# Structure and Dynamics of the Deprotonated Demethoxycurcumin and Bisdemethoxycurcumin Anions

## TL;DR

This paper studies the structure and behavior of two curcuminoid anions, finding they behave similarly to curcumin in terms of electronic structure and energy transfer.

## Contribution

The first gas-phase ion spectroscopy study of deprotonated demethoxycurcumin and bisdemethoxycurcumin anions.

## Key findings

- Deprotonated curcuminoid anions have an electronic structure similar to deprotonated curcumin anions.
- All studied anions show similar adiabatic detachment energies and internal conversion after photoexcitation.
- Curcuminoids may perform similar biological roles to curcumin due to their structural and dynamic similarities.

## Abstract

The curcuminoids
are polyphenols found in the spice turmeric, where
its principal polyphenol, curcumin, has been attributed with many
of turmeric’s beneficial therapeutic properties. However, as
curcumin has a low bioavailability, other curcuminoids, which have
fewer terminal methoxy substituents and have been reported to have
a higher bioavailability, have been investigated as possible therapeutics.
In this article, we report the results of the first gas-phase ion
spectroscopy study of the deprotonated anionic forms of two prevalent
curcuminoids: demethoxycurcumin and bisdemethoxycurcumin. The results
indicate that the deprotonated curcuminoid anions have an electronic
structure very similar to that of the deprotonated curcumin anion,
with one bound electronically excited state and two low-lying anion
resonances. Furthermore, all of the deprotonated curcuminoid anions
have similar adiabatic detachment energies and show clear evidence
of internal conversion following photoexcitation. Therefore, the curcuminoids
studied here may be expected to perform a similar biological and/or
therapeutic role to curcumin, given their similar electronic structure
and energy transfer dynamics.