Isolation, Physicochemical Properties and Toxicities of Territrem A' and B'

We have isolated two new metabolites of territrem, designated as territrem $A'\;(TRA';\;C_{28}H_{30}O_{10})$ and $B'\;(TRB';\; C_{29}H_{34}O_{10})$ from chloroform extract of rice culture of Aspergillus terreus 23-1, using the same isolation procedure as that for territrem A, B and C(TRA, TRB, TRC). The present isolation procedure gave about 5 mg of TRA' and 10 mg of TRB' from 4 kg of rice culture per batch. Analysis of the high resolution mass spectrum showed that the molecular composition of TRA' and TRB' are $C_{28}H_{30}O_{10}$ and $C_{29}H_{34}O_{10}$ respectively, Some results of physicochemical properties were presented in this paper. Single crystal X-ray diffractometry of TRB' showed that the three dimensional structure of TRB' has not changed significantly from that of $TRB\;(C_{29}H_{34}O_9)$, except for the insertion of one oxygen atom into TRB to make additional pyran in the E-ring. It is also suggested that the aromatic moiety of TRA' is similar to that of $TRA\;(C_{28}H_{30}O_9)$ and the rest non-aromatic portions resemble to those of TRB'. The tremorgenic activity, lethality and inhibitory effect on acetylcholine esterase of TRA' and TRB' are greatly reduced comparing to that of TRA and TRB.