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Ligand displacement reactions of fac-(η2-C60)(η2-phen)M(CO)3 (M = Mo, Cr, and W)
(2009)
A mechanistic description of the ligand exchange reactions of fac-(η2-C60)(η2-phen)M(CO)3 (M = Cr, W and Mo); phen = 1,10-phenanthroline) will be presented in this work. The Lewis bases (L) piperidine (pip), triphenyl ...
Sulfmyoglobin formation pathway upon reaction of oxy-myoglobin and hydrogen sulfide
(2019-12-03)
Myoglobin (Mb) binds oxygen with high affinity as a low spin singlet complex and thus functions as an oxygen storage protein. Quantum chemical calculations of oxy-Mb models with hydrogen sulfide (H2S) in the active site ...
Synthesis, chemical and biochemical characterization of TiIV and VIV complexes with anti-tumor activity
(2010)
At the present time in which the metallocene dihalides have shown to possess antitumoral activity, scientists of all around the world have been working with the synthesis and structural modifications to improve their ...
Synthesis, characterization, cytotoxic activity and biological interactions of tungstenocene (lv) derivatives
(2012)
The design of medicinal compounds for cancer therapy is still a challenge. Organometallics offer a wide variety of promising anticancer drug candidates but this field is largely unexplored. This study has been focused on ...
Development of calibration models for the in-line prediction of active pharmaceutical ingredient concentration in the range 0-100% W/W by near infrared and Raman spectroscopy
(2013)
The development of quantitative calibration models by near infrared (NIR) and Raman spectroscopy with the capability of predicting concentration in a wider range than the currently used approach will be described. Current ...
Fourier transform infrared mapping to determine the distribution of active ingredients in pharmaceutical formulations
(2007)
A basic problem in pharmaceutical manufacturing is that a relatively simple formulation can produce widely varying therapeutic performance depending upon how the ingredients are distributed in the final matrix. Many methods ...
Bacterial outer membrane vesicles as mediators of colibactin toxicity
(2021-09-27)
Colibactin is the product of a hybrid non-ribosomal peptide/polyketide synthase complex (pks island) found in some strains of Escherichia coli. Bacterial strains harboring the pks island show peculiar toxicity toward mammalian cells in culture with a distinctive phenotype that includes DNA damage, cell cycle arrest, and megalocytosis of the infected cells. It has been shown by our group that the pks island can be found in the normal gut microflora and its presence is positively correlated with colorectal cancer (CRC). Despite the notable interest in elucidating the mode of action of colibactin, its structure, the detailed mechanism of action, and the mechanism by which colibactin is transported to host cells remains unknown. The broad objective of this investigation was to develop molecular strategies towards the isolation of colibactin in pursuance of its structure and eventually, its mode of action. To do so, we first made a variant strain of the pks+ E. coli IHE3034 deficient of clbP gene, a key enzyme involved in the activation of colibactin. In our strain, removal of clbP did not cause a complete decrease in the megalocytosis phenotype (toxicity) on infected cells as expected but caused the accumulation of an unknown product of 994 Da. In addition, since the production of colibactin takes place in the space between the inner and outer membranes, we explored the involvement of bacterial outer membrane vesicles (OMVs) in colibactin toxicity. In all cases, we compared a natural producer of colibactin, strain IHE3034 with the mutant ΔclbP. We further found that (1) colibactin production does not have any detectable effects on the chemical composition, size, and amount of bacterial OMVs, (2) OMVs were sufficient to elicit the colibactin hallmarks of genotoxicity, including megalocytosis and DNA Damages on treated cells. However, we also found that (3) OMVs from both the pks+ strain and the ΔclbP mutant did not cause interstrand crosslinks, contrary to what was expected based on the proposed genotoxic mode of action of colibactin. Interestingly and an unforeseen outcome, we found that OMVs from the strain incapable to produce the active colibactin ΔclbP mutant, caused a substantial amount of toxicity towards cells. From these efforts, we conclude that OMVs vesicles are involved in the genotoxicity of colibactin although we have yet to find the compound in these vesicles....
Affecting intracellular iron and copper via transmetalation and study of drug delivery systems to improve the specificity of Ti(IV)-based anticancer compounds
(2022-04-27)
Cancer is the principal cause of death globally, and research and how it works have become crucial. Iron (Fe) and Copper (Cu) are essential metals present in many critical biological processes in the human body. These ...
The potential of natural polysaccharides: chemical approaches for bone tissue regeneration
(2021-11-16)
There are approximately 44 million people in the United States alone who suffer from diseases that cause bone density loss; and as life expectancy increases, so do the probabilities of being inflicted with such diseases. ...
Cross-linked cytochrome c-based nanoparticles for targeted and controlled cancer therapy
(2022-05-06)
Cancer is a major public health problem worldwide and is the second leading cause of death in the United States. The persistent need to develop cancer therapeutics with improved safety and efficacy provides constant fuel ...