Glu300 and Ade300-400 were prepared by loading 1 g of D-glucose or 2 g of adenine into an alumina crucible or a quartz glass boat with a lid and heating at different temperatures between 300 and 400 o C in a tube furnace with a heating rate of 3 K•min -1 . A gentle stream of N2 (0.1 L min -1 ) was ensured during the reaction. The hold-time was 2h. The reaction products were retained and grinded in a ball mill (diameter of ball: 1cm) for 1h with a speed of 600 rpm to obtain finely powdered products Glu300 or Ade300-380 (Figure ).