Dihydrophenanthrene Dimers: Why and Where It Is Possible to Isolate Their Precursors

An interesting class of compounds of natural origin is dihydrophenanthrene dimers, which are characterizedby a series of remarkable biological properties. Considering the hypothesis that each dimer is obtained througha biosynthetic mechanism that involves the coupling of the corresponding radicals of the single dihydrophenan-threne unit, we identified 29 dihydrophenanthrenes. Of these dihydrophenanthrenes, 11 were new compoundsthat could be isolated from 10 different plant species; 11 had already been identified, but not yet isolated in the17 different plant species from which the corresponding dimers had been isolated; and 7 were known and hadbeen isolated in the same plant sources of the corresponding dimers. A targeted analysis of several naturalextracts from specific plant sources would allow the identification of known or new molecules with potentialand/or specific biological activities and, in a final analysis, would confirm the relative biosynthetic mechanism.