Bioprospecting of "New" or "Old" Plant Species?
Plant diversity still offered major opportunities for finding new substances for development novel pharmaceuticals. However, it is estimated that only a small percentage (less than 3%) of all currently known plant species have been chemically investigated. On the other hand, more than 60% of the available anticancer drugs were directly based on or developed from natural products. Screening of plant materials has become an important tool in discovery of new sources of biologically active compounds that are active against a wide range of assay targets. New compounds are to be described from poorly studied species and even in species that are considered chemically well known, new chemical strains are still detected. Bryophytes represent a poorly explored part of biodiversity. Milestone investigations on bryophytes are attributed to Japanese researcher Asakawa and his colleagues [1,2]. A global approach on Bryophyta investigations appears to be essential in developing new and viable biotechnological processes which could be afford suitable amounts of unique compounds. Another group of organisms that provides very promising sources of bioactive substances with potential anticancer, antiviral, antibacterial, antiparasitic, antiinflammatory, antihyperglycemic, epatoprotective, and cardioprotective activities are lichens and mushrooms [3,4]. Approximately 300 species are known to have medicinal activity and another 1800 species have been identified with potential medicinal properties [5]. The huge biological diversity of lichens that maintained by 18800 different species [6], is highly promising source of unique secondary metabolites and polysaccharides of which some have already been proved to be effective against various cancer in vitro models [7].