Curcuminoids stability

Tomren, M. A. Masson, M. Loftsson, T. Tonnesen, H. H., Studies on curcumin and curcuminoids XXXI. Symmetric and asymmetric curcuminoids Stability, activity and complexation with cyclodextrin. International Journal of Pharmaceutics (2007) 338, 27-34. 

Tpnnesen, H.H, Masson, M., and Loftsson, T., Studies on curcumin and curcuminoids. XXVII. Cyclodextrin complexation solubility, chemical an photochemical stability, Int. J. Pharm., 244, 127, 2002. 

The main coloured substances in the rhizomes are curcumin (1,7-bis (4-hydroxy-3-methoxy prenyl)-l, 6-heptadiene-3, 5-dione) and two related demethoxy compounds, demethoxy curcumin and fczs-demethoxy curcumin, which belong to the group of diarylheptanoids (see Fig. 6.1). Besides these three forms of curcuminoids, three minor constituents have also been isolated (Srinivasan, 1952) that are supposed to be geometrical isomers of curcumin. One of these is assumed to be a cis-trans geometrical isomer of curcumin based on its UV spectrum, lower m.p. and lower stability when compared with curcumin, which has a trans-trans configuration. Heller (1914) isolated an isomer of curcumin with a diketone structure. 

Tonnesen HH, Karlsen J. Studies on curcumin and curcuminoids. VI. Kinetics of cur-cumin degradation in aqueous solution. Z Lebensm-Unters-Forsch 1985 180 402. Tonnesen HH, Karlsen J, van Henegouwen BG. Studies on curcumin and curcuminoids. VIII. Photochemical stability of curcumin. Z Lebensm-Unters-Forsch 1986 183 116. 

Tonnesen HH. Studies on curcumin and curcuminoids. XXVIII. Solubility, chemical and photochemical stability of curcumin in surfactant solution. Pharmazie 2002 57 ... 

Tonnesen HH, Karlsen J. Studies on curcumin and curcuminoids. XL Stabilization of photolabile drugs in serum samples by addition of curcumin. Int J Pharm 1988 41 75. 

The primary focus of tumteric research today is based on its properties as an amio- idam (Zi) and a.s an anticarcinogen (4,5,6). The antioxidant properties of turmeric are based on the ability of curcumin to form complexes with metals and to form a rcsojiance stabilized free radical. Curcumin, along with the other curcuminoids. 

Figure 13. Stabilization Effect of Phenolic Radical by Meihoxyl Oxygen and Olefin of Curcuminoids (2 6, 2 8, and 31).

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