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排序方式: 共有628条查询结果,搜索用时 15 毫秒
1.
Selvakumar N Yadi Reddy B Sunil Kumar G Khera MK Srinivas D Sitaram Kumar M Das J Iqbal J Trehan S 《Bioorganic & medicinal chemistry letters》2006,16(16):4416-4419
A series of conformationally constrained analogues of Linezolid were synthesised by employing a tandem SN(2) and SNAr reaction as the key step and tested for antibacterial activity. While the hexahydroazolo-quinoxaline compounds were inactive, the tetrahydroazolo-benzothiazine compounds exhibited interesting antibacterial activity. The introduction of fluorine in the aromatic ring further made the compounds more potent in acetamide compounds resulting in an interesting analogue 32. However, the introduction of fluorine (analogue 34) on the already potent non-fluorine thiocarbamate 21 did not have any influence on the activity. 相似文献
2.
Mahboob Ahmad Malik M. Ahmad Rifat Hamid M. Z. Abdin Saleem Javed 《Mycotoxin Research》2013,29(1):39-45
Aflatoxins are one of the most important secondary metabolites. These extrolites are produced by a number of Aspergillus fungi. In this study, we demonstrate the effect of media components and enhanced aflatoxin yield shown by A. flavus using response surface methodology in response to different nutrients. Different components of a chemically defined media that influence the aflatoxin production were monitored using Plackett–Burman experimental design and further optimized by Box–Behnken factorial design of response surface methodology in liquid culture. Interactions were studied with five variables, namely sorbitol, fructose, ammonium sulfate, KH2PO4, and MgSO4.7H2O. Maximum aflatoxin production was envisaged in medium containing 4.94 g/l sorbitol, 5.56 g/l fructose, 0.62 g/l ammonium sulfate, 1.33 g/l KH2PO4, and 0.65 g/l MgSO4·7H2O using response surface plots and the point prediction tool of the DESIGN EXPERT 8.1.0 (Stat-Ease, USA) software. However, a production of 5.25 μg/ml aflatoxin production was obtained, which was in agreement with the prediction observed in verification experiment. The other component (MgSO4.7H2O) was found to be an insignificant variable. 相似文献
3.
Florian Noulin Javed Karim Manesia Anna Rosanas-Urgell Annette Erhart Céline Borlon Jan Van Den Abbeele Umberto d'Alessandro Catherine M. Verfaillie 《PloS one》2014,9(11)
The predilection of Plasmodium vivax (P. vivax) for reticulocytes is a major obstacle for its establishment in a long-term culture system, as this requires a continuous supply of large quantities of reticulocytes, representing only 1–2% of circulating red blood cells. We here compared the production of reticulocytes using an established in vitro culture system from three different sources of hematopoietic stem/progenitor cells (HSPC), i.e. umbilical cord blood (UCB), bone marrow (BM) and adult peripheral blood (PB). Compared to CD34+-enriched populations of PB and BM, CD34+-enriched populations of UCB produced the highest amount of reticulocytes that could be invaded by P. vivax. In addition, when CD34+-enriched cells were first expanded, a further extensive increase in reticulocytes was seen for UCB, to a lesser degree BM but not PB. As invasion by P. vivax was significantly better in reticulocytes generated in vitro, we also suggest that P. vivax may have a preference for invading immature reticulocytes, which should be confirmed in future studies. 相似文献
4.
Human chorionic gonadotropin (hCG) was initially believed to be secreted exclusively by the embryo with its primary function being "rescue" of the corpus luteum. However, recently it has been found that the hormone (or its individual subunits) is also secreted by many cancers and that in many cases secretion is associated with poor patient prognosis. In this study, we assessed the presence of hCG in colorectal cancer cells (CCL-253) and evaluated the anti-tumour effects of anti-hCG antibodies in vitro and in vivo. Anti-hCG antibodies were reactive with CCL-253, as revealed by confocal immunoflourescence microscopy; both cell surface and intracellular expression were observed. Western blot analysis showed that antibodies appeared to interact with several moieties, indicating a level of cross-reactivity. Anti-hCG antiserum specifically reduced the viability of tumor cells and the addition of complement increased in vitro anti-tumor effects. In nude mice implanted with CCL-253 cells, administration of anti-hCG antiserum caused a significant reduction in tumor volume; all treated animals survived, while mortality was observed in control animals. Results suggest that anti-hCG antibodies can mediate significant anti-tumor activity both in vitro and in vivo and lend support to the rationale of anti-hCG immunization in the therapy of gonadotropin- sensitive cancers. 相似文献
5.
6.
Das J Sitaram Kumar M Subrahmanyam D Sastry TV Prasad Narasimhulu C Laxman Rao CV Kannan M Roshaiah M Awasthi R Patil SN Sarnaik HM Rao Mamidi NV Selvakumar N Iqbal J 《Bioorganic & medicinal chemistry》2006,14(23):8032-8042
In an effort to discover potent antibacterials based on the entropically favored 'bioactive conformation' approach, a series of novel tricyclic molecules mimicking the conformationally constrained structure of Linezolid is reported. Based on the initial tricyclic molecule 1, the benzazepine derivative 2 was designed where the tricyclic structure had more flexibility around C-N bond compared to 1. While, the molecule 2 was less active, the molecule 3 showed promising antibacterial activity presumably after having obtained rigidity due to pyrrole ring. The syntheses, SAR studies, and evaluation of 3 as a lead compound are reported. 相似文献
7.
