Biflavonoids: Occurrence, Structural features and Bioactivity. A Review

MERCADER, ANDREW G.; POMILIO, ALICIA, B.

JOURNAL OF NATURAL PRODUCTS

AMER CHEMICAL SOC

Año: 2010

0163-3864

Biflavonoids comprise a group of the flavonoid family that possess a variety of structures, and biological activities of high relevance, such as anticancer, antibacterial, antifungal, antiviral, antiinflammatory, antinociceptive, antioxidant, vasodilator, anticlotting, among others, irrespective of the bioactivity of each monomer unit. The chemistry of biflavonoids is very important in many fields of research, especially since these compounds are structurally different bioactive molecules with potential for biomedical application.  This work aims to highlight the structural biflavonoid variability, rearrangements, and different stereochemistry through about 460 structures distributed in some species of Angiosperms (monocots and dicots), Gymnosperms, ferns (Pteridophyta), and mosses (Bryophyta). Their distribution is shown to provide the latest picture of their natural sources, biological activities, and traditional uses.   The chemical structures include (1) Simple dimers with several C-C, C-O-C and C-CH2-C linkages of the known flavonoid monomers. (2) Complex biflavonoids, which are derivatives of furochromen-4-one, furo[2,3-f]chromanone, furo[2,3-h]benzopyran, naphthalene, dihydronaphthalene, and tetrahydronaphthalene derivatives, substituted cyclobutane, substituted tetrahydrofuran, substituted benzofuran and benzodihydrofuran, and related compounds. (3) Rearranged biflavonoids, simple and prenylated ketalized dimers, and rearranged ketalized dimers. (4) Natural Diels-Alder type adducts including substituted cyclohexene derivatives, prenylbiflavonoids (ketalized  Diels-Alder-type adducts), and 2-arylbenzofuran-ketalized Diels-Alder adducts, and finally (5) Spirobiflavonoids.    The most important general characteristics, structures and nomenclature of the biflavonoids have been covered, and biological activities are carefully displayed. The structural aspects of the biflavonoids are shown in a detailed list of figures, thus providing an overview of their structural features. The current status and future prospects for structure-activity studies of these compounds are also discussed.