Glucopyranoside oxidation

The reaction of the sodium salts of pyrido[2,3-e]-l,2,4-triazin-3(4//)-one 1-oxide 22 (Y = N) or l,2,4-benzotriazin-3(4//)-one 1-oxide 23 with acetobro-moglucose results in tetra-(9-acetyl derivatives of /3-D-glucopyranosides 24, 25 deacetylation of 25 gives nucleosides 26 (82JHC497). 

Phenyl tetra-O-acetyl-a-D-glucopyranosyl sulfoxide or phenyl 2,3,4,6-tetra-Oacetyl-1-thio-a-D-glucopyranoside S-oxide... 

Aldrich and used for all oxidation experiments. TEMPO, sodium hydroxide, sodium sulfide, formaldehyde, ethylamine and methyl-a-D-glucopyranoside were reagent grade or higher and were used as received from Sigma and Aldrich. 

An extract from Lactuca indica showed significant free radical scavenging activity, and protected phixl74 supercoiled DNA against strand cleavage and reduced oxidative stress in human promyelocytic leukemia HL-60 cells. On account of protocatechulic acid, methyl p-hydroxybenzoate, caffeic acid, 3,5-dicaffeoylquinic acid, luteolin 7-O-fT glucopyranoside, and quercetin 3-0-(3-g 1 ucopyranoside are the major antioxidative constituents (111). 

Decomposition of salicin (2-(hydroxymethyl)phenyl-/ -D-glucopyranoside) yields two alcohols glucose (a compound with numerous 1°, 2°, and a 3° hydroxyl functionalities, Fig. 13.4.6) and l-0H-2-CH20H-benzene (a 1° alcohol, Fig. 13.4.7). Further oxidation of l-0H-2-CH20H-benzene leads to the formation of salicylic acid ... 

The aforementioned deuterated derivatives were prepared by way of reduction of a ketone, aldehyde, or ester with sodium borodeu-teride, or by deuteroboration of an alkene. An interesting reaction, perhaps eventually applicable to direct deuteration of polysaccharides, was reported by Koch and Stuart413 and by them and their coworkers,41b who found that treatment of methyl a-D-glucopyranoside with Raney nickel catalyst in deuterium oxide results in exchange of protons attached to C-2, C-3, C-4, and C-6. In other compounds, some protons of CHOH groups are not replaced, but the spectra may nevertheless be interpreted with the aid of a- and /3-deuterium effects. 

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