Synthesis and biological activities of new hydroxy-3-pyrazolyl-4H-chromen-4-ones and their O-glucosides

1260-1270The synthesis of a number of 7-hydroxy-3-pyrazolyl-chromen-4H-ones and their O-glucosides has been described. 7-Hydoxy-3-formyl chromen-4H-one 1 on condensation with substituted acetophenones in the presence of piperidine in dry alcohol affords 7-hydroxy-3-(3-oxo-3-arylprop-1-enyl)-4H-chromen-4-ones 2 which on cyclization with phenyl hydrazine hydrochloride leads to the formation of 7-hydroxy-3-(1-phenyl-3-aryl-1H-pyrazol-5-yl)-4H-chromen-4-ones 3. 7-O-β-D-Glucopyranosyloxy-3-(1-phenyl-3-aryl-1H-pyrazol-5-yl)-4H-chromen-4-ones 5 have been synthesized by the reaction of 2, 3, 4, 6-tetra-O-acetyl-⍺-D-glucopyranosyl bromide with potassium salt of 3 followed by deacetylation with Zn(CH₃COO)₂ in absolute methanol. Some of the newly synthesized compounds have been screened for their antimicrobial and antioxidant activity

Synthesis and biological activities of new 7-<i style="">o</i>-<img src='/image/spc_char/beta.gif' border=0>-D-glucopyranosyloxy-3-(3-oxo-3-arylprop-1-enyl)-chromones

1548-1557A convenient route to synthesize some new medicinally important 7-hydroxy-3-(3-oxo-3-arylprop-1-enyl)-chromones 2 is described by the interaction of 7-hydroxy-3-formyl chromone 1 with various substituted acetophenones which on condensation with 2,3,4,6-tetra-o-acetyl--D-glucopyranosyl bromide affords 2,3,4,6-tetra-o-acetyl--D-glucopyranosyloxy-3-(3-oxo-3-arylprop-1-enyl)-4H-chromen-4-ones 3. Later on deacetylation with anhydrous zinc acetate in methanol gives 7-o--D-glucopyranosyloxy-3-(3-oxo-3-arylprop-1-enyl)-4H-chromen-4-ones 4. These compounds are evaluated for their in vitro antimicrobial and antioxidant activity. The structures of these newly synthesized compounds are established by IR, NMR, mass spectra, elemental analysis and chemical analysis

Chromone: A valid scaffold in medicinal chemistry

Chromones are a group of naturally occurring compounds that are ubiquitous in nature, especially in plants. The word chromone is derived from the Greek word chroma, meaning “color”, which point out that many chromone derivatives can exhibit a diversity of colors.This work was supported by the Foundation for Science and Technology (FCT), Portugal (projects PTDC/QUI-QUI/113687/2009 and PEst-C/QUI/UI0081/2013). A.G. (SFRH/BD/43531/2008) and M.J.M. (SFRH/BD/61262/2009) thank FCT for grants