(Difference between pages)

Page 1

Page 1Revision 1

Page 2

Page 2Revision 2

Content deleted Content addedVisualWikitext

Revision as of 12:26, 15 February 2012 editBeetstra (talk | contribs)Edit filter managers, Administrators172,031 edits Saving copy of the {{chembox}} taken from revid 473939302 of page Levan_polysaccharide for the Chem/Drugbox validation project (updated: 'CASNo').		Latest revision as of 06:04, 4 March 2024 edit Deinocheiridae (talk | contribs)37 editsm →Discovery: added full name and included link to Edmund Oscar von Lippmann
Line 1:		Line 1:
	{{ambox | text = This page contains a copy of the infobox ({{tl|chembox}}) taken from revid of page ] with values updated to verified values.}}
	{{Chembox		{{Chembox
	| Verifiedfields = changed		| Verifiedfields = changed
			| Watchedfields = changed
	| verifiedrevid = 458270249		| verifiedrevid = 476994082
	| ImageFile = levan.png		| ImageFile = levan.png
	| ImageSize = 200px		| IUPACName =
	| IUPACName = Levan
	| OtherNames = Polyfructose		| OtherNames = Polyfructose
	| Section1 = {{Chembox Identifiers		|Section1={{Chembox Identifiers
	| CASNo_Ref = {{cascite|changed|??}}		| CASNo_Ref = {{cascite|changed|??}}
	| CASNo = <!-- blanked - oldvalue: 9013-95-0 -->		| CASNo = 9013-95-0
	| PubChem = 440946		| PubChem =
			| ChEBI_Ref = {{ebicite|changed|EBI}}
⚫	| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
	| ChemSpiderID = NA		| ChEBI = 16703
		⚫	| ChemSpiderID_Ref = {{chemspidercite|changed|chemspider}}
			| ChemSpiderID = 17216231
	| SMILES = }}		| SMILES = }}
	| Section2 = {{Chembox Properties		|Section2={{Chembox Properties
	| Formula =		| Formula =
	| MolarMass =		| MolarMass =
Line 22:		Line 23:
	| BoilingPt =		| BoilingPt =
	| Solubility = }}		| Solubility = }}
	| Section3 = {{Chembox Hazards		|Section3={{Chembox Hazards
	| MainHazards =		| MainHazards =
	| FlashPt =		| FlashPt =
	| Autoignition = }}		| AutoignitionPt = }}
	}}		}}
			]
			]
			'''Levan''' is a naturally occurring ] present in many plants and microorganisms.<ref>{{Citation|last=Meyer|first=Diederick|title=Chapter Two - Health Benefits of Prebiotic Fibers|date=2015-01-01|url=http://www.sciencedirect.com/science/article/pii/S1043452614000035|journal=Advances in Food and Nutrition Research|volume=74|pages=47–91|editor-last=Henry|editor-first=Jeyakumar|publisher=Academic Press|language=en|doi=10.1016/bs.afnr.2014.11.002|pmid=25624035|access-date=2020-05-10}}</ref> This polymer is made up of ], a monosaccharide sugar, connected by 2,6 beta ]. Levan can have both branched and linear structures of relatively low molecular weight.<ref name=":12">{{Cite journal|last1=Gehatia|first1=M.|last2=Feingold|first2=D. S.|date=1957-02-01|title=The structure and properties of levan, a polymer of D‐fructose produced by cultures and cell‐free extracts of aerobacter levanicum|journal=Journal of Polymer Science|volume=23|issue=104|pages=783–790|doi=10.1002/pol.1957.1202310421|issn=1542-6238|bibcode=1957JPoSc..23..783F}}</ref> Branched levan forms a very small, sphere-like structure<ref>{{Cite journal|last1=Arvidson|first1=Sara A.|last2=Rinehart|first2=B.Todd|last3=Gadala-Maria|first3=Francis|date=July 2006|title=Concentration regimes of solutions of levan polysaccharide from Bacillus sp.|journal=Carbohydrate Polymers|volume=65|issue=2|pages=144–149|doi=10.1016/j.carbpol.2005.12.039|issn=0144-8617}}</ref> with basal chains 9 units long. The 2,1 branching allows methyl ethers to form and create a spherical shape. The ends of levan also tend to contain a glucosyl residue.