Liverworts Plagiochila

Huneck, S., Connolly, J. D., Harrison, L. J., Joseph, R. S. L, and Poes, T. 1984. l-(3, 4-Dihydroxy-5-methoxyphenyl)-3-methylbut-2-ene from the liverwort Plagiochila rutilans. Phytochemistry 23 2396-2397. 

Wu, C-L, Liou C-S, Ean U-J (2001) Fusicoccane Diterpenoids and Bisbibenzyls from the Liverwort Plagiochila peculiaris. J Chin Chem Soc 48 1197... 

The nor-ketone rudbeckianone (244) has been identified in Rudbeckia lacini-ata A very interesting new sesquiterpenoid ketone, (+)-bicyclohumulenone (245), has been isolated from the leafy liverwort Plagiochila acanthophylla subsp. japonica The structure and absolute stereochemistry of this compound were ascertained by X-ray crystallographic analysis of the mono-p-bromobenzoate of the derived triol (246). This ketone co-occurs with the two enantiomeric sesquiterpenoids (-)-maalioxide (247) and (+)-cyclocolerenone (248). 

A continuing investigation of the sesquiterpenoids from liverworts (Plagiochila species) has revealed the presence of more seco-aromadendrane compounds, namely plagiochilines A (652), B (653), C (654), D (655), E (656), and F (657). Plagiochilide (658) has been found in the Swiss species of P. asplenioides but not in the French version. The presumed precursor of these compounds, (-)-bicyclogermacrene (659), has also been identified in the extracts... 

An examination of the sesquiterpenoid constituents of the liverwort Plagiochila semidecurrens has resulted in the isolation of ovalifoliene (=plagiochiline C) (671), hanegokidial (672), and ovalifolienalone (673). A related and wide ranging investigation of other Plagiochila species... 

The work described so far has involved extensive international collaboration, but I would like to conclude by returning to Scotland and discussing some compounds isolated from a leafy liverwort Plagiochila spinulosa, a plant described as having an Atlantic distribution (i.e. liking a damp climate) and collected by myself near Glasgow. One of the new compounds isolated, 16, is a close relative of lunularic acid, 17, a growth inhibitor which seems to be ubiquitous in liverworts. 

C28H22O4 M 422.479 Constit. of the liverwort Plagiochila fruticosa. 10-Hydroxy [159194-78-2]. Isoplagiochin B C28H22O5 M 438.479 Constit. of P. fruticosa. 

Hashimoto, T., Y. Noma, Y. Goto, S. Takaoka, M. Tanaka, andY. Asakawa, 2003c. Biotransformation of sesquiterpenoids from the liverwort Plagiochila species. Proceedings of 47th TEAC, pp. 139-141. 

Maalioxide (349), mp 65-66°, [a]n -34.4° obtained from the liverwort, Plagiochila sciophila was inoculated and cultivated rotatory (100 rpm) in Czapek-peptone medium (pH 7.0) at 30°C for 2 days. (-)-Maalioxide (349) (100 mg OO mL) was added to the medium and further cultivated for 2 days to afford three metabolites, ip-hydroxy-(350), ip,9P-dihydroxy- (351), and ip,12-dihydroxy-maalioxides (352), of which 351 was predominant (53.6%). When the same substrate was cultured with Aspergillus cellulosae in the same medium for 9 days, 7P-hydroxymaalioxide (353) was obtained as a sole product in 30% yield. The same substrate (349) was also incubated with the fungus Mucor plumbeus to obtain a new metabolite, 9P-hydroxymaalioxide (354), together with two known hydroxylated products (350,353) (Wang et al., 2006). 

Hashimoto T, Tori M, Asakawa Y (1987) Sacculaplagin, a new highly oxidized sacculatane diterpenoid hemiacetal from the liverwort Plagiochila acanthophylla subsp. japonica. Tetrahedron Lett 28 6293-6294... 

Hashimoto T, Kananyama S, Kan Y, Tori M, Asakawa Y (1996) Isoplagiochins C and D, new type of macrocyclic bis(bibenzyls), having two biphenyl linkages from the liverwort Plagiochila fruticosa. Chem Lett 25 741... 

Lorimer SD, Perry NB (1993) An antifungal bibenzyl from the New Zealand liverwort, Plagiochila stephensoniana. Bioactivity-directed isolation, synthesis, and analysis. J Nat Prod 56 1444-1450... 

Matsuo, A., K. Atsumi, M. Nakayama, S. Hayashi, and K. Kuriyama (+)-Ovahfoliene and (—)-Hanegokedial, Two Novel Sesquiterpenoids of the Ent-2,3-seco-alloaromadendrane skeleton from the Liverwort Plagiochila semidecurrens. Chem. Commun. 1979, 1010. 

Matsuo, A., K. Nad ay a, M. Nakayama, and S. Hayashi Plant Growth Inhibitors Isolated from the Liverwort, Plagiochila ovalifolia. Nippon Kagaku Kaishi 1981, 665. Matsuo, A., T. Nakamoto, M. Nakayama, and S. Hayashi Jungermanool, a New Labdane Diol from the Lf v erwort, Jungermannia torticalyx Steph. Experientia 32, 966 (1976). 

Matsuo, A., M. Nakayama, S. Sato, T. Nakamoto, S. Uto, and S. Hayashi (—)-Maalioxide and (+)-Cyclocolorenone, Enantiomeric Sesquiterpenoids from the Liverwort, Plagiochila acanthophylla japonica. Experientia 30, 321 (1974). 

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