Metabolites of curcuminoids detected in incubation media.

<p>(A) NT2/D1 cells were incubated with media containing 47 µM curcuminoids (SOLID+DMSO) for 5 h. Left panel: The elution profile at 310 nm wavelength of metabolites derived from BDMC (B*), DMC (D*), and CUR (C*) in the media. Center and right panels: The elution profiles at 427 nm wavelength of curcuminoids extracted from cells and media, respectively. The relative areas under the curve of each peak are indicated in square brackets. (B) Time course of the generation of curcuminoid metabolites (OD at 310 nm wavelength) in the media under three incubation conditions: Incubation of cells with 47 µM curcuminoids in 5% FCS (I, ▪), with 24 µM curcuminoids in 2.5% FCS (II, ○), or with 24 µM curcuminoids in 5% FCS (III, •). Insert: The value of the slope (m) of curve II (I/II, hatched bar) and III (I/III, hatched bar) relative to the value of the slope of curve I (I/I, black bar). The resulting ratios were similarly compared to the ratios of curcuminoids bound to cells (b, solid bars) after 5 h under the same respective incubation conditions (C) Putative structure of the metabolic product of CUR (C*) based on the evaluation of mass spectrometry and absorption properties.