Novel neurotrophic isocuparane-type sesquiterpene dimers, mastigophorenes A, B, C and D, isolated from the liverwort Mastigophora diclados

Abstract

Four dimeric isocuparane-type sesquiterpenes, mastigophorenes A, B, C and D, isolated together with a new 3,4-dihydroxylated isocuparene from the liverwort Mastigophora diclados, have been assigned structures on the basis of detailed spectroscopic analyses. Among them, mastigophorenes A, B and D have been found to accelerate neuritic sprouting at 10^–5–10^–7 mol dm^–3 in a neuritic cell culture of foetal rat cerebral hemisphere; their biosynthesis, initiated by phenolic oxidation of (–)-herbertenediol, is proposed.