A colourless crystalline compound (m. p. 200-205`C) isolated from Streptomyces-ahygroscopicus was identified as gougerotin by mass-spectrometric analysis. In order to study the effect of anode temperature, FD spectra of gougerotin were also measured at 15, 17 and 19 mA wire current on a Varian MAT-731 spectrometer. The 15-and 17-mA spectra exhibit the (M + H)+ as base peak. At 19 mA, fragment ions which were characteristic to the structure of gougerotin were observed at m/z 69, 88, 111, 113, 157, 269, 312 and 426.

Key words: FIELD IONIZATION MASS SPECTROMETRY, GOUGEROTIN