Three new Lycopodium alkaloids from Huperzia carinata and Huperzia squarrosa

Eleven Lycopodium alkaloids with lycodine-type, lycopodine-type, and fawcettimine-related skeletons were isolated from the whole plants of Huperzia carinata (Desv. Ex. Poir.) Trevis and Huperzia squarrosa (G. Forst) Trevis (Huperziaceae). Among them, 8,15-dihydrohuperzine A (2), lycocarinatine A (3), and lycoposerramine U N-oxide (11) are new compounds. The structures of these new alkaloids were elucidated on the basis of 2D NMR correlations. Some of these isolated alkaloids were assayed for acetylcholinesterase (AChE) inhibitory activity.     

Unusual octalactones from Corynespora cassiicola, an endophyte of Laguncularia racemosa

Chemical investigation of the EtOAc extract of the mangrove-derived endophyte Corynespora cassiicola, isolated from Laguncularia racemosa (Combretaceae), afforded five new secondary metabolites, named coryoctalactones A–E (1–5). The structures of the new compounds were determined on the basis of 1D- and 2D-NMR spectroscopy as well as high-resolution mass spectrometry. The absolute configuration of the side chain in 1–3 and 5 were tentatively deduced based on biogenetic consideration in comparison with xestodecalactones, previously isolated from C. cassiicola. All isolated compounds were evaluated for their antimicrobial, cytotoxic, and antitrypanosomal activities.     

2,6-Cyclo-xenicanes from the brown algae Dilophus fasciola and Dilophus spiralis

Seven new diterpenes, featuring the rare 2,6-cyclo-xenicane skeleton, along with eleven previously reported metabolites were isolated from the organic extracts of the brown algae Dilophus fasciola and Dilophus spiralis. The structure elucidation of the isolated natural products was based on detailed analyses of their spectroscopic data (NMR, MS, IR, UV), whereas the assignment of their relative configurations was assisted by molecular modelling studies.     

Benzocoumarins from the rhizomes of Juncus acutus

Investigation of the ethyl acetate extract of Juncus acutus rhizomes revealed seven benzocoumarins, probably derived from oxidation of phenanthrenes already isolated from the plant. The structures were determined by means of spectroscopic methods. The anti-algal activity of the isolated compounds tested on the green alga Pseudokirchneriella subcapitata are reported here.     

A xanthone and a polyketide derivative from the leaves of Cassia obtusifolia (Leguminosae)

A new xanthone, 1,8-dihydroxy-3-methoxy-6-methylxantone and a new polyketide derivative, (4R^∗,5S^∗,6E,8Z)-ethyl-4-((E)-but-1-enyl)-5-hydroxypentdeca-6,8-dienoate, together with 20 known secondary metabolites, including 2 steroids, 4 xanthones, 10 anthraquinones, 2 triterpenoids, 1 fatty ester, and (E)-eicos-14-enoic acid, were isolated from the leaves of Cassia obtusifolia. To the best of our knowledge, the last compound was isolated from a natural source for the first time. The structures of all the compounds were elucidated on the basis of 1D and 2D NMR experiments. Some of the compounds were tested against Salmonella typhi, Staphylococcus aureus, Candida albicans ATCC 9002, and Candida tropicalis, they did not show any activity.     

A pair of new atropisomeric cupressuflavone glucosides isolated from Juniperus communis var. depressa

A pair of new atropisomers, (M)- and (P)-cupressuflavone 4′-O-β-d-glucoside, were isolated from Juniperus communis var. depressa, and their absolute structures and axial configurations were determined using 2D NMR and circular dichroism. These are the first reported stable (M)- and (P)-isomers of cupressuflavone glucosides isolated from natural sources.     

A novel labdane diterpene from Acritopappus longifolius

A novel labdane diterpene was isolated from the plant Acritopappus longifolius. The structure of this compound was established by 1D- and 2D-nuclear magnetic resonance spectroscopic techniques and mass spectrometry data. N-Methyl-4-hydroxy-trans-proline, stigmasterol-3-O-β-d-glycoside, and the flavonoids quercetin, luteolin, kaempferol, and rutin were also isolated.     

