Absorption, Distribution and Excretion
Xylose has been shown to enter the aqueous humor of rats via systemic circulation, thereby reaching the lens. Absorption/ Absorbed via the gastrointestinal tract…5 g dose…absorbed more quickly and completely than the 25 g dose…at least 60%…absorbed in the proximal small intestine…independent of the presence of bile or pancreatic juice… Peak Plasma Concentration/1 to 2 hours…decreases to 0 after 5 hours (human, oral 5 g or 25 g). Plasma Half-Life…approximately 1 hour (intravenous administration)…approximately 60%…metabolized to carbon dioxide and water, D-threitol, and…unidentified metabolites…excreted in the urine…approximately 25% of the 25 g/dose and approximately 35% of the 5 g/dose are excreted unchanged in the urine within 5 hours (human, oral). Urinary Excretion/Primarily via glomerular filtration…a small amount of tubular reabsorption may occur (human, oral).
For more complete data on the absorption, distribution, and excretion of (D)-xylose (8 types), please visit the HSDB record page.

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Metabolism/Metabolites
……Rat liver microsomal catalysis……xylose transfer to bilirubin, from……UDP-xylose……
Approximately 60% of absorbed xylose is metabolized to carbon dioxide and water, D-threitol, and other unidentified metabolites/human, oral/.
After intraperitoneal injection of (14)C-labeled D-xylose into guinea pigs, 10.8 radioactive carbon dioxide was recovered from exhaled carbon dioxide within 4 hours and 41.3 radioactive (14) carbon was recovered from urine within 5 hours. Approximately 60% of the radioactivity in urine was D-xylose.
(14)C-labeled D-xylose can be oxidized to labeled carbon dioxide in the kidneys and liver of intact animals, both in vivo and in vitro. The oxidation of D-xylose in guinea pigs may involve its initial conversion to D-xylose followed by decarboxylation.
In vitro, the kidneys and liver can oxidize D-xylose to carbon dioxide. Liver extracts can catalyze its conversion to D-xylonic acid with pyridine nucleotides as a cofactor. This enzyme activity differs from that of hepatic glucose dehydrogenase.

Interactions
D-xylose mitigated the inhibitory effects of puromycin and cyclohexylimide on the incorporation of chondroitin sulfate into embryonic chicken cartilage. Addition of guar gum during oral administration of D-xylose in volunteers slowed gastrointestinal absorption. Total D-xylose absorption and plasma half-life were unaffected. Concomitant administration of indomethacin, neomycin, phenformin, colchicine, or high doses of aminosalicylic acid inhibited intestinal absorption of D-xylose, thereby reducing glucose excretion… Aspirin reduced urinary excretion of D-xylose, possibly by altering renal function. Non-human Toxicity Values Oral LD50 in mice: 23 g/kg Intravenous LD50 in mice: 11,300 mg/kg

Aldehyde-D-xylose is a type of D-xylose. It is a metabolite in both humans and Saccharomyces cerevisiae. DL-xylose has been reported in Elliottia paniculata, Tecoma stans, and other organisms with relevant data. Aldehyde-D-xylose is a metabolite found or produced in Saccharomyces cerevisiae. See also: D-xylose (note moved here).

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Therapeutic Uses
Xylose Blood Concentration Assay… used to determine whether abnormally low urinary xylose excretion is due to malabsorption or renal insufficiency. Blood Xylose Level / Assay / 2 hours after administration of a 25g dose. / Differentiation / Steatorrhea due to pancreatic insufficiency versus steatorrhea due to malabsorption / 5g dissolved in 150ml water or 25g dissolved in 250ml water, followed by oral administration of 250ml water. Urine is collected and xylose content is determined over the next 5 hours.
Assess intestinal absorption…Diagnose malabsorption caused by intestinal mucosal disease/Dissolve 5g in 150ml of water, or 25g in 250ml of water, then orally administer 250ml of water. Collect urine and determine xylose levels within the next 5 hours.
Diagnose malabsorption caused by… /Assess/ the degree of malabsorption or treatment response/5g dissolved in 250ml of water orally. Fluid supplementation is permitted. Collect urine at 2 and 3 consecutive hours. Determine xylose levels/.
For incontinent infants, young children, or elderly patients…Intestinal absorption can be assessed using xylose blood concentrations/500mg/kg body weight (or a maximum dose of 25g), orally in a 5-10% aqueous solution. Xylose levels are determined by collecting blood samples at 30 minutes, 1 hour, and 2 hours after xylose administration.

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Drug Warnings
Urinary xylose excretion is generally lower in patients over 60 years of age…Xylose testing should only be used in pregnant women or women who may become pregnant when the potential benefit outweighs the possible risks.
Situations that may lead to false positive test results include: vomiting, gastric retention, thyroid dysfunction, and severe diarrhea after taking the test dose.
Patients with thyrotoxicosis have increased urinary xylose excretion.
Close attention to technical details is required when using xylose tests… Patients with impaired renal function, dehydration, insufficient circulating blood volume, edema, or massive ascites may have lower than normal urinary D-xylose excretion, leading to false positive test results.

C5H10O5

150.1299

150.053

25990-60-7

25702-75-4

644160

White to off-white solid powder

1.757g/cm3

333.2ºC at 760mmHg

133-136ºC

155.3ºC

-2.3

4

5

4

10

104

3

C([C@H]([C@@H]([C@H](C=O)O)O)O)O

PYMYPHUHKUWMLA-VPENINKCSA-N

InChI=1S/C5H10O5/c6-1-3(8)5(10)4(9)2-7/h1,3-5,7-10H,2H2/t3-,4+,5+/m0/s1

(2R,3S,4R)-2,3,4,5-tetrahydroxypentanal

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

H2O : ~125 mg/mL (~832.61 mM)

Solubility in Formulation 1: 50 mg/mL (333.04 mM) in PBS (add these co-solvents sequentially from left to right, and one by one), clear solution; with sonication.

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 (Please use freshly prepared in vivo formulations for optimal results.)