Nutrient Requirements and Functions Laboratory, Beltsville Human Nutrition Research Center, USDA, ARS, Bldg 307C, Rm 223, Beltsville, Maryland 20705-2350, Nuclear Magnetic Resonance Laboratory, ARS, USDA, Beltsville, Maryland 20705-2350, Food Composition Laboratory, Beltsville Human Nutrition Research Center, USDA, ARS, Beltsville, Maryland 207 05-2350, and Department of Molecular Cellular and Development Biology, University of California, Santa Barbara, California 93106-9610

Richard A. Anderson C. Leigh Broadhurst Marilyn M. Polansky Walter F. Schmidt Alam Khan Vincent P. Flangagan Norberta W. Schoene Donald J. Graves

The causes and control of type 2 diabetes mellitus are not clear, but there is strong evidence that dietary factors are involved in its regulation and prevention. We have shown that extracts from cinnamon enhance the activity of insulin. The objective of this study was to isolate and characterize insulin-enhancing complexes from cinnamon that may be involved in the alleviation or possible prevention and control of glucose intolerance and diabetes. Water-soluble polyphenol polymers from cinnamon that increase insulin-dependent in vitro glucose metabolism roughly 20-fold and display antioxidant activity were isolated and characterized by nuclear magnetic resonance and mass spectroscopy. The polymers were composed of monomeric units with a molecular mass of 288. Two trimers with molecular mass of 864 and a tetramer with a mass of 1152 were isolated. Their protonated molecular masses indicated that they are A type doubly linked procyanidin oligomers of the catechins and/or epicatechins. These polypenolic polymers found in cinnamon may function as antioxidants, potentiate insulin action, and may be beneficial in the control of glucose intolerance and diabetes.

	Keywords: Glucose; Insulin; diabetes; cinnamon; polyphenols; spice

Source: J. Agric. Food Chem. 2004, 52, 65-70