Anticomplement compounds from Polygonum chinense

Abstract Five new compounds including two phenyldilactones ( 1 , 2 ), two coumarins ( 3 , 4 ) and a dimer of N-E -feruloyl tyramine ( 5 ) together with twenty-three known compounds ( 6 – 28 ) were isolated from a medicinal plant Polygonum chinense. The structures of the new compounds were established by detailed spectral analysis. The absolute configurations of 1 and 5 were elucidated by Mosher’s method, Mo 2 (OAc) 4 -induced electronic circular dichroism (ECD) data, and ECD calculation. All the compounds were found to show potent anticomplement activity with CH 50 and AP 50 values ranging from 0.18 to 1.45 mM, and 0.26 to 2.80 mM, respectively. Phenyldilactones and phenylpropionic tyramines were firstly reported as anticomplement agents. The targets of compounds 1 , 3 , 5 and 10 in complement activation cascade were identified as well.