthesis of nanomaterials is an attractive and emerging prospect for a future sustainable industrial production. In this paper, optimization of fermentation conditions for enhanced production of Co3O4, CuO, Fe3O4, NiO, and ZnO nanoparticles by the endophytic A. terreus ORG-1 was studied. Different cultivation conditions were evaluated. Then, a response surface methodology program was used to optimize physical conditions controlling the biosynthesis of these NPs. Finally, the use of gamma irradiation for improvement of NPs’ production was adopted. Under the optimum conditions and after gamma irradiation, the final yields of the respective NPs reached 545.71, 651.67, 463.19, 954.88, 1356.42 mg L−1. To the best of our knowledge, this is the first report on the production and enhancement of different types of nanomaterials from one microbial culture that can open up the way towards the industrialization of the microbial production of nanomaterials. 相似文献