Flavonoids of the liverwort Marchantia polymorpha

The major flavonoids of Marchantia polymorpha var. polymorpha and aquatica are the 7-O-β-d-glucuronides of apigenin and luteolin, luteolin 3′-O-β-d-glucuronide, luteolin 7,3′-di-O-β-d-glucuronide, and the 7,4′-di-O-β-d-glucuronides of apigenin and luteolin. These are accompanied by minor amounts of apigenin, luteolin, luteolin 3′,4′-di-O-β-d-glucuronide and luteolin 7,3′,4′-tri-O-β-d-glucuronide. All the luteolin di- and triglucuronides except the 3′,4′-di- substituted compound are new natural products.     

Enantiomeric type sesquiterpenoids of the liverwort Marchantia polymorpha

A series of ent-sesquiterpenoids corresponding to the optical antipodes of those in higher plants have been isolated from the liverwort Marchantia polymorpha. These sesquiterpenoids provide yet another example of the peculiar stereospecificity of the biogenesis of the liverwort sesquiterpenoids and suggest a special taxonomic position of the liverworts in the plant kingdom.     

Flavonoids of the liverwort Marchantia foliacea

The major flavonoids of Marchantia follacea are the 7-O-β-d-glucuronides of apigenin, chrysoeriol and tricin, and apigenin-6,8-di-C-glucoside (vicenin-2). Minor constituents include the rhamnosylglucuronides of the above flavones. Apparent isomerization of the glucuronides on hydrolysis (MeOH-HCl) proved to be due to methylation of the sugar carboxyl group.     

Lunularic acid in cell suspension cultures of Marchantia polymorpha

Lunularic acid (LNA) was isolated from the cultured cells of the liverwort Marchantia polymorpha. Quantitative analysis by reverse phase HPLC showed that the content of LNA in the cells changed markedly during their growth, ranging from 1 to 7μg/mg dry wt. The accumulation of LNA was greatly enhanced by a deficiency of phosphate in the culture medium.     

Sesquiterpene hydrocarbons of the liverwort Scapania ornithopodioides

The liverwort, Scapania ornithopodioides, was investigated for sesquiterpene hydrocarbons by utilizing GC and GCIMS and 17 components were identified. Among these, the major component, aromadendrene, and two minor ones, cyclosativene and α-farnesene are reported for the first time as constituents of liverworts. In addition, aromadendrene also occurred in three other Taiwanese liverworts examined.     

Flavonoids of the primitive liverwort Takakia and their taxonomic and phylogenetic significance

The flavonoid chemistry of Takakia is described for the first time. T. lepidozioides, thought to be amongst the most primitive of extant liverworts, contains a high level and wide variety of flavone C- and O-glycosides, many of which are unique. New flavonoids include the 8-O-glucuronide and 8-O-xylosylglucoside of takakin (8-hydroxyacacetin), luteolin 6-C-arabinoside-8-C-pentoside, kaempferol 3-O-glucoside-7-O-xyloside and a number of tricetin C-glycosides. The only other known Takakia species, T. ceratophylla, contains the same 4 major constituents but significantly lacks flavonols. The often suggested relationship of Takakia with the order Calobryales is not supported by the available flavonoid data. Biochemical affinities of Takakia with all major liverwort orders are noted and the flavonoid data are interpreted as supporting the concept of Takakia as an isolated branch among the ancestors of modern bryophytes.     

Chirality of terpenoids isolated from the liverwort Conocephalum conicum

Reinvestigation of a Japanese sample of the thalloid liverwort Conocephalum conicum afforded (+)-bornyl ferulate and bornyl 2 - methoxy - 4 - hydroxycinnamate together with (?) - limonene, (?) - β - sabinene, (+) - bicycloelemene, (+) - β - elemene, (?) - bicyclogermacrene, lunularin, and the two compounds, 1 - octen - 3 - ol and 1 - octen - 3 - yl acetate, responsible for the mushroom-like odour of the crushed thallus. The chirality of the compounds isolated is discussed.     

Sesquiterpenoids from the liverwort Lophozia ventricosa

Two sesquiterpenoids, previously reported as ventricosins A and B, from Lophozia ventricosa have been identified as ent-4(15),7(11)-eudesmadien-8-one and ent-maalioxide, respectively.     

