Novel prenyl bibenzyls from the New Zealand liverwort Marsupidium epiphytum

The ether extract of the New Zealand liverwort Marsupidium epiphytum gave four new prenyl bibenzyl derivatives, along with a known prenyl bibenzyl derivative which has been isolated from the Ecuadorian liverwort Lethocolea glossophylla; their structures were determined by 2D-NMR spectrum. The chemical constituents of Marsupidium epiphytum are highly characteristic since they elaborate dihydrooxepin type compounds and prenyl type bibenzyls. These structures are closely related to those found in Radula spp. (Radulaceae), although bibenzyls with two prenyl groups have not been isolated from the Radula spp. Although Marsupidium spp. are different from Radula spp. morphologically, the constituents are closely related. This is the first example of isolation of prenyl bibenzyl derivatives from M. epiphytum, a species which has not previously been investigated phytochemically.     

Diterpenoids and aromatic compounds from the three New Zealand liverworts Jamesoniella kirkii, Balantiopsis rosea, and Radula species

Three new aromatics were isolated from the New Zealand liverwort Balantiopsis rosea. A new bibenzyl was isolated from an unidentified Radula species, together with known bibenzyls. Jamesoniella kirkii yielded three known ent-isopimarane and two ent-kaurane diterpenoids. Their structures were confirmed by NMR techniques, chemical reaction, and X-ray crystallographic analysis.     

Terpenoids and bibenzyls from three Argentine liverworts

A new rosane diterpenoid, 3a-hydroxy-5,15-rosadien-11-one (3), was isolated, together with a known rosane diterpenoid, 5,15-rosadiene-3,11-dione (4), and an aromadendrane sesquiterpenoid, ent-cyclocolorenone (5), from the Et(2)O extract of an unidentified Argentine liverwort Anastrophyllum species. Moreover, four known sesquiterpene lactones 6-9 and two known bibenzyls 10, 11 were isolated from the Et(2)O extracts of Argentine Frullania brasiliensis and Radula voluta, respectively. The structures of compounds 3-11 were determined by the use of NMR techniques.     

New chroman derivatives from the Japanese liverworts Metacalypogeia cordifolia and Cephalozia otaruensis.

The diethyl ether extract of the Japanese liverwort Metacalypogeia cordifolia yielded five new chroman type derivatives in addition to known sesquiterpenoids. One of the new chroman derivatives was also isolated from the ether extract of another liverwort, Cephalozia otaruensis. Their structures were established by extensive two dimensional (2D) NMR techniques and chemical evidence. They were shown to be 2,2-dimethyl-7-(3-methyl-2-butenyl)-chroman derivatives. This was the first example of the isolation of the chroman-type compounds, although various types of aromatic compounds have been isolated from liverworts.     

Efficient synthesis of isoplagiochin D, a macrocyclic bis(bibenzyls), by utilizing an intramolecular Suzuki-Miyaura reaction

Isoplagiochin D, a highly strained macrocyclic bis(bibenzyls) with two biaryl units isolated from the liverwort Pladiochila fruticosa, was prepared in 10.6% overall yield for the 11 steps by an efficient synthetic approach involving the construction of two bibenzyl and one biaryl units using Horner-Wadsworth-Emmons and Suzuki-Miyaura protocols.     

Rapid detection of multiple chlorinated bis(bibenzyls) in bryophyte crude extracts using laser desorption/ionization time-of-flight mass spectrometry

Chlorinated bis(bibenzyls) of the bazzanine type were detected in crude bryophyte plant extracts of Bazzania trilobata from different locations using laser desorption/ionization time-of-flight (LDI-TOF) mass spectrometry without addition of an additional chemical matrix. The degree of chlorination could be identified by the characteristic isotope patterns. These results suggest that these chlorinated compounds are not artefacts of an incidental occurrence, or of the sample preparation, but are genuine natural products produced by the liverwort or by an endosymbiotic metabolism.     

