6-Hydroxykaempferol

Molecules, 2007, 12(1):86-97.

Inhibitory effects of 5,6,7-trihydroxyflavones on tyrosinase.[Pubmed: 17693955]

METHODS AND RESULTS:
Baicalein (1), 6-Hydroxyapigenin (6), 6-hydroxygalangin (13) and 6-hydroxy-kaempferol (14), which are naturally occurring flavonoids from a set of 14 hydroxy-flavones tested, exhibited high inhibitory effects on tyrosinase with respect to L-DOPA, while each of the 5,6,7-trihydroxyflavones 1, 6, 13 or 14 acted as a cofactor to monophenolase. Moreover, 6-Hydroxykaempferol (14) showed the highest activity and was a competitive inhibitor of tyrosinase compared to L-DOPA. 5,6,7-Trihydroxyflavones 1, 6, 13 or 14 showed also high antioxidant activities.
CONCLUSIONS:
Hence, we conclude that the 5,6,7-trihydroxy-flavones are useful as good depigmentation agents with inhibitory effects in addition to their antioxidant properties.

Phytochemistry.1992;31(11):4001–4004.

6-hydroxykaempferol and its glycosides from Carthamus tinctorius petals.[Reference: WebLink]

METHODS AND RESULTS:
From the dried petals of Carthamus tinctorius, five flavonoids, 6-Hydroxykaempferol, 6-Hydroxykaempferol 3-glucoside, 6-Hydroxykaempferol 3,6-diglucoside, 6-Hydroxykaempferol 3,6,7-triglucoside and 6-Hydroxykaempferol 3-rutinoside-6-glucoside, were isolated along with 13 known compounds, and their structures determined by spectroscopic means including 2D NMR.