Streptomyces saganonensis No. 4075 used for production of herbicidins A and B has also produced other two antibiotics, herbicidins C and E in submerged culture. Isolation of the antibiotics was performed by adsorption on resinous adsorbent followed by elution with aqueous MeOH and completed by silica-gel chromatography. Physico-chemical characteriation revealed that herbicidins C and E are new nucleoside antibiotics having an adenine moiety in their structures. Herbicidins C and E indicated inhibitory activity against germination of chinese cabbage at 12.5 micrograms/ml and 25 micrograms/ml, respectively, and Anacystis nidulans, a blue green algae, at 100 approximately 200 micrograms/ml.