STUDIES OF DISSOLVED OXYGEN IN PRODUCTION OF D-RIBOSE BY FERMENTATION

This paper mainly dealt with the dissolved oxygen in production of D-ribose by fermentation. The oxygen transfer coefficients of common flask, buffed flask and jar fermentor were determined.

Synthesis of N-alkyl substituted iminosugars from D-ribose

An effective and facile method for the synthesis of N-alkylated hydroxylpyrrolidine and hydroxylpiper- idine is described, A number of N-alkyl substituted iminosugars were prepared using iodine-induced intramolecular cyclization of acyclic alkenylamines as key step.

Effect of external electric field upon charge distribution, energy and dipole moment of selected monosaccharide molecules

External electric field of 0.001, 0.01 and 0.05 a.u. changes distribution of the electron density in α- and β-D-glucose, α- and β-D-galactose, α- and β-fructopyranoses and α- and β-fructofuranoses, α- and β-D-ribofuranoses and α and β-D-xylo- furanoses. Hyper-Chem 8.0 software was used together with the AM1 method for optimization of the conformation of the molecules of monosaccharides under study. Then polarizability, charge distribution, potential and dipole moment for molecules placed in the external electric field of 0.000, 0.001, 0.01 and 0.05 a.u. were calculated involving DFT 3-21G method. Application of the external field induced polarizability of electrons, atoms and dipoles, the latter resulting in eventual reorientation of the molecules along the applied field of the molecules and the electron density redistribution at particular atoms. Increase in the field strength generated mostly irregular changes of the electron densities at particular atoms of the molecules as well as polarizabilities. Energy of these molecules and their dipole moments also varied with the strength of the field applied. Results of computations imply that saccharides present in the living organisms may participate in the response of the living organisms to the external electric field affecting metabolism of the molecules in the body fluids by fitting molecules to the enzymes. Structural changes of saccharide components of the membranes can influence the membrane permeability.

Dietary ribose supplementation improves flesh quality through purine metabolism in gibel carp(Carassius auratus gibelio)

Since the aquaculture industry is currently observing a deterioration in the flesh quality of farmed fish,the use of nutrients as additives to improve the flesh quality of farmed fish species is a viable strategy.The aim of this study was to investigate the effect of dietary D-ribose(RI)on the nutritional value,texture and flavour of gibel carp(Carassius auratus gibelio).Four diets were formulated containing exogenous RI at 4 gradient levels:0(Control),0.15%(0.15RI),0.30%(0.30RI)and 0.45%(0.45RI).A total of 240 fish(150±0.31 g)were randomly distributed into 12 fibreglass tanks(150 L per tank).Triplicate tanks were randomly assigned to each diet.The feeding trial was carried out in an indoor recirculating aquaculture system for 60 d.After the feeding trial,the muscle and liver of gibel carp were analysed.The results showed that RI supplementation did not result in any negative impact on the growth performance and 0.30RI supplementation significantly increased the whole-body protein content compared to the control group.The contents of collagen and glycogen in muscle were enhanced by RI supplementation.The alterations in the flesh indicated that RI supplementation improved the texture of the flesh in terms of its water-holding capacity and hardness,therefore improving the taste.Dietary RI facilitated the deposition of amino acids and fatty acids in the muscle that contributed to the meaty taste and nutritional value.Furthermore,a combination of metabolomics and expression of key genes in liver and muscle revealed that 0.30RI activated the purine metabolism pathways by supplementing the substrate for nucleotide synthesis and thereby promoting the deposition of flavour substance in flesh.This study offers a new approach for providing healthy,nutritious and flavourful aquatic products.

Purines:From Diagnostic Biomarkers to Therapeutic Agents in Brain Injury

The purines constitute a family of inter-related compounds that serve a broad range of important intracellular and extracellular biological functions.In particular,adenosine triphosphate(ATP)and its metabolite and precursor,adenosine,regulate a wide variety of cellular and systems-level physiological processes extending from ATP acting as the cellular energy currency,to the adenosine arising from the depletion of cellular ATP and responding to reduce energy demand and hence to preserve ATP during times of metabolic stress.This inter-relationship provides opportunities for both the diagnosis of energy depletion during conditions such as stroke,and the replenishment of ATP after such events.In this review we address these opportunities and the broad potential of purines as diagnostics and restorative agents.