Antioxidant and antibacterial effects of a new macrocyclic bis(bibenzyl) ether from (Combretaceae).

A new compound, combrebisbibenzyl () as well as two sterols including stigmasterol () and 3---D-glucopyranoside of -sitosterol () and seven triterpenoids namely mollic acid (), oleanolic acid (), ursolic acid (), arjunglucoside I (, arjungenin (), bellericagenin B () and combregenin () were isolated from the root of . Compounds , and AcOEt and MeOH extracts exhibited moderate antioxidant activity with an IC value of 179.32, 185.21, 195.11 197.41 and 170.21 μg/mL, respectively, for reactive oxygen species inhibition and, inhibition percent value of 57.23, 64.52, 53.55, 67.42 and 65.04, respectively, for DPPH free-radical scavenging. The presented a moderate antibacterial activity against with DIZs value of 10.1 ± 0.2 from 800 μg/mL while the others tested strains were not sensitive. However, most of the tested bacteria, (, and ) were moderately sensitive to from 800 μg/mL with DIZs value of 8.2 ± 0.1. From the E. AcOEt, five of the isolated compounds were tested against four bacteria strains using the disc-dilusion method. The results showed that compound and exhibited very good antibacterial activity against all the tested bacteria at the concentration of 30 μg/mL with respective DIZ value of 22.2 and 25.4 for , 20.2 and 30.2 for , 22.3 and 23.1 for and, 22.1 and 24.1 for . This antibacterial activity significantly depends on the concentration.