RESUMO
In the title compound, C19H17BrO3, the ring skeleton is located on a crystallographic mirror plane; two C atoms of the cyclo-hexene ring are disordered over the two locations to satisfy the preferred ring conformation. In the crystal, C-Hâ¯O hydrogen bonds link the mol-ecules into chains along the a axis. π-π stacking inter-actions between benzo-quinone rings, with a centroid-centroid distance of 3.7225â (4)â Å, are also observed, which connect the chains into a two-dimensional networkparallel to the ab plane.
RESUMO
OBJECTIVE: To study the chemical constituents of the flowers of Bupleurum chinese. METHODS: The compounds were separated by column chromatography with silica gel. Their structures were identified by spectral methods and chemical analysis. RESULTS: Five compounds were isolated and identified as 8-(3',6'-dimethoxy)-4,5-cyclohexadiene-(delta11,12-dioxide-methylene) -dense-dihydrogen-isocoumarin(I), quercetin(II), rutin(III), calcifenol (IV), isorhamnetin (V). CONCLUSION: Compounds I and IV are obtained from the genus for the first time. Compound I is a new compound.
Assuntos
Bupleurum/química , Ergocalciferóis/isolamento & purificação , Flores/química , Quercetina/isolamento & purificação , Medicamentos de Ervas Chinesas/química , Ergocalciferóis/química , Flavonóis/química , Flavonóis/isolamento & purificação , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Plantas Medicinais/química , Quercetina/química , Rutina/química , Rutina/isolamento & purificaçãoRESUMO
The title compound, C(18)H(14)O(3), consists of a four-ring system which contains three six-membered rings forming a phenanthrene-dione system and a five-membered 1,2-dihydro-methyl-furan ring. A three-dimensional supra-molecular framework is formed via non-classical inter-molecular C-Hâ¯O hydrogen bonds.
