Bioproduction of Depsidones for Pharmaceutical Purposes

摘要: Lichens are intimate and long-term specific symbioses of photosynthetic algae or cyanobacteria heterotrophic fungi joined to form a new biological entity different from its individual components (Galun & Kardish, 1995). Mainly chlorolichens produce unique phenolic substances, depside, depsidones some dibenzofurans, such as usnic acids (Huneck Yoshimura, 1996), that not produced by other plants, show activities with interesting applications pharmacological point view, mainly antiviral agents for dermatological treatments. Although semisynthetic organic processes have been attempted the production (Elix et al., 1987), they results very tedious, expensive inappropriate industrial applications. Alternatively, extraction lichen thalli collected in nature implies high rate biomass destruction which cannot be balanced because slow growth these organisms. This last condition also invalidates use transgenic specimens. Thus, bioreactors using small amounts seems yet most viable alternative rapid efficient depsidones. Depsidones compounds consisting two linked together both ester ether bonds. So far, type I polyketide synthases (PKSs) suggested catalysts biosynthesis (Muggia Grube, 2010). It is generally accepted come depsides, formed molecules orsellinic acid derivatives an bond, means formation was carried out on previously depsides. despide closely related biogenetically all seem belong only one group chemical structures. therefore definite evolved same primary compound, variations being brought about oxidation reduction, simple reactions (Seshadri, 1944). Polyketide synthases, known PKSs, family enzymes enzyme complexes polyketides, large class secondary metabolites bacteria, fungi, few animals lineages. The biosyntheses polyketides share striking similarities fatty (Khosla 1999; Jenke-Kodama 2005). pathway