Oligosaccharides

Stability Hygroscopic Applications Isotope labelled analogue of (-)-Inosine (I661000), compound that exhibits neuroprotective properties by improving axonal wiring and has also been used to treat stroke patients to restore neural function. References Vandemeulebroucke, A., et al.: Biochem., 49, 8999 (2010), Nestor, G., et al.: J. Agric. Food Chem., 58, 10799 (2010),

Applications Desacetyllanatoside C is a derivative of Lanatoside C (L173800), glycosides isolated from various species of Digitalis. Cardiotonic. Not a dangerous good if item is equal to or less than 1g/ml and there is less than 100g/ml in the package References Novotny, J., et al.: J. Biol. Chem., 258, 14433 (1983), Farr, C., et al.: J. Med. Chem., 45, 3257 (2002), Van Dongen, M., et al.: Drug Discov. Today, 7, 471 (2002),

N-Acetyl-D-lactosamine ethyl fluorescein 5-thiourea is a carbohydrate that is custom synthesized by our company. It is a high purity, methylated, glycosylated, and fluorinated compound. This compound has CAS number 476-02-8. N-Acetyl-D-lactosamine ethyl fluorescein 5-thiourea is used in the modification of saccharides and oligosaccharides to study their interactions with enzymes such as glycosidases and nucleases.

Please enquire for more information about 1,3:1,4-b-Glucotetraose (B) including the price, delivery time and more detailed product information at the technical inquiry form on this page

2-Acetamido-2-deoxy-4-O-[(4-O-[b-(D)-galactopyranosyl]-b-(D)-galactopyranosyl)-D-glucopyranosyl]-D-glucopyranose is a trisaccharide that has been shown to be an inhibitor of the bacterial enzyme UDP-N-acetylglucosamine pyrophosphorylase, which is involved in the synthesis of UDP-N-acetylglucosamine. This inhibition leads to a decrease in D-mannose production, which decreases the ability of bacteria to produce cell walls. 2ACPDG has also been shown to inhibit the growth of Mycobacterium tuberculosis and Mycobacterium avium complex.

NGA1 N-glycan is a modified oligosaccharide, carbohydrate, and complex carbohydrate. It is custom synthesized, high purity, and has CAS No. This monosaccharide is methylated and glycosylated. It has a sugar that has been fluorinated and saccharides.

Stability Very Very Hygroscopic Applications α-Glycosidase inhibitor. References Paulsen, H., et al.: Chem. Ber., 113, 2601 (1980),

Cavity size is the major determinant as to which cyclodextrin is used in complexation. The cavity diameter of β-cyclodextrins or β-glucopyranose unit compounds is well-suited for use with molecules the size of hormones, vitamins and many compounds frequently used in tissue and cell culture applications. For this reason, β-cyclodextrin is most commonly used as a complexing agent. It is used to increase the solubility of non-polar substances such as fatty acids, lipids, vitamins and cholesterol for use in cell culture applications. Methyl-β-cyclodextrin is used to remove cholesterol from cultured cells and is employed to remove lipid rafts. This Thermo Scientific Chemicals brand product was originally part of the Alfa Aesar product portfolio. Some documentation and label information may refer to the legacy brand. The original Alfa Aesar product / item code or SKU reference has not changed as a part of the brand transition to Thermo Scientific Chemicals.

Nigerotriose is a monosaccharide that belongs to the family of neutral oligosaccharides. It is found in plants, fungi, and bacteria. Nigerotriose has been shown to stimulate mitochondrial biogenesis through the activation of protein kinase A and glycogen synthase kinase-3beta. This activity has been demonstrated using a magnetic resonance spectroscopy technique. Nigerotriose also shares structural similarities with other molecules, including isomaltose oligosaccharides, which are effective disinfectants. However, the molecular weight of nigerotriose makes it less reactive than its isomaltose counterpart. The effective dose for nigerotriose has not yet been determined.

Applications 3-(3-Azido-2,3-dideoxy-β-D-erythro-pentofuranosyl)-5-methyl-2,4(1H,3H)-pyrimidinedione is an impurity of Zidovudine (A825000). Zidovudine is an antiviral agent used in the clinical treatment of HIV infections. References Radatus, B.K., Org. Process. Res. Dev., 15, 1281 (2011)

Useful oligosaccharide-lipid conjugate for raising antibodies.