Muhammad Khan Amara Maryam Javed Iqbal Qazi Tonghui Ma 《International journal of biological sciences》2015,11(9):1100-1112
Cancer is the second leading cause of deaths worldwide. Despite concerted efforts to improve the current therapies, the prognosis of cancer remains dismal. Highly selective or specific blocking of only one of the signaling pathways has been associated with limited or sporadic responses. Using targeted agents to inhibit multiple signaling pathways has emerged as a new paradigm for anticancer treatment. Icariside II, a flavonol glycoside, is one of the major components of Traditional Chinese Medicine Herba epimedii and possesses multiple biological and pharmacological properties including anti-inflammatory, anti-osteoporosis, anti-oxidant, anti-aging, and anticancer activities. Recently, the anticancer activity of Icariside II has been extensively investigated. Here, in this review, our aim is to give our perspective on the current status of Icariside II, and discuss its natural sources, anticancer activity, molecular targets and the mechanisms of action with specific emphasis on apoptosis pathways which may help the further design and conduct of preclinical and clinical trials.Icariside II has been found to induce apoptosis in various human cancer cell lines of different origin by targeting multiple signaling pathways including STAT3, PI3K/AKT, MAPK/ERK, COX-2/PGE2 and β-Catenin which are frequently deregulated in cancers, suggesting that this collective activity rather than just a single effect may play an important role in developing Icariside II into a potential lead compound for anticancer therapy. This review suggests that Icariside II provides a novel opportunity for treatment of cancers, but additional investigations and clinical trials are still required to fully understand the mechanism of therapeutic effects to further validate it in anti-tumor therapy. 相似文献
8.
Mulakayala N Kandagatla B Ismail Rapolu RK Rao P Mulakayala C Kumar CS Iqbal J Oruganti S 《Bioorganic & medicinal chemistry letters》2012,22(15):5063-5066
A convenient and practical methodology for the synthesis of 2-aryl quinazolin-4(3H)-ones by the condensation of o-aminobenzamides with aromatic aldehydes under mild conditions using catalytic InCl(3) with good yields and high selectivities. This method has been extended for the synthesis of 5-aryl pyrazolo[4,3-d]pyrimidin-7(6H)-ones which have potential applications in medicinal chemistry. Many of these compounds were evaluated for their anti-proliferative properties in vitro against four cancer cell lines and several compounds were found to be active. Further in vitro studies indicated that inhibition of sirtuins could be the possible mechanism of action of these molecules. 相似文献
9.
Abdallah A. Hassanin Sayed Haidar Abbas Raza Javed Ahmed Ujjan Ayshah Aysh ALrashidi Basel M. Sitohy Ameena A. AL-surhanee Ahmed M. Saad Tahani Mohamed Al -Hazani Osama Osman Atallah Khalid M. Al Syaad Ahmed Ezzat Ahmed Ayman A. Swelum Mohamed T. El-Saadony Mahmoud Z. Sitohy 《Saudi Journal of Biological Sciences》2022,29(4):1981-1997
The emergence of coronavirus disease 2019 (COVID-19) pandemic in Wuhan city, China at the end of 2019 made it urgent to identify the origin of the causal pathogen and its molecular evolution, to appropriately design an effective vaccine. This study analyzes the evolutionary background of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 or SARS-2) in accordance with its close relative SARS-CoV (SARS-1), which was emerged in 2002. A comparative genomic and proteomic study was conducted on SARS-2, SARS-1, and Middle East respiratory syndrome coronavirus (MERS), which was emerged in 2012. In silico analysis inferred the genetic variability among the tested viruses. The SARS-1 genome harbored 11 genes encoding 12 proteins, while SARS-2 genome contained only 10 genes encoding for 10 proteins. MERS genome contained 11 genes encoding 11 proteins. The analysis also revealed a slight variation in the whole genome size of SARS-2 comparing to its siblings resulting from sequential insertions and deletions (indels) throughout the viral genome particularly ORF1AB, spike, ORF10 and ORF8. The effective indels were observed in the gene encoding the spike protein that is responsible for viral attachment to the angiotensin-converting enzyme 2 (ACE2) cell receptor and initiating infection. These indels are responsible for the newly emerging COVID-19 variants αCoV, βCoV, γCoV and δCoV. Nowadays, few effective COVID-19 vaccines developed based on spike (S) glycoprotein were approved and become available worldwide. Currently available vaccines can relatively prevent the spread of COVID-19 and suppress the disease. The traditional (killed or attenuated virus vaccine and antibody-based vaccine) and innovated vaccine production technologies (RNA- and DNA-based vaccines and viral vectors) are summarized in this review. We finally highlight the most common questions related to COVID-19 disease and the benefits of getting vaccinated. 相似文献
10.
Two DNA fingerprinting techniques, random amplified polymorphic DNA (RAPD) and inter-retrotransposon amplified polymorphism
(IRAP), were used to characterize somaclonal variants of banana. IRAP primers were designed on the basis of repetitive and
genome-wide dispersed long terminal repeat (LTR) retrotransposon families for assessing the somaclonal variation in 2Musa clones resistant and susceptible toFusarium oxysporum f. sp.cubense race 4. RAPD markers successfully detected genetic variation within and between individuals of the clones. IRAP makers amplified
either by a single primer or a combination of primers based on LTR orientation successfully amplified different retrotransposons
dispersed in theMusa genome and detected new events of insertions. RAPD markers proved more polymorphic than IRAP markers. Somaclonal variation
seems to be the result of numerous indels occurring genome-wide accompanied by the activation of retroelements, as a result
of stress caused by micropropagation. It is concluded that characterization of the somaclonal variants requires more than
one DNA marker system to detect variation in diverse components of the genome. 相似文献