32 イモリのテトロドトキシン新誘導体について(口頭発表の部) 32 NEW TETRODOTOXIN ANALOGS IN NEWTS
The newt Cynops ensicauda collected in Okinawa, Japan, contained tetrodotoxin (TTX)(1) and its new analogs. Two analogs, compound A and B, were isolated by successive treatment of AcOH extracts on columns of charcoal, BioGel P-2, BioRex70, and Hitachigel 3011C gel. From 3.5kg of the newts 120mg of TTX, 18mg of compound A, and 30mg of compound B were obtained. High resolution FAB mass spectra taken on a JEOL JMS-DX-303HF indicated A to have the same molecular formula as TTX(C_<11>H_<17>O_8N_3) and B to be deoxyTTX (C_<11>H_<17>O_7N_3). ^1H NMR spectra of A showed a high field shift of 11-CH_2 suggested the CH_2OH at C-6 to be axial, 6-epiTTX(2) The axial configuration was further confirmed by NOE measurments. Configuration at C-9 was proved to be the same as TTX. Likewise B was assigned to 11-deoxyTTX(3), and its 11-CH_3 was suggested equatorial as same as TTX. Both 2 and I were in a tautomeric equilibrium between hemilactal (2a,3a) and lactone (2b,3b) forms that were confirmed by NOESY measurments which indicated the saturation transfer between two froms.
天然有機化合物討論会講演要旨集 29(0), 240-247, 1987