Hepaticae diterpenoids

The distribution of diterpenoids in the Hepaticae is restricted to certain genera. Representatives of two new types, the sacculatanes and verruco-sanes, as well as labdane-, pimarane- and kaurane-type diterpenoids have been encountered so far in the Hepaticae, although there are many minor unidentified diterpenoids in each species. 

The labdane-, pimarane- and kaurane-type diterpenoids so far isolated from the Hepaticae belong to the -series while higher plants produce both normal and /-labdanes, pimaranes and kauranes. 

Gorham(72< ) reported that lunularin (595) and lunularic acid (598) were found in the Hepaticae, but not in the Musci and the Anthocerotae. Chemical differentiation between the Hepaticae and the Musci is also observed with respect to terpenoids and lipophilic aromatic compounds. The Hepaticae produce mono-, sesqui- and diterpenoids as well as lipophilic aromatic compounds. By contrast neither mono- and sesquiterpenoids nor lipophilic aromatic compounds have been found in the Musci which have been analyzed so far, except for the presence of one kaurane-type diterpene (508) in Saelania species (272). This characteristic difference in chemical constituents is due to the following fact. Most species of the Hepaticae possess oil bodies which contain the terpenoids and the lipophilic aromatic compounds, whereas, the Musci do not contain oil bodies. Terpenoids and aromatic compounds are major constituents of the Hepaticae and can be used as important chemosystematic markers at different taxonomic levels 13a, 19, 21, 25a, 26—29, 33, 34, 45—47, 67, 69, 74, 334). Although flavonoids are not major components of the Hepaticae, these can also be used as chemical markers (187—198, 200—205, 259, 264, 310—312, 328, 329). Taxonomic use of biochemical data for all hierarchical levels of the bryophytes was reviewed by Suire and Asakawa (310—312). The chemosystematics of the Marchantiales were reviewed by Markham and Porter (199). 

Connolly, J. D., and I. M. S. Thornton . E /-kaurene Diterpenoids from Solenostoma triste (Nees) K. Mull. (Hepaticae). J. Chem. Soc. Perkin Trans. I 1973, 736. 

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