Absorption, Distribution and Excretion
When 12 normal healthy subjects were given an intravenous D-xylose dosing of 10 grams and then an oral dose of 25 grams a week later, the observed absorption percentage was about 69.4% (p < 0.002) and the observed absorption rate was approximately 1.03/hr (p< 0.05). The maximum concentration observed in the subjects was 0.53 mg/L with 71 minutes being the time to reach the maximum concentration. The absolute bioavailability recorded was 69%.
In patients with normal kidney function, renal excretion accounts for approximately half (50%) of their total D-xylose elimination. Any non-renal D-xylose elimination is presumed to be hepatic clearance.
The volume of distribution observed for d-xylose in normal healthy subjects is 0.22 L/kg.
The renal clearance rate observed in healthy individuals is 89 ml/min. The accompanying plasma and non-renal clearances are 180 and 91 ml/min, respectively.
XYLOSE HAS BEEN SHOWN TO GET INTO AQ HUMOR /OF RATS/ FROM GENERAL CIRCULATION & THEREFORE TO HAVE ACCESS TO LENS.
/ABSORBED/ FROM GI TRACT...5-G DOSES...ABSORBED MORE RAPIDLY & COMPLETELY THAN ARE 25-G DOSES...AT LEAST 60%...ABSORBED IN PROXIMAL PART OF SMALL INTESTINE... NOT DEPENDENT UPON PRESENCE OF BILE OR PANCREATIC JUICE.../PEAK BLOOD LEVELS/ 1 TO 2 HR...TO 0 AFTER...5 HR /HUMAN, ORAL 5 OR 25 G/.
PLASMA HALF-LIFE...ABOUT 1 HR /IV ADMIN/...ABOUT 60%...METABOLIZED TO CARBON DIOXIDE & WATER, D-THREITOL, &...UNIDENTIFIED METABOLITES...EXCRETED IN URINE...ABOUT 25% OF 25 G /DOSE/ & ABOUT 35% OF 5 G /DOSE/ EXCRETED UNCHANGED IN URINE WITHIN 5 HR /HUMAN, ORAL/.
URINARY EXCRETION /MAINLY BY/ GLOMERULAR FILTRATION...SOME TUBULAR RESORPTION MAY OCCUR /HUMAN, ORAL/.
For more Absorption, Distribution and Excretion (Complete) data for (D)-XYLOSE (8 total), please visit the HSDB record page.

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Metabolism / Metabolites
The most common and traditional metabolism pathway for xylose is the oxidoreductase pathway (or xylose reductase-xylitol dehydrogenase, XR-XDH pathway). In this pathway, xylose is first reduced to xylitol using the xylitol dehydrogenase (XDH) enzyme with NADH or NADPH. The resultant xylitol is subsequently oxidized to D-xylulose by the xylitol dehydrogenase (XDH) enzyme while utilizing the cofactor NAD. Finally, the D-xylulose is phosphorylated by an ATP utilizing kinase (xylulose kinase enzyme) to generate D-xylulose-5-phosphate, which serves as an intermediate in the pentose phosphate pathway for nucleotide synthesis.
...RAT-LIVER MICROSOMES CATALYZE THE TRANSFER OF...XYLOSE TO BILIRUBIN, FROM...UDP-XYLOSE...
ABOUT 60% OF ABSORBED XYLOSE IS METABOLIZED TO CARBON DIOXIDE & WATER, D-THREITOL, & OTHER UNIDENTIFIED METABOLITES /HUMAN, ORAL/.
AFTER IP INJECTION OF (14)C-LABELED D-XYLOSE INTO GUINEA PIGS, 10.8 OF RADIOACTIVITY WAS RECOVERED AS EXPIRED CARBON DIOXIDE IN 4 HR & 41.3 AS URINARY (14)CARBON IN 5 HR. APPROX 60 OF URINARY RADIOACTIVITY WAS D-XYLOSE.
(14)C-LABELED D-XYLONIC ACID WAS OXIDIZED TO LABELED CARBON DIOXIDE BY INTACT ANIMALS & IN VITRO BY KIDNEY & LIVER. OXIDATION OF D-XYLOSE BY GUINEA PIG PROBABLY INVOLVES ITS INITIAL CONVERSION TO D-XYLONIC ACID & SUBSEQUENT DECARBOXYLATION.
IN VITRO KIDNEY & LIVER COULD OXIDIZE D-XYLOSE TO CARBON DIOXIDE. LIVER EXTRACT COULD CATALYZE CONVERSION TO D-XYLONIC ACID WITH PYRIDINE NUCLEOTIDE AS COFACTOR. THIS ENZYME ACTIVITY WAS DIFFERENT FROM HEPATIC GLUCOSE DEHYDROGENASE.

