SYNTHESIS, PHYSICOCHEMICAL AND SPECTROPHOTOMETRIC ANALYSIS OF CURCUMIN ANALOGS WITH CYCLOHEXANONE CORE

Due to the presence of specific functional groups in its structure, curcumin has demonstrated a wide range of therapeutic properties for which it has garnered significant interest over the past twenty years. Despite this, curcumin's low chemical stability owing to keto-enol tautomerism and poor water solubility results in low bioavailability, limit its use in therapy. In this study were synthetized seven curcumin analogs with cyclohexanone core: Ia, Ib, Ic, IF5NO2, Id, Ie and If. Analogs were prepared by Claisen-Schmidt condensation reaction between corresponding benzaldehyde and arylaldehyde. Several spectroscopic techniques were used to confirm the structure of the obtained analogs. The effective synthesis and the presence of a conjugated dienone system can be inferred from the infrared spectra. The analogs color, which range from light yellow to orange and their UV-Vis spectra, which have λmax values above 300 nm, further substantiate the extended conjugation indicating that there are several double bonds adjacent, and their bonding orbitals can interact and form one huge delocalized system. From the infrared spectra it can be seen that analogs exhibited an absorption band below 1700 cm–1, which is likewise consistent with the literature and suggests the existence of a conjugated carbonyl group. As part of this paper, chromatographic methods (HPLC-DAD-MS) were applied to determine the purity of the synthesized curcumin analogues with cyclohexanone core. These analogues can further be tested and analyzed in terms of their cytotoxicity or therapeutic potency.