The structures of two novel triterpenes, adiantutirucallene B and adiantula
nostene, isolated from the aerial parts of Adiantum venustum, have been est
ablished as tirucall-8, 22-cyclic-24(25)-ene and 13, 14-seco-8,22-cyclic-la
nost-5(6), 24(25)-diene, respectively on the basis of spectral analyses and
chemical reactions.