Chemical Constituents And Biological Activities Of Three Liverworts

Bryophytes are the second largest group of plants except angiosperms.There are three classes of bryophytes,namely moss,hornwort and liverwort.It has been suggested that liverworts,considered to be the oldest terrestrial plants,are the earliest embryophyte taxa,and are the ancestors of all other land plants.As the first residents of terrestrial habitats,they were frequently exposed to adverse environmental conditions,such as microorganism attack,insect predation and competitions from other higher plants.In general,liverworts display a low morphological complexity,but have a high chemical diversity.Liverwort’s unique cellular microorgans,the oil bodies,store complex and diverse secondary metabolites,which play an important role in liverwort-environment interactions and also show a variety of biological activities such as the virulence activity to protozoa,bacteria,fungi and cells;insect antifeedant and plant growth regulation.Three liverwort plants were systematically studied in this paper,including Chandonanthus birmensis Steph.collected from Fujian Province,Calypogeia neesiana(mass.et car.)k.mull.and Bazzania ovistipula(Steph.)Mizut.collected from Sichuan Province.Traditional separation means such as column chromatography and high-performance liquid chromatography were used to separate and purify the crude extract.The structures of the pure compounds were identified by high-resolution mass spectrum(MS),infrared spectrum(IR)and ultraviolet spectrum(UV),nuclear magnetic resonance spectrum(NMR)and circular dichroism(CD).A total of 30 compounds were isolated and identified,including 5 new compounds.Then,the toxicity of the new compounds to fungi and tumor cells was tested.15 compounds including 4 novel compounds were isolated and identified form the Chinese liverwort Chandonanthus birmensis Steph.among which two new cembrane diterpenoids chandonanones J(2)and K(4)exhibit spontaneous transesterification in solution to achieve tautomerization.What’s more,the dolabellane diterpenoid 3,4-epoxydolabella7(E),18dien-2α-ol(1)shows the inhibition of C.albicans CDR1-and CDR2-efflux-pumpdeficient strain DSY654.5 known compounds were isolated and identified form the Chinese liverwort.10 compounds in total were isolated and identified form the Chinese liverwort Bazzania ovistipula(Steph.)Mizut.one of which was previously undiscovered and was a rare cuparanolide.