Chemocatalytic value addition of glucose without carbon–carbon bond cleavage/formation reactions: an overview

As the monomeric unit of the abundant biopolymer cellulose, glucose is considered a sustainable feedstock for producing carbon-based transportation fuels, chemicals, and polymers. The chemocatalytic value addition of glucose can be broadly classified into those involving C–C bond cleavage/formation reactions and those without. The C₆ products obtained from glucose are particularly satisfying because their syntheses enjoy a 100% carbon economy. Although multiple derivatives of glucose retaining all six carbon atoms in their moiety are well-documented, they are somewhat dispersed in the literature and never delineated coherently from the perspective of their carbon skeleton. The glucose-derived chemical intermediates discussed in this review include polyols like sorbitol and sorbitan, diols like isosorbide, furanic compounds like 5-(hydroxymethyl)furfural, and carboxylic acids like gluconic acid. Recent advances in producing the intermediates mentioned above from glucose following chemocatalytic routes have been elaborated, and their derivative chemistry highlighted. This review aims to comprehensively understand the prospects and challenges associated with the catalytic synthesis of C₆ molecules from glucose.

Recent advances on the production and applications of major C₆ products from glucose have been reported in this review. The preparation and derivative chemistry of sorbitol, sorbitan, 5-(hydroxymethyl)furfural, and isosorbide have been elaborated.     

Virulence factors and drug resistance in Escherichia coli isolated from extraintestinal infections

PURPOSE: To determine the virulence factors produced by Escherichia coli isolated from extraintestinal infections, to study the drug resistance pattern in E. coli with special reference to extended spectrum beta -lactamase (ESBL) and to evaluate screening methods for ESBL. METHODS: A total of 152 isolates of E. coli from various extraintestinal infections were screened for virulence factors such as haemolysin, surface hydrophobicity, serum resistance and protease. All the isolates were also studied for antibiotic susceptibility pattern using modified Kirby Bauer disk diffusion method. ESBL production was screened by standard disk diffusion method and confirmed using phenotypic confirmatory method. RESULTS: Among 152 isolates, 36 (23.7%) were haemolytic, 42 (27.6%) were hydrophobic, 132 (86.8%) were serum resistant and only four were positive for protease. Multiple virulence factor were observed in 67 (44%) of isolates. Seventy-nine (51.4%) isolates produced ESBL. ESBL producing isolates showed multidrug resistance. There was a significant association ( P E. coli . CONCLUSIONS: The present study shows the expression of virulence factors and multidrug resistance in E. coli isolated from various extraintestinal infections. The study also shows that appropriate methods of detecting drug resistance and ESBL production are required for the judicious use of antibiotics in managing these infections.     

Tryptophan Metabolism Along the Kynurenine Pathway Downstream of Toll‐like Receptor Stimulation in Peripheral Monocytes

Tryptophan degradation along the kynurenine pathway is of central importance for the immune function. Toll‐like receptors (TLRs), representing the first line of immune defence against pathogens, are expressed in various cell types. The most abundant expression is found on monocytes, macrophages and dendritic cells. The aim of this study was to investigate whether stimulation with different TLR ligands induces the kynurenine pathway in human peripheral monocytes. Cell supernatants were analysed using a liquid chromatography/mass spectrometry to measure kynurenine, kynurenic acid (KYNA), quinolinic acid (QUIN) and tryptophan. Stimulation of TLR‐2, TLR‐3, TLR‐4, TLR‐7/8 and TLR‐9 was found to induce the production of kynurenine, but only stimulation of TLR‐3 increased levels of further downstream metabolites, such as KYNA and QUIN. Stimulation of TLR‐1, TLR‐5 and TLR‐6 did not induce the kynurenine pathway. Taken together, this study provides novel evidence demonstrating that TLR activation induces a pattern of downstream tryptophan degradation along the kynurenine pathway in monocytes. The results of this study may implicate that TLRs can be used as new drug targets for the regulation of aberrant tryptophan metabolism along this pathway, a potential therapeutic strategy that may be of importance in several disorders.     

Patterns of weight gain in a group of patients treated for anorexia nervosa

Patterns of weight gain up to matched population mean levels arising within the constraints of a specific treatment program for patients with anorexia nervosa have revealed certain group characteristics. Weight gain was most rapid initially and related to rehydration. Thereafter, maximum fluctuations occurred within the range of 44.0–48.9 kg. The authors suggest that this is related to biological and consequent experiential factors commonly arising at this level of body weight. Furthermore, the authors suggest that such weight charts reflect the individual's constitution, including her personality, her potential social coping capacities and also her ability to engage with and express her feelings, and that, as such, they may have prognostic value.     

Antiinflammatory, Analgesic and Antipyretic Activity of Certain Thiazolidinones

The thiazolidin-4-one derivatives and the corresponding spiro compounds were synthesized from sulphanilamide and were evaluated for anti-inflammatory and analgesic activity in acute and sub acute models. Compounds were also evaluated for antipyretic and cyclooxygenase enzyme inhibitory activity. All the compounds showed significant antiinflammatory, analgesic and antipyretic activity at 100 mg/kg in all the models. The compounds B1, B2, B5, B6, and B8 showed maximum inhibition of COX-2 activity without inhibiting the COX-1 activity. The nimesulide was used as standard drug for comparison. The substitution at R, R₁ and R₂ with the functional groups Cl, OCH₃, NO₂ and OH in the aromatic ring resulted in increased activity as compared to unsubstituted thiazolidin-4-ones. However the substitution at R₃ with spiro group did not improve the activity. The study suggests that COX-2 binding site may not be a rigid structure but might adopt to various related molecules.     

Healing of root resorption: a case report

External resorption is sequelae of necrotic periodontal membrane over a large area of root following an injury to the tooth. This usually occurs after severe dental injuries such as intrusion, severe luxations or exarticulation injuries complicated by a prolonged extra oral period. This case report presents a clinical and radiographic follow up (13 months) of treatment of inflammatory external root resorption on maxillary central incisor using Vitapex. Gradual healing of resorption was observed radiographically with no tenderness or pathological mobility.