On a search of biologically active compounds in bryophytes: Chemical composition and major secondary metabolites

Bryophytes can be found in any location around the world. They are the second largest group in Plant kingdom, and they are divided in 3 groups- Musci, Marchantiophyta and Anthocerotophyta. It is assumed that bryophyte extracts have antimicrobial, antifungal and antitumor activity. Although there have been some studies in this area, it is important to take in account that bryophyte chemical composition may differ between species, growth environment and geographical localization. Based on this assumption bryophytes common for Northern Europe were analyzed. Twenty bryophyte species found in Latvia were analyzed. We have studied bryophyte basic chemical composition using elemental composition analysis, FTIR, ¹³C NMR spectra and Py/GC/MS. Basic chemical composition analysis reveal nearly total absence of lignin and lignin like structures. To study secondary metabolites sequential extraction approach was used and the extraction efficiency was studied, including microwave extraction and others. In the extracts total characteristics such as dry residue, total phenolics, sugars, antioxidant activity and other were determined. Lipophilic extracts (obtained after extraction with chloroform) were analyzed using GC/MS. There have been found more than 60 different compounds. Bryophyte sample analysis using Py/GC/MS showed that the dominant compounds in lipophilic fraction of bryophytes were: phenol and 4-ethenylphenol. Results have shown that studied bryophytes contain some substances with aromatic ring, but none of the found bryophytes showed any prove of lignin content. The studied extracts of bryophytes demonstrate antimicrobial activity as demonstrated on example of E. coli, B. cereus, P. aeruginosa, S. aureus, S. epidermidis, M. luteus, B. subtilis as well as cytotoxic activity in respect to rat glioma, human epiderm carcinoma, human lung carcinoma and mouse melanoma cell line.