Moreover, other bioactive anthraquinone dimers including alterporriols B-E (113-116), N The same study demonstrated that alterporriol Q (118) and R (119) showed no antimicrobial activity against various tested microbes up to a concentration of 10.0 μM . This finding was confirmed in another study which showed that both compounds did not display any antibacterial activity against different Gram-positive as well as E. coli from the Gram-negative bacteria up to a concentration of 20.0 μM . However, alterporriol Q (118) exhibited strong antiviral activity against the porcine reproductive and respiratory syndrome virus (PRRSV)