Oligosaccharide
Encyclopedia
An oligosaccharide is a saccharide
polymer
containing a small number (typically two to ten) of component sugars, also known as simple sugars (monosaccharides)
. Oligosaccharides can have many functions; for example, they are commonly found on the plasma membrane of animal cells where they can play a role in cell–cell recognition.
In general, they are found either O- or N-linked
to compatible amino acid side-chains in proteins or to lipid
moieties (see glycans
).
(FOS), which are found in many vegetables, consist of short chains of fructose
molecules. (Inulin
has a much higher degree of polymerization
than FOS and is a polysaccharide.) Galactooligosaccharides
(GOS), which also occur naturally, consist of short chains of galactose
molecules. These compounds can be only partially digested by humans.
Oligosaccharides are often found as a component of glycoproteins or glycolipids and as such are often used as chemical markers, often for cell recognition. An example is ABO blood type
specificity. A and B blood types have two different oligosaccharide glycolipids embedded in the cell membranes of the red blood cells, AB-type blood has both, while O blood type has neither.
Mannan Oligosaccharides (MOS) are widely used animal feed
to improve gastrointestinal health, energy levels and performance. They are normally obtained from the yeast cell walls of Saccharomyces cerevisiae
. Research at the University of Illinois has demonstrated that Mannan Oligosaccharides differ from other Oligosaccharides in that they are not fermentable and their primary mode of actions include agglutination of type-1 fimbrae pathogens and immunomodulation
Clinical studies have shown that administering FOS, GOS, or inulin can increase the number of these friendly bacteria
in the colon while simultaneously reducing the population of harmful bacteria.
, burdock
, chicory
, leeks, onion
s, and asparagus
. FOS products derived from chicory root contain significant quantities of inulin, a fiber widely distributed in fruits, vegetables and plants. Inulin is a significant part of the daily diet of most of the world’s population. FOS can also be synthesized by enzymes of the fungus Aspergillus niger
acting on sucrose. GOS is naturally found in soybeans and can be synthesized from lactose
(milk sugar). FOS, GOS, and inulin are available as nutritional supplements in capsules, tablets, and as a powder.
Not all natural oligosaccharides occur as components of glycoproteins or glycolipids. Some, such as the raffinose
series, occur as storage or transport carbohydrates in plants. Others, such as maltodextrin
s or cellodextrins
, result from the microbial breakdown of larger polysaccharides such as starch
or cellulose
.
Carbohydrate
A carbohydrate is an organic compound with the empirical formula ; that is, consists only of carbon, hydrogen, and oxygen, with a hydrogen:oxygen atom ratio of 2:1 . However, there are exceptions to this. One common example would be deoxyribose, a component of DNA, which has the empirical...
polymer
Polymer
A polymer is a large molecule composed of repeating structural units. These subunits are typically connected by covalent chemical bonds...
containing a small number (typically two to ten) of component sugars, also known as simple sugars (monosaccharides)
Monosaccharide
Monosaccharides are the most basic units of biologically important carbohydrates. They are the simplest form of sugar and are usually colorless, water-soluble, crystalline solids. Some monosaccharides have a sweet taste. Examples of monosaccharides include glucose , fructose , galactose, xylose...
. Oligosaccharides can have many functions; for example, they are commonly found on the plasma membrane of animal cells where they can play a role in cell–cell recognition.
In general, they are found either O- or N-linked
Glycosidic bond
In chemistry, a glycosidic bond is a type of covalent bond that joins a carbohydrate molecule to another group, which may or may not be another carbohydrate....
to compatible amino acid side-chains in proteins or to lipid
Lipid
Lipids constitute a broad group of naturally occurring molecules that include fats, waxes, sterols, fat-soluble vitamins , monoglycerides, diglycerides, triglycerides, phospholipids, and others...
moieties (see glycans
Glycans
The term glycan refers to a polysaccharide or oligosaccharide. Glycans usually consist solely of O-glycosidic linkages of monosaccharides. For example, cellulose is a glycan composed of beta-1,4-linked D-glucose, and chitin is a glycan composed of beta-1,4-linked N-acetyl-D-glucosamine...
