Two fatty acids, (2E,4Z)-decadienoic acid and (2E,4Z,7Z) -decatrienoic acid
, the latter being described for the first time as a natural product, were
detected in the culture filtrate of Streptomyces viridochromogenes Tu 6105
by HPLC-diode array screening, purified by chromatographic methods and stru
cturally elucidated by NMR techniques. Both metabolites show strong herbici
dal activity against Lemna minor and Lepidium sativum. The herbicidal activ
ities of the isolated compounds were compared with those of similar fatty a
cids and derivatives. (C) 1999 Society of Chemical Industry.