Crystal structure and configuration revision of 9-hydroxy-7,8-dehydro-sarcotrocheliol and sarcotrocheliol

Herein, we report the isolation and stereo-structure of rare pyrane-based cembranoid diterpenes, 9-hydroxy-7,8-dehydro-sarcotrocheliol (1) and sarcotrocheliol (2), from Sarcophyton trocheliophorum collected from Red Sea. Absolute configurations of both compounds were revised based on single crystal X-ray analyses.     

Further New Cembranoid Diterpenes from the Hainan Soft Coral Sarcophyton latum

Four new cembranoid diterpenes, sarcophytonolides I–L ( 1 – 4 ), were isolated from the Hainan soft coral Sarcophyton latum. Their structures were established by detailed analysis of 1D and 2D NMR spectra and by comparison with related model compounds.     

Two new ionone glycosides from the roots of Rehmannia glutinosa Libosch.

Two new ionone glycosides, named frehmaglutoside G (1) and frehmaglutoside H (2), together with six known compounds, rehmapicroside (3), sec-hydroxyaeginetic acid (4), dihydroxy-β-ionone (5), trihydroxy-β-ionone (6), rehmaionoside A (7) and rehmaionoside C (8), were isolated from the 95% EtOH extract of the dried roots of Rehmannia glutinosa Libosch. Their structures were determined on the basis of extensive spectroscopic analyses, including HR-ESI-MS, UV, IR, 1D and 2D NMR (¹H–¹H COSY, HSQC, HMBC and NOESY) methods. The absolute configurations were confirmed via the circular dichroism spectra.     

Two new diarylheptanoids isolated from the roots of Juglans mandshurica

Two new diarylheptanoids, ( ? )-threo-3′,4″-epoxy-1-(4-hydroxyphenyl)-7-(3-methoxyphenyl)heptan-2,3-diol (1) and (1α,3β,5α,6α)-1,5-epoxy-3,6-dihydroxy-1,7-bis(3-methoxy-4-hydroxy-phenyl)-heptane (2), along with one known diarylheptanoid, rhoiptelol B (3), were isolated from the roots of Juglans mandshurica. The structures of compounds 1 and 2 were identified based on HR-ESI-MS, 1D and 2D NMR including ¹H–¹H COSY, HMQC, HMBC and NOESY spectroscopic methods.     

Two new abietane diterpenes huperphlegmarins A and B from Huperzia phlegmaria

Two new abietane diterpenes, huperphlegmarin A–B (1–2), were isolated from the aerial parts of Huperzia phlegmaria (L.) Rothm. (Lycopodiaceae), in addition to five known compounds including lycoxanthol (3), 21β-hydroxyserrat-14-en-3β-yl acetate (4), 21α-hydroxyserrat-14-en-3β-yl acetate (5), 21α-hydroxyserrat-14-en-3β-ol (6), and fawcettidine (7). Their structures were determined by the combination analyses of spectroscopy, including 1D-, 2D-NMR, HRESIMS, CD and comparison with the reported data in the literature. Huperphlegmarin B (2) presented the rare 1,11-epoxy group in the molecule. Compounds 3, 4, 5 and 6 were performed for AChE inhibitory activity and compound 3 showed the inhibitory activity against AChE with IC₅₀ of 465.6 μg/mL.     

Amberinone,a new guaianolide from Amberboa ramosa

The Amberboa is a medicinally important genus present in the family Asteraceae; members of this genus are mainly distributed in Pakistan and India. It has been used in different systems of traditional medicines for different diseases. Amberinone (1), a new sesquiterpene lactone, has been isolated from the ethyl acetate (EtOAc) soluble fraction of Amberboa ramosa together with chrysin (2), quercitine (3), eriodictyol (4) and keamferol (5). This is the first report of these compounds from this species. The structures of the isolated compounds have been elucidated by 1D and 2D ¹H ¹³C NMR spectroscopy.     

A new chromene from the fruiting bodies of Chroogomphus rutilus

A new chromene, acetic acid 2R-(4,8-dimethylnona-3,7-dienyl)-8-hydroxy-2-methyl-2H-chromen-6-yl ester (1), was isolated from the fruiting bodies of Chroogomphus rutilus, together with six known compounds (2–7). The structures of these compounds were identified based on 1D and 2D NMR, including ¹H–¹H COSY, HMQC and HMBC spectroscopic methods. Of