Bioactive Compounds in Turmeric

Abstract

Turmeric (Curcuma longa L.) is a well-known spice, colouring matter and preservative, which has enormous applications in the field of medicines and pharmacology that exhibits antioxidant, anti-bacterial, anticarcinogenic, anti-HIV, anti-inflammatory, antiparasitic, antispasmodic and nematocidal activities. Chemical constituents of various tissues of turmeric include at least 235 compounds which are identified as primarily phenolic compounds and terpenoids. They comprise of 22 diarylheptanoids and diarylpentanoids; 8 phenylpropene and other phenolic compounds; 68 monoterpenes, 5 diterpenes, 3 triterpenoids 109 sesquiterpenes; 2 alkaloids, 4 sterols and 14 other compounds. Curcuminoids (diarylheptanoids) and essential oils, primarily accumulated in rhizomes are the major bioactive ingredients. Essential oils derived from the leaves and flowers are dominated by monoterpenes while from the roots and rhizomes primarily contain sesquiterpenes. The curcuminoid contents and essential oils in turmeric rhizomes often show variations with sources, geographical locations, varieties, cultivation conditions and different extraction methods. Superoxide anion scavenging activity is more in pure curcumin as compared to demethoxycurcumin or bisdemethoxycurcumin. Curcumin is a potent bioprotectant, can act as a pro-oxidant in the presence of transition metal ions (Cu and Fe) and has a potentially wide range of therapeutic applications. Curcumin, demethoxycurcumin and bisdemethoxycurcumin are used as marker compounds for the quality control of rhizomes, powders and extracted (curcumin) products. On the other hand Ar-turmerone, α-turmerone and β-turmerone are used to control the product quality of oleoresin and oil of turmeric. Evaluation of turmeric produce for their characterization aspect and bioactive performance can be governed through lists of available chromatographic, NMR and DNA marker techniques.