New ent-kaurene-type diterpenoids possessing cytotoxicity from the New Zealand liverwort Jungermannia species

Two new ent-kaurene-type and a new rearranged ent-kaurene-type diterpenoids possessing cytotoxicity against a human leukemia cell line have been isolated from the New Zealand liverwort Jungermannia species, together with previously known ent-kaurene-type diterpenoids. Their structures were established based on extensive NMR techniques.     

New Polyphenols and Triterpene from the Pseudobulbs of Pleione Formosana

Three new polyphenolic compounds including a dihydrophenanthrene, pleioanthrenin ( 1 ), two bibenzyls, pleiobibenzynin A ( 2 ) and B ( 3 ), and a new cycloartane triterpenoid, (24R)‐cyclomargenyl p‐coumarate ( 4 ), together with eight known compounds, were isolated from the pseudobulbs of Pleione formosana. The structures of the new compounds were elucidated by extensively spectroscopic analysis.     

New ent-Verticillane Diterpenoids from the Japanese Liverwort Jackiella javanica

Three new ent-verticillane diterpenoids have been isolated from the Japanese liverwort Jackiella javanica, together with known sesqui- and diterpenoids. Their absolute configurations were established by X-ray crystallographic analysis and circular dichroism spectroscopy.     

New humulane-type sesquiterpenes from the liverworts Tylimanthus tenellus and Marchantia emarginata subsp. tosana

The ether extract of the New Zealand liverwort Tylimanthus tenellus produced three new sesquiterpenes, together with (+)-3,11-eudesmadiene and (-)-4(15),11-eudesmadiene which were enantiomeric to those isolated from higher plants. The structures of the new sesquiterpenes were established by 2D NMR spectral data and/or X-ray crystallographic analysis. Those structures were shown to be humulane type sesquiterpene alcohol, and its esters of 2,4-hexadienedioic acid 3,4-dihydroxy-2,5-diphenyl-gamma-lactone. 1,6-Humuladien-10-ol was also isolated from Japanese liverwort Marchantia emarginata subsp. tosana. The absolute configuration of 1,6-humuladien-10-ol was determined by (1)H-NMR resolution of its diastereomeric methoxy-alpha-trifluoromethylphenylacetyl (MTPA) esters. It was shown to be (3S,10R)-1,6-humuladien-10-ol.     

Study of bis(bibenzyls) in bryophytes using electron ionization time-of-flight and electrospray ionization triple-quadrupole mass spectrometry

A detailed analysis of mass spectra generated from bis(bibenzyl) compounds in bryophytes under electron ionization time-of-flight (EI-TOF) and electrospray ionization triple-quadrupole (ESI-TQ) mass spectrometry conditions is reported. Proposed structures of the fragment ions were obtained by tracking the functional groups of 15 bis(bibenzyls), the structures of which are similar except for some alkoxyl substituents and linkage sites of biphenyl ether bonds. The elucidation was aided by the use of accurate mass measurements. Attempts have been made to provide rational pathways for the formation of these fragment ions, and a generalized fragmentation mechanism is proposed. The bis(bibenzyls) mentioned in this study include three types according to their structure characteristics, i.e. one biphenyl ether bond (A-type), two biphenyl ether bonds (B-type), one biphenyl ether and one biphenyl bond (C-type). The three types display different EI-MS and ESI-MS/MS product profiles, by which the bis(bibenzyl) type and the number of alkoxyl substituents can be identified. Isomers of bis(bibenzyls) can be differentiated to some extent, while the linkage sites of biphenyl ether bonds are difficult to identify. The structure-fragmentation relationships will facilitate the characterization of other bis(bibenzyls) and this will be of value for the high-throughput screening of novel bis(bibenzyls) in bryophytes.     

New sesquiterpenoids from the New Zealand liverwort Chiloscyphus subporosus

A new aromadendrane-type sesquiterpenoid, 4(15)-aromadendren-12,5alpha-olide and an aromadendrane-guaianolide dimer have been isolated from the New Zealand liverwort Chiloscyphus subporosus. Their structures were established by extensive NMR techniques and X-ray crystallographic analysis.     

