Retigeranic acid, a novel sesterterpene isolated from the lichens of group

Asymmetric total synthesis of (−)-lingzhiol via a Rh-catalysed [3+2] cycloaddition

“…The structure of 10b was confirmed by X-ray crystallographic analysis. We also investigated the application of our newly developed reaction as a general method for the construction of [4,3,0] ring systems (Table 3). Enynols 15a-19a were prepared and subjected to the optimized reaction conditions to afford the corresponding products 15b-19b in good-to-acceptable yields, bearing two syn-configured vicinal quaternary stereocentres.…”

“…Crinipellin A (2), isolated from the fungus Crinipellis stipitaria (Agaricales), has been reported to exhibit potent antibiotic activity 2 . Retigeranic acid (3) is a representative member of the sesterterpenoid family of compounds and exhibits a broad range of biological activities [3][4][5][6][7] . Although compounds of this type are well known to elicit a variety of interesting biological responses, efficient methods for their construction are scarce.…”

Two New Retigerane‐Type Sesterterpenoids from the Lichen Leprocaulon microscopicum

“…The structure of retigeranic acid was previously established by Kaneda et al (1972) only by X-Ray analysis and confirm by total synthesis of the racemate [6,12]. On the basis of the above results, compound 1 was characterized as retigeran-11-ol reported for the first time.…”

“…Sesterterpenes (C25) are the rarest of the terpenoid classes of secondary metabolites isolated from terrestrial fungi, marine organisms and more occasionnaly from insects, higher plants or lichen [2]. The carbon framework of known sesterterpenes shows Retigeranic acid was the only sesterterpenes reported in lichens and was isolated from Lobaria retigera [6,[17][18]. A possible pathway for the biosynthesis of 1 is suggested in Fig.…”

“…Only one sesterterpene; retigeranic acid, has been described in two lichen species belonging to the Genus Lobaria [6]. Leprocaulon microscopicum (Vill.)…”