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71.
Matkar SS Wrischnik LA Hellmann-Blumberg U 《Archives of biochemistry and biophysics》2008,477(1):43-52
Sanguinarine and chelerythrine are naturally occurring benzophenanthridines with multiple biological activities. Sanguinarine is believed to be a potential anticancer agent but its mechanism of action has not been fully elucidated. We previously found that it causes oxidative DNA damage and very rapid apoptosis that is not mediated by p53-dependent DNA damage signaling. Here we show that sanguinarine and chelerythrine cause the production of large amounts of reactive oxygen species (ROS), in particular hydrogen peroxide, which may deplete cellular antioxidants and provide a signal for rapid execution of apoptosis. Several oxidoreductases contribute to cell death induced by sanguinarine and chelerythrine which appear to be reduced upon entering the cell. We propose a model in which the generation of lethal amounts of hydrogen peroxide is explained by enzyme-catalyzed redox cycling between the reduced and oxidized forms of the phenanthridines and discuss the implications of such a mechanism for potential pharmaceutical applications. 相似文献
72.
Christopher A Willoughby Steven M Hutchins Keith G Rosauer Madhumeeta J Dhar Kevin T Chapman Gary G Chicchi Sharon Sadowski David H Weinberg Smita Patel Lorraine Malkowitz Jerry Di Salvo Stephen G Pacholok Kang Cheng 《Bioorganic & medicinal chemistry letters》2002,12(1):93-96
Preparation and screening of mixture libraries based on a 2-arylindole scaffold resulted in the discovery of potent ligands for a variety of G-protein coupled receptors. 相似文献
73.
Ashok V. Bankar Ameeta R. Kumar Smita S. Zinjarde 《Applied microbiology and biotechnology》2009,84(5):847-865
Yarrowia lipolytica is a fungus that degrades hydrophobic substrates very efficiently. The fungus displays several important characteristics
that have encouraged researchers to study various basic biological and biotechnological applications in detail. Although the
organism has been used as model system for studying dimorphism, salt tolerance, heterologous protein expression, and lipid
accumulation, there are no recent reviews on the environmental and industrial applications of this organism. Included here
are applications in bioremediation of environments contaminated with aliphatic and aromatic compounds, organic pollutants,
2,4,6-trinitrotoluene, and metals. A variety of industrially important recent processes for the synthesis of β-hydroxy butyrate,
l-dopa, and emulsifiers have also been reviewed. Production of unique inherent enzymes (inulinases, α-mannosidases), novel
applications of esterases and lipases, and the use of the fungus for heterologous expression of biotechnologically relevant
products have also been highlighted. The review while entailing a general overview focuses critically on some of the recent
advances on the applications of this yeast. The examples cited here demonstrate the use of wild-type, mutant as well as genetically
manipulated strains of Y. lipolytica for the development of different products, processes, and technologies. This also throws light on how a single organism can
be versatile with respect to its metabolic abilities and how it can be exploited for a variety of purposes. This review will
thus form a base for future developments in this field. 相似文献
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Summary Gram negative bacterial isolated PCB-106 produced significant amounts of bioemulsifiers in the late log phase of growth during the shake cultivation in minimal medium with ethanol (115 units/ml). About 3 fold higher emulsification activity was achieved by manipulating the medium components. The emulsifier was found to be more effective towards the mixture of aliphatic and aromatic than individual hydrocarbons. 相似文献
77.
78.
In the present study, a laboratory-scale biofilter column was designed and fabricated. It was packed with a mixture of coal and compost as a packing medium. The column was enriched with an indigenous bacterial strain Pseudomonas taiwanensis isolated from aerobic mixed culture of Sewage Treatment Plant, BITS-Pilani, Pilani campus. The removal of hexavalent chromium [Cr(VI)] from aqueous solution was investigated in the biofilter column. The entire biofiltration operation was divided into five phases (I to V) for a period of 63 days. Biofilter column was subjected to shock loading conditions for 20 days immediately after 63 days of operation. The maximum removal efficiency of 89.4% was obtained during phase V for Cr(VI) inlet concentration of 40 mg L?1. During shock loading, maximum removal efficiency was obtained as 90% for 48.5–50 mg L?1 of initial Cr(VI) concentration. Kinetic parameters of biofiltration process for Cr(VI) removal were also determined by fitting Michaelis-Menten kinetic model with experimental data. The Michaelis-Menten kinetic constants were obtained as 0.258 mg L?1 min?1 and 26.83 mg L?1. It was found that Ottengraf-Van den Oever model with zero-order diffusion limitation fit the experimental data quite well for phases III, IV, and V with coefficient of determination (R2) values .97, .99, and .984, respectively. A possible method for safe disposal of packing medium was also presented in this study. 相似文献
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80.
Shouvik Kumar Nandy Sattwik Das Sadanand Pandey Pallab Kalita Manoj K. Gupta Atul Kabra Pankaj Wadhwa Deepak Kumar 《Luminescence》2024,39(5):e4771
The second-most common cause of death resulting from genetic mutations in DNA sequences is cancer. The difficulty in the field of anticancer research is the application of the traditional methods, which also affects normal cells. Mutations, genetic replication alterations, and chromosomal abnormalities have a direct impact on the effectiveness of anticancer drugs at different stages. Presently, therapeutic techniques utilize nanotechnology, transition metal dichalcogenides (TMDCs), and robotics. TMDCs are being increasingly employed in tumor therapy and biosensing applications due to their biocompatibility, adjustable bandgap, versatile functionality, exceptional photoelectric properties, and wide range of applications. This study reports the advancement of nanoplatforms based on TMDCs that are specifically engineered for responsive and intelligent cancer therapy. This article offers a thorough examination of the current challenges, future possibilities for theranostic applications using TMDCs, and recent progress in employing TMDCs for cancer therapy. Currently, there is significant interest in two-dimensional (2D) TMDCs nanomaterials as ultrathin unique physicochemical properties. These materials have attracted attention in various fields, including biomedicine. Due to their inherent ability to absorb near-infrared light and their exceptionally large surface area, significant efforts are being made to prepare multifunctional nanoplatforms based on 2D TMDCs. 相似文献