In the course of our screening program for new bioactive substances from microorganisms using the advanced compound-identification system designated as 'MBJ's special selection,1,2 with which we have selected over 50 strain culture samples and consequently have succeeded in discovering new cytotoxic eremophilane derivatives MBJ-0009, MBJ-0010 and MBJ-0011, MBJ-0012 and MBJ-0013 from Nectria sp. f261113 and Apiognomonia sp. f24023,1 respectively, and new chaetoglobosin derivatives MBJ-0038, MBJ-0039 and MBJ-0040 from Chaetomium sp. f24230.2 Further screening resulted in the isolation of a new hydroxamate metabolite, designated as MBJ-0003 (1, Figure 1a), from the culture of Micromonospora sp. 29867. In this paper, we described the fermentation, isolation, structure elucidation and brief biological activities of 1.