Sugar-aglycon interactions

J. M. Berry, L. D. Hall, D. G. Welder, and K. F. Wong, Proton spin lattice relaxation A new quantitative measure of aglycon sugar interactions, in W. A. Szarek and D. Horton, (Eds.), Anomeric Effect, Origin and Consequences, No. 87, American Chemical Society, Washington, DC, 1979, pp. 30-49, (Chapter 3). 

Proton Spin-Lattice Relaxation A New, Quantitative ( ) Measure of Aglycon-Sugar Interactions (1)... 

Saponins consist of a terpenoid core (the aglycone), having oxygenated positions bound to sugar moieties (up to ten monosaccharidic units). In water they form colloidal solutions which foam on shaking and precipitate cholesterol. When saponins are near cell membranes, their interaction with cholesterol may create pore-like structures that eventually cause the membrane to burst. Hemolysis is an example of this phenomenon (i.e. the distraction of erythocyte membranes, but not hemoglobin). Occasionally, they cause hypersecretion, which could explain their expectorant activities and also their toxicity to fish. 

A summary is given of the potential of proton spin-lattice relaxation rates as a measure of the steric interactions between the protons of a sugar and those of an aglycon. Particular emphasis is given to the use of specific deuteration as a direct method for quantifying inter-proton relaxation contributions. 

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