Oplopanes from the leaves of Senecio mexicanus

Evaluation of the Anti-Inflammatory and Antioxidant Activities of the Plastoquinone Derivatives Isolated from Roldana barba-johannis

“…To the best of our knowledge only four of its species have been studied phytochemically. Two species afforded pyrrolizidine alkaloids [2], [3], and the remaining two species gave sesquiterpenes with the eremophilane or oplopane skeleton [4], [5]. The present paper describes the secondary metabolites isolated from the not previously studied Roldana barba-johannis (DC.)…”

“…Initially only sargachromenol (4) and sargahydroquinoic acid (5) were isolated as a mixture (1 : 4) and during the purification process sargaquinoic acid (6) was formed. The in vitro transformation of dihydroplastoquinone 5 into plastoquinone 6, which in turn is converted to sargachromenol (4) was previously reported [8], [9].…”

Eremophilane esters of Robinsonecio gerberifolius and their rearranged products. Study of the coupling constants 2JH, H, 3JH, H and 4JH, H

“…1 The more common secondary metabolites of Senecioneae are sesquiterpenes with an eremophilane skeleton. 2 Pyrrolizidine alkaloids 2 and sesquiterpenes of the oplopane type 3 are also common.…”

“…The rearranged sesquiterpenes 5 and 6 were produced by alkaline treatment of the eremophilanes 1 and 2, the peroxide 10 was obtained from saponification of 3, and the compound 7 was obtained by autooxidation of 1. The calculation of the coupling constants 2 J H,H , 3 J H,H , and 4 J H,H for the peroxide 10 and the complete optimization of its geometry, at the B3LYP/6-31G(d, p) level, were also performed. 5 …”

Spectral Data of Two New Asymmetric Sesquiterpene Alcohols: (14R)-β-Oplopenol and (14S)-β-Oplopenol

“…The oplopane derivatives were well represented from plants of the Senecioneae family [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 ]. The sesquiterpenic ketone β -oplopenone was identified as a major component of the essential oil of Adenostyles briquetii , an endemic species from the island of Corsica [ 9 ].…”