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

Analysis of composition of CHCl surface extract of leaves of Vis. revealed 16 sesquiterpene lactones with guaianolide skeleton, so called amphoricarpolides, typical for this genus. Four of them, -, were new derivatives and their structures were elucidated by detailed analyses of IR, NMR and MS data. Amphoricarpolide (), its 15--acetyl derivative (), and two 9-hydroxyamphoricarpolides, 3,15-di--acetyl- and 3--acetyl-15--isovaleroyl derivatives ( and , respectively) were tested for 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.