glycosyl
{{short description|Molecular substituent derived from cyclic monosaccharides}}
Image:beta-D-Glucopyranosyl.png]]
In organic chemistry, a glycosyl group is a univalent free radical or substituent structure obtained by removing the hydroxyl ({{chem2|\sOH}}) group from the hemiacetal ({{chem2|\sCH(OH)O\s}}) group found in the cyclic form of a monosaccharide and, by extension, of a lower oligosaccharide. Glycosyl groups are exchanged during glycosylation from the glycosyl donor, the electrophile, to the glycosyl acceptor, the nucleophile.{{Cite journal |last=Crich |first=David |date=2010-08-17 |title=Mechanism of a Chemical Glycosylation Reaction |url=https://pubs.acs.org/doi/10.1021/ar100035r |journal=Accounts of Chemical Research |language=en |volume=43 |issue=8 |pages=1144–1153 |doi=10.1021/ar100035r |pmid=20496888 |issn=0001-4842|url-access=subscription }} The outcome of the glycosylation reaction is largely dependent on the reactivity of each partner.{{Cite journal |last1=van der Vorm |first1=Stefan |last2=van Hengst |first2=Jacob M. A. |last3=Bakker |first3=Marloes |last4=Overkleeft |first4=Herman S. |last5=van der Marel |first5=Gijsbert A. |last6=Codée |first6=Jeroen D. C. |date=2018-07-02 |title=Mapping the Relationship between Glycosyl Acceptor Reactivity and Glycosylation Stereoselectivity |journal=Angewandte Chemie International Edition |language=en |volume=57 |issue=27 |pages=8240–8244 |doi=10.1002/anie.201802899 |issn=1433-7851 |pmc=6032835 |pmid=29603532}} Glycosyl also reacts with inorganic acids, such as phosphoric acid, forming an ester such as glucose 1-phosphate.{{cite journal|title=Structures and mechanisms of glycosyl hydrolases|first1=Gideon|last1=Davies|first2=Bernard|last2=Henrissat|doi=10.1016/S0969-2126(01)00220-9|pmid=8535779|journal=Structure|volume=3|issue=9|date=September 1995|pages=853–859|doi-access=free}}
Examples
In cellulose, glycosyl groups link together 1,4-β-D-glucosyl units to form chains of (1,4-β-D-glucosyl)n.
Other examples include ribityl in 6,7-Dimethyl-8-ribityllumazine, and glycosylamines.
Alternative substituent groups
Image:beta-D-Glucopyranos-3-O-yl.png
Instead of the hemiacetal hydroxyl group, a hydrogen atom can be removed to form a substituent, for example the hydrogen from the C3 hydroxyl of a glucose molecule. Then the substituent is called D-glucopyranos-3-O-yl as it appears in the name of the drug Mifamurtide.
Recent detection of Au3+ in vivo used C-glycosyl pyrene. Its fluorescence and permeability through cell membranes helped detect Au3+.{{Cite journal|date=2019-01-15|title=A triazole linked C-glycosyl pyrene fluorescent sensor for selective detection of Au3+ in aqueous solution and its application in bioimaging|journal=Sensors and Actuators B: Chemical|language=en|volume=279|pages=476–482|doi=10.1016/j.snb.2018.09.105|issn=0925-4005|last1=Dolai|first1=Bholanath|last2=Nayim|first2=Sk|last3=Hossain|first3=Maidul|last4=Pahari|first4=Pallab|last5=Kumar Atta|first5=Ananta|s2cid=104657218 }}