Sauroine—a novel Lycopodium alkaloid from Huperzia saururus

A novel Lycopodium alkaloid, sauroine (7,8-dihydroxylycopodine, 1) was isolated from the aerial parts of the medicinal species Huperzia saururus. The structure and relative stereochemistry of 1 were elucidated on the basis of its spectral data.     

Hupermine A,a novel C16N2-type Lycopodium alkaloid from Huperzia phlegmaria

A novel C₁₆N₂-type Lycopodium alkaloid consisting of a quinolizidine with a 6-dimethylaminohexyl side chain, hupermine A (1), was isolated from the club moss of Huperzia phlegmaria, and the structure and relative stereochemistry were elucidated on the basis of spectroscopic data.     

New constituents from Mikania laevigata Shultz Bip. ex Baker

A new phenylpropanoid and two new diterpenes were isolated from the leaves of the plant Mikania laevigata Shultz Bip. ex Baker. The structures of these compounds were established by 1D- and 2D-nuclear magnetic resonance spectroscopic techniques and mass spectrometry data. Taraxerol, lupeol, coumarin, syringaldehyde, trans-melilotoside, cis-melilotoside, adenosine, patuletin 3-O-β-d-glucopyranoside, kaempferol 3-O-β-d-glucopyranoside, quercetin 3-O-β-d-glucopyranoside, methyl 3,5-di-O-caffeoyl quinate, and 3,3′,5-trihydroxy-4′,6,7-trimethoxyflavone were isolated too. In addition, the compounds dihydrocoumarin, spathulenol, caryophyllene oxide, kaurenoic acid, beyerenoic acid, and lupeol acetate were identified by GC-MS.     

Calyciphyllines E and F, novel hepta- and pentacyclic alkaloids from Daphniphyllum calycinum

Two new Daphniphyllum alkaloids, calyciphyllines E (1) and F (2), have been isolated from the leaves of Daphniphyllum calycinum (Daphniphyllaceae), and the structures and relative stereochemistry were elucidated on the basis of spectroscopic data.     

Isolation of strains degrading poly(Vinyl alcohol) at high temperatures and their biodegradation ability

Thermophilic strains were isolated for the first time using activated sludge retrieved from waste water treatment plant of a poly(vinyl alcohol) (PVA) producing factory for biodegradation of PVA at relatively high temperatures. The isolated strains were identified to be Geobacillus tepidamans, Brevibacillus brevis and Brevibacillus limnophilus. The former strain degraded PVA for itself, while the latter 2 strains digested PVA symbiotically. PVA degradation activity of the isolated strains was assessed at first by the halo zone size formed around the colonies and finally by the modified Sturm test. The biodegradation rate of PVA was explored also in the presence of different dyes, because most of the waste water from PVA-consuming factories contains waste dyes.     

Concise total synthesis of flavone C-glycoside having potent anti-inflammatory activity

The total synthesis of anti-inflammatory active flavone C-glycoside isolated from oolong tea extract is achieved. Introducing a C-glucosyl moiety to an aryl system and constructing a fused tetracyclic ring characteristic to this natural product were conducted based on the O-to-C rearrangement of sugar moiety and the successive intramolecular Mitsunobu reaction, respectively. This concise and efficient synthetic pathway is applicable to the large-scale synthesis of target flavone and for constructing a large library of related compounds.     

Calyciphyllines H-M, new Daphniphyllum alkaloids from Daphniphyllum calycinum

Six new Daphniphyllum alkaloids, calyciphyllines H-M (1-6), were isolated from the leaves and stems of Daphniphyllum calycinum (Daphniphyllaceae). The structures and relative stereochemistry of 1-6 were elucidated on the basis of spectroscopic data, and the absolute stereochemistry of 3 was assigned by PGME method.     

Dilospiranes A and B: diterpenes featuring novel carbocyclic units from the brown alga Dilophus spiralis

Dilospiranes A and B (1 and 2), two diterpenes featuring unprecedented carbocycles, were isolated from the organic extract of the brown alga Dilophus spiralis, collected from the coast of Elafonissos Island, Greece. The structures and the relative configurations of the isolated natural products were determined on the basis of extensive analyses of their spectroscopic data.     