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Biological Half-Life
The elimination half-life observed in healthy individuals is 75 minutes.

Protein Binding
Readily accessible data regarding the protein binding of xylose within the context of the human body is not available.

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Interactions
D-XYLOSE RELIEVED INHIBITION BY PUROMYCIN & CYCLOHEXIMIDE OF INCORPORATION OF ACETATE INTO CHONDROITIN SULFATE IN WHOLE TIBIAS & FEMURS OF EMBRYONIC CHICKEN CARTILAGE.
ADDN OF GUAR TO ORAL DOSAGE OF D-XYLOSE SLOWED DOWN GI ABSORPTION OF D-XYLOSE IN VOLUNTEERS. TOTAL AMT ABSORBED & PLASMA T/2 OF D-XYLOSE WERE NOT AFFECTED.
CONCOMITANT ADMIN OF INDOMETHACIN, NEOMYCIN, PHENFORMIN, COLCHICINE, OR LARGE DOSES OF AMINOSALICYLIC ACID WITH D-XYLOSE INHIBITS INTESTINAL ABSORPTION OF D-XYLOSE /REDUCING/ QUANTITIES OF SUGAR BEING EXCRETED...ASPIRIN /REDUCES URINARY EXCRETION OF D-XYLOSE/ APPARENTLY BY ALTERING RENAL FUNCTION.

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Non-Human Toxicity Values
LD50 Mouse oral 23 g/kg
LD50 Mouse iv 11,300 mg/kg

[1]. The implementation of high fermentative 2,3-butanediol production from xylose by simultaneous additions of yeast extract, Na2EDTA, and acetic acid. N Biotechnol. 2015 Aug 3.

[2]. Bacterial xylose isomerases from the mammal gut Bacteroidetes cluster function in Saccharomyces cerevisiae for effective xylose fermentation. Microbial Cell Factories May, 2015, 14:70.

[3]. Construction of efficient xylose utilizing Pichia pastoris for industrial enzyme production. Microbial Cell Factories February 2015, 14:22.

D-xylopyranose is d-Xylose in its pyranose form.
Xylose is a monosaccharide of the aldopentose type consisted of five carbon atoms and an aldehyde functional group. Xylose is a sugar isolated from wood. D-Xylose is a sugar widely used as a diabetic sweetener in food and beverage. Xylose has also been used as a diagnostic agent to observe malabsorption. Reduction of xylose by catalytic hydrogenation produces the common food additive sweetener substitute xylitol [DB11195]. The dextrorotary form of xylose, D-xylose, refers usually to the endogenously occurring form of the sugar in living things. The levorotary form, L-xylose, can refer to the form that is synthesized. Nevertheless, xylose by itself may not necessarily serve many purposes immediately - but its metabolism results in a variety of substrates that can serve important nutritional and biological purposes.
D-Xylose is a metabolite found in or produced by Escherichia coli (strain K12, MG1655).
D-Xylose has been reported in Malus, Elliottia paniculata, and other organisms with data available.
Xylose or wood sugar is an aldopentose - a monosaccharide containing five carbon atoms and an aldehyde functional group. It has chemical formula C5H10O5 and is 40% as sweet as sucrose. Xylose is found in the embryos of most edible plants. The polysaccharide xylan, which is closely associated with cellulose, consists practically entirely of d-xylose. Corncobs, cottonseed hulls, pecan shells, and straw contain considerable amounts of this sugar. Xylose is also found in mucopolysaccharides of connective tissue and sometimes in the urine. Xylose is the first sugar added to serine or threonine residues during proteoglycan type O-glycosylation. Therefore xylose is involved in the biosythetic pathways of most anionic polysaccharides such as heparan sulphate and chondroitin sulphate. In medicine, xylose is used to test for malabsorption by administering a xylose solution to the patient after fasting. If xylose is detected in the blood and/or urine within the next few hours, it has been absorbed by the intestines. Xylose is said to be one of eight sugars which are essential for human nutrition, the others being galactose, glucose, mannose, N-acetylglucosamine, N-acetylgalactosamine, fucose, and sialic acid. (Wikipedia).