<ref name=":22">{{Cite journal|last1=Srikanth|first1=Rapala|last2=Reddy|first2=Chinta H S S Sundhar|last3=Siddartha|first3=Gudimalla|last4=Ramaiah|first4=M. Janaki|last5=Uppuluri|first5=Kiran Babu|date=April 2015|title=Review on production, characterization and applications of microbial levan|journal=Carbohydrate Polymers|volume=120|pages=102–114|doi=10.1016/j.carbpol.2014.12.003|pmid=25662693|issn=0144-8617}}</ref> Branched levan tends to be more stable than linear polysaccharides.<ref name=":02">{{Cite journal |last1=Öner |first1=Ebru Toksoy |last2=Hernández |first2=Lázaro |last3=Combie |first3=Joan |date=September 2016 |title=Review of Levan polysaccharide: From a century of past experiences to future prospects |journal=Biotechnology Advances |volume=34 |issue=5 |pages=827–844 |doi=10.1016/j.biotechadv.2016.05.002 |issn=0734-9750 |pmid=27178733}}</ref> However, the amount of branching and length of polymerization tends to vary among different species.<ref name=":22" /> The shortest levan is 6-], a chain of two fructose molecules and a terminal glucose molecule.
			== Discovery ==
			Levan was first discovered through research on ], a traditional Japanese dish.<ref name=":02" /> Natto was known as a "]" which promoted health and longevity in Japan during the late 1800s.<ref name=":02" /> In 1881, ] first discovered "lävulan" (levan) as the remaining gum from ] in sugar beet production.<ref>{{Cite journal |last=v. Lippmann |first=Edmund O. |date=January 1881 |title=Ueber das Lävulan, eine neue, in der Melasse der Rübenzuckerfabriken vorkommende Gummiart |url=https://zenodo.org/record/2240181 |journal=Berichte der Deutschen Chemischen Gesellschaft |volume=14 |issue=1 |pages=1509–1512 |doi=10.1002/cber.188101401316 |issn=0365-9496}}</ref> Later in 1901, Greig-Smith coined the name “levan” based on the ] properties of this substance in ].
			== Production ==
			Levan is synthesized in ], fungi, bacteria, and a limited number of plant species. Fructans such as levan are synthesized from ], a ] containing glucose and fructose.<ref name=":02" /> In plants, the ] is where fructan production occurs. Sucrose:sucrose/fructan 6-fructosyltransferase is the ] in the vacuole which creates the beta 2,6 linkages to form the linear form of levan.<ref name=":02" /> Bacteria also use a fructosyltransferase known as levansucrase to form levan.<ref name=":02" /> These enzymes in bacteria form the 2,1 linkages in the linear basal chains of levan to allow for branching points to occur.<ref name=":02" /> Many bacteria produce levan in the cell exterior.<ref name=":02" /> This production can be sensitive to temperature, oxygen concentration, pH, and other factors.<ref name=":02" /> Levan production in bacteria is typically a sign of growth in population.<ref name=":02" /> There are also possible ways to produce by fracturing ] ].{{cn|date=January 2022}}
