(+)-Xylose

150.13

150.13

1562108

200-400-7

A1TA934AKO

760130

Monoclinic needles or prisms|White crystalline powder

29400090

90.15000

-2.58230

White Fine Crystalline Powder

1.525 g/cm³ @ Temp: 20 °C

153-154 °C

415.5°C at 760 mmHg

> 100°(212°F)

1.543

H2O: 1 M at 20 °C, clear, colorless

Store at RT.

1.22E-08mmHg at 25°C

20 º (c=10, H2O)

Very sweet

pKa = 12.14 @ 18 °C

Shows mutarotation; reduces warm Fehling's soln

2

36/37/38

24/25-36-26

ZF2285000

Xi

Irritant

Stable. Incompatible with strong oxidizing agents.

SRP: At the time of review, criteria for land treatment or burial (sanitary landfill) disposal practices are subject to significant revision. Prior to implementing land disposal of waste residue (including waste sludge), consult with environmental regulatory agencies for guidance on acceptable disposal practices.

Although many national health agencies like the FDA and Health Canada have concluded that the addition or use of food additive sweeteners like xylose is safe and effective for their intended purposes of use in food, it is also known that eating too much of these substances can also ultimately cause gastrointestinal discomfort and laxative effects. These effects are largely the result of excessive amounts of ingested sugar alcohols being poorly taken up from the gastrointestinal tract. Regardless, the extent to which these kinds of effects occur depends on variances between individuals and it is also possible for individuals to develop a tolerance via frequent consumption of such sweetener containing products. In doing so, such individuals can increase consumption of these agents without experiencing adverse effects. The acute oral toxicity (LD50) for the mouse animal model has been recorded as 23000 mg/kg [MSDS].

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.

LD50 Mouse oral 23 g/kg|LD50 Mouse iv 11,300 mg/kg

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

D-Xylose is found naturally in plant materials, especially wood (maple, cherry) in straw and hulls(1). It is not found in the free state, but occurs as xylan, a polysaccharide built from xylose units and occurring in association with cellulose(1).

D-Xylose's production and use as a non-nutritive sweetener(1) and as a tanning or dyeing agent(2) may result in its release to the environment through various waste streams(SRC).

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 2(SRC), determined from an estimated log Kow of -1.98(2,SRC) and a regression-derived equation(3), indicates that D-xylose is expected to have very high mobility in soil(SRC). Volatilization of D-xylose from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 1.2X10-9 atm-cu m/mole(SRC), using a fragment constant estimation method(4). D-Xylose is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 6.4X10-7 mm Hg(SRC), determined from a fragment constant method(5). D-Xylose is a simple monosaccharide and should be readily biodegradable in the environment(SRC).|AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 2(SRC), determined from an estimated log Kow of -1.98(2,SRC) and a regression-derived equation(3), indicates that D-xylose is not expected to adsorb to suspended solids and sediment in water(SRC). Volatilization from water surfaces is not expected(3) based upon an estimated Henry's Law constant of 1.2X10-9 atm-cu m/mole(SRC), developed using a fragment constant estimation method(4). According to a classification scheme(5), an estimated BCF of 1(SRC), from its log Kow(2) and a regression-derived equation(3), suggests the potential for bioconcentration in aquatic organisms is low(SRC). D-Xylose was biodegraded 63 percent in a 15-day river die away test(6).|ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), D-xylose, which has an estimated vapor pressure of 9.6X10-7 mm Hg at 25 °C(2), is expected to exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase D-xylose is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be 5 hours(SRC) from its estimated rate constant of 7.4X10-11 cu cm/molecule-sec at 25 °C(SRC), determined from a fragment constant estimation method(3). Particulate-phase D-xylose may be removed from the air by wet and dry deposition(SRC).

The rate constant for the vapor-phase reaction of D-xylose with photochemically-produced hydroxyl radicals has been estimated as 7.4X10-11 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 5 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). D-Xylose is not expected to undergo hydrolysis in the environment due to the lack of hydrolyzable functional groups(2) nor to directly photolyze due to the lack of absorption in the environmental UV spectrum.

An estimated BCF of 1 was calculated for D-xylose(SRC), using an estimated log Kow of -1.98(1,SRC) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is low(SRC).

The Koc of D-xylose is estimated as approximately 2(SRC), using an estimated log Kow of -1.98(1,SRC) and a regression-derived equation(2). According to a classification scheme(3), this estimated Koc value suggests that D-xylose is expected to have very high mobility in soil(SRC).

The Henry's Law constant for D-xylose is estimated as 1.2X10-9 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This Henry's Law constant indicates that D-xylose is expected to be essentially nonvolatile from water surfaces(2). D-Xylose's Henry's Law constant(1) indicates that volatilization from moist soil surfaces is not expected(SRC). D-Xylose is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 9.6X10-7 mm Hg(SRC), determined from a fragment constant method(3).

SURFACE WATER: D-Xylose was detected in the Tama River, Japan at concns of 14.1-20.7 ug/l(1).

NIOSH (NOES Survey 1981-1983) has statistically estimated that 11,636 workers (10,399 of these are female) are potentially exposed to D-xylose in the US(1). Occupational exposure to D-xylose may occur through inhalation of dust particles and dermal contact with this compound at workplaces where D-xylose is produced or used(SRC).

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.

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/.

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.

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.

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.

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.

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

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.

LOW INCIDENCE OF SIDE EFFECTS. NAUSEA, INTESTINAL BLOATING, BORBORYGMI, CRAMPING, ABDOMINAL DISCOMFORT, & DIARRHEA OCCUR FREQUENTLY FOLLOWING 25-G ORAL DOSE...RARELY OCCUR FOLLOWING 5-G ORAL DOSE, EXCEPT IN VERY SMALL INFANTS /ADVERSE EFFECT, ORAL/|XYLOSE WAS NONCARIOGENIC AFTER 1 WK AS COMPARED TO SUCROSE CONTROL.|NON-TOXIC

D Xylose

Grades: Reagent, Technical

Upon heating with water in closed tube to 140 °C or by boiling with dil H2SO4 furfurol is formed. Hydrazones of D-xylose are more sol than those of L-arabinose & used to separate the 2 sugars.

AOAC 950.57. Arabinose, Galactose, and Xylose and other sugars in sugars and sirups.

D-XYLULOSE & D-XYLOSE DETERMINATION WITH D-XYLOSE ISOMERASE BY SPECTROPHOTOMETRY OR COLORIMETRY. DP BURMA & BL HORECKER, J BIOL CHEM 231, 1053 (1958).|METHOD OF ESTIMATING XYLOSE DETECTING COLOR @ 410 NM.