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

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