Protective effect of biflavones from Araucaria bidwillii Hook in rat cerebral ischemia/reperfusion induced oxidative stress

Biaryls in nature: a multi-facetted class of stereochemically, biosynthetically, and pharmacologically intriguing secondary metabolites.

Robustaflavone, a naturally occurring compound, is an inhibitor of hepatitis B virus replication in vitro. Robustaflavone is a biflavanoid composed of two units of apigenin (5,7,4‘-trihydroxyflavone) joined via a biaryl linkage between the 6-position of one unit and the 3‘-position of the other (I6,II3‘-biapigenin). The natural material was isolated from the seed-kernels of Rhus succedanea. To provide ready access to sufficient quantities of material for continued biological studies, as well as to provide a general route for the preparation of structural analogues, a total synthesis of robustaflavone was pursued. The total synthesis was approached by constructing apigenin ethers containing functionalities at the 6- and 3‘-positions which could be cross-coupled using transition metal catalysis. Key steps of the synthesis included development of a regioselective iodination of an apigenin derivative at the 6-position. Also key was the formation of an apigenin 3‘-boronate using a palladium-catalyzed exchange ...

Total Synthesis of Robustaflavone, a Potential Anti-Hepatitis B Agent

Antiviral activity-guided fractionation from Araucaria angustifolia leaves extract

Distribution, traditional uses, isolated chemical constituents and pharmacological activities of some common species of the genus Araucaria are reviewed in this paper. Almost 19 species belong to the genus, Araucaria. It is indigenous to North America. Biflavanoid, diterpene, phenyl propanoid and lignans are abundant in the genus. The most common pharmacological activity of Araucaria in modern medicines is anti-inflammatory. It also possesses other pharmacological activities such as antiulcer, antiviral, neuro-protective, anti-depressant and anti-coagulant. The aim of the present paper is to present an extensive review of the plants in this genus including their traditional uses, chemical constituents and pharmacology. Keywords : Araucaria, Ethnopharmacology, Phytochemistry, Biflavanoids, Diterpene

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Phytochemical and Ethno-Pharmacological Review of the Genus Araucaria - Review

Biflavones from the leaves of Araucaria bidwillii Hooker and Agathis alba foxworthy (araucariaceae)

Isolierung und Strukturaufklärung eines neuen Typs der Biflavone ausAgathis robusta.

M. Okigawa

Papers

Biflavones from the leaves of Araucaria bidwillii Hooker and Agathis alba foxworthy (araucariaceae)

Robustaflavone—the first member of a new series of biflavones