Isolation of 4-chlorocinnamic acid from <i>Streptomyces griseocarneus</i> R132, and its inhibition activity against sweet pepper postharvest anthracnose

<i>Streptomyces griseocarneus</i> R132 is an actinobacterium capable of controlling fungi in sweet peppers. The crude <i>S. griseocarneus</i> R132 methanol extract was fractionated in a polystyrene-divinylbenzene column eluted with 20–100% acetone gradient. Compound <b>1</b> isolated from the 60% fraction was identified as 4-chlorocinnamic acid. This fraction and 4-chlorocinnamic acid inhibited <i>Colletotrichum gloeosporioides</i> growth by 28% and 65%, respectively, and reduced the diameter of lesions caused by the phytopathogen in <i>Capsicum annuum</i> L. fruits by 33.19% and 31.92%, respectively. The isolated 4-chlorocinnamic acid was not toxic to MRC-5 fibroblasts.