Neoflavonoid

Neoflavonoids are a class of polyphenolic compounds. While flavonoids (in the narrow sense) have the 2-phenylchromen-4-one backbone, neoflavonoids have the 4-phenylchromen backbone with no hydroxyl group substitution at position 2.

Types

Neoflavonoids include 4-arylcoumarins (neoflavones), 4-arylchromanes, dalbergiones and dalbergiquinols.

Neoflavones are derived from the 4-phenylcoumarin (or 4-aryl-coumarin) backbone (C₁₅H₁₂O₂). The first neoflavone isolated from natural sources was calophyllolide from Calophyllum inophyllum seeds (1951). It is also found in the bark and timber of the plant Mesua thwaitesii, endemic to Sri Lanka.
Neoflavenes possess the 4-phenylchromen backbone (C₁₅H₁₀O₂). Dalbergichromene, extracted from the stem-bark and heartwood of Dalbergia sissoo, is an example of such compounds

Other examples

Coutareagenin (5-hydroxy-7-methoxy-4-(3,4-dihydroxyphenyl)-2H-benzo-1-pyran-2-on) found in Hintonia latiflora
Dalbergin
Nivetin isolated from Echinops niveus