Structural requirements of flavonoids for inhibition of protein glycation and radical scavenging activities.

To clarify the structural requirements of flavonoids for formation of advanced glycation end-products (AGEs), various flavonoids were examined. The results suggested the following structural requirements of flavonoids for the inhibition of AGEs formation: (1). as the hydroxyl groups at the 3'-, 4'-, 5-, and 7-positions increased in number, the inhibitory activities became stronger; (2).

Antiallergic principles from Alpinia galanga: structural requirements of phenylpropanoids for inhibition of degranulation and release of TNF-alpha and IL-4 in RBL-2H3 cells.

The 80% aqueous acetone extract of the rhizomes of Alpinia galanga was found to inhibit release of beta-hexosaminidase, as a marker of antigen-IgE-mediated degranulation in RBL-2H3 cells. Nine known phenylpropanoids and p-hydroxybenzaldehyde were isolated from the extract. Among them, 1'S-1'-acetoxychavicol acetate and 1'S-1'-acetoxyeugenol acetate exhibited potent inhibitory activity with IC(50) values of 15 and 19 microM.

Medicinal flowers. VIII. Radical scavenging constituents from the flowers of Prunus mume: structure of prunose III.

The methanolic extract and its fractions from the fresh flowers of Prunus mume SIEB. et ZUCC. were found to show scavenging effects on 1,1-diphenylpicryl-2-hydrazyl (DPPH) radical and superoxide.

Structural requirements of flavonoids for inhibition of antigen-Induced degranulation, TNF-alpha and IL-4 production from RBL-2H3 cells.

To clarify the structure-activity relationships of flavonoids for antiallergic activity, the inhibitory effects of various flavonoids on the release of beta-hexosaminidase, as a marker of degranulation of RBL-2H3 cells, were examined. Among them, luteolin (IC(50)=3.0 microM), diosmetin (2.