An Improved Synthesis of Apigenin

Abstract

Two routes for the synthesis of the flavone apigenin are described. In the first, taxicatigenin was converted to 2-hydroxy-4,6dimethoxyacetophenone and then by condensation with anisaldehyde to 2′-hydroxy-4,4′,6′-trimethoxychalcone. The latter was cyclised with iodine and demethylated with pyridine hydrochloride to form apigenin in 53% overall yield. In the second route, a single step for the preparation of the chalcone was used in which 1,3,5-trimethoxybenzene was acylated with p-methoxycinnamic acid. Although the synthesis of apigenin was achieved in a lower overall yield of 34%, the process was simpler.

Modified Syntheses of the Dietary Flavonoid Luteolin

“…We have reported the synthesis of luteolin from 1,3,5-trimethoxybenzene using two routes in 47% and 32% yield, respectively. 26 As a continuation of our investigations on the synthesis of the bioactive natural flavonoids and their biological activities, 26,[27][28][29][30][31][32][33][34][35][36] we have carried out further studies and we now report the preparation of luteolin 1 using easily available starting materials, and by an improved procedure with satisfactory yields. JOURNAL OF CHEMICAL RESEARCH 2015 551 temperature apparatus, 1 H NMR spectral data were recorded on a Bruker Avance 400 NMR spectrometer or a Bruker DRX 500 NMR spectrometer, chemical shifts were reported in ppm against internal tetramethylsilane.…”

“…The initial step of the first route was the preparation of 2-hydroxy-4,6-dimethoxyacetophenone 3 which has been decribed previously. [34][35][36] Aldol condensation of 3 with 3,4-dimethoxybenzaldehyde (room temperature, 78 h) gave the chalcone 4 in decent yield (81%). The conversion of 4 to 5 was catalysed by iodine in dimethyl sulfoxide (120 °C, 5 h), and the resulting product 5 (82%) was demethylated with pyridine hydrochloride under an N 2 atmosphere (190 °C, 6 h) to give the target natural product 1 in good yield (89%).…”

Apigenin improves cytotoxicity of antiretroviral drugs against HTLV-1 infected cells through the modulation of AhR signaling

“…Of these compounds, Apigenin has been seen to possess little toxicity even at high doses [ 17 , 18 ]. Apigenin demonstrates anti-inflammatory, antioxidant, and neuroprotective properties in several cell and tissue systems [ 19 , 20 ]. As a result, Apigenin has been used to treat many diseases for centuries such as Parkinson’s, neuralgia, shingles, and others (Reviewed in [ 17 ]).…”

Practical Synthesis of Naringenin

“…We have reported the synthesis of naringenin in five steps from 1,3,5-trimethoxybenzene or phloroglucinol with a moderate overall yield. 17 As a continuation of our investigations on the synthesis of the bioactive natural flavonoids and their biological activity, 17,[18][19][20][21][22][23][24][25] we have carried out further studies and we now report the preparation of 1 using commercially available starting materials, and by an improved procedure with satisfactory yields.…”