intermediates in the production of all flavonoids, but rarely accumulated, isomeric with flavanones, the A ring being derived from acetate and with a phloroglucinol oxidation pattern, the B ring from a phenylpropanoid precursor, and with an allyl bridge (-CH:CH.CO) separating the two rings, yellow in colour and most often found in flowers, c.f. chalcones; they are anthochlors.