We report the first asymmetric, total synthesis of (-)-isosilybin A. A late-stage catalytic biomimetic cyclization of a highly functionalized chalcone is employed to form the characteristic benzopyranone ring. A robust and flexible approach to this chalcone provides an entry to the preparation of the entire isomeric family of silybin natural products.

Promoters are thought to play a major role in adaptive evolution, yet little is known about the regulatory diversity within species, where microevolutionary processes take place. To investigate the potential for evolutionary change in the promoter of a gene, we examined nucleotide and functional variation of the Chalcone Synthase (CHS) cis-regulatory region in Arabidopsis thaliana. CHS is the b...

Chalcone derivatives are frequently found in bioactive compounds, natural products, and pharmaceuticals. In this study, we developed a KOtBu/DMF catalytic system to efficiently synthesize chalcone by isomerizing propargylic alcohols bearing aryl substituents at the 1- 3-positions. Mechanistic investigations confirmed that 1,3-hydride shift was key process for successful reaction. Our method doe...

A novel approach to the synthesis of pyrazole derivatives from tosylhydrazones of alpha,beta-unsaturated carbonyl compounds possessing a beta-hydrogen is proposed, exploiting microwave (MW) activation coupled with solvent free reaction conditions. The cycloaddition was studied on three ketones (trans-4-phenyl-3-buten-2-one, beta-ionone and trans-chalcone). The corresponding 3,5-disubstituted-1H...

In this study, light-emitting diodes (LEDs) used as secure, low-cost and possessing long emission wavelengths irradiation sources were applied in photopolymerization. Seven novel anthracene derivatives (noted A1-A7) proposed evaluated photosensitive systems. Three of them never synthesized before (A1, A2 A7) the other fields. Due to in-silico design molecular structure by modeling, chalcone-ant...

Hymenoclea salsola, Asteraceae, Resin Flavonoids, 2',4',6 'OH Chalcone Hymenoclea salsola (Asteraceae), a dominant shrub of the desert areas of California and Baja California, Mexico, secretes high amounts of resin on the leaf surface. Chemi­ cal analysis of the resin revealed the presence of a complex mixture of flavonoid aglycones. Among the compounds identified is the rare 2',4',6'-OH chalco...

The aim of this study was to investigate novel chalcones with potent angiogenic activities in vivo. Chalcone-based derivatives were evaluated using a transgenic zebrafish line with fluorescent vessels to real-time monitor the effect on angiogenesis. Results showed that the chalcone analogues did not possess anti-angiogenic effect on zebrafish vasculatures; instead, some of them displayed potent...

In Arabidopsis thaliana, silencing of hydroxycinnamoyl-CoA shikimate/quinate hydroxycinnamoyl transferase (HCT), a lignin biosynthetic gene, results in a strong reduction of plant growth. We show that, in HCT-silenced plants, lignin synthesis repression leads to the redirection of the metabolic flux into flavonoids through chalcone synthase activity. Several flavonol glycosides and acylated ant...

Chalcones are open-chain flavonoids that are biosynthesized in various plants. Some of them possess anti-inflammatory activity. We previously found that chalcone glycosides from Brassica rapa L. 'hidabeni' suppress lipopolysaccharide (LPS)-induced nitric oxide (NO) production in rat microglia highly aggressively proliferating immortalized (HAPI) cells. In this study, to explore chalcone derivat...

We report the first fluorescent diamino-chalcone library and its application in the discovery of a mouse embryonic stem cell (mESC) probe. CDg4, a novel green fluorescent mESC probe was discovered through a high-content image based screening of 160 members of the chalcone library. Interestingly, the molecular binding target of CDg4 was identified as the glycogen of the stem cell colony surface,...