Studies on toad venom (2): Examination of the drying processing method.

Abstract

To examine the influence on the quality of toad venom processed by different drying methods, each 10 g sample of fresh toad venom collected in Shang-Dong Province, China, were dried, (1) in the sun for 133 h, (2) in the shade for 224 h, (3) heated at 60 degrees C for 33 h, (4) heated at 105 degrees C for 4 h, (5) freeze-dried for 6 h. Twelve bufadienolides, including bufalin and bufotalin, in each sample were then quantitatively analyzed by HPLC. The total contents of bufadienolides in 1000 mg of the dried samples were as follows: 235.39 mg for dehydrolyzed fresh toad venom, 94.39 mg for (1), 148.46 mg for (2), 59.22 mg for (3), 133.40 mg for (4), and 184.77 mg for (5), respectively. The color of dried venom became darker in the order of (5), (2), (1), (3) and (4). Though the color of (4) should be the worst as a standard quality evaluation in Shang-Dong Province, as far as bufadienolides was concerned, (4) was superior to (1) in the contents and was almost same to (2). These results suggest that it is possible to dry toad venom by heating at high temperature for several hours. This will remarkably shorten the term for making high quality toad venom, in comparison to the traditional processing method in China that needed more than two years for drying venom.