13-Chloro-3-O-β-d-glucopyranosylsolstitialin from Leontodon palisae: the first genuine chlorinated sesquiterpene lactone glucoside

Apart from a number of known sesquiterpenoids, a novel chlorinated sesquiterpene lactone glucoside--13-chloro-3-O-β-d-glucopyranosylsolstitialin--has been isolated from the Southwestern European plant Leontodon palisae (Asteraceae, tribe Lactuceae). The structure has been established by high resolution mass spectrometry and 1D as well as 2D NMR spectroscopy. The compound represents the first naturally occurring chlorinated sesquiterpene lactone glucoside. The cytotoxicity of the new compound and related ones was evaluated using the MTT assay.     

Jiadifenlactone A,a novel diseco-prezizaane-type sesquiterpenoid from the fruits of Illicium jiadifengpi

Jiadifenlactone A (1), the first example of cleavage of bond [4, 9] of the seco-prezizaane-type sesquiterpenoid with a unique 9-membered ring moiety, together with its biosynthetic related compound 2, were isolated from the fruits of Illicium jiadifengpi. The structure of 1 and its relative configuration were determined by spectroscopic methods and single-crystal X-ray diffraction analysis. The inhibitory rates of compound 1 on the HBeAg and HBsAg expressions were 37.91 ± 2.78% and 17.21 ± 3.78%, respectively.     

Saikachinoside A, a novel 3-prenylated isoguanine glucoside from seeds of Gleditsia japonica

A new isoguanine glucoside designated saikachinoside A has been isolated from the seeds of Gleditsia japonica. The structure was determined as 7-β-d-glucopyranosyl-3-[(Z)-4-hydroxy-3-methyl-2-butenyl]isoguanine by interpretation of the spectroscopic data and was confirmed by X-ray crystallographic analysis. Saikachinoside A accelerated acetylcholinesterase activity.     

Chamigrenelactone, a polyoxygenated sesquiterpene with a novel structural type and devoid of halogen from Laurencia obtusa

A biogenetically interesting halogen-devoid metabolite chamigrenelactone 1, with a high oxygen-content, has been isolated from Laurencia obtusa from Isla Grande (Caribbean Panama). Its structure and stereochemistry were determined on the basis of spectral studies.     

Lacitemzine, a novel sesquiterpene acid from the Tunisian plant Pulicaria laciniata (Coss. et Kral.) Thell.

The flowers of Pulicaria laciniata (Coss. et Kral.) Thell. (Asteraceae) afforded a new sesquiterpene acid 1, named lacitemzine together with the three known compounds, 4-hydroxy-3-methoxypyridine 2, β-sitosterol-3-O-β-d-glucoside 3 and 1,3,5-trimethoxybenzene 4. The structure of compound 1, 2-(2,6-dimethyl-3,4,5,6,7,8,9,10-octahydro-5,8-oxaazulen-9-yl)acrylic acid, contains a guaiane skeleton and was elucidated by spectroscopic procedures including 2D-NMR and X-ray diffraction.     

Platypodiol a novel clerodane diterpene from Baccharis platypoda

There is an urgent need for effective leishmanicidal drugs to replace or supplement those in current use. Our group has been bioprospecting many Brazilian plants looking for potential new ‘hits’ to combat leishmaniasis. We found that Baccharis platypoda was one of the Asteraceae species that displayed leishmanicidal activity. We now describe the isolation of the new clerodane diterpene (1), named platypodiol after its ethanolic leaf extract. Its structure was determined by detailed NMR and ESI-TOF/MS/MS experiments. Considering the few publications about this species, this result has increased the phytochemical knowledge about B. platypoda.     

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.     

Kunzeanones A, B, and C: novel alkylated phloroglucinol metabolites from Kunzea ambigua

Three new metabolites, kunzeanones A (1), B (2), and C (3), along with three known compounds, cryptostrobin (4), (+)-spathulenol (5), and (−)-globulol (6), were isolated from the non-polar fraction of the dried leaves of Kunzea ambigua (Myrtaceae), which shows ichthyotoxicity toward a small fish, medaka. The structures of these new compounds were elucidated as condensates of alkylated phloroglucinol with methylflavanone and germacrane-type sesquiterpene, respectively, on the basis of spectral analyses including 1-D and 2-D NMR spectra. The stereochemistries of kunzeanones A and B were determined by X-ray crystallographic analysis. A sesquiterpene, (+)-spathulenol (5), among the isolates was characterized as the ichthyotoxic principle of the extract.     

Sinutriangulin A, a novel diterpenoid from the soft coral Sinularia triangula

A novel compound, named sinutriangulin A (1), was isolated from the soft coral Sinularia triangula. The compound possesses a new carbon skeleton that is derived from the cubitane skeleton. The structure was determined by extensive spectroscopic analyses. In addition, compound 1 exhibited weak cytotoxicity toward human tumor cell lines CCRF-CEM and DLD-1.     