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Drug Indication
The predominant everyday nutritional usage of xylose is as a parent sugar alcohol from which another sugar alcohol - xylitol- can be derived from and used as an extremely common food additive or sweetener to be used in place of regular sugars as a lower calorie alternative. Alternatively, xylose was also involved in a procedure known as a D-xylose absorption test that used to be employed to evaluate how well an individual was capable of absorbing a simple sugar like D-xylose from the intestines. By measuring the amount of D-xylose in urine and blood samples after an individual ingested a certain amount of the simple sugar dissolved in some water, the test sought to determine if nutrients were being properly absorbed in the patient's gastrointestinal tract.

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Mechanism of Action
Xylose is metabolized into various chemical intermediates that can play critical functions in the biological homeostasis of the human body. Via the oxido-reductase metabolism pathway of xylose in eukaryotic organisms, xylose is ultimately catabolized into (D)-xylulose-5-phosphate, which functions as an intermediate in the pentose phosphate pathway. Within the pentose phosphate pathway, NADPH, pentose 5-carbon sugars, and ribose 5-phosphate are generated as materials and precursors for the synthesis of nucleotides. In particular, xylulose-5-phosphate can be used to directly generate glycerinaldehyde-3-phosphate in the pathway. Other studies have also demonstrated that xylulose-5-phosphate may also play a role in gene expression, perhaps by promoting ChREBP transcription factor in the well-fed state.

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Therapeutic Uses
XYLOSE BLOOD LEVEL MEASUREMENTS...TO DETERMINE WHETHER ABNORMALLY LOW URINARY XYLOSE EXCRETION IS DUE TO IMPAIRED ABSORPTION OR RENAL INSUFFICIENCY. BLOOD XYLOSE LEVELS /DETERMINED/ 2 HR AFTER INGESTION OF 25 G DOSE.
/DIFFERENTIATE/ STEATORRHEA CAUSED BY PANCREATIC INSUFFICIENCY FROM THAT CAUSED BY MALABSORPTION /5 G DISSOLVED IN 150 ML WATER OR 25 G DISSOLVED IN 250 ML WATER, FOLLOWED BY 250 ML WATER, ORAL. URINE POOLED DURING NEXT 5 HR & QUANTITY OF XYLOSE DETERMINED/.
EVALUATE INTESTINAL ABSORPTION...DIAGNOSIS OF MALABSORPTIVE STATES DUE TO DISEASES INVOLVING INTESTINAL MUCOSA /5 G DISSOLVED IN 150 ML WATER OR 25 G DISSOLVED IN 250 ML WATER, FOLLOWED BY 250 ML WATER, ORAL. URINE POOLED DURING NEXT 5 HR & QUANTITY OF XYLOSE DETERMINED/.
DIAGNOSIS OF MALABSORPTIVE STATES DUE TO...SURGICAL RESECTION. /ASSESS/ DEG OF IMPAIRED ABSORPTION OR EXTENT OF RESPONSE TO THERAPY /5 G DISSOLVED IN 250 ML WATER & ADMIN ORALLY. ADDITIONAL FLUIDS PERMITTED. URINE COLLECTED IN 2 CONSECUTIVE PERIODS OF 2 & 3 HR. XYLOSE CONTENT DETERMINED/.
FOR INFANTS, YOUNG CHILDREN OR ELDERLY INCONTINENT PATIENTS...XYLOSE BLOOD LEVELS MAY BE USED TO EVALUATE INTESTINAL ABSORPTION /500 MG/KG BODY WT (OR MAX OF 25 G) AS 5-10% AQ SOLN, ORAL. XYLOSE LEVELS ARE DETERMINED IN BLOOD SAMPLES TAKEN 30 MIN, 1 HR, & 2 HR AFTER XYLOSE ADMIN/.