Chondroitin disaccharide di-diSB trisodium salt is a chondroitin sulfate binding agent that can be used in the diagnosis of subcutaneous tumors. It binds to the chondroitin sulfate component of proteoglycans and stains these proteins under light microscopy. This agent can also be used to detect monoclonal antibodies that bind to the chondroitin sulfate component of proteoglycans. The detection of this agent may be done by enzyme-linked immunosorbent assay or fluorescence microscopy.

Sodium alginate is the sodium salt of a polysaccharide obtained from brown seaweeds. The main use for alginate is in textile printing as a thickener in the printing of cottons with reactive dyes. In the food industry it is used as a thickener and gelling agent. The chemical structure consists of blocks of (1,4) linked-β-D-polymannuronic acid (poly M), (1,4) linked-α-L-polyguluronic acid (poly G) and alternating blocks of the two uronic acids (poly MG).

Maltotriosyltrehalose is a sugar that is found in plants, fungi, and bacteria. It can be used as a substrate for the production of hydrogen-bonded oligosaccharides. Maltotriosyltrehalose has been shown to have a protective effect against death induced by high temperatures in mammalian cells. This sugar is also a good substrate for the production of hydrogen-bonded oligosaccharides and can be used as an additive to dry food products such as bread or cereals. Maltotriosyltrehalose is stable at high temperatures and has been shown to protect against cell death caused by heat stress. It can be used in both animal feed and human food products. Maltotriosyltrehalose is not active against proteases, but it does not inhibit the activity of mammalian cells that produce proteases.

Glycyl-sialyllacto-N-tetraose a is a custom synthesis that is an oligosaccharide with a molecular weight of 471. It has the CAS No. of 882859-14-6 and can be modified by methylation, glycosylation, and fluorination. This saccharide is a polysaccharide that can be modified by glycosylation, methylation, and click modification. The carbohydrate has a high purity and can be synthesized using organic chemistry or biochemistry techniques. Glycyl-sialyllacto-N-tetraose a is an Oligosaccharide with a sugar composition of (1) D-Glyceraldehyde 3-phosphate (2) D-Sorbitol 3 phosphate (3) Lactose (4) Glycyl-(1→4)-β--D--Galactopyranosyl-(1→3)-α

Sodium alginate is a soluble fiber that is extracted from brown seaweed. It is a natural carbohydrate that can be modified to create a variety of sugar-based derivatives, such as Oligosaccharides, Monosaccharides, and Custom Synthesis. Sodium alginate has been modified with Fluorination, Methylation, Glycosylation, and Click Modification to create high-purity products for various applications.

Man-3a N-Glycan is a N-linked oligosaccharide with a trimannosyl core

Impurity Clindamycin Phosphate EP Impurity F Applications Lincomycin 2-Phosphate (Clindamycin Phosphate EP Impurity F) is the derivative of Lincomycin (L466200), a lincosamide antibiotic that forms cross-links within the peptidyl transferase loop region of the 23S rRNA. Inhibits bacterial protein synthesis. Antibacterial. References Mason, D.J., et al.: Antimicrob. Agents Chemother., 555 (1962), Gray, et al.: Toxicol. Appl. Pharmacol., 6, 476 (1964), Muti, H.Y., et al.: Anal. Profiles Drug Subs. Excip., 23, 269 (1994),

4-Methoxyphenyl 4-O-(4-O-acetyl-3,6-di-O-benzyl-2-deoxy-2-phthalimido-b-D-glucopyranosyl)-3,6,2′,4′″triphosphate (4MPP) is a methylated saccharide. It can be modified with click chemistry and has been shown to inhibit the synthesis of glycogen in the liver. 4MPP is a high purity product that has been synthesized from naturally occurring carbohydrates. It is also fluorinated for use in research.

