... Chem., 2009, 7, 4763-4776 Show Compounds Show Chemical Terms Show Biomedical Terms. ... 22 The methylene group precludes any enzymatic cleavage due to the extreme stability of P–C bonds ... 23 The analogs obtained, m 7 GpCH 2 ppG, m 2 7,3′-O GppCH 2 pG, and m 2 ...