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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2014/05/30 09:27:00」(JST)

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Structure of the amylopectin molecule

Amylopectin /ˌæmɨloʊˈpɛktɨn/ is a soluble^[1]^[2] polysaccharide and highly branched polymer of glucose found in plants. It is one of the two components of starch, the other being amylose.

Glucose units are linked in a linear way with α(1→4) glycosidic bonds. Branching takes place with α(1→6) bonds occurring every 24 to 30 glucose units, resulting in a soluble molecule that can be quickly degraded as it has many end points for enzymes to attach onto. In contrast, amylose contains very few α(1→6) bonds, or even none at all. This causes it to be hydrolyzed more slowly but have higher density and be insoluble.

Its counterpart in animals is glycogen, which has the same composition and structure, but with more extensive branching that occurs every 8 to 12 glucose units.

Plants store starch within specialized organelles called amyloplasts. When energy is needed for cell work, the plant hydrolyzes the starch, releasing the glucose subunits. Humans and other animals that eat plant foods also use amylase, an enzyme that assists in breaking down amylopectin.

Starch is made of about 70% amylopectin by weight, though it varies depending on the source (higher in medium-grain rice to 100% in glutinous rice, waxy potato starch, and waxy corn, and lower in long-grain rice, amylomaize, and russet potato, for example). Amylopectin is highly branched, being formed of 2,000 to 200,000 glucose units. Its inner-chains are formed of 20-24 glucose subunits.

Dissolved amylopectine starch has a lower tendency of retrogradation (gelling) during storage and cooling. For this main reason the waxy starches are used in different applications mainly as thickening agent or stabilizer.

References

^ "Amylose, Amylopectin (starch)". GMO Compass. Archived from the original on 31 December 2010. Retrieved 2011-02-07.
^ Green, Mark M.; Blankenhorn, Glenn; Hart, Harold (November 1975). "Which Starch Fraction is Water-Soluble, Amylose or Amylopectin?". Journal of Chemical Education 52 (11): 729. doi:10.1021/ed052p729. Subscription required for online access.

External links

International Starch Institute

UpToDate Contents

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1. 食事中の炭水化物 dietary carbohydrates
2. 栄養の吸収および吸収不良の機序 mechanisms of nutrient absorption and malabsorption
3. グリコーゲン分枝酵素欠損症（糖原病IV型、アンダーセン病） glycogen branching enzyme deficiency glycogen storage disease iv andersen disease

English Journal

Improved understanding of rice amylose biosynthesis from advanced starch structural characterization.

Li E1, Wu AC, Li J, Liu Q, Gilbert RG.
Rice (New York, N.Y.).Rice (N Y).2015 Dec;8(1):55. doi: 10.1186/s12284-015-0055-4. Epub 2015 Jun 17.
BACKGROUND: It has been shown from the chain length distributions (CLDs) that amylose chains can be divided into at least two groups: long and short amylose chains. These molecular structures influence some functional properties of starch, such as digestibility and mouth-feel. GBSSI is the key enzym
PMID 26082161

Nutrient composition and starch characteristics of Quercus glandulifera Bl. seeds from China.

Li S1, Zhou Y2, Liu M1, Zhang Y1, Cao S1.
Food chemistry.Food Chem.2015 Oct 15;185:371-6. doi: 10.1016/j.foodchem.2015.03.147. Epub 2015 Apr 7.
The chemical composition and starch characteristics of acorn (Quercus glandulifera Bl.) were studied. The moisture content of acorn seeds was 7.55%. The crude fat, crude protein, dietary fiber, total ash, and nitrogen-free extract contents of acorn seed were 4.20%, 10.16%, 2.95%, 0.03%, and 82.66%,
PMID 25952881

Improved material properties of solution-cast starch films: Effect of varying amylopectin structure and amylose content of starch from genetically modified potatoes.

Menzel C1, Andersson M2, Andersson R3, Vázquez-Gutiérrez JL3, Daniel G4, Langton M3, Gällstedt M5, Koch K3.
Carbohydrate polymers.Carbohydr Polym.2015 Oct 5;130:388-97. doi: 10.1016/j.carbpol.2015.05.024. Epub 2015 May 19.
High-amylose potato starches were produced through genetic modification resulting in changed granule morphology and composition, with higher amylose content and increased chain length of amylopectin. The increased amylose content and structural changes in amylopectin enhanced film-forming behavior a
PMID 26076640

Japanese Journal

Properties of Endosperm Starches and Physical Properties of Cooked Rice from Japanese Upland Rice Cultivars Containing M-type Amylopectin

NAKAURA Yoshiko,UEDA Tomoyuki,UMEMOTO Takayuki,OKAMOTO Kazuyuki,INOUCHI Naoyoshi
Journal of applied glycoscience 59(3), 111-117, 2012-08-20
NAID 10030704180

The Amylose Content and Amylopectin Structure Affect the Shape and Hardness of Rice Bread

AOKI Noriaki,UMEMOTO Takayuki,HAMADA Shigeki,SUZUKI Keitaro,SUZUKI Yasuhiro
Journal of applied glycoscience 59(2), 75-82, 2012-05-20
NAID 10030317937

Related Pictures

★リンクテーブル★

リンク元	「アミロペクチン」
拡張検索	「amylopectinosis」

「アミロペクチン」

Amylopectin
Identifiers
CAS number	9037-22-3
PubChem	439207
ChemSpider	388347
UNII	4XO4QFV777
EC number	232-911-6
	InChI InChI=1S/C30H52O26/c31-1-6-11(35)13(37)19(43)28(50-6)55-24-9(4-34)52-27(21(45)16(24)40)48-5-10-25(56-29-20(44)14(38)12(36)7(2-32)51-29)17(41)22(46)30(53-10)54-23-8(3-33)49-26(47)18(42)15(23)39/h6-47H,1-5H2/t6-,7-,8-,9-,10-,11-,12-,13+,14+,15-,16-,17-,18-,19-,20-,21-,22-,23-,24-,25-,26+,27+,28-,29-,30-/m1/s1 ; Key: WMGFVAGNIYUEEP-WUYNJSITSA-N InChI=1/C30H52O26/c31-1-6-11(35)13(37)19(43)28(50-6)55-24-9(4-34)52-27(21(45)16(24)40)48-5-10-25(56-29-20(44)14(38)12(36)7(2-32)51-29)17(41)22(46)30(53-10)54-23-8(3-33)49-26(47)18(42)15(23)39/h6-47H,1-5H2/t6-,7-,8-,9-,10-,11-,12-,13+,14+,15-,16-,17-,18-,19-,20-,21-,22-,23-,24-,25-,26+,27+,28-,29-,30-/m1/s1; Key: WMGFVAGNIYUEEP-WUYNJSITBP ;
Properties
Molecular formula	variable
Molar mass	variable
Appearance	white powder
	Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
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	Infobox references

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関

同: amylopectin

英: [[]]
同: amylopectin

-amylopectin

「amylopectinosis」

　　[★] アミロペクチン症

関: Andersen disease、glycogen storage disease type IV

[1] "Amylose, Amylopectin (starch)". GMO Compass. Archived from the original on 31 December 2010. Retrieved 2011-02-07.

[2] Green, Mark M.; Blankenhorn, Glenn; Hart, Harold (November 1975). "Which Starch Fraction is Water-Soluble, Amylose or Amylopectin?". Journal of Chemical Education 52 (11): 729. doi:10.1021/ed052p729. Subscription required for online access.

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amylopectin