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Drug Warnings
URINARY EXCRETION OF XYLOSE IN PATIENTS OLDER THAN 60 YR OF AGE IS USUALLY LOW...XYLOSE TEST SHOULD BE USED IN PREGNANT WOMEN OR WOMEN WHO MAY BECOME PREGNANT ONLY WHEN POTENTIAL BENEFITS OUTWEIGH POSSIBLE HAZARDS.
CONDITIONS WHICH CAN PRODUCE "FALSE-POS" TEST VALUES INCLUDE VOMITING, GASTRIC STASIS, THYROID DYSFUNCTION & SEVERE DIARRHEA FOLLOWING INGESTION OF TEST DOSE. PATIENTS WITH THYROTOXICOSIS HAVE SHOWN INCREASED URINARY EXCRETION OF XYLOSE.
USE OF XYLOSE TEST REQUIRES CLOSE ATTENTION TO TECHNICAL DETAILS...IN PATIENTS WITH IMPAIRED RENAL FUNCTION, DEHYDRATION, INADEQUATE CIRCULATING BLOOD VOL, EDEMA OR MASSIVE ASCITES, URINARY EXCRETION OF D-XYLOSE WILL BE LOWER THAN NORMAL & THUS PRODUCE "FALSE-POS" TEST VALUES.

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Pharmacodynamics
Xylose is often used as a parent sugar alcohol from which the commonly used food additive sweetener, xylitol, can be derived via the hydrogenation of xylose. Xylitol possesses many characteristics that make it a healthy and effective alternative to regular sugar. For example, although it looks and tastes exactly like ordinary sugar, having a 100% relative sweetness versus normal sucrose, it also has a low impact on blood sugar and insulin secretion and a minimal caloric value of 2.4 calories/gm. Furthermore, xylitol is non-fermentable and thus cannot be transformed to acids by oral bacteria, allowing it to restore a proper alkaline/acid balance in the mouth. Various studies cite this effect for allowing xylitol products like chewing gum to be effective at reducing dental caries. Altogether, these characteristics make xylose and its xylitol metabolite an effective alternative sweetener for healthy food choices for individuals who may be diabetic or for individuals simply wanting to make healthy dietary choices for their bodies.

C5H10O5

150.1299

150.052

58-86-6

135191

Monoclinic needles or prisms
White crystalline powder

1.5±0.1 g/cm3

415.5±38.0 °C at 760 mmHg

148-158 ºC

219.2±23.3 °C

0.0±2.2 mmHg at 25°C

1.544

-2.39

4

5

0

10

117

3

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

SRBFZHDQGSBBOR-IOVATXLUSA-N

InChI=1S/C5H10O5/c6-2-1-10-5(9)4(8)3(2)7/h2-9H,1H2/t2-,3+,4-,5?/m1/s1

(3R,4S,5R)-oxane-2,3,4,5-tetrol

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)

DMSO : ~50 mg/mL (~333.04 mM)
H2O : ≥ 50 mg/mL (~333.04 mM)

Solubility in Formulation 1: ≥ 2.5 mg/mL (16.65 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: ≥ 2.5 mg/mL (16.65 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.

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Solubility in Formulation 3: ≥ 2.5 mg/mL (16.65 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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Solubility in Formulation 4: 100 mg/mL (666.09 mM) in PBS (add these co-solvents sequentially from left to right, and one by one), clear solution; with ultrasonication.

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