Synthesis and Anti-VSMC Vegetation Activities of New Aurone Derivatives

A series of new aurone derivatives was prepared by means of a practical route and their anti-vascular smooth muscle cells（VSMC） vegetation activities were evaluated by the 3-（4,5-dimethylthlazol-2-yl）-2,5- diphenyltetrazolium bromide（MTT） method with tetrandrine as a positive contrast drug. The structures of the com- pounds were confirmed by 1H NMR, 13C NMR and electrospray ionization mass spectrometry（ESI-MS）. Several new compounds exhibited promising activity against VSMC proliferation and the preliminary structure-activity relation- ships（SAR） were discussed in order to investigate the essential structures required for their bioactivities.

Transforming the Snapdragon Aurone Biosynthetic Genes into Petunia Alters Coloration Patterns in Transgenic Flowers

Aurones belong to a small class of flavonoids that provide yellow color in some floricultural plants including snapdragon. To explore novel flower coloration, two full-length cDNAs encoding chalcone 4'-O-glucosyltransferase (designated as SRY4'CGT) and aureusidin synthase (designated as SRYAS1) in the aurone biosynthetic pathway were cloned from yellow flowers of snapdragon (Antirrhinum majus cv. Ribbon Yellow). Binary vectors were constructed and transformed separately into Petunia hybrida harboring blue flowers. Only a few flowers in 4 out of 9 transgenic SRY4'CGT plants showed variegated blue-white sectors;as time passed, amounts of variegated flowers and proportion of white sectors in the background blue color of the new-born flowers gradually increased, until finally, the petal color was completely white in all late-born flowers. In contrast, a few flowers in 3 out of 13 transgenic SRYAS1 plants showed variegated blue-white sectors;but, the amounts of variegated flowers did not increase over the whole flowering stage, and no complete white flowers were observed. RNA samples isolated from blue and white sectors of T1 transgenic SRY4'CGT plants were analyzed by reverse transcription-PCR, transgenic SRY4'CGT transcripts were detected in both sectors;however, transcripts of an upstream gene, chalcone synthase (CHS), were abundantly detected in the blue sectors but largely reduced in the white sectors, suggesting that the expression of CHS gene was suppressed in white sectors of transgenic plants. Furthermore, HPLC coupled with mass spectrometry demonstrated cyandin, malvidin and their derivatives were absent in white sectors, causing the white phenotype. Our findings may be attractive to molecular breeders.

Total synthesis of a hydrated aurone derivative

The total synthesis of a hydrated aurone derivative, 2-benzyl-4-methoxy-2,6-dihydroxybenzofuran-3（2H）-one, has been achieved for the first time with 2.4% overall yield. Using phloroglucinol as the starting material, the key steps included Friedel-Crafts acylation, Williamson synthesis, hydrogenolysis, aldol condensation, enolization and Rubottom oxidation.

Aurone derivatives as Vps34 inhibitors that modulate autophagy

We report in this study the identification of a natural product-like antagonist(1a) of Vps34 as a potent autophagy modulator via structure-based virtual screening. Aurone derivative 1a strongly inhibited Vps34 activity in cell-free and cell-based assays. Significantly, 1a prevents autophagy in human cells induced either by starvation or by an mT OR inhibitor. In silico modeling and kinetic data revealed that 1a could function as an ATP-competitive inhibitor of Vps34. Moreover, it suppressed autophagy in vivo and without inducing heart or liver damage in mice. 1a could be utilized as a new motif for more selective and efficacious antagonists of Vps34 for the potential treatment of autophagy-related human diseases.

Regioselective Synthesis of Aurone Derivatives via PBu_(3)-Catalyzed Cyclization of 2-Alkynoylphenols

Aurone derivatives were synthesized in good to high yields by PBu_(3)-catalyzed intramolecular 5-exo cyclization of 2-alkynoylphenols.The reaction proceeds in high regioselectivity without forming 6-endo cyclization products.

Synthesis and Trypanocidal Evaluation of Some Novel 2-(Substituted Benzylidene)-5, 7-Dibromo-6-Hydroxy-1-Benzofuran-3(2<i>H</i>)-Ones

Substituted 2-benzylidene-1-benzofuran-3-ones are commonly known as aurones. This class of bioactive heterocycles belongs to flavonoid family. The article intends to put forth the rational design and synthesis of a new series of aurones using 3’,5’-dibromo-2’,4’-dihydroxychalcones and copper bromide in presence of DMF-water mixture (8:2, v/v) for the first time. Preliminary bioassay shows that most of compounds have good trypanocidal activity against Trypanosoma cruzi at 10 μg/mL. Few compounds are equally potent to the standard drugs Benznidazole and Nifurtimox. The structures of the newly synthesized products 2a-n were established by elemental analysis, FTIR, 1H NMR, 13C NMR and mass spectroscopic studies.

低端新兵——德国坦克AURON 5.1 Fun声卡

低端产品虽然利润微薄，但出货量大，历来是兵家必争之地。Terra Tec(德国坦克）在成功进军中高端以后，适时推出其低端声卡AURON 5.1 Fun，做工扎实是其特点。