Biochemical and structural characterization of an endoplasmic reticulum-localized late embryogenesis abundant (LEA) protein from the liverwort Marchantia polymorpha

Late embryogenesis abundant (LEA) proteins, which accumulate to high levels in seeds during late maturation, are associated with desiccation tolerance. A member of the LEA protein family was found in cultured cells of the liverwort Marchantia polymorpha; preculture treatment of these cells with 0.5 M sucrose medium led to their acquisition of desiccation tolerance. We characterized this preculture-induced LEA protein, designated as MpLEA1. MpLEA1 is predominantly hydrophilic with a few hydrophobic residues that may represent its putative signal peptide. The protein also contains a putative endoplasmic reticulum (ER) retention sequence, HEEL, at the C-terminus. Microscopic observations indicated that GFP-fused MpLEA1 was mainly localized in the ER. The recombinant protein MpLEA1 is intrinsically disordered in solution. On drying, MpLEA1 shifted predominantly toward α-helices from random coils. Such changes in conformation are a typical feature of the group 3 LEA proteins. Recombinant MpLEA1 prevented the aggregation of α-casein during desiccation–rehydration events, suggesting that MpLEA1 exerts anti-aggregation activity against desiccation-sensitive proteins by functioning as a “molecular shield”. Moreover, the anti-aggregation activity of MpLEA1 was ten times greater than that of BSA or insect LEA proteins, which are known to prevent aggregation on drying. Here, we show that an ER-localized LEA protein, MpLEA1, possesses biochemical and structural features specific to group 3 LEA proteins.     

Three verrucosane diterpenoids,verrucosane triol and related compounds from the liverwort Mylia verrucosa

Three new diterpenoids of the verrucosane class were isolated as minor constituents of the methanol extract of the liverwort Mylia verrucosa and their structures shown to be 2β,9α,13β-trihydroxyverrucosane,9α-acetoxy-2β,13β-dihydroxyverrucosane and 2β,13β-dihydroxy-9-oxoverrucosane.     

Lignan derivatives from the liverwort Bazzania trilobata

Eight lignan derivatives trilobatin D-K, as well as jamesopyrone were isolated from the liverwort Bazzania trilobata. Their structures have been elucidated based on extensive NMR spectral evidence.     

Neurotrophic secoaromadendrane-type sesquiterpenes from the liverwort Plagiochila fruticosa

A new sesquiterpene dialdehyde, plagiochilal B, isolated from the liverwort Plagiochila fruticosa exhibits not only acceleration of neurite sprouting but also enhancement of choline acetyltransferase activity on a neuronal cell culture of fetal rat cerebral hemisphere at 10⁻⁵ M. Additionally, two new secoaromadendranes, plagiochilines J and K were isolated. The structures of the new secoaromadendrane-type sesquiterpenes were established by extensive 2D NMR data and chemical correlation with plagiochiline A.     

Sesquiterpenoid lactones from the liverwort Frullania tamarisci

Four isomeric sesquiterpenoid lactones have been isolated from the liverwort Frullania tamarisci They have been identified as the simple eudesmanolides (I–III) and costunolide (IV).     

Sacculatane diterpenoids from axenic cultures of the liverwort Fossombronia wondraczekii

Five new sacculatane diterpenoids, 17,18-epoxy-7-sacculaten-12,11-olide, 7,17-sacculatadien-11,12-olide, 11beta,12-epoxy-7,17-sacculatadien-11alpha-ol, 1beta-acetoxy-11beta,12-epoxy-7,17-sacculatadien-11alpha-ol and 1beta,15xi-diacetoxy-11,12-epoxy-8(12),9(11),17-sacculatatriene along with sacculatal and sacculatanolide have been isolated from axenic cultures of the liverwort Fossombronia wondraczekii and their structures assigned on the basis of their spectroscopical properties.     

Sesquiterpenoids of Riccardia and Pallavicinia species

Riccardia species (Metzgeriales) contain various types of sesquiterpenes. R. jackii produces ent-selinane-, ent-aromadendrane-and ent-bicyclogermacrane-type sesquiterpenes together with (R)-cuparene and α-barbatene. Aneura pinguis (= Riccardia pinguis) is chemically quite different from R. multifida and R. jackii. The former produces a large amount of pinguisone. R. multifida contains 6-(3-methyl-2-butenyl)-indole and (+)-β-elemene as the major components. Pallavicinia longispina (Dilaenaceae; Metzgeriales) produces mainly spathulenol. The chiral properties of the sesquiterpenes isolated from R. jackii are quite similar to those of red algae, Laurencia species.     

Secondary metabolites from the liverwort Tylimanthus renifolius

Two new herbertane sesquiterpenoids, (-)-herbertene-1,12-diol and (-)-gamma-herbertenol, a new aromadendrane, 9-acetoxy-10-hydroxyaromadendrane, a new rosane diterpenoid, 5,15-rosadiene-3,11-dione and a new phytane, 2Z-phytene-1,15,20-triol, along with the known (-)-alpha-herbertenol have been isolated from the liverwort Tylimanthus renifolius. Several flavones and flavanones with an unsubstituted ring B were also identified. This is the first report of this class of flavonoids from the Hepaticae. All structures were elucidated by NMR spectroscopy.