Grandione, a new heptacyclic dimeric diterpene from Torreya grandis Fort.

Collective Syntheses of Icetexane Natural Products Based on Biogenetic Hypotheses

“…The first reported example of such an icetexane dimerw as grandione, which was isolated by Riccio and co-workers in 1999 from Toreya grandis [34] and synthesized by Ta keya and co-workers in 2005 (and the structure was reassigned) [35] by solid-state hetero-Diels-Alder dimerizationo fo-quinone 31.O btusinones D( 34)a nd E ( 35), which were recently isolated by Salae and Boonnak, were suggested to originate biogeneticallyf rom as imilar Diels-Alder dimerization of przewalskin E( 32). The first reported example of such an icetexane dimerw as grandione, which was isolated by Riccio and co-workers in 1999 from Toreya grandis [34] and synthesized by Ta keya and co-workers in 2005 (and the structure was reassigned) [35] by solid-state hetero-Diels-Alder dimerizationo fo-quinone 31.O btusinones D( 34)a nd E ( 35), which were recently isolated by Salae and Boonnak, were suggested to originate biogeneticallyf rom as imilar Diels-Alder dimerization of przewalskin E( 32).…”

Diabietane Ether, a New Dimeric Abietane with an Ether Linkage from Taxus cuspidata Needles

“…Compound 1 appears to be particularly interesting because the two monomers are connected through a single ether linkage, which, to the best of our knowledge, is only the second example among the dimeric diterpenes [10]. A macrodiolide [9], and dimers with two ether or hemiacetal linkages have been reported [11]. Compound 2, obtained as an amorphous powder, was identical with margocillin first isolated from neem trees Azadirachta indica [12], and also from T. mairei [5].…”

Dinimbidiol Ether, a Novel Bioactive Dimeric Diterpene from the Root Extract of Cnidoscolus souzae

“…Fraction D3 (1.38g) was passed through Sephadex LH-20, eluting with CHCl 3 :MeOH:n-hexane (1:1:2), to produce eight fractions (E1-8). Fraction E7 (304.5 mg) was identified as 7-deoxynimbidiol (1) by comparing its spectroscopic data with those previously reported [5]. Final purification of fraction E3 (358.5 mg) by CC eluting with dichlometane:n-hexane:EtOAc (40:50:10) yielded nine fractions (F1-9…”