Sacculatal and isosacculatal,two new exceptional diterpenedials from the liverwort, trichocoleopsis sacculata

The stereostructures of the two new exceptional diterpene dialdehydes from the liverwort, Trichocoleopsis sacculata: sacculatal (1), responsible for the characteristic pungent taste, and isosacculatal (2) have been determined by the spectral evidence and by comparison with polygodial (3), isopolygodial (4), and drimanediol (6) of known relative configurations.     

Terpenoids from the liverwort Chandonanthus hirtellus

A new bicyclogermacrane sesquiterpenoid, two new cembrane diterpenoids and five new dolabellane diterpenoids, along with known terpenoids, have been isolated from the Malaysian liverwort Chandonanthus hirtellus. The structures of the new compounds were established by spectroscopic and chemical methods in addition to X-ray crystallographic studies.     

Three New Bibenzyl Derivatives from the Chinese Liverwort Marchantia polymorpha L.

From the Et₂O extract of the Chinese liverwort Marchantia polymorpha L., three new bibenzyl (=1,1′‐(ethane‐1,2‐diyl)bisbenzene) derivatives, compounds 1 – 3 , were obtained, together with the two known compounds marchantin J and perrottetin E. Their structures were established by NMR and HR‐EI‐MS analyses. Polymorphatin A ( 1 ) represents a new type of bis[bibenzyl] skeleton, and compound 3 is the first example of a bibenzyl oxidatively coupled to a phenylmethanol.     

Chemical constituents of malagasy liverworts, part V: prenyl bibenzyls and clerodane diterpenoids with nitric oxide inhibitory activity from Radula appressa and Thysananthus spathulistipus

3Beta,4beta:15,16-diepoxy-13(16),14-clerodadiene (1) and a new clerodane diterpenoid designated thysaspathone (2) were isolated from the liverwort Thysananthus spathulistipus, while Radula appressa produced radulannin A (3), radulannin L (4), 2-geranyl-3,5-dihydroxybibenzyl (5), 2(S)-2-methyl-2-(4-methyl-3-pentenyl)-7-hydroxy-5-(2-phenylethyl) chromene (o-cannabichromene) (6), 6-hydroxy-4-(2-phenylethyl) benzofuran (7), and o-cannabicyclol (8). All of the isolated compounds inhibited nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells and the greatest inhibition was attributed to compound 5, with an IC50 value of 4.5 microM.     

Cytotoxic and apoptosis-inducing ent-kaurane-type diterpenoids from the Japanese liverwort Jungermannia truncata NEES

Five new ent-kaurane-type diterpenoids and a new gymnomitrane (=barbatane)-type sesquiterpenoid have been isolated from the Japanese liverwort Jungermannia truncata NEES, together with twelve previously known ent-kaurane-type diterpenoids. The structures of the new compounds were elucidated by two-dimensional (2D) NMR experiments and chemical reaction. Some of the isolated compounds showed cytotoxicity against human leukemia cell lines and induced apoptosis.     

New sesquiterpenoid from the New Zealand liverwort Lepidozia spinosissima

A new cyclogorgonane-type sesquiterpenoid, 1,5-cyclo-3,6-gorgonadien-15,11-olide was isolated from the New Zealand liverwort Lepidozia spinosissima, together with three known sesquiterpenoids. Their structures were established by the extensive NMR techniques and chemical reaction.     

Clerodane-type diterpenoids from the japanese liverwort Jungermannia infusca (Mitt.) Steph

Three new clerodane-type diterpenoids have been isolated from the Japanese liverwort Jungermannia infusca (Mitt.) Steph., together with previously known compounds, nine clerodane- and four labdane-type diterpenoids, and 5-tocopherol. The structures of the new compounds were confirmed by 2D NMR experiments and X-ray crystallographic analysis.     

Bazzanane sesquiterpenoids from the New Zealand liverwort Frullania falciloba

Two new bazzanane-type sesquiterpenoids have been isolated from the New Zealand liverwort Frullania falciloba. Their structures were confirmed by NMR and CD spectroscopy and chemical reactivity.