Hericirine,a novel anti-inflammatory alkaloid from Hericium erinaceum

A novel ergosterol conjunction-type alkaloid, hericirine (1), was isolated from the dried fruiting bodies of Hericium erinaceum. The overall framework of 1 was isolated, and combined with hericerin and ergosterol. Its structure was elucidated based on spectroscopic analysis using 1D and 2D NMR, IR and HRESIMS techniques. We found that hericirine significantly inhibited protein expression of iNOS and COX-2 and reduced NO, PGE₂, TNF-α, IL-6 and IL-1β production in RAW264.7 cells exposed to LPS.     

Naupliolide, a sesquiterpene lactone with a novel tetracyclic skeleton from Nauplius graveolens subsp. odorus

The aerial parts of Nauplius graveolens subsp. odorus (Schousb) Wikl. afforded a novel sesquiterpene lactone (1) named naupliolide together with the known 6,7,9,10-tetradehydroasteriscanolide 2 and asteriscunolides A-D 3a-d. The structure of compound 1 corresponds to a novel skeleton of 14,15-dimethyl-7,13-dioxotricyclic[6.4.0.0^9,11]dodeca-12,13-olide, and was established on the basis of spectroscopic methods including 2D-NMR. The coexistence of naupliolide 1 together with the structurally related sesquiterpene lactones asterisculolides A-D (3a-d) and 6,7,9,10-tetradehydroasteriscanolide 2, seems to indicate their biosynthetic relationship.     

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.     

Cochinchistemonine, a novel skeleton alkaloid from Stemona cochinchinensis

Cochinchistemonine (1), an alkaloid with a novel skeleton, was isolated from the roots of Stemona cochinchinensis collected from northern Vietnam. Its structure was established on the basis of one- and two-dimensional NMR and other spectroscopic studies. The relative configuration was confirmed by single crystal X-ray diffraction experiment.     

Infectopyrone, a potential mycotoxin from Alternaria infectoria

A new metabolite, infectopyrone (1), has been isolated from the filamentous fungus Alternaria infectoria. The structure of 1 was elucidated by analysis of 2D NMR spectroscopic data. Compound 1 is an α-pyrone resembling known toxins, and is a useful phenotaxonomic marker for the A. infectoria species-group. Infectopyrone (1) was also produced by species within Stemphyllium and Ulocladium, and found in mouldy food.     

Multidione, a novel diterpenoid from Jatropha multifida

A novel diterpenoid, multidione, has been isolated from the stems of Jatropha multifida and its structure has been settled from 1D and 2D NMR spectra. The compound possesses a phenolic moiety and a long side chain, structurally similar to the B ring of other lathyrane-diterpenoids in seco-form.The compound has possibly been derived biogenetically from a related lathyrane-diterpenoid.     

Lycopladine H, a novel alkaloid with fused-tetracyclic skeleton from Lycopodium complanatum

A novel Lycopodium alkaloid, lycopladine H (1), with a fused-tetracyclic ring system consisting of an azocane ring connected to a [2,2,2]-bicyclooctane ring and a 3-piperidone ring, was isolated from the club moss Lycopodium complanatum. The structure and relative stereochemistry of 1 were elucidated on the basis of spectroscopic data.     

Rumphellaone A, a novel caryophyllane-related derivative from the gorgonian coral Rumphella antipathies

A novel 4,5-seco-caryophyllane sesquiterpenoid derivative, rumphellaone A (1), which was found to possess an unprecedented γ-lactone moiety, was isolated from the gorgonian coral Rumphella antipathies. The structure of 1 was elucidated by spectroscopic method. A plausible biosynthetic pathway of compound 1 was proposed.     

Daphniglaucin C, a novel tetracyclic alkaloid from Daphniphyllum glaucescens

A novel Daphniphyllum alkaloid with an unprecedented tetracyclic ring system consisting of an octahydroindole and a hexahydroazulene rings, daphniglaucin C (1), has been isolated from the leaves of Daphniphyllum glaucescens and the structure and relative stereochemistry were elucidated on the basis of spectroscopic data. Daphniglaucin C (1) inhibited the polymerization of tubulin.     

N-Demethyl-sauroxine,a novel Lycodine Group alkaloid from Huperzia saururus

The present study describes the isolation and identification of N-demethyl-sauroxine, a novel Lycopodium alkaloid obtained from Huperzia saururus (Lam.) Trevis. (Lycopodiaceae). Its structure and relative stereochemistry were elucidated on the basis of its spectral data and chemical correlations. Additionally, acetylcholinesterase inhibitory activity was evaluated (IC₅₀ = 209.6 ± 1.1 μM). The structure of the already identified alkaloid sauroxine was also re-validated through two dimensional NMR data.     

Sulfur-containing sesquiterpenes from Thapsia villosa

Three new sesquiterpenoids bearing sulfurated ester groups have been isolated from the roots of Thapsia villosa L. Their structures have been elucidated by spectroscopic means. This is the first time that a methylthiopropionic acid ester is isolated from natural sources.