Carthamin acetate, (3S,3′S)-1-[5-(p-acetoxycinnamoyl)-3-C-(β-d-2″,3″,4″,6″-tetra-O-acetylglucopyranosyl)-3,4-dihydroxy-2,6-diketo]cyclohex-4-enylidene-1′-[5′-(p-acetoxycinnamoyl)-3′-C-(β-d-2″′,3″′,4″′, 6″′-tetra-O-acetylglucopyranosyl)-2′,3′,4′-trihydroxy-6′-keto]cyclohexa-1′,4′-dienylmethane 7a and its (3R, 3′R)-epimer 7b were synthesized via the C-glycosylation of 2-acetyl-1,3,4,5-benzenetetrol using acetobromoglucose in the presence of sodium hyride, followed by aldol condensation with p-hydroxybenzaldehyde after methyl-protection of the enolic hydroxy group, and subsequent dimerization with triethyl orthoformate after demethylation, in a total yield of 0.6%. Their absolute configurations were determined by X-ray analysis of the key intermediate 4b.
The structure 6, 1-(2,6-diketo-3-glucosyl-3,4-dihydroxy-5-p-hydroxycinnamoyl)-cyclohex-4-enylidene-1′-(2′,3′,4′-trihydroxy-3′-glucosyl-5′-p-hydroxycinnamoyl-6′-keto)-cyclohexa-1′,4′-dienylmethane, was assigned for carthamin on the basis of its spectroscopic evidence and hydrolytic behavior.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.