).
Examples
Fructo-oligosaccharidesFructooligosaccharide
Fructooligosaccharides also sometimes called oligofructose or oligofructan, are oligosaccharide fructans, used as an alternative sweetener. FOS exhibits sweetness levels between 30 and 50 percent of sugar in commercially-prepared syrups...
(FOS), which are found in many vegetables, consist of short chains of fructose
Fructose
Fructose, or fruit sugar, is a simple monosaccharide found in many plants. It is one of the three dietary monosaccharides, along with glucose and galactose, that are absorbed directly into the bloodstream during digestion. Fructose was discovered by French chemist Augustin-Pierre Dubrunfaut in 1847...
molecules. (Inulin
Inulin
Inulins are a group of naturally occurring polysaccharides produced by many types of plants. They belong to a class of fibers known as fructans. Inulin is used by some plants as a means of storing energy and is typically found in roots or rhizomes...
has a much higher degree of polymerization
Degree of polymerization
The degree of polymerization, or DP, is usually defined as the number of monomeric units in a macromolecule or polymer or oligomer molecule.For a homopolymer, there is only one type of monomeric unit andthe number-average degree of polymerization is given by...
than FOS and is a polysaccharide.) Galactooligosaccharides
Galactooligosaccharides
Galacto-oligosaccharides , also known as oligogalactosyllactose, oligogalactose, oligolactose or transgalactooligosaccharides , belong, because of their indigestible nature, to the group of prebiotics. Prebiotics are defined as non-digestible food ingredients that beneficially affect the host by...
(GOS), which also occur naturally, consist of short chains of galactose
Galactose
Galactose , sometimes abbreviated Gal, is a type of sugar that is less sweet than glucose. It is a C-4 epimer of glucose....
molecules. These compounds can be only partially digested by humans.
Oligosaccharides are often found as a component of glycoproteins or glycolipids and as such are often used as chemical markers, often for cell recognition. An example is ABO blood type
Blood type
A blood type is a classification of blood based on the presence or absence of inherited antigenic substances on the surface of red blood cells . These antigens may be proteins, carbohydrates, glycoproteins, or glycolipids, depending on the blood group system...
specificity. A and B blood types have two different oligosaccharide glycolipids embedded in the cell membranes of the red blood cells, AB-type blood has both, while O blood type has neither.
Mannan Oligosaccharides (MOS) are widely used animal feed
Compound feed
Compound feeds are feedstuffs that are blended from various raw materials and additives. These blends are formulated according to the specific requirements of the target animal...
to improve gastrointestinal health, energy levels and performance. They are normally obtained from the yeast cell walls of Saccharomyces cerevisiae
Saccharomyces cerevisiae
Saccharomyces cerevisiae is a species of yeast. It is perhaps the most useful yeast, having been instrumental to baking and brewing since ancient times. It is believed that it was originally isolated from the skin of grapes...
. Research at the University of Illinois has demonstrated that Mannan Oligosaccharides differ from other Oligosaccharides in that they are not fermentable and their primary mode of actions include agglutination of type-1 fimbrae pathogens and immunomodulation
Therapeutic effects
When oligosaccharides are consumed, the undigested portion serves as food for the intestinal microflora. Depending on the type of oligosaccharide, different bacterial groups are stimulated or suppressed.Clinical studies have shown that administering FOS, GOS, or inulin can increase the number of these friendly bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
in the colon while simultaneously reducing the population of harmful bacteria.
Sources
FOS and inulin are found naturally in Jerusalem artichokeJerusalem artichoke
The Jerusalem artichoke , also called the sunroot, sunchoke, earth apple or topinambour, is a species of sunflower native to eastern North America, and found from Eastern Canada and Maine west to North Dakota, and south to northern Florida and Texas...
, burdock
Burdock
Burdock is any of a group of biennial thistles in the genus Arctium, family Asteraceae. Native to the Old World, several species have been widely introduced worldwide....
