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21.
Endogenous gibberellins (GAs) were extracted and purified from apical buds of Eucalyptus nitens (Deane and Maid.) Maid. and the cambial region of E. globulus (Labill.). then analysed by capillary gas chromatography-mass spectrometry. GA1 GA19 GA20 and GA29 were identified by full scan mass spectra. Kovats retention indices and high resolution selected ion monitoring. Using deuterated internal standards. GA1. GA19. GA20 and putative GA29 and GA53 were quantified in the apical buds, while GA4. GA8. GA9 and GA44 were shown to be either absent or present at very low levels. From the cambial region. GA1 and GA20 were quantified at levels of 0.30 ng (g fresh weight)-1 and 8.8 ng (g fresh weight)-1 respectively. These data suggest that the early 13-hydroxylation pathway is the dominant pathway for GA biosynthesis in Eucalyptus .  相似文献   
22.
The effect of fungicides on the production of aflatoxin byAspergillus flavus IMI 89717, diacetoxyscirpenol and zearalenone byFusarium graminearum was studied. In a yeast extract - sucrose medium, dicloran, iprodione and vinclozolin fungicides significantly inhibited mycelial growth ofA. flavus at 250 ppm and significantly decreased aflatoxin production at 100, 250 and 500 ppm, respectively. In potato — dextrose broth, these fungicides diminished the mycelial growth ofF. graminearum and production of diacetoxyscirpenol and zearalenone at 100 ppm. Sensitivity of toxigenic mycelia to fungicides increased approximately five-fold in a yeast extract-starch medium with an appreciable reduction in sugar uptake andα-amylase activity.  相似文献   
23.
Schiff bases (imines or azomethines) are versatile ligands synthesized from the condensation of amino compounds with active carbonyl groups and used for many pharmaceutical and medicinal applications. In our study, we aimed to determine the cytotoxic, antifungal and larvicidal activities of biologically potent bis-sulfonamide Schiff base derivatives that were re-synthesized by us. For this aim, 16 compounds were re-synthesized and tested for their cytotoxic, antifungal and larvicidal properties. Among this series, compounds A1B2 , A1B4 , A4B2 , A4B3 , and A4B4 were shown to have cytotoxic activity against tested cancer lung cell line (A549). The most potent antifungal activity was observed in compounds A2B1 and A2B2 against all fungi. A1B1 showed the strongest larvicidal effect at all concentrations at the 72nd h (100% mortality). These obtained results demonstrate that these type of bis-substituted compounds might be used as biologically potent pharmacophores against different types of diseases.  相似文献   
24.
Cancer is one of the main challenges of the health system around the world. This disease is increasing in developing countries and imposes heavy costs on patients and governments. On the other hand, despite various drugs, the death rate among cancer patients is still high and the current treatments have many harmful effects. In the traditional medicine of different countries, there are many medicinal plants that can be effective in the treatment of cancer. Ferula plants are traditionally used as spices and food or for medicinal purposes. Ferula assa-foetida is one of the famous plants of this genus, which has been used for the treatment of various diseases since ancient times. Among the main compounds of this plant, we can mention monoterpenes, sulfide compounds and polyphenols, which can show different therapeutic effects. This article has been compiled with the aim of collecting evidence and articles related to the anti-cancer effects of extracts, derived compounds, essential oils and nanoparticles containing Ferula assa-foetida. This review article was prepared by searching the terms Ferula assa-foetida and cancer, and relevant information was collected through searching electronic databases such as ISI Web of Knowledge, PubMed, and Google Scholar. Fortunately, the results of this review showed that relatively comprehensive studies have been conducted in this field and shown that Ferula assa-foetida can be very promising in the treatment of cancer.  相似文献   
25.
A thiol compound, glutathione, is essential for healthy cell defence against xenobiotics and oxidative stress. Glutathione reductase (GR) and glutathione S-transferase (GST) are two glutathione-related enzymes that function in the antioxidant and the detoxification systems. In this study, potential inhibitory effects of methyl 4-aminobenzoate derivatives on GR and GST were examined in vitro. GR and GST were isolated from human erythrocytes with 7.63 EU/mg protein and 5.66 EU/mg protein specific activity, respectively. It was found that compound 1 (methyl 4-amino-3-bromo-5-fluorobenzoate with Ki value of 0.325±0.012 μM) and compound 5 (methyl 4-amino-2-nitrobenzoate with Ki value of 92.41±22.26 μM) inhibited GR and GST stronger than other derivatives. Furthermore, a computer-aided method was used to predict the binding affinities of derivatives, ADME characteristics, and toxicities. Derivatives 4 (methyl 4-amino-2-bromobenzoate) and 6 (methyl 4-amino-2-chlorobenzoate) were estimated to have the lowest binding energies into GR and GST receptors, respectively according to results of in silico studies.  相似文献   
26.