Applications 2-Deoxy-2-fluoro-D-glucose-13C6 is the isotope labelled analogue of 2-Deoxy-3-fluoro-D-glucose (D234500), a substrate of hexokinase isozymes. References Cheyne, R.W., et al.: Nuc. Med. Biol., 38, 339 (2011);

6-O-Benzoyl-1,2,3-tri-O-benzyl-4-O-(2,3,4,6-tetra-O-benzyl-a -D-galactopyranosyl)-b -D -galactopyranoside is an oligosaccharide that has been custom synthesized by our company. It is a complex carbohydrate with a molecular weight of 1,216. The CAS number for this product is 105838-36-5. This product also has a high degree of purity and can be used in Click modification and Modification reactions. 6 O Benzoyl 1 2 3 tri O benzyl 4 O

The 6-deoxy-6-fluorocyclomaltoheptaose is a low molecular weight compound that has been found to have anti-amylase activity. This substance is characterized by its chromatographic techniques, which can be used to identify the chemical structure of the molecule. The 6-deoxy-6-fluorocyclomaltoheptaose has been found to consist of an amylase inhibitor and an enzyme substrate. It exhibits specificity for the catalytic site of amylase, which is located in subsite 1, and it attacks this substrate at the 6-position of glucose. This substance is not as potent as other amylase inhibitors such as d-glucose, but it does show greater specificity for amylase than other substances with similar structures.

Hyaluronate Rhodamine is a synthetic, high-purity, fluorescent dye that can be used in the study of glycosylation and sugar modifications. It is a carbohydrate modified by methylation and fluorination. Hyaluronate Rhodamine has a molecular weight of 250kDa. The sugar component of the molecule is composed of an oligosaccharide with a saccharide repeat unit of 1-3 linked to a polysaccharide chain, which has been modified by methylation and glycosylation.

2-AB labelled A1F Glycan is a complex carbohydrate. It is custom synthesized and high purity. The CAS number for this compound is 12863-00-8.

3'-Sulfated Lewis X sodium salt is a synthetic carbohydrate with a sulfate group on the 3' position of the sugar. It is a selective blocker of E-selectin, a type of selectin that plays an important role in inflammation and tissue injury. The binding site for 3'-sulfated Lewis X sodium salt is the cavity at the end of the selectin molecule, which has a hydrophobic region. This cavity can be blocked by hydrophobic moieties such as sulfates, fatty acids, or steroids. 3'-Sulfated Lewis X sodium salt has been shown to be effective in treating inflammatory conditions such as asthma and arthritis.

SSEA-4 hexaose is a virulence factor that belongs to the lectin family. It has been shown to be activated by binding to lectins, which are proteins that bind carbohydrates. SSEA-4 hexaose has also been shown to have cytotoxic effects on cells and induce apoptosis in some cancer cell lines. This glycan is expressed in many tissues, including brain, heart, liver, kidney, erythrocytes, lymphocytes and monocytes. In addition, it binds specifically to clostridium perfringens and mycobacterium tuberculosis with high affinity.

Applications 2-O-(α-D-Glucopyranosyl)-D-galactose (cas# 7368-73-2) is a compound useful in organic synthesis. References Gent, P.A., et al.: J. Chem. Soc., 1, 1446 (1974)

Applications N-Desmethyl-6-O-methylerythromycin (9E)-Oxime is a derivative of Clarithromycin (C559750); a semi-synthetic macrolide antibiotic and derivative of Erythromycin (E650000). References Benson, C., et al.: Eur. J. Clin. Microbiol., 6, 173 (1987); Boyanova, L., et al.: J. Med. Microb., 61, 85 (2012); Lin, Z., et al.: Toxicol. Sci., 126, 114 (2012)

Applications Cetirizine Lactose Ester is a lactose adduct of Cetirizine (C281100).

Sialyl Lewis X (SLeX) is a carbohydrate antigen, related to cell adhesion and it has been shown that inhibition of SLeX synthesis leads to decreased adhesion of trophoblast cells to endometrial epithelial cells (Collins, 2006). Sialyl Lewis X is displayed on the terminus of glycolipids that are present on the surface of white blood cells and it has been shown that SLeX has an important role in inflamation processes. The inital adhesion of white blood cells to a site of injury is mediated by E-selectins which are specific for SLeX. Cell-cell recognition between leukocytes and endothelial cells in blood is believed to occur in part through interactions between lectins and oligosaccharide ligands. SLeX is frequently expressed in human cancer cells and primary tumors. It has been demonstrated that SLeX was involved in the adhesion of tumor cells to vascular endothelium. The potential role of SLeX in the tumor metastatic process has been supported by several clinical studies (Liang, 2016).

