(E)-2-Benzylidenebenzocyclanones, part VIII: spectrophotometric determination of pKa values of some natural and synthetic chalcones and their cyclic analogues

摘要: UV–Vis spectrophotometry was used to determine acid dissociation constant (pK a) values of the natural flavonoids phloretin, phlorizin, naringenin, and naringin, as well 4′-hydroxychalcone, 4′-(dimethylamino)chalcone, their cyclic analogues. Comparison results with those previously reported for showed applied method is a relatively straightforward easy-to-perform technique determination pK compounds low solubility. Comparative analysis synthetic chalcones strong correlation between degree conjugation strength respective different geometry. Our provide further evidence that modification three-dimensional structure open-chain bioactive choice modify not only stereochemistry but also physicochemical properties.