Potential Medicinal Compounds from Liverworts

Almost all liverworts (Figures 1 & 2) possess beautiful cellular oil bodies. Over several hundred new terpenoids and phenolic compounds with more than 40 new carbon skeletons have been found in this class, for example, 1-hydroxysacculatal (1) and marchantin A (2). The most interesting chemistry of liverworts is that most of sesqui- and diterpenoids are enantiomers of those found in higher plants [1–5].

Fig.1: Pellia endiviifolia.

Fig.2: Reboulia hemisphaerica.

Some of the isolated terpenoids and aromatic compounds from liverworts show allergenic contact dermatitis, cytotoxicity, antiviral, antimicrobial, antifungal, insect antifeedant and mortality, antioxidant, NO production and plant growth inhibitory, neurotrophic and piscicidal activity, 5-lipoxigenase, calmodulin, hyalunoidase and cyclooxygenase inhibitory, tublin polymerization inhibitory, muscle relaxing, and liver X-receptor (LXR)α agonist and (LXR)β antagonist activity [1]. The typical chemical structures of terpenoids and phenolic compounds found in several liverworts and some biological activity including fragrant and tasty components as well as sex pheromones are surveyed. Total and hemisynthesis of bioactive terpenoids and phenolics isolated from liverworts are also reported. References: [1] Asakawa Y, Progress in the Chemistry of Organic Natural Products. Vienna: Springer. 42: 1–285. Ibid., 65: 1–618 (1995), Asakawa Y. Ludwiczuk A, Nagashina F. ibid. 95: (2012) in press. Asakawa Y (2008) Curr Pharm Design 14: 3067–3088. [2] Asakawa Y, Chemical Constituents of the Bryophytes.1995, Ibid. Vol. 65: 1–618. [3] Asakawa Y, Ludwiczuk A, Nagashima F, Chemical Constituents of Bryophytes: Bio- and Chemical Diversity, Biological Activity and Chemosystematics. 2011, Ibid. Vol. 93 (in preparation). [4] Asakawa Y, (2004) Phytochemistry 65: 623–669. [5] Asakawa Y, Ludwiczuk A, et al. (2009) Heterocycles 77: 99–150. [6] Asakawa Y, (2008) Curr Pharm Design 14: 3067–3088.