Three chlamydocin analogues that show activity for reducing the height of rice seedlings without blotch and wilting were isolated from the culture filtrate of the soil fungus Peniophora sp. and were characterized by spectral data and chemical conversion. For two of these, it is their first isolation as natural products. The proposed role of the functional groups of the 2-amino-8-oxodecanoic acid moiety of these analogues is discussed in terms of growth retardant activity.