| Bryophytes,considered being the first plant type to successfully make the transition from water to land,are taxonomically placed between the algae and the pteridophytes.Morphologically,they are divided into three classes,liverworts(Hepaticae),mosses(Musci)and hornworts(Anthocerotae).Among the bryophytes,liverworts are a rich source of terpenoids and aromatic compounds with intriguing biological activities such as cytotoxic,antifungal,allelopathic,insect antifeedant,andantioxidant properties,which might because they possess appealing,characteristic cell organelles:cellular oil bodies.In the second chapter of this paper,we introduced the extraction and antifungal activity of Tritomaria quinquedentata(Huds.)Buch..We isolated nineteen sesquiterpenes from Chinese liverwort T.quinquedentata,including five new compounds.Among them,five eudesmane sesquiterpenes were ineffective against Candida albicans wild strain SC5314 but active towards efflux pumps-deficient strain DSY654 using Alamar blue assay.Further test of the most active agent of ent-isoalantolactone(8,ent-iLL)showed that it also inhibited the yeast-to-hyphal switch of DSY654 cells.The intracellular content measurement using high performance liquid chromatography revealed that ent-iLL was intracellularly accumulated in C.albicans when efflux pumps were deficient or inhibited by Cdrs inhibitor riccardin D,suggesting that the activity of ent-iLL was compromised by efflux pumps Cdrs.ent-iLL.Moreover,ent-iLL potentially inhibited the activity of Erg11 and Erg6 of DSY654 and thereby resulted in the alteration of sterol composition by decreasing ergosterol contents and increasing zymosterol and lanosterol accumulation.Our study demonstrated that eudesmane sesquiterpenes,as the substrates of Cdrs,could interfere with sterol synthesis of C.albicans to exert antifungal activity when co-applied with Cdrs inhibitors.In the third chapter of this paper,we introduced the extraction and anti-inflammatory activity of Lepidozia reptans(L.)Dumort..Five new terpenoids including two dollabellane-type,one ent-kaurane-type diterpenoids and two sesquiterpenoids were isolated from the Chinese liverwort L.reptans,together with fifteen known terpenoids.Their structures were determined on the basis of analysis of MS and NMR spectroscopic data,single-crystal X-ray diffraction and electronic circular dichroism calculations.The selected compounds were screened for anti-inflammatory activities by the model of LPS-induced nitric oxide(NO)production with macrophage cells,and the mechanisms of the active dollabellane-type compounds were further explored. |