, chicory
Chicory
Common chicory, Cichorium intybus, is a somewhat woody, perennial herbaceous plant usually with bright blue flowers, rarely white or pink. Various varieties are cultivated for salad leaves, chicons , or for roots , which are baked, ground, and used as a coffee substitute and additive. It is also...
, leeks, onion
Onion
The onion , also known as the bulb onion, common onion and garden onion, is the most widely cultivated species of the genus Allium. The genus Allium also contains a number of other species variously referred to as onions and cultivated for food, such as the Japanese bunching onion The onion...
s, and asparagus
Asparagus
Asparagus officinalis is a spring vegetable, a flowering perennialplant species in the genus Asparagus. It was once classified in the lily family, like its Allium cousins, onions and garlic, but the Liliaceae have been split and the onion-like plants are now in the family Amaryllidaceae and...
. FOS products derived from chicory root contain significant quantities of inulin, a fiber widely distributed in fruits, vegetables and plants. Inulin is a significant part of the daily diet of most of the world’s population. FOS can also be synthesized by enzymes of the fungus Aspergillus niger
Aspergillus niger
Aspergillus niger is a fungus and one of the most common species of the genus Aspergillus. It causes a disease called black mold on certain fruits and vegetables such as grapes, onions, and peanuts, and is a common contaminant of food...
acting on sucrose. GOS is naturally found in soybeans and can be synthesized from lactose
Lactose
Lactose is a disaccharide sugar that is found most notably in milk and is formed from galactose and glucose. Lactose makes up around 2~8% of milk , although the amount varies among species and individuals. It is extracted from sweet or sour whey. The name comes from or , the Latin word for milk,...
(milk sugar). FOS, GOS, and inulin are available as nutritional supplements in capsules, tablets, and as a powder.
Not all natural oligosaccharides occur as components of glycoproteins or glycolipids. Some, such as the raffinose
Raffinose
Raffinose is a trisaccharide composed of galactose, fructose, and glucose. It can be found in beans, cabbage, brussels sprouts, broccoli, asparagus, other vegetables, and whole grains. Raffinose can be hydrolyzed to D-galactose and sucrose by the enzyme α-galactosidase , an enzyme not found in the...
series, occur as storage or transport carbohydrates in plants. Others, such as maltodextrin
Maltodextrin
Maltodextrin is a polysaccharide that is used as a food additive. It is produced from starch by partial hydrolysis and is usually found as a creamy-white hygroscopic spraydried powder. Maltodextrin is easily digestible, being absorbed as rapidly as glucose, and might be either moderately sweet or...
s or cellodextrins
Cellodextrins
Cellodextrins are glucose polymers of varying length resulting from cellulolysis, the breakdown of cellulose.-Classification:...
, result from the microbial breakdown of larger polysaccharides such as starch
Starch
Starch or amylum is a carbohydrate consisting of a large number of glucose units joined together by glycosidic bonds. This polysaccharide is produced by all green plants as an energy store...
or cellulose
Cellulose
Cellulose is an organic compound with the formula , a polysaccharide consisting of a linear chain of several hundred to over ten thousand β linked D-glucose units....
.
See also
- Oligosaccharide synthesisCarbohydrate synthesisCarbohydrate synthesis is a sub-field of organic chemistry concerned specifically with the generation of natural and unnatural carbohydrate structures...
- Oligosaccharide nomenclatureOligosaccharide nomenclatureOligosaccharides and polysaccharides are an important class of polymeric carbohydrates found in virtually all living entities. Their structural features make their nomenclature challenging and their roles in living systems make their nomenclature important.- Oligosaccharides :Oligosaccharides are...
- PolysaccharidePolysaccharidePolysaccharides are long carbohydrate molecules, of repeated monomer units joined together by glycosidic bonds. They range in structure from linear to highly branched. Polysaccharides are often quite heterogeneous, containing slight modifications of the repeating unit. Depending on the structure,...
- Mannan Oligosaccharides, MOS