Leaf-surface guaianolides from Amphoricarpos neumaeyri showing protective effect on human lymphocytes DNA

Analysis of composition of CH₂Cl₂ surface extract of leaves of Amphoricarpos neumayeri Vis. revealed 16 sesquiterpene lactones with guaianolide skeleton, so called amphoricarpolides, typical for this genus. Four of them, 13-16, were new derivatives and their structures were elucidated by detailed analyses of IR, NMR and MS data. Amphoricarpolide (9), its 15-O-acetyl derivative (5), and two 9β-hydroxyamphoricarpolides, 3,15-di-O-acetyl- and 3-O-acetyl-15-O-isovaleroyl derivatives (3 and 6, respectively) were tested for in vitro protective effect on chromosome aberrations in peripheral human lymphocytes using cytochalasin-B blocked micronucleus (CBMN) assay. The tested compound exerted a beneficial effect by decreasing DNA damage of human lymphocytes.