Biologically active compounds from bryophytes

The bryophytes are placed taxonomically between algae and pteridophytes; there are about 24 000 species in the world. They are further divided into three classes, Musci (mosses, 14 000 species), Hepaticae (liverworts, 6000 species) and Anthocerotae (hornworts, 300 species). The Hepaticae contain cellular oil bodies which are easily extracted with organic solvents, while the other two classes do not. A number, of bryophytes (in particular, mosses) have widely been used as medicinal plants in China, to cure burns, bruises, external wounds, etc. [1-5]. The mosses and liverworts shown in Table 1 are medicinal plants and are said to possess certain biological activity and effect [1-5]. Some bryophytes show characteristic fragrant odors and an intense hot and bitter or saccharine-like taste. Generally, bryophytes are not damaged by insects, snails, slugs, and other small animals. Furthermore, some liverworts cause intense allergenic contact dermatitis and allelopathy. We have been interested in these biologically active substances found in bryophytes and have studied about 1000 species of liverworts collected in North and South Africa, North and South America, Argentina, Australia, Europe, French Polynesia, India, Japan, Madagascar, Nepal, New Zealand, Pakistan, and Taiwan, with respect to their chemistry, pharmacology, and application as sources of cosmetics, and medicinal or agricultural drugs. It has been demonstrated that most of the Hepaticae contain mainly lipophilic mono-, sesqui-, and diterpenoids, aromatic compounds (bibenzyls, bis-bibenzyls, benzoates, cinnamates, long-chain alkyl phenols, naphthalenes, phthalides, isocoumarins), and acetogenins which constitute the oil bodies. The biological activities of liverworts are due to these substances [6-10]. At present, over 400 new compounds have been isolated and their structures elucidated [6,10]. The biological characteristics of the terpenoids and aromatic compounds isolated from the liverworts in our laboratory are: (1) characteristic scents; (2) pungency and bitterness; (3) allergenic contact dermatitis; (4) cytotoxic, anti-HIV, and DNA polymerase P inhibitory; (5) antimicrobial and antifungal activity; (6) insect antifeedant activity, mortality, and nematocidal activity; (7) superoxide anion radical release inhibitory activity; (8) 5-lipoxygenase, calmodulin, hyaluroridase, cyclooxygenase inhibitory activity, and nitric oxide (NO) production inhibitory activity; (9) piscicidal and plant growth inhibitory activity; (10) neurotrophic activity; (11) muscle relaxing activity; (12) cathepsins B and L inhibitory activity; (13) cardiotonic and vasopressin antagonist activity; (14) antiobesity activity; and (15) synthesis of bioactive compounds from liverwort constituents will be discussed.