the chemical shifts and relaxation enhancements induced by the addition of paramagnetic ions to the aqueous phase indicate that the surface cholesterol molecules in hdl ( 2 ) , and hdl ( 3 ) are exposed to the water and that the 4- ( 13 ) c atom of cholesterol is located in the region of the phospholipid acylcarboxyl groups .
C0023822
cholesterol
C0008377
cholesterol