Disease relevance of lyxo-Hexulose

• Lactose and D-galactose metabolism in Staphylococcus aureus. IV. Isolation and properties of a class I D-ketohexose-1,6-diphosphate aldolase that catalyzes the cleavage of D-tagatose 1,6-diphosphate [1].
• D-Tagatose would potentially be helpful in body weight control, especially in diabetic subjects because of its antidiabetogenic effects [2].
• Plasmid linkage of the D-tagatose 6-phosphate pathway in Streptococcus lactis: effect on lactose and galactose metabolism [3].
• In addition, D-tagatose completely prevented oxidative cell injury inflicted by toxic iron overload with ferric nitrilotriacetate (100 microM) [4].
• 90-Day oral toxicity study of D-tagatose in rats [5].

High impact information on lyxo-Hexulose

• Lactose and D-galactose metabolism in Staphylococcus aureus. II. Isomerization of D-galactose 6-phosphate to D-tagatose 6-phosphate by a specific D-galactose-6-phosphate isomerase [6].
• The enzyme catalyzed the nucleoside triphosphate-dependent phosphorylation of both D-tagatose 6-phosphate and D-fructose 6-phosphate [7].
• No microbial fermentation of D-tagatose occurred in the stomach or in the small intestine, whereas the sugar was fermented in the cecum and colon [8].
• In vitro fermentation pattern of D-tagatose is affected by adaptation of the microbiota from the gastrointestinal tract of pigs [8].
• We conclude that D-tagatose is not fermented in the upper gastrointestinal tract, and the ability of the large intestinal microbiota to ferment D-tagatose is dependent on adaptation [8].

Chemical compound and disease context of lyxo-Hexulose

• L-Sorbose but not D-tagatose induces hemolysis of dog erythrocytes in vitro [9].
• Wild-type strain of Pseudomonas cichorii ST-24 was unable to grow on D -psicose and inductively produced D -tagatose 3-epimerase (D -TE) with D -tagatose as an inducer [10].
• The genes and enzymes for the catabolism of galactitol, D-tagatose, and related carbohydrates in Klebsiella oxytoca M5a1 and other enteric bacteria display convergent evolution [11].

Biological context of lyxo-Hexulose

• Gluconeogenesis from D-tagatose by isolated rat and hamster liver cells [12].
• In a double-blind and balanced cross-over design, we measured 24-h energy expenditure in eight normal weight humans in a respiration chamber during the consumption of 30 g D-tagatose or 30 g sucrose/d. Metabolic measurements were performed before and after a 2-wk adaptation period with a 30-g daily intake of the test sugar [13].
• All substrate-induced energy losses from D-tagatose, with sucrose as reference standard, were determined as a single value accounting for the sum of the energy losses to feces, urine, gaseous hydrogen and methane and substrate-induced thermogenesis [2].
• To further explore the underlying mechanisms of cytoprotection, we investigated the effects of D-tagatose on both the generation of superoxide anion radicals and the consequences of oxidative stress driven by prooxidant compounds in intact cells [4].
• D-tagatose was not found to increase the number of revertants per plate relative to vehicle controls in either the S. typhimurium tester strains or the WP2uvrA- tester strain with or without metabolic activation at doses up to 5000 microg/plate [14].

Anatomical context of lyxo-Hexulose

• The digestibility of D-tagatose was 25.8 +/- 5.6% in the distal third of the small intestine [15].
• The digestibility of D-tagatose, its effect on the digestibility of macronutrients and the metabolic response of the microbiota of the gastrointestinal tract to the ingestion of this carbohydrate were studied in pigs [15].
• D-Tagatose served as a substrate for the microbiota in the cecum and proximal colon as indicated by a reduced pH, and a greater ATP concentration, adenylate energy charge (AEC) ratio and concentration of short-chain fatty acids [15].
• In vitro fermentation experiments with pig intestinal contents and bacteria harvested from the gastrointestinal tract of pigs were used to investigate the degradation of D-tagatose and the formation of fermentation products [8].
• In the present study, the susceptibility of dog erythrocytes to D-tagatose, a stereoisomer of L-sorbose, was examined [9].

Associations of lyxo-Hexulose with other chemical compounds

• This enzyme is also of commercial interest as it catalyzes the conversion of D-galactose to D-tagatose in vitro [16].
• We suggest that the genes linked to the lactose plasmid in S. lactis are more numerous than previously envisaged, coding for all of the enzymes involved in lactose metabolism from initial transport to the formation of triose phosphates via the D-tagatose 6-phosphate pathway [3].
• The antioxidant properties of D-tagatose may result from sequestering the redox-active iron, thereby protecting more critical targets from the damaging potential of hydroxyl radical [4].
• Effects of oral D-tagatose, a stereoisomer of D-fructose, on liver metabolism in man as examined by 31P-magnetic resonance spectroscopy [17].
• Continuous D-tagatose production by immobilized thermostable L-arabinose isomerase in a packed-bed bioreactor [18].

Gene context of lyxo-Hexulose

• The ability to convert D-galactose into D-tagatose was compared among a number of bacterial L-arabinose isomerases ( araA) [19].
• Antioxidant and cytoprotective properties of D-tagatose in cultured murine hepatocytes [4].
• D-Tagatose production using an immobilized L-arabinose isomerase has a high potential for commercial application [20].
• Dietary levels of 5% and about 15-20% were determined as no-effect levels (NOEL) for D-tagatose- and fructose-induced liver enlargement, respectively [21].
• Direct conversion of lactose to D-tagatose in a single reactor was demonstrated using a thermostable beta-galactosidase together with the thermostable L-arabinose isomerase [19].

Analytical, diagnostic and therapeutic context of lyxo-Hexulose

• An improved procedure for the chemical synthesis of D-tagatose 6-phosphate is described, and resolution of the anomers of D-tagatose 6-phosphate by gas-liquid chromatography is reported [6].
• Small-bowel absorption of D-tagatose and related effects on carbohydrate digestibility: an ileostomy study [22].
• A randomized parallel design involving two treatment periods (adaptation to D-tagatose and subsequent energy balance) and two control groups (to control for treatment effects in each period) was used [2].
• Genotoxicity tests on D-tagatose [14].
• Site-directed mutagenesis at these sites showed that the aromatic ring at amino acid 164 and the size of amino acid 475 were important for D: -tagatose production [23].

References