In this study, we investigated the combined treatment of 5-fluorouracil (5-FU) and Anatolian propolis extract (PE) on colorectal cancer (CRC)using in vitro and in vivo studies. We exposed luciferase-transfected (Lovo-Luc CRC) cells and healthy colon cells (CCD-18Co) to varying concentrations of 5-FU and PE to assess their genotoxic, apoptotic, and cytotoxic effects, as well as their intracellular reactive oxygen species (iROS) levels. We also developed a xenograft model in nude mice and evaluated the anti-tumor effects of PE and 5-FU using various methods. Our findings showed that the combination of PE and 5-FU had selectivity against cancer cells, particularly at higher doses, and enhanced the anti-tumor effectiveness of 5-FU against colon CRC. The results suggest that PE can reduce side effects and increase the effectiveness of 5-FU through iROS generation in a dose-dependent manner.  相似文献   
27.
Mycobacteria have the ability to persist within host phagocytes, and their success as intracellular pathogens is thought to be related to the ability to modify their intracellular environment. After entry into phagocytes, mycobacteria-containing phagosomes acquire markers for the endosomal pathway, but do not fuse with lysosomes. The molecular machinery that is involved in the entry and survival of mycobacteria in host cells is poorly characterized. Here we describe the use of organelle electrophoresis to study the uptake of Mycobacterium bovis bacille Calmette Guerin (BCG) into murine macrophages. We demonstrate that live, but not dead, mycobacteria occupy a phagosome that can be physically separated from endosomal/lysosomal compartments. Biochemical analysis of purified mycobacterial phagosomes revealed the absence of endosomal/lysosomal markers LAMP-1 and β-hexosaminidase. Combining subcellular fractionation with two-dimensional gel electrophoresis, we found that a set of host proteins was present in phagosomes that were absent from endosomal/lysosomal compartments. The residence of mycobacteria in compartments outside the endosomal/lysosomal system may explain their persistence inside host cells and their sequestration from immune recognition. Furthermore, the approach described here may contribute to an improved understanding of the molecular mechanisms that determine the intracellular fate of mycobacteria during infection.  相似文献   
28.
29.
According to the rate of depletion of CD4 cell counts, we grouped 12 cases of human immunodeficiency virus type 1 (HIV-1) infection as 6 rapid (21.0 to 33.8 cells per microl per month) and 6 slow (0.9 to 7.9 cells per microl per month) progressors and determined the individual viral quasispecies patterns by sequencing the genome region encoding the V1, V2, and V3 loops of envelope protein. Although the quasispecies structures varied widely from one individual to another, a strong correlation was observed between a low rate of disease progression and a high degree of genetic diversity of HIV-1. Furthermore, the V2 loop extension was observed specifically in individuals with slow or no disease progression, whereas basic amino acid substitutions in V3 characteristic of a viral phenotype shift from non-syncytium inducing to syncytium inducing were observed in patients with advanced stages of disease regardless of their rate of disease progression. Studies with recombinant viruses suggested that elongation of V2 potentially restricts the capacity of HIV-1 to replicate in macrophages. Thus, our results suggest the association of distinct sequence features of both V3 and V2 with particular patterns of disease progression. Elongation of the V2 loop may be a good predictor of slow disease progression, while basic substitutions of V3 without elongation of V2 are characteristic of rapid progression.  相似文献   
30.
Genetic regulation of gibberellin deactivation in Pisum   总被引:2,自引:0,他引:2  
The regulation of gibberellin (GA) deactivation was examined using the sin (slender) mutation in the garden pea (Pisum sativum L.). This mutation blocks the deactivation of GA20, the precursor of the bioactive GA1. Firstly, crosses were made to combine sin with the GA biosynthesis mutations na, lhi and le-3. The combination sin na produced a novel phenotype, with long (‘slender’) basal internodes and extremely short (‘nana’) upper internodes. In contrast, the double mutant sin lhi was phenotypically dwarf. The mutation sin causes an accumulation of GA20 in maturing seeds, and this was unaffected by na, since the na mutation is not expressed in seeds. In contrast, lhi seeds did not accumulate GA20, since lhi imposes an early block on GA biosynthesis. Secondly, the effects of sin on several steps in GA deactivation were investigated. In maturing seeds, the mutation sin blocks two steps in GA20 metabolism, namely, GA20 to GA29, and GA29 to GA29-catabolite. In the vegetative plant, on the other hand, sin blocked the step GA20 to GA29, but not GA29 to GA29-catabolite; the steps GA20 to GA81 and GA20 to GA1 were also not impaired in this mutant. It is clear that the effects of sin, like those of na, are strongly organ-specific. The presence of separate enzymes for the steps GA20 to GA29 and GA29 to GA29-catabolite was suggested by the observation that GA8 inhibited the latter step, but not the former, and by the inability of GA20 and GA29 to inhibit each other's metabolism. It is suggested that the Sin gene may be a regulatory gene controlling the expression of two structural genes involved in GA deactivation.  相似文献   
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