Turmeric curcuminoids

The choice of the method of analysis depends on the question to address. Spectrophotometry is sufficient for total curcuminoid content determination in a turmeric extract. Separation techniques coupled to mass spectrometry detection and MALDl-TOF are highly sensitive techniques that are more adapted to the identification of metabolites in biological fluids such as urine or plasma. ... 

He, X.G. et al, Liquid chromatography-electrospray mass spectrometric analysis of curcuminoids and sesquiterpenoids in turmeric Curcuma longa), J. Chromatogr. A, 818, 127, 1998. 

Taylor, S.J. and McDowell, I.J., Determination of the curcuminoid pigments in turmeric (Curcuma domestica Val) by reversed-phase high performance liquid chromatography, Chmmatographia, 34, 73, 1992. 

Turmeric contains two main classes of compounds the curcuminoids responsible for the yellow color and the aroma compounds. The coloring principle of turmeric consists of three major phenolic derivatives curcumin, demethoxycurcumin, and bisdemethoxycurcumin. Commercially available products called curcumins contain curcumin (l,7-bis(4-hydroxy-methoxyphenyl)-l,6-heptadiene-3,5-dione) as the major component (about 77% of total curcuminoids). Some other minor phenohc compounds such as cyclocurcumin and calebin were also isolated from turmeric. See Figure 5.2.1. 

FIGURE 5.2.1 Chemical structures of curcuminoid pigments and some aroma compounds of turmeric. 

Four different commercially available varieties of turmeric containing curcumin were isolated, separated by column chromatography, and identified by spectroscopy. The purity of the curcuminoids was analyzed by an improved HPLC method, performed on a Ci8 column using methanol, acetic acid, and acetonitrile and detection at 425 nm. The total percentages of curcuminoids in turmeric were between 2.34... 

Curcuminoids, yellow colorants, from turmeric (Curcuma)... 

Curcumin is a hydrophobic polyphenol derived from turmeric the rhizome of the herb Curcuma longa. Traditionally, turmeric and other curcuminoids have been used in therapeutic preparations for various ailments in different parts of the world. Numerous therapeutic effects of curcumin/turmeric have been confirmed by modern scientific research. It is a highly pleiotropic molecule that modulates numerous targets, including the activation of transcription factors (e.g., NF-kB, STAT-3, AP-1, NRF-2, PPR-y, HIF-1), receptors (e.g., HER-2, IL-8, CXCR-4), kinases (e.g., EGFR, ERK, JAK, AAPK), cytokines (e.g., TNF, IL, MIP, MCP), enzymes (e.g., MMP, iNOS, GST, ATPase), and... 

Further studies are required to unravel this mystery of how the methoxy substitutions and the a, p-unsaturated p-diketone moiety actually influence conformational changes, lipophillicity, electron density distribution, and redox properties of curcuminoids. Correlating these physicochemical properties with the unique pleiotropic effects of curcuminoids is a rewarding exercise. Such studies would definitely provide proper reasoning in understanding these markedly different antioxidant, antitumor, and anti-inflammatory activities of natural curcuminoids from turmeric. 

Several spices possess antioxidative properties — a turmeric extract (curcuminoid), a hexane extract of rosemary, and the a-tocopherol-supplemented capsicum pigment exhibit their antioxidative effects in vivo by dietary supplementation. Turmeric extract has demonstrated the ability to reduce liver triacylglycerol deposition as well as cholesterol. 

Ramirez Ahumada, M. del C., Timmermann, B.N. and Gang, D.R. (2006) Biosynthesis of curcuminoids and gingerols in turmeric (Curcuma longa) and ginger (Zingiber officinale) identification of curcuminoid synthase and hydroxycinnamoyl-CoA thioesterases. Phytochemistry 67(18), 201 7-2029. 

Curcumin, or curcuminoids concentrate, for use as a food colour, is not a regular article of commerce because the cheaper turmeric oleoresin has been found suitable for most current uses. Curcumin is included in the list of colours with a restricted use because it has been allotted a low ADI (acceptable daily intake) of 0-1 mg/kg body weight/day. Curcumin gives a bright yellow colour even at doses of 5-200 ppm. A variety of blends are available to suit the colour of the product (Henry, 1998). 

Turmeric, dried and cured, generally yields from 1.5 to 5.0% volatile oil. However, C. aromatica Salisb. is generally high in volatile oil (4-8%) and low in curcuminoids... 

Isolation of curcuminoids from turmeric has been reported by numerous workers. However, extraction of pure curcumin from the plant... 

Turmeric powder irradiated for 2 and 4min with microwave showed marginally higher extraction of curcuminoids in 60 min by acetone (Dandekar and Gaikar, 2002). 

The anti-inflammatory activity of curcumin and its derivatives is associated with the hydroxyl and phenol groups in the molecule, which are also essential for the inhibition of prostaglandins, PG synthetase and leucotriene synthesis (LT) (Kiuchi et al., 1982, 1992 Iwakami, et al, 1986). Claeson et al. (1993, 1996) suggested that the antiinflammatory action and the antiparasitic activity were associated with the (3-dicarbo-nylic system with conjugated double bonds (dienes) (Araujo et al., 1998, 1999). The better skin penetration and lipophylicity is attributed to the presence of a diene ketone system. Calebin-A, a novel curcuminoid isolated from turmeric, protects neuronal cells from (3-amyloid insult. The hydroxy group at para-position of this compound is most critical for the expression of biological activity (Kim et al., 2001). 

Recently, curcuminoid synthase has been identified as being capable of forming the curcuminoids in turmeric (Maria et al., 2006). This activity required malonyl-CoA and phenylpropanoid pathway-derived hydroxycinnamoyl-CoA esters as substrates, suggesting that the corresponding protein was a polyketide synthase or an enzyme that was closely related. It is postulated that this activity could be the result of a single enzyme, or of multiple enzymes in sequence. 

Besides curcuminoids and oils, C. longa also contains some polysaccharides. Three acidic polysaccharides were isolated from turmeric ( Ukon ) by hot water extraction, followed by precipitation with ethanol, with remarkable activity on the reticuloendothelial system (RES) (Gonda et al., 1990). The components were purified on a column of DEAE Sephadex A-25 and named as Ukon A, Ukon B and Ukon C. 

Curcuminoids and other constituents of turmeric are well known for their antiinflammatory activity. Turmeric extract, volatile oils from turmeric and curcuminoids were reported to possess this property in different experimental models of inflammation in mice, rats, rabbits and pigeons (Arora et ah, 1971 Ghatak and Basu, 1972 Chandra and Gupta, 1972). Thus, curcuminoids are effective against carrageenan-induced oedema in rats (Srivastava et al.,... 

Kiuchi, F., Goto, Y., Sugimoto, N., Akao, N., Kondo, K. and Tsuda, Y. (1 993) Nematocidal activity of turmeric synergistic action of curcuminoids. Chemical and Pharmaceutical Bulletin 41, 1 640-1643. 

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