Cyclic bis(bibenzyls) and related compounds from the liverworts Marchantia polymorpha and Marchantia palmata

A Synthesis-Driven Structure Revision of ‘Plagiochin E’, a Highly Bioactive Bisbibenzyl

“…13 Considering these results, we now are able to exclude the structures 4 and 5 for the isolated compound. Finally, comparing the spectroscopic data of the four bisbibenzyls namely synthetic 4 and 5 as well the earlier reported 6 24 and 7 25 with the isolated 'plagiochin E', 13 we suggest that the isolated compound may be riccardin D (6). It should be noted that the published NMR data of 6 24 and 4 13 were obtained in different solvents.…”

Abscisic acid induces biosynthesis of bisbibenzyls and tolerance to UV-C in the liverwort Marchantia polymorpha

“…Moreover, the characteristic olefin proton signal of bisbibenzyls, which was shifted to approximately d H 5.5 ppm, was observed in the 1 H NMR spectra of these compounds. Through detailed investigations of MS and NMR spectroscopic data (Table S1), compounds 1, 2, and 3 were determined as isoriccardin C (1), marchantin C (2), and riccardin F (3), respectively (Asakawa et al, 1987;Speicher and Holz, 2010;Yoshida et al, 1996) (Fig. 1b).…”

Syntheses of Macrocyclic Bis(bibenzyl) Compounds Derived from Perrottetin E

“…Isolation from liverworts [4] Biological activities [17,18] Total synthesis 6 riccardin C Reboulia hemisphaerica (1982) [9] et al [4] COX inhibition [4] 1990 [27] Ptagiochasm intermedlum (2010) [19] cytotoxic [20,21] 1998 [5] inhibitory activities against HIV-1 RT [21] 2005 [28] inhibition of NOS [22,23] 2009 [25] LXRα agonist but LXRβ antagonist [24,25] antifungal [19] apoptosis of human prostate cancer [26] 8 plagiochin H ---9 isoriccardin C Marchantia polymorpha, M. palmata (1987) [10] COX inhibition [4] Plagiochasma rupestre (1999) [29] Ptagiochasm intermedlum (2010) [19] …”

“…The theoretical conformational strain in these compounds had been computed before [2] and several representatives were found in bryophytes (Table 1). Earlier reports were given on the isolation of riccardin C (6), [9] isoriccardin C (9) [10] and riccardin D (11). [11] In the case of the bis(bibenzyl)-type derived from 3 through coupling at the 6-and 6Ј-positions, only compounds with additional methylation and/or hydroxylation have been isolated, in the form of plagiochins A-D (structures not shown in Scheme 2).…”