Hydroquinone derivatives and monoterpenoids from the Neotropical liverwort Plagiochila rutilans

A New Ionone Glucoside and Terpenoid Constituents from Achillea biebersteinii and their Antifungal Activity

A new ionone glucoside, (-)(4R*, 5R*)-5-(β-D-glucopyranosyloxymethyl)-4-hydroxy-3,5-dimethyl-4-((E)-3-oxobut-1-enyl)cyclohex-2-enone (biebersteiniside) (1), in addition to four known compounds, 6-epiroseoside (2), ascaridole (3), strictic acid (4) and centipedic acid (5) have been isolated from the aerial parts of Achillea biebersteinii Afan. The structures were determined from extensive 500 MHz NMR 1D (1H and 13C NMR) and 2D (1H-1H COSY, HMQC, HMBC and NOESY) spectroscopic data. Compounds 2–5 are reported for the first time from this plant. In addition, compounds 1a and 3–5 showed antifungal activity.

Total synthesis of 3,7-dimethyl-7-hydroxy-2-octen-1,6-olide and 3,7-dimethyl-2,6-octadien-1,6-olide

3,7-Dimethyl-7-hydroxy-2-octen-1,6-olide and 3,7-dimethyl-2,6-octadien-1,6-olide, the natural bioactive compounds isolated from the fruit of Litsea cubeba and the liverwort Plagiochila rutilans, were totally synthesized using easily available cis-geraniol as raw material in short, convenient, and low-cost, five-step reactions including three steps of oxidation, cyclization, and dehydration, with an overall yield of 47.5% and 37.3%.

Bioactive polychlorinated bibenzyls from the liverwort Riccardia polyclada

GC-MS and (1)H NMR spectroscopic profiling of a CDCl 3 extract of the liverwort Riccardia polyclada (syn. R. umbrosa) revealed the presence of four main compounds bearing several chlorine atoms on a bibenzyl skeleton. Separation of a CH 2Cl 2 extract was achieved using preparative TLC, and structures 1- 4 were proposed on the basis of spectroscopic evidence. Compounds 1- 4 were active in a brine shrimp lethality bioassay ( Artemia salina). In addition, 2 and 4 displayed moderate antifeedant activity in disk-choice bioassays with Spodoptera littoralis larvae and inhibited the growth of Cladosporium herbarum cultures on TLC plates.

Sesquiterpene constituents from the essential oil of the liverwort Plagiochila asplenioides

The essential oil of the liverwort Plagiochila asplenioides from two different locations in Northern Germany were investigated by chromatographic and spectroscopic methods. Seven compounds were isolated by preparative gas chromatography (GC) and their structures investigated by mass spectrometry (MS), NMR techniques and chemical correlations in combination with enantioselective GC. In addition to known constituents, aromadendra-1(10),3-diene, two aromatic sesquiterpene hydrocarbons, bisabola-1,3,5,7(14)-tetraene and bisabola-1,3,5,7-tetraene, three sesquiterpene ethers, muurolan-4,7-peroxide, plagiochilines W and X, in addition to ent-4-epi-maaliol, could be identified as natural compounds for the first time.

Chemosystematics of the hepaticae

Most liverworts (Hepaticae) contain oil bodies which are composed of lipophilic terpenoids and aromatic compounds. The chemosystematics of 36 families of the Jungermannidae and seven families of the Marchantiidae of the Hepaticae are discussed using terpenoid and aromatic components.