The first total synthesis of the ramonanin family of lignan natural products is described. The short synthesis involves a 2,5-diaryl-3,4-dimethylene tetrahydrofuran intermediate, which participates in an unexpectedly facile Diels-Alder dimerization, generating all four natural products. Insights into the reactivity and stereoselectivity of the key dimerization are provided through computational...

A new phenolic glycoside (1), named methyl 2-phenylpropanoate-2-O-β-D-apiofuranosyl-(1→6)-O-β-D-glucopyranoside, was isolated from the barks of Cinnamomum cassia, along with three known phenolic glycosides and four known lignan glycosides. The structure of 1 was elucidated by extensive interpretation of spectroscopic data and chemical method. Selected compounds were evaluated for their immunosu...

Three new labdane diterpenoids, calomacrins A-C (1-3), and a new diaryl butyrolactone-type lignan, calomacrol A (8), as well as four known labdane diterpenoids and six known lignans, were isolated from the twigs and leaves of Calocedrus macrolepis. Structures of the new compounds were elucidated on the basis of their spectroscopic methods, including 1D and 2D NMR techniques. Compounds 3-14 were...

The asymmetric synthesis of the new lignan cubebin dimethyl ether was accomplished in eight steps with an overall yield of 40 %. In addition, the known lignans (+)-hinokinin and (+)-dihydrocubebin were synthesized by this route. Our approach involves the highly diastereoselective and enantioselective (de ≥ 98%, ee ≥ 98%) construction of a trans-substituted 2,3dibenzylbutyrolactone through an as...

3- or 4-Aroylfurans have been prepared selectively and in high yields from a common precursor by simple tuning of reaction conditions in Friedel-Crafts acylation promoted by triflic anhydride. The formation of products can be explained on the basis of the ring-chain tautomerism occurring in compounds equipped with two neighbouring carboxylic functions. Since 4-aroylfuran derivatives show a typi...

Phytochemical examination of corncob extracts led to the isolation of a new lignan identified as 7,7'-dihydroxy-3'-O-demethyl-4-methoxymatairesinol, together with seven known compounds, identified as β-sitosterol, β-sitosteryl-β-D-glucoside, 6β-hydroxy-campest-4-en-3-one, 5α,8α-epidioxyergosta-6,22-dien-3β-ol, tricin, kaempferol and p-coumaric acid. The isolated compounds were identified by one...

The new lignan glucoside, acutumoside (1), was isolated from Sinomenium acutum rhizomes together with nine known compounds (2-10). The structure of 1 was elucidated on the basis of extensive spectroscopic analyses, including two-dimensional nuclear magnetic resonance and chemical reactions. Compounds 2, 7, 8, and 10 displayed potential antiproliferative activity against A549, SK-OV-3, SK-MEL-2,...

Six lignan and neolignan derivatives (1-6) were isolated from the n-BuOH-soluble fraction of a MeOH extract of the leaves of Glochidion zeylanicum. On the basis of spectral data, their structures were elucidated to be (+)-isolarisiresinol 3a-O-beta-glucopyranoside (1), dihydrodehydrodiconiferyl alcohol 4-, 9- and 9'-O-beta-D-glucopyranosides (2-4, respectively), (+)-isolarisiresinol 2a-O-beta-D...

A new dibenzocyclooctadiene lignan named angustifolin D (1) together with four known lignans: kadsulignan L (2), kadsulignan N (3), schisantherin P (4) and meso-dihydroguaiaretic acid (5) were isolated from the stems of Kadsura angustifolia. Their structures and stereochemistries were elucidated by spectral studies. Compounds 2 and 5 showed moderate platelet-activating factor (PAF) antagonistic...