Rubrocurcumin

Rubrocurcumin is a red-colored dye that is formed by the reaction of curcumin and boric acid.

Synthesis

The reaction of curcumin with borates in presence of oxalic acid produces rubrocurcumin.

Rubrocurcumin produces a red-colored solution.
Rubrocurcumin is a neutral molecule, while rosocyanine is ionic. In rubrocurcumin, one molecule of curcumin is replaced with oxalate compared to rosocyanine.
Complexes with boron such as rubrocurcumin are called 1,3,2-dioxaborines.