[In vitro O-demethylation of rotundine by recombinant human CYP isoenzymes].

Rotundine (1 micromol L(-1)) was incubated with a panel of rCYP enzymes (1A2, 2C9, 2C19, 2D6 and 3A4) in vitro. The remained parent drug in incubates was quantitatively analyzed by an Agilent LC-MS. CYP2C19, 3A4 and 2D6 were identified to be the isoenzymes involved in the metabolism of rotundine.

[Study on effect of demethoxycurcumin in Curcuma long on stability of curcumin].

Objective: To investigate effect of demethoxycurcumin on stability of curcumin.

Methods: To add the demethoxycurcumin to pure curcumin, the change of curcumin was determined by HPLC and the dynamics of curcumin degradation was investigated.

Result: The stability both obtained from alcohol and demethoxycurcumin improved the stabilization of curcumin, the demi-period of curcumin prolonged with the addition of demethoxycurcumin.