A Facile Synthesis of 6β-Hydroxy-7α(H)-eudesma-4-en-3-one

A stereoselective total synthesis of 6β-hydroxy-7α(H)-eudesma-4-en-3- 1startingfrom (+)-dihydrocarvone 7 has been described.

Antioxidant Activity of the Natural Flavonoid 7-Hydroxy-5,6,4’-trimethoxyflavone Isolated from the Leaves of Lippia rugosa A. Chev

Phytochemical studies and antioxidant activities were carried out on n-hexane, ethyl acetate, ethanol and methanol extracts of the leaves of Lippia rugosa A. Chev (Verbenaceae), a medicinal plant used traditionally in the Cameroonian savannah’s region to protect foodstuffs and to cure degenerative diseases. Results indicated that theses extracts contain terpenoids, phenolic and flavonoid compounds. Except the n-hexane extract, all of the obtained extracts exhibit antioxidant activities with the ethanol extract being the most effective with an inhibition percentage of 85.668% ± 1.233% and an inhibition concentration (IC50) of 58 μg/ml (R2 = 0.987, P < 0.01) at a concentration of 100 mg/ml. Chromatographic separation on silica gel of the ethanol extract led to the isolation of a pure organic compound which was characterized as 7-hydroxy-5,6,4'-trimethox- yflavone by extensive 1D and 2D NMR spectroscopy, a flavonoid exhibiting antioxidative activity with an inhibitory percentage of 25.506% ± 0.205% and inhibition concentration (IC50) of 221 μg/ml (R2 = 0.966, P < 0.01). This is the first time that 7-hydroxy-5,6,4'-trimethoxyflavone is being isolated from L. rugosa and its antioxidant activity evaluated.

Argentum 5-Hydroxy-7-methoxy-2-phenyl-4H-chromen-4-one-6-sulfonate:Synthesis,Crystal Structure and Antitumor Activity

In order to improve the water solubility and bioavailability of 5-hydroxy-7-methoxyflavone,argentum 5-hydroxy-7-methoxy-2-phenyl-4H-chromen-4-one-6-sulfonate[Ag4(H2O)6](C(16)H(11)O4SO3)4·H2O(1,C(16)H(11)O4SO3=5-hydroxy-7-methoxy-2-phenyl-4H-chromen-4-one-6-sulfonate)was synthesized by sulfonation reaction.The structure of 1 was characterized by FT-IR,elemental analysis and X-ray single-crystal diffraction.Complex 1 belongs to the triclinic system,space group P1,a=8.077(4),b=12.365(4),c=17.735(7)A,V=1685.0(12)A3,Z=1,μ=1.372 mm^–1,Dc=1.936 g/cm^3,F(000)=984,the final R=0.0819 and wR=0.2332 with I>2σ(I).3D structure of 1 exhibits alternating organic and inorganic regions.O–H×××O hydrogen bonds and Ag–O coordination interactions exist among crystal water,coordinated water and sulfo group,which constructed an organic zone.Flavone skeletons form organic region of 1.Sulfo group is the bridge linking these two regions.The in vitro antitumor activity of 1 against human lymphoma cells U937 and human breast cancer cells MCF-7 were evaluated with CCK-8 assay.The result shows that 1 showed inhibitory activity against tumour cell U937 and MCF-7,and indicated that flavone sulfonate derivatives may be potential leads for further biological screenings and may generate drug-like molecules.

A New Chromone Derivative from Stellera chamaejasme L

A new chromone derivative, 3-[1- (2, 4, 6-trihydroxyphenyl) 3-di-(4-hydroxyphenyl) 1-propanone-2-yl] 5,7-dihydroxy-8-di(4-hydroxyphenyl)methyl-4H-1-benzopyran-4-one, named as isomohsenone was isolated from the roots of Stellera chamaejasme L. together with known chamaechromone. Its structure was determined by the analysis of MS and NMR data, especially 2D NMR spectra.

New flavan and unusual chalcone glycosides from Drypetes parvifolia

Two new compounds 7-hydroxy-5-O-（β-D-glucopyranoside） flavan （1） and （Z）-4＇,6＇-dihydroxy-2＇-O-（β-D-glucopyranoside） chalcone （2）, along with eight known compounds, were isolated from the stem bark of Drypetes parvifolia （Euphorbiaceae）. Their structures were established on the basis of spectroscopic analysis and chemical evidence.