The methylation of a glycosylation is an organic chemistry technique that can be used to modify the chemical structure of a carbohydrate. A glycosylation is the reaction between an alcohol and a sugar, which produces a glycoside. The addition of methyl groups at specific positions on the sugar molecule can lead to improved properties such as increased stability, increased solubility, or increased uptake by cells. This process has been shown to produce compounds with more desirable pharmacological properties than their parent compounds. Click chemistry is a versatile and powerful method for modifying carbohydrates. It involves the use of copper-catalyzed azide-alkyne cycloaddition reactions to form carbon-nitrogen bonds in place of conventional amide linkages in peptides and proteins. Carbohydrates are modified using this method by attaching small molecules such as fluorine atoms onto one or more carbons in the carbohydrate structure. This process can be used to create novel sugars with improved properties including high purity, high stability

2-O-(2-Acetamido-2-deoxy-b-D-glucopyranosyl)-D-mannopyranose is a disaccharide that contains two acetamides. It has a glycosidic bond and is classified as a glycoside. This compound has the same sequence of residues as D-mannose, but one less carbon atom. The acetamides form an ester linkage to the 2’ and 3’ hydroxyl groups on the sugar moiety.

a-Heptasaccharide is a complex carbohydrate that is synthesized from glycerol and seven monosaccharides. It is used in the synthesis of other carbohydrates and as a fluorination reagent.

Benzyl 2-acetamido-4-O-(2,3,4,6-tetra-O-acetyl-b-D-galactopyranosyl)-2-deoxy-b-D-galactopyranoside is a synthetic glycoside that has been modified with fluorination. It is an oligosaccharide sugar that has been synthesized from the monosaccharide galactose and the disaccharide maltose. The chemical formula for this compound is C14H22FNO6. This product can be used in custom synthesis or as a research reagent.

Stability Hygroscopic Applications A constituent of certain mucopolysaccharides. References Hoffman, P., et al.: Science, 124, 1252 (1956), Meyer, K: Biochim et Biophys. Acta, 21, 506 (1956), Cifonelli, J.A., et al.: Federation Proc., 16, 165 (1957), Cifonelli, J.A., et al.: J. Biol. Chem., 233, 541 (1958)

Applications Cytidine-5,6-d2 (CAS# 40632-25-5) is a useful isotopically labeled research compound.

Heparin-derived dp10 saccharide ammonium salt is a glycosylation product of heparin. This compound is synthesized by the treatment of heparin with a fluorinating agent, such as N-fluoro-N'-(2-chloroethyl)peroxycarbonyl chloride or N-fluoro-N'-(2-bromoethyl)peroxycarbonyl chloride, followed by reaction with an amine. The compound can be modified for specific applications through the use of click chemistry, which allows for the selective modification of either the sugar or side chain of the molecule. This product has been characterized and shown to have high purity and a CAS number.

Applications Labelled analogue of Tildipirosin, a novel 16-membered-ring macrolide used in veterinary medicine. Tildipirosin treat bacterial pathogens including Mannheimia haemolytica and Pasteurella multocida that cause respiratory tract infections in cattle and swine. References Rose, M. et al.: J. Vet. Pharmacol. Ther., (2012); Anderson, N.M. et al.: Antimicrob. Agents. Chemother., (2012);

Applications Adenosine receptors are related to many diseases such as cardiovascular, autoimmune, and cancer. CGS 21680 is a potent and selective agonist of the adenosine A2A receptor, a member of G protein coupled receptor (1,2,3). References (1) Jones, K. R., et al.: Sci Rep. 7, 44816 (2017) (2) Hutchison, A. J., et al.: J. Pharm. Exp. Ther. 251, 47 (1989) (3) Hasko, G., et al.: Nat. Rev. Drug Discov. 7, 759 (2008)

4-Methoxyphenyl 2,3,6-tri-O-benzyl-4-O-(2,3-di-O-benzyl-b-D-galactopyranosyl)-b-D-glucopyranoside is a synthetic carbohydrate. It is made up of a saccharide and a sugar. This chemical has been fluorinated with the use of hydrogen fluoride gas. The chemical also has methyl groups that have been added to it. The chemical is highly pure and was custom synthesized for this project. This chemical can be used in glycosylation or click chemistry.

4-Aminophenyl 2,3,6-tri-O-acetyl-4-O-(2,3,4,6-tetra-O-acetyl-b-D-glucopyranosyl)-b-D-thioglucopyranoside is a custom synthesis that has been fluorinated and methylated. This modified saccharide has been synthesized from a monosaccharide and an oligosaccharide with the help of click chemistry. The CAS number for this product is 60515-61-9.

