A curcuminoid is a linear diarylheptanoid, a relatively small class of plant secondary metabolites that includes curcumin, demethoxycurcumin, and bisdemethoxycurcumin, all isolated from turmeric ( curcuma longa). These compounds are

natural phenol In biochemistry, naturally occurring phenols are natural products containing at least one phenol functional group. Phenolic compounds are produced by plants and microorganisms. Organisms sometimes synthesize phenolic compounds in response to eco ...

s and produce a pronounced yellow color that is often used to color foods and medicines. Curcumin is obtained from the root of turmeric. Curcuminoids are soluble in

dimethyl sulfoxide Dimethyl sulfoxide (DMSO) is an organosulfur compound with the formula ( CH3)2. This colorless liquid is the sulfoxide most widely used commercially. It is an important polar aprotic solvent that dissolves both polar and nonpolar compounds a ...

(DMSO), acetone and ethanol, but are poorly soluble in lipids. It is possible to increase curcuminoid solubility in aqueous phase with

surfactant Surfactants are chemical compounds that decrease the surface tension between two liquids, between a gas and a liquid, or interfacial tension between a liquid and a solid. Surfactants may act as detergents, wetting agents, emulsifiers, foaming ...

s or co-surfactants. Most common derivatives have different

substituent A substituent is one or a group of atoms that replaces (one or more) atoms, thereby becoming a moiety in the resultant (new) molecule. (In organic chemistry and biochemistry, the terms ''substituent'' and ''functional group'', as well as ''side ...

s on the

phenyl group In organic chemistry, the phenyl group, or phenyl ring, is a cyclic group of atoms with the formula C6 H5, and is often represented by the symbol Ph. Phenyl group is closely related to benzene and can be viewed as a benzene ring, minus a hydrogen ...

s. There is an increasing demand for demethoxycurcumin, bisdemethoxycurcumin, and other curcuminoids because of their

biological activity In pharmacology, biological activity or pharmacological activity describes the beneficial or adverse effects of a drug on living matter. When a drug is a complex chemical mixture, this activity is exerted by the substance's active ingredient or ...

Cyclodextrins

Curcuminoids form a more stable complex with solutions which contain cyclodextrin towards hydrolytic degradations. The stability differs between size and characterization of the cyclodextrins that are used. Dissolution of demethoxycurcumin, bisdemethoxycurcumin and curcumin are greatest in the hydroxypropyl-γ-cyclodextrin (HPγCD) cavity. The curcuminoids which have a

connected to the phenyl groups show more affinity for the HPγCD compound. Degradation rate is depended on pH of the solution and how much protection the cyclodextrins provide the curcuminoids. The derivatives are usually more stable than curcumin against hydrolysis in cyclodextrin solution. No

covalent bond A covalent bond is a chemical bond that involves the sharing of electrons to form electron pairs between atoms. These electron pairs are known as shared pairs or bonding pairs. The stable balance of attractive and repulsive forces between atoms ...

s are present between the cyclodextrins and the curcuminoids so they are easily released from the complex by simple solvent effects.

Composition and production

The curcumin derivatives demethoxycurcumin and bisdemethoxycurcumin may have

antioxidant Antioxidants are compounds that inhibit oxidation, a chemical reaction that can produce free radicals. This can lead to polymerization and other chain reactions. They are frequently added to industrial products, such as fuels and lubricant ...

activities useful in maintaining shelf-life of food products. Pure chemicals of curcumin and its derivatives are not available in the open market. Commercially available curcumin contains 77% curcumin, 17% demethoxycurcumin and 3% bisdemethoxycurcumin from the

herb In general use, herbs are a widely distributed and widespread group of plants, excluding vegetables and other plants consumed for macronutrients, with savory or aromatic properties that are used for flavoring and garnishing food, for medicinal ...

'' Curcuma longa''. Curcumin is mainly produced in industry as a pigment by using turmeric oleoresin as the starting material which curcuminoids can be isolated from. After the isolation of the curcuminoids, the

extract An extract is a substance made by extracting a part of a raw material, often by using a solvent such as ethanol, oil or water. Extracts may be sold as tinctures, absolutes or in powder form. The aromatic principles of many spices, nuts, h ...

which is about 75%

liquor Liquor (or a spirit) is an alcoholic drink produced by distillation of grains, fruits, vegetables, or sugar, that have already gone through alcoholic fermentation. Other terms for liquor include: spirit drink, distilled beverage or hard ...

mainly contains oil, resin and more curcuminoids which can be isolated further.

Research

Laboratory and clinical studies have not confirmed any medical use for curcumin, which is difficult to study because it is both unstable and poorly bioavailable, and is unlikely to produce useful lead compounds for drug development. Curcumin, which shows positive results in most

drug discovery In the fields of medicine, biotechnology and pharmacology, drug discovery is the process by which new candidate medications are discovered. Historically, drugs were discovered by identifying the active ingredient from traditional remedies or by ...

assays, is regarded as a false lead that medicinal chemists include among "

pan-assay interference compounds Pan-assay interference compounds (PAINS) are chemical compounds that often give false positive results in high-throughput screens. PAINS tend to react nonspecifically with numerous biological targets rather than specifically affecting one desired ...

". This attracts undue experimental attention while failing to advance as viable therapeutic or drug leads.
See also:

References

{{Curcuminoid Experimental medical treatments