Constituents of the Leaves and Stem Bark of Aglaia foveolata

The previously known potent cytotoxic agent silvestrol (1) (0.002% w/w yield) and five new flavagline derivatives (2-6) were isolated from the leaves of Aglaia foveolata collected in Indonesia. The new compound 5 has an unprecedented cyclic amide moiety in its cyclopenta[b]benzopyran skeleton, while compound 6 is a novel benzo[b]oxepine derivative in which the oxepine ring is cleaved. Pyramidatine (7), a biogenetic precursor of the new flavaglines 2-6, was isolated from the leaf extract investigated. Silvestrol was also isolated from the stem bark of A. foveolata (yield of 0.02% w/w) along with a new baccharane-type triterpenoid (8). The structures of the new compounds were elucidated on the basis of their NMR and mass spectrometric data. All new compounds isolated were tested against a panel of cancer cell lines, but only compound 2 was cytotoxic (IC₅₀ range=1.4-1.8 μM), and is the first member of the cyclopenta[b]benzopyran class found to exhibit this type of activity. Compound 2 also showed significant NF-κB inhibitory activity in an Elisa assay (IC₅₀=0.37 μM).     

New cytotoxic sesquiterpenes from the red algae Laurencia obtusa and Laurencia microcladia

Three new sesquiterpenes (1-3), along with five known (5-9), were isolated from the organic extract of the red alga Laurencia obtusa, collected from the coastal rocks of Serifos in the Aegean Sea. A new dimeric sesquiterpene of the cyclolaurane-type (4) along with four previously reported (7, 10-12) metabolites, were isolated from the extract of Laurencia microcladia, collected at Chios island in the North Aegean Sea. The structures and the relative stereochemistry of the compounds are proposed on the basis of their spectral data. The cytotoxicity of the isolated metabolites was evaluated against several cell lines including human tumor cell lines.     

Cyclic tetrapeptides from marine bacteria associated with the seaweed Diginea sp. and the sponge Halisarca ectofibrosa

A Pseudomonas sp. was cultured which was associated with the Japanese seaweed Diginea sp. Crude extracts prepared from this bacterial culture were found to inhibit the growth of other marine bacterial strains. From this bacterial culture, two new peptides cyclo-[phenylalanyl-prolyl-leucyl-prolyl] (3) and cyclo-[isoleucyl-prolyl-leucyl-alanyl] (4) have been isolated together with two known peptides (1) and (2). The crude extract from a culture of Pseudoalteromonas sp. associated with the Thai sponge Halisarca ectofibrosa was found to inhibit the growth of Bacillus subtilis and Vibrio anguillarum. Isolation studies yielded a fraction containing two peptides that were identified as cyclo-[phenylalanyl-leucyl]₂ (5) and cyclo-[leucyl-isoleucyl]₂ (6) by means of LC-MS and 2D NMR data. Absolute stereochemistry was confirmed by the synthesis of cyclo-[l-phenylalanyl-l-leucyl]₂. Peptides (1)-(3) were also isolated from this bacterial strain. None of the individual peptides isolated in this study showed antibiotic activity.     

Calyciphylline G, a novel alkaloid with an unprecedented fused-hexacyclic skeleton from Daphniphyllum calycinum

Calyciphylline G (1), a novel Daphniphyllum alkaloid with an unprecedented fused-hexacyclic skeleton containing a 5-azatricyclo[6.2.1.0^1,5]undecane ring, has been isolated from the stem of Daphniphyllum calycinum (Daphniphyllaceae), and the structure and relative stereochemistry were elucidated on the basis of spectroscopic data.     

Overlapping chemical and genetic diversity in Ligularia lamarum and Ligularia subspicata. Isolation of ten new eremophilanes and a new seco-bakkane compound

Root chemicals and DNA sequences were analyzed for Ligularialamarum samples collected in Yunnan and Sichuan Provinces of China and the relationship between the plant and Ligulariasubspicata, its taxonomically closest species, was examined. Both species produce furanoeremophilanes and eremophilan-8-one derivatives as the major components. Eleven new compounds, including a new seco-bakkane compound, were isolated. The two species were found to harbor overlapping intra-specific diversities with respect to the chemicals and the DNA sequences.