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should disaccharides be glycosides?

Open ValWood opened this issue 1 year ago • 3 comments

Carbohydrates Robert J. Ouellette, J. David Rawn, in Organic Chemistry Study Guide, 2015 26.8 Disaccharides Disaccharides are glycosides formed from two monosaccharides that can be either aldoses or ketoses.

For the background discussion see https://github.com/geneontology/go-ontology/issues/23300 (I don't think you were ever contacted)

ValWood avatar Nov 20 '23 12:11 ValWood

@ValWood I have contacted a few experts in carbohydrate chemistry and will update you once i hear back from them.

amalik01 avatar Nov 29 '23 09:11 amalik01

Hi @ValWood,

I contacted Gerard Moss, author of 2-carb (IUPAC recommendations on the nomenclature of carbohydrates - https://iupac.qmul.ac.uk/2carb/). He raised this issue with the carbohydrate group and they do not think that dissacharides are glycosides. They are currently working on a glossary of carbohydrate terms for the gold book and their current revised definition for glycoside is:

glycosides: Mixed acetals resulting from the attachment of a glycosyl group to a non-acyl group RO– [and chalcogen replacements thereof (RS–, RSe–)].

I also read 2-Carb-36.2 (https://iupac.qmul.ac.uk/2carb/36.html) where it states that disaccharides without a free hemiacetal group are named as glycosyl glycosides whereas the ones that have a free hemiacetal group are named as glycosylglycose.

amalik01 avatar Dec 04 '23 13:12 amalik01

Thanks, we will update the GO definition of Glycoside to match this one.

Just to confirm, doe s this mean that some disaccharides are glycoside, but not all disaccharides are glycosides?

ValWood avatar Dec 05 '23 13:12 ValWood