10458-35-2Relevant academic research and scientific papers
Solvent-free synthesis of functionalized flavones under microwave irradiation
Seijas, Julio A.,Vazquez-Tato, M. Pilar,Carballido-Reboredo, Raquel
, p. 2855 - 2858 (2005)
(Chemical Equation Presented) Eco-friendly direct solvent-free synthesis of flavones is achieved by microwave irradiation of phloroglucinol and β-ketoesters. Heating with microwaves versus under classical conditions was shown to be higher yielding, cleaner, and faster. The reaction goes through a cycloaddition of an α-oxo ketene intermediate followed by an uncatalyzed thermal Fries rearrangement.
Importance of the B ring and its substitution on the α-glucosidase inhibitory activity of baicalein, 5,6,7-trihydroxyflavone
Gao, Hong,Kawabata, Jun
, p. 1858 - 1864 (2007/10/03)
Hydroxychroniones and B-ring-substituted 5,6,7-trihydroxyflavones were prepared to evaluate the contribution of the B ring of baicalein (5,6,7-trihydroxyflavone, 1) to its potent α-glucosidase inhibitory activity. Hydroxychromones, which lack 6-hydroxyl substitution, did not show any inhibitory activity, while 5,6,7-trihydroxy-2-methylchromone (5) showed high activity. Among the tested B-ring-substituted 5,6,7-trihydroxyflavones, the 4′-hydroxy-, 3′,4′-dihydroxy-, and 3′,4′,5′- trihydroxy-substituted derivatives were found to give more activity than that of 1. The methoxy-substituted derivatives, however, showed less activity than 1. The results suggest that the B ring of 1 was not essential, although advantageous to the activity; hydroxyl substitution on the B ring of 5,6,7-trihydroxyflavones was favorable to the activity, whereas methoxyl substitution was unfavorable; at least 4′-hydrosyl substitution of 5,6,7-trihydroxyflavones was required for enhanced activity, in which the number of hydroxyl groups did not take part.
