نتایج جستجو برای: stilbenes
تعداد نتایج: 1217 فیلتر نتایج به سال:
In this article the authors deal with the experimental and theoretical interpretation of the vibrational spectra of trans-resveratrol (3,5,4'-trihydroxy-trans-stilbene) of diverse beneficial biological activity. Infrared and Raman spectra of the compound were recorded; density functional calculations were carried out resulting in the optimized geometry and several properties of the molecule. Ba...
The photoisomerization dynamics of trans-stilbene have been well studied in the lowest excited state, but much less is known about the behavior following excitation to higher-lying electronically excited states. This contribution reports a combined study of the spectroscopy and dynamics of two-photon accessible states above S1. Two-photon absorption (2PA) measurements using a broadband pump-pro...
The crystal structure of the title compound, C(25)H(27)NO(4), shows the presence of a double bond with Z geometry which connects the quinuclidin-3-one ring and the trimeth-oxy-resveratrol moiety. The dihedral angle between the two benzene rings in the stilbene skeleton is 32.80 (8)°.
Seven stilbenes and one catechin were bioactivity-guidedly isolated from the rhizomes of Rheum palmatem. Their structures were identified as piceatannol(1), resveratrol(2), piceid(3), rhapontigenin(4), piceatannol-3'-O-β-D-glucopyranoside(5), rhaponticin(6), catechin(7) and desoxyrhapontigenin(8). Anti-monoamine oxidase (MAO) activities of compounds 1–8 were tested. Compounds 1 and 8 showed sig...
Plant secondary metabolites play significant roles in plant-environment interactions. Plant derived secondary metabolites are compounds that can be widely used in industry, medicine, food sciences etc. In this review, we summarize the research methods applied to analyse biosynthetic pathways of plant secondary metabolites. Moreover we present an up to date overview of the studies that were perf...
The practical synthesis of important natural polyphenolic stilbenes, including resveratrol, piceatannol and oxyresveratrol, through Perkin methodology is described. Starting from 3,5-dihydoxyacetophenone (1), the common intermediate 3,5-dimethoxyphenylacetic acid (3) can be obtained via methylation and Willgerodt-Kindler reaction. Perkin condensations between (3) and substituted phenylaldehydes...
After Mallory described in 1964 the use of iodine as catalyst for the photochemical cyclisation of stilbenes, this reaction has proven its effectiveness in the synthesis of phenanthrenes, other PAHs and phenacenes with a surprisingly large selection of substituents. The "early age" of the reaction was reviewed by Mallory in 1984 in a huge chapter in the Organic Reactions series, but the develop...
Effects of natural and structurally transformed lignans compared with stilbenes or stilbenoids on production of nitric oxide (NO) triggered by lipopolysaccharide (LPS) and interferon-γ (IFN-γ), tested under in vitro conditions using murine resident peritoneal macrophages, are reviewed. Relation between the molecular structure and immunobiological activity was investigated, and implication of su...
Seven stilbenes and one catechin were bioactivity-guidedly isolated from the rhizomes of Rheum palmatem. Their structures were identified as piceatannol(1), resveratrol(2), piceid(3), rhapontigenin(4), piceatannol-3'-O-β-D-glucopyranoside(5), rhaponticin(6), catechin(7) and desoxyrhapontigenin(8). Anti-monoamine oxidase (MAO) activities of compounds 1–8 were tested. Compounds 1 and 8 showed sig...
Shikimic acid and its role in the formation of aromatic amino acids, benzoic acids, and cinnamic acids is described, along with further modifications leading to lignans and lignin, phenylpropenes, and coumarins. Combinations of the shikimate pathway and the acetate pathway are responsible for the biosynthesis of styrylpyrones, flavonoids and stilbenes, flavonolignans, and isoflavonoids. Terpeno...
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