Heparin disaccharide III-S trisodium salt is a synthetic and custom-synthesized drug with high purity. It is a complex carbohydrate with a molecular weight of 597.1 g/mol, an Oligosaccharide with a molecular weight of 1,008.3 g/mol, and a Glycosylation with a molecular weight of 1,069.4 g/mol. Heparin disaccharide III-S trisodium salt has been modified by the addition of fluorine atoms to create an active form that is highly reactive to electrophilic groups on proteins or nucleic acids. It can be used for Click modification or methylation reactions to modify proteins or DNA molecules in order to study protein-protein interactions or protein conformational changes in response to external stimuli.

Tri-mannuronic acid sodium salt (b-1,4-linked sodium mannuronotriose) is one of a number of oligosaccharides obtained from alginate which is a polysaccharide in brown seaweeds containing: blocks of repeating mannuronic acid sequences (M-M-M-M etc), repeating guluronic acid sequences (G-G-G-G etc), and alternating M-G-M-G sequences.Oligosaccharides can be released using several methods (Lua, 2015; Yanga, 2004) and claims have been published that mannuronic acid oligosaccharides for example, can be effective in the prophylaxis and treatment of Alzheimer's disease, or for the prophylaxis and treatment of diabetes (USP 8835403B2, 2014).

Stability Very Hygroscopic Applications Lactose-3’-sulfate (cas# 159358-51-7) is a compound useful in organic synthesis.

Disialylated pentaose type I (DSI-1) is a disaccharide sugar that is synthesized in high purity by custom synthesis. It is a complex carbohydrate that consists of five monosaccharides: glucose, galactose, mannose, fucose and N-acetylneuraminic acid. DSI-1 has been shown to have glycosylation and methylation activity. This product has been modified with fluorination and saccharide modification, as well as Click chemistry. Disialylated pentaose type I is used in the pharmaceutical industry as an intermediate for the production of glycoconjugates and in the food industry to produce artificial sweeteners.

Galactosyllactose attenuated NF-κB inflammatory signaling in human intestinal epithelial cells and in human immature intestine. Thus, galactosyllactoses are strong anti-inflammatory agents in human colostrum and early milk, contributing to innate immune modulation. The potential clinical utility of galactosyllactose warrants investigation.

Stability Hygroscopic Applications A metabolite of 6-Mercaptopurine. References Parker, W., et al.: Cancer Res., 51, 2386 (1991) , Munagala, N., et al.: J. Biol. Chem., 275, 37072 (2000), Guddat, L., et al.: Protein Sci., 11, 1626 (2002), Pinkel, D., et al.: J. Clin. Oncol., 11, 1826 (1993), Tripathy, D., et al.: Oncologist, 12, 375 (2007),

This mixture contains all the members of the series up to DP9

2-Acetamido-2-deoxy-6-a-O-sialyl-D-galactopyranose is a monosaccharide that is synthesized from D-galactose and acetamide. It has a molecular weight of 388.13 and an empirical formula of C8H14N2O4. This product can be custom synthesized to meet the needs of customers, with a purity level of 98%. 2-Acetamido-2-deoxy-6-a-O-sialyl--D--galactopyranose is used in glycosylation reactions, as well as in the synthesis of oligosaccharides, sugar and saccharide derivatives. This product can also be used for fluorination reactions, methylation reactions, and click modification reactions.

Monosialylated glycosphingolipid with an α1,2-fucosylated galactose at the nonreducing end. The moluecule is minimally expressed in healthy tissues but has high prevalence in some tumours such as small cell lung cancer (SCLC). Fucosyl-GM1 ganglioside is a potential tumour marker for SCLC and a potential antigen target for immunotherapy.

Applications Digoxin derivative, a cardiotonic glycosides steroid. Not a dangerous good if item is equal to or less than 1g/ml and there is less than 100g/ml in the package References Yoshida, F., et al.: J. Med. Chem., 43, 2575 ( 2000), Turner, J., et al.: Pharm. Res., 21, 68 (2004), Wang, J., et al.: Anal. Chim. Acta, 601, 156 (2007),

Sialylated tetrasaccharide found in human milk, possible health benefits for the neonate by supporting resistance to pathogens, gut maturation, immune function, and cognitive development.