			Levans are produced by microbes during colonization of a food ]. '']'' exudes levan and ] as part of its ]. Together they contribute to its ].<ref name="Mansfield-et-al-2012">{{cite journal | last1=Mansfield | first1=John | last2=Genin | first2=Stephane | last3=Magore | first3=Shimpei | last4=Citovsky | first4=Vitaly | last5=Sriariyanum | first5=Malinee | last6=Ronald | first6=Pamela | last7=Dow | first7=Max | last8=Verdier | first8=Valérie | last9=Beer | first9=Steven V. | last10=Machado | first10=Marcos A. | last11=Toth | first11=Ian | last12=Salmond | first12=George | last13=Foster | first13=Gary D. | title=Top 10 plant pathogenic bacteria in molecular plant pathology | journal=] | publisher=] (]) | volume=13 | issue=6 | date=2012-06-05 | issn=1464-6722 | doi=10.1111/j.1364-3703.2012.00804.x | pages=614–629| pmid=22672649 | pmc=6638704 }}</ref> In 2016, Ua-Arak et al. developed a ] method with high levan output (among other ]s).<ref name="Lynch-et-al-2019">{{cite journal | last1=Lynch | first1=Kieran M. | last2=Zannini | first2=Emanuele | last3=Wilkinson | first3=Stuart | last4=Daenen | first4=Luk | last5=Arendt | first5=Elke K. | title=Physiology of Acetic Acid Bacteria and Their Role in Vinegar and Fermented Beverages | journal=] | publisher=] (]) | volume=18 | issue=3 | date=2019-04-02 | issn=1541-4337 | doi=10.1111/1541-4337.12440 | pages=587–625| pmid=33336918 | s2cid=132210454 | doi-access=free | hdl=10468/7852 | hdl-access=free }}</ref>
			== Properties ==
			The beta 2,6 linkages of levan allow for it to be soluble in both water and oil; however, the water temperature varies the degree of ].<ref>{{Cite journal|last=Ouwehand|first=Arthur|date=2012-06-18|title=Prebiotic developments|journal=Microbial Ecology in Health & Disease|volume=23|pages=10.3402/mehd.v23i0.18583|doi=10.3402/mehd.v23i0.18583|issn=1651-2235|pmc=3747740}}</ref> Levan also is insoluble in many organic solvents such as methanol, ethanol, and isopropanol.<ref name=":22" /> The branching of levan allows it to have a high tensile and cohesive strength, while the hydroxyl groups contribute to adhesion with other molecules.<ref name=":22" /> The intrinsic viscosity n, a measure of the substance effect on viscosity of a solution, tends to be very low for levan.<ref name=":22" /> This allows levan to be utilized in a pharmaceutical setting.
			== Real world implications ==
			Many industries such as ], beverages, cosmetics, and even medicine utilize levan in their products. One of the reasons levan is able to be used in such a versatile way is that it fulfills all safety guidelines. Levan does not cause any form of skin or ], has not shown any allergenic effects, and poses no threat of ].<ref>{{Cite web|url=http://www.polysaccharides.us/|title=Montana Polysaccharides Corp.|website=www.polysaccharides.us|access-date=2019-05-15}}</ref>
			=== Food ===
			In the food industry, levan is incorporated due to its ] effects, ] ability, and adhesive properties.<ref name=":22" /> It also occurs naturally in low amounts in food for human consumption.<ref name=":22" /> Levan is also included in many dairy products as fiber or sweetener.<ref name=":22" /> Commercial, non-alcoholic beverages use levan as well in ultra-high-fructose-syrups.<ref>{{Cite journal|last1=Bello|first1=Fabio Dal|last2=Walter|first2=Jens|last3=Hertel|first3=Christian|last4=Hammes|first4=Walter P.|date=January 2001|title=In vitro study of Prebiotic Properties of Levan-type Exopolysaccharides from Lactobacilli and Non-digestible Carbohydrates Using Denaturing Gradient Gel Electrophoresis|journal=Systematic and Applied Microbiology|volume=24|issue=2|pages=232–237|doi=10.1078/0723-2020-00033|pmid=11518326|issn=0723-2020}}</ref> Interestingly, levan causes useful bacterial growth and proliferation which can be especially important in the gut because it causes a decrease in population of the pathogenic bacteria.<ref name=":32">{{Cite journal|last1=Ritsema|first1=Tita|last2=Smeekens|first2=Sjef|date=June 2003|title=Fructans: beneficial for plants and humans|journal=Current Opinion in Plant Biology|volume=6|issue=3|pages=223–230|doi=10.1016/s1369-5266(03)00034-7|pmid=12753971|issn=1369-5266}}</ref>
