I am a PhD student in Chemical Sciences involved in the development of Curcumin derivatives.
For what concerns my PhD research project, I am trying to develop Curcumin bioconjugates, with a view to enhancing its stability and solubility by esterifying -OH moieties of Curcumin aromatic rings.
What I would like to share is what I notice right after reaction and work-up: by performing UV spectrophotometric analysis of the conjugate (red curve) in a mixture DMSO 9:1 H2O, there is an uplifting of the peak in the UV region (between 250-270 nm) of the phenolic ring, and a subsequent lowering of the Cur (1,6-heptadiene-3,5-dione) conjugated system peculiar peak at 420-440 nm in the VIS region.
Compared to the behaviour of bare Cur (blue curve), the evidenced trend is opposed (lower peak in the UV region and a higher peak at ≃ 430nm).
Could this result be attributable to an auxochrome effect of phenolic -OH after esterification and contribution of adjacent carbonyl moiety linked ?
It is noteworthy that the polymer scaffold chosen for the esterification is not UV active, according to the absence of any insaturation within the structure.
Thanks in advance to who will give a hand.
