529-52-2

Upstream product

• 67-56-1 methanol 
• 480-40-0 5,7-dihydroxy-2-phenyl-chromen-4-one 
• 124-41-4 sodium methylate 
• 74-88-4 methyl iodide 
• 14004-47-8 5,7-dimethoxy-8-methyl-2-phenylchromen-4-one 
• 628-13-7 pyridine hydrochloride 
• 55969-56-7 5,7-dihydroxy-8-methyl-2-phenylchromen-4-one 
• 93-97-0 benzoic acid anhydride 
• 109845-46-7 1-(2-hydroxy-4,6-dimethoxy-3-methyl-phenyl)-3-phenyl-propane-1,3-dione 
• 14004-48-9 5-hydroxy-7-methoxy-8-methylflavone 
• 88-03-9 2,4,6-trihydroxytoluene 
• 2657-28-5 2,4,6-trihydroxy-3-methyl-acetophenon 
• 55969-57-8 5-hydroxy-7-methoxy-6-methyl-2-phenyl-chromen-4-one 
• 10034-85-2 hydrogen iodide 

Downstream Products

• 55969-57-8 5-hydroxy-7-methoxy-6-methyl-2-phenyl-chromen-4-one 

Relevant academic research and scientific papers

C-isoprenylation of flavonoids enhances binding affinity toward P-glycoprotein and modulation of cancer cell chemoresistance

Previous studies have shown that flavones bind to P-glycoprotein (Pgp) with higher affinity than isoflavones, flavanones, and glycosylated derivatives. In the present work, a series of C- or O-substituted hydrophobic derivatives of chrysin were synthesized to further investigate structural requirements of the A ring toward Pgp modulation. Increasing hydrophobicity at either position 6, 8, or 7 increased the affinity of in vitro binding to a purified cytosolic domain of Pgp, but only benzyl and 3,3-dimethylallyl C-substitution produced a high maximal quenching of the protein intrinsic fluorescence. Inhibition of membrane Pgp within leukemic cells, characterized by intracellular drug accumulation, was specifically produced by isoprenylated derivatives, with 8-(3,3-dimethylallyl)chrysin being even more efficient than the commonly used cyclosporin A.

Synthesis of novel C-methylflavones

If the Baker-Venkataraman rearrangement of C-methylphloracetophenone triaroyl esters is carried out in DMSO with powdered NaOH, the result greatly depends on the substitution pattern both of the phloracetophenone moiety possessing either one or two C-methyl groups and of the aroyl parts bearing a conjugated methoxy group (or not such a group) with respect to the carbonyl group. With benzoyl, 4-methoxybenzoyl or 3,4-dimethoxybenzoyl as aroyl group the 3,5-dimethylphloracetophenone triaroyl esters 10a-c directly yield the corresponding unsubstituted ring B or 4′-methoxy- and 3′,4′-dimethoxy-substituted 5,7-dihydroxy-6,8-dimethylflavones 11a-c. In contrast, the 3-methylphloracetophenone triaroyl esters 3a-c react quite differently, depending on the aroyl substitution pattern. Thus, the triester 3a containing benzoyl groups gives the hemiketal Wessely-Moser isomers 5a, 5a′ whereas the triesters 3b and 3c containing 4-methoxy- or 3,4-dimethoxybenzoyl groups are converted into compounds existing as two equilibria of two β-diketo and two β-keto enol tautomers. Finally, dehydration of each mixture furnishes solely the corresponding unsubstituted ring B or 4′-methoxy- and 3′,4′-dimethoxy-substituted 5,7-dihydroxy-6-methylflavones 8a-c. Methylation of 11c affords 7-O-methyl and 5,7-di-O-methyl derivatives 12a and b. VCH Verlagsgesellschaft mbH, 1996.