			=== Cosmetics ===
			Levan can be used for ] and ]. In hair care products, levan acts to form a film which creates a hair holding effect utilized in various gels and mousses.<ref name=":02" /> Levan is used as a skin whitener as well because it has been tested to show inhibition on melanin production by decreasing the activity of the enzyme ] which is responsible for ].<ref name=":02" />
			=== Medicine ===
			Levan has shown uses for burned tissue, ], and ]. By combining levan into a thin film, it is able to activate an enzyme known as metalloproteinase which increases the recovery and healing process.<ref>{{Cite journal |last1=Sözgen |first1=Güler |last2=Özdoğan |first2=Gökçenaz |last3=Kaplan Türköz |first3=Burcu |date=2018-11-01 |title=Zymomonas mobilis levansukraz enziminin levan üretiminde kullanılması |trans-title=Use of Zymomonas mobilis levansucrase in levan production |journal= Gida / The Journal of Food|volume=43 |issue=6 |pages=1061–1074 |doi=10.15237/gida.gd18087 |issn=1300-3070 |language=tr|doi-access=free }}</ref> In the case of inflammation, levan interacts with the aggregating cells and affects their adhesion to the blood vessel causing reduced accumulation.<ref>{{Citation|last=Apostolopoulos|first=Nikos C.|chapter=Study One: Acute Inflammatory Response to Stretching|date=2018|pages=131–143|publisher=Springer International Publishing|isbn=9783319967998|doi=10.1007/978-3-319-96800-1_3|title=Stretch Intensity and the Inflammatory Response: A Paradigm Shift}}</ref> In aquaculture, results have shown that levan incorporated diets could possibly cause an increase in aggregation of viruses allowing for easier ] removal.<ref name=":42">{{Cite journal |last1=Rairakhwada |first1=D. |last2=Pal |first2=A. |last3=Bhathena |first3=Z. |last4=Sahu |first4=N. |last5=Jha |first5=A. |last6=Mukherjee |first6=S. |date=May 2007 |title=Dietary microbial levan enhances cellular non-specific immunity and survival of common carp (Cyprinus carpio) juveniles |journal=Fish & Shellfish Immunology |volume=22 |issue=5 |pages=477–486 |doi=10.1016/j.fsi.2006.06.005 |pmid=17158064 |issn=1050-4648}}</ref> Levan produced by ''Pantoea agglomerans'' ZMR7 was reported to decrease the viability of rhabdomyosarcoma (RD) and breast cancer (MDA) cells compared with untreated cancer cells. In addition, it has high antiparasitic activity against the promastigote of ''Leishmania tropica''<ref>{{Cite journal|last1=Al-Qaysi|first1=Safaa A. S.|last2=Al-Haideri|first2=Halah|last3=Al-Shimmary|first3=Sana M.|last4=Abdulhameed|first4=Jasim M.|last5=Alajrawy|first5=Othman I.|last6=Al-Halbosiy|first6=Mohammad M.|last7=Moussa|first7=Tarek A.|last8=Farahat|first8=Mohamed G.|date=2021-04-05|title=Bioactive levan type exopolysaccharide produced by Pantoea agglomerans ZMR7: characterization and optimization for enhanced production|journal=Journal of Microbiology and Biotechnology|volume=31|issue=5|pages=696–704|doi=10.4014/jmb.2101.01025|issn=1738-8872|pmid=33820887|pmc=9705920 |doi-access=free}}</ref>
			==See also==
			* ]
			* ]
			==References==
			{{reflist|2}}
			{{Carbohydrates}}
			]
			]