> 50 0.2 0.39 0.39 1.56 1.56 in SABOURAUD glucose agar medium* 28 C 2 days.** 28 C 7 days. the spectrum lacks fine structure. The NMR spectrum of trichostatin B, unexpectedly, does not show any proton signals. Therefore, it was assumed that trichostatin B should include a paramagnetic metal presumably an iron atom, in its molecule. This fact in combination with the acidic nature of trichostatin A led to the assumption that trichostatin should have a hydroxamic acid function. As expected, the treatment of trichostatin A with ferric chloride in chloroform solution gave a red solution and the IR spectrum of the product was identical with that of trichostatin