Glycosides, alkaline hydrolysis

XVIII has now been excluded,42 since the methyl glycoside of the sugar reacts rather rapidly with one mole of periodate per mole furthermore, in contrast to the behavior of mycaminose (XXI), no moiety with one carbon atom less has been isolated from the products of periodate oxidation. Oxidation of mycarose with hypoiodite affords a crystalline lactone with the empirical formula C7H12O4 this observation eliminates the possibility of the keto structure XX. Thus, mycarose appears to be a 2,6-dideoxy-3-C -methylhexose (XIX). In the original compound, the isovaleryl group must be esterified to the alcohol function at C4, since the methyl glycoside isovalerate obtained from carbomycin is only attacked by periodate after alkaline hydrolysis. 

Operculinic acids E (hexadecanoic acid, (115)-[(0-6-deoxy-a-L-mannopyranosyl-(1 4)-0-6-deoxy-a-L-mannopyranosyl-(1 4)-0-6-deoxy-a-L-mannopyranosyl-(1 2)-jS-D-glucopyranosyl)oxy]) and F (hexadecanoic acid, (115)-[(0-6-deoxy-a-L-mannopyranosyl-(1 4)-0-6-deoxy-a-L-mannopyranosyl-(1 4)-0-6-deoxy-a-L-mannopyranosyl-(1 2)-/i-D-xylopyranosyl)oxy]) were obtained by alkaline hydrolysis of the ether-soluble crude resin glycosides from the roots of Ipomoea... 

The alkaline hydrolysis of the ether-insoluble resin glycoside fraction from seeds of Ipomoea nil (L.) Roth (syn. Pharbitis nil Choisy) yielded a pentasaccharide of ipurolic acid, which was named pharbitic acid C (tetradecanoic acid, ll-[(0-6-deoxy- S-D-glucopyranosyl-(1 4)-0-6-deoxy-a-L-mannopyranosyl-(l—>6)-0-[6-deoxy-a-L-mannopyranosyl-(l—>2)-0-jS-D-glucopyranosyl-(l—>2)]- S-D-glucopyra-nosyl)oxy]-3-hydroxy). On complete hydrolysis, it produced two o-glucoses, two L-rhamnoses, one o-quinovose, and the aglycone moiety (77). 

Alaniya MD, Kinetics of the alkaline hydrolysis of flavonoid glycosides. Chem Nat... 

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