Chemical Constituents of Two Liverworts <i>Metacalypogeia Alternifolia</i> and <i>Chandonanthus Hirtellus</i>

Abstract

Abstract A novel linear dihydrodichromene derivative, metacalypogin, was identified from the Taiwanese liverwort Metacalypogeia alternifolia . Together with data from M. cordifolia , the chemical marker of the genus Metacalypogeia is obvious chroman derivatives, which is far different from that of Calypogeia , the other genus in the same family. In addition, two isomeric diterpenoids of cembrane‐type were identified from the Chinese liverwort Chandonanthus hirtellus . The relative stereostructures of the latter two isomers were proved by X‐ray crystallography. Both compounds were unstable in chloroform solution and further oxidized to the corresponding peroxy hemiacetal derivatives.