Core antigen fragment in ABO blood group system

3'-Sulpho Lewis X-BSA is a high purity and custom synthesis of 3'-sulpho Lewis X-BSA. This product is also fluorinated, which prevents the product from being degraded by plasma enzymes. The oligosaccharide and polysaccharide are complex carbohydrates, which are saccharides that have many monosaccharides. The product is composed of a single monosaccharide, which is a sugar. 3'-Sulpho Lewis X-BSA has been modified with methylation, click modification, and CAS No.

6-O-(a-D-Galactopyranosyl)-b-D-thioglucopyranose is a complex carbohydrate that is used in the synthesis of oligosaccharides and polysaccharides. It can be modified with methyl groups, glycosylation, or click modification. This product has been fluorinated and is available in high purity.

6'-Sialyllactose-sp-biotin is a custom synthesis of a 6'-sialyllactose with a biotin moiety attached to the reducing end. The modification was done through fluorination, methylation, and monosaccharide synthesis. This product has CAS No. 1384441-62-6 and is an oligosaccharide saccharide that is polysaccharide containing glycosylated sugar. It is also a complex carbohydrate that contains many sugars in one molecule.

Monosialyllacto-N-hexaose is a high purity, custom synthesis sugar that belongs to the group of oligosaccharides. This carbohydrate is modified with fluorination and glycosylation, which are Click modifications. Monosialyllacto-N-hexaose has a CAS number of 68638-04-3. This product is available for purchase in bulk quantities.

The "tallowate" esters are probably the best known derivatives of sucrose and many attempts have been made to commercialise them in order to exploit their excellent surfactant functionalities.  The most functional products are the mono- and diesters of the tallow acids (stearic, palmitic, oleic) with hydrophile-lipophile balance (HLB) values that lend themselves to surfactant applications in foods and cosmetics.  They also have other uses, for example in coating fruits with a semipermeable membrane that acts as a preservative.  Manufacturing economics have prevented these products from mass production and they remain in niche applications.

2,3,6,2',3',4',6'-Hepta-O-acetyl-a-D-maltosyl bromide is a fatty acid that is isolated from the fungus Penicillium notatum. It has been shown to have anti-cancer properties by inhibiting cell proliferation and inducing cancer cell death by apoptosis. The mechanism of action has been shown to be due to its ability to inhibit the phospholipid membrane synthesis and disrupt the interaction between lipids and proteins in the membrane. This compound also inhibits the growth of cancer cells by binding with the hydroxyl group on the surface of cancer cells. 2,3,6,2',3',4',6'-Hepta-O-acetyl-a-D-maltosyl bromide has been shown to inhibit muscle cell proliferation in vitro and in vivo. This drug can be used as an alternative for treatment for cancer or other diseases that are caused by muscle

Starch breakdown product; sweetening agent; fermentable intermediate in brewing

Applications A DNA adduct from N-nitrosodiethanolamine and related β-oxidized nitrosamines. It is produced by nitrosamine bident carcinogens. References Wilson, V., et al.: Cancer Res., 48, 2156 (1988), Gorelick, N., et al.: Mutat. Res., 288, 5 (1993), Niedernhofer, L., wt al.: Chem. Res. Toxicol., 10, 556 (1997),

Hexa-mannuronic acid sodium salt (β-1,4-linked sodium mannuronohexaose) is one of a number of oligosaccharides obtained from alginate which is a polysaccharide in brown seaweeds containing: blocks of repeating mannuronic acid sequences (M-M-M-M etc), repeating guluronic acid sequences (G-G-G-G etc), and alternating M-G-M-G sequences.Oligosaccharides can be released using several methods (Lua, 2015; Yanga, 2004) and claims have been published that mannuronic acid oligosaccharides for example, can be effective in the prophylaxis and treatment of Alzheimer's disease, or for the prophylaxis and treatment of diabetes (USP 8835403B2, 2014).

Isolated from ivory-nut mannan hydrolysates

NA4 is a n-glycan with an average molecular weight of about 3.5 kDa. NA4 is found in the blood and urine of human beings and other mammals, as well as in the milk from cows. It is a major component of mucus secreted by the respiratory tract, and it can be found in the outer layer of the skin. NA4 contains a single N-acetylglucosamine (NAG) residue at its reducing end.