29 ブホトキシンおよび関連化合物の合成

概要

論文の詳細を見る
Early chemical studies of bufotoxin type toad venom constituents culminated in the bufotalin 14-suberoylarginine structure for bufotoxin (vulgarobufotoxin) in 1941. Structural evidence has been accumulating that both bufotoxin (5)and marinobufotoxin (23), which was recently isolated from the Brazilian toad Bufo icerticus Spix by Linde-Temple, are in fact the each 3-suberoylarginine esters of bufotalin (1) and marinobufagin (18). We now wish to report the portial synthesis of bufotoxin (vulgaro-bufotoxin) (5) from bufotalin (1) and also synthesis of marino-bufotoxin (23) from marinobufagin (18). This particular interconversion unequivocally supports the 3-suberoylarginine proposal for the so-called bufotoxin structure. In an analogous series of experimentals, bufalin (6) was converted into bufalin 3-suberoylarginate (bufalitoxin; 7), and also resibufogenin (8) was converted into resibufogenin 3-suberoylarginate (resibufotoxin; 9). The preceding experimental should provide a useful model for synthesis of related toad poison toxins. In addition, we wish to report conversion of the 14β-hydroxy-bufadienolides, telocinobufagin (10), bufotalin (24), and gamabufotalin (37) into the 14β,15β-epoxy-bufadienolides, marinobufagin (18), cinobufagin (30), and 11α-hydroxy-resibufogenin (45), respectively, employing the 14-dehydro compounds (12, 25, and 40) as relay, as shown in scheme 4, 5, and 6.
天然有機化合物討論会の論文
1972-10-01