31 research outputs found
Exceptional activity of gallium(III) chloride and chlorogallate(III) ionic liquids for BaeyerâVilliger oxidation
The extremely high activity of chlorogallate(iii) ionic liquids and GaCl3 in promoting BaeyerâVilliger oxidation of cyclic ketones with H2O2 to lactones is reported.</p
Nuclear fate of yeast snoRNA is determined by co-transcriptional Rnt1 cleavage
Small nucleolar RNA (snoRNA) are conserved and essential non-coding RNA that are transcribed by RNA Polymerase II (Pol II). Two snoRNA classes, formerly distinguished by their structure and ribonucleoprotein composition, act as guide RNA to target RNA such as ribosomal RNA, and thereby introduce specific modifications. We have studied the 5'end processing of individually transcribed snoRNA in S. cerevisiae to define their role in snoRNA biogenesis and functionality. Here we show that pre-snoRNA processing by the endonuclease Rnt1 occurs co-transcriptionally with removal of the m7G cap facilitating the formation of box C/D snoRNA. Failure of this process causes aberrant 3'end processing and mislocalization of snoRNA to the cytoplasm. Consequently, Rnt1-dependent 5'end processing of box C/D snoRNA is critical for snoRNA-dependent methylation of ribosomal RNA. Our results reveal that the 5'end processing of box C/D snoRNA defines their distinct pathway of maturation
Defining Known Drug Space Using DFT.
A density functional theory (DFT) study was performed on a collection of clinically approved drugs, or Known Drug Space (KDS), to determine the statistical distribution of four properties: dipole moment (DM), polarisability (POL), ionisation potential (IP) and electron affinity (EA). The DM and POL are linked to cell permeability of drugs whereas IP and EA reflect their redox stability thus ease of metabolism. A benchmarking exercise showed a good correlation between experimental values and their predicted counterparts. It was found that KDS occupies the volume of chemical space defined by: DMâ€10â
D, POLâ€68â
Ă
3, IP 6.0â9.0â
V and EAâ1.5â2.0â
eV. Only 16â% of the drugs are outside one or more of these parameters. Three categories based on known oral absorption and bioavailability (low/medium/high) were established and compared. Predominately, drugs designated as âlowâ were found outside the established parameters. The properties were compared with mainstream molecular descriptors and a strong correlation was seen for POL to MW (r2=0.899), which can explain the success of the latter since POL reflects the ability of molecules to interact with polar and non-polar environments such as water and interior of a membrane
Silica-supported chlorometallate(III) ionic liquids as recyclable catalysts for DielsâAlder reaction under solventless conditions
The first catalytic application of supported chlorometallate(iii) ionic liquids as recyclable heterogeneous catalysts for a DielsâAlder reaction under solventless conditions.</p
Functional Magnetic Resonance Imaging and ObesityâNovel Ways to Seen the Unseen
Obesity remains a pandemic of the 21st century. While there are many causes of obesity and potential treatments that are currently known, source data indicate that the number of patients is constantly increasing. Neural mechanisms have become the subject of research and there has been an introduction of functional magnetic resonance imaging in obesity-associated altered neural signaling. Functional magnetic resonance imaging has been established as the gold standard in the assessment of neuronal functions related to nutrition. Thanks to this, it has become possible to delineate those regions of the brain that show altered activity in obese individuals. An integrative review of the literature was conducted using the keywords ââfunctional neuroimagingâ OR âfunctional magnetic resonance âOR âfmriâ and âobesityâ and âreward circuit and obesityâ in PubMed and Google Scholar databases from 2017 through May 2022. Results in English and using functional magnetic resonance imaging to evaluate brain response to diet and food images were identified. The results from functional magnetic resonance imaging may help to identify relationships between neuronal mechanisms and causes of obesity. Furthermore, they may provide a substrate for etiology-based treatment and provide new opportunities for the development of obesity pharmacotherapy
Studies on the solubility of terephthalic acid in ionic liquids
Low solubility of terephthalic acid in common solvents makes its industrial production very difficult and not environmentally benign. Ionic liquids are known for their extraordinary solvent properties, with capability to dissolve a wide variety of materials, from common solvents to cellulose, opening new possibilities to find more suitable solvents for terephthalic acid. This work presents studies on the solubility of terephthalic acid in ionic liquids, and demonstrates that terephthalic acid is soluble in ionic liquids, such as 1-ethyl-3-methylimidazolium diethylphosphate, 1-butyl-3-methylimidazolium acetate, and dialkylimidazolium chlorides up to four times higher than in DMSO. Additionally, the temperature effect and correlation of ionic liquid structure with solubility efficiency are discussed
Inexpensive and tuneable protic ionic liquids based on sulfuric acid for the biphasic synthesis of alkyl levulinates
Tailoring ionic liquid catalysts: structure, acidity and catalytic activity of protonic ionic liquids based on anionic clusters, [(HSO4)(H2SO4)x]â (x = 0, 1, or 2)
The speciation of a family of inexpensive, easily prepared protonic ionic liquids, their physico-chemical properties and their performance as catalysts in the model esterification reaction have been correlated.</p