Table 1.

Composition of turmeric extract based on the analysis of nine batches from three different companies. The results are expressed as % (w/w)

Constituent	Chemical formula	Molecular weight	CAS No	Meana	Range
				% (w/w)	% (w/w)
Curcumin (I)	C21H20O6	368.39	458‐37‐7	77.02	74.84–78.76
Desmethoxycurcumin (II)	C20H18O5	338.39	33171‐16‐3	16.34	15.3–18.46
Bis‐desmethoxycurcumin (III)	C19H16O4	308.39	33171‐05‐0	3.62	2.18–4.58
Total curcuminoids				96.68	94.88–97.68

CAS No: Chemical Abstracts Service number.

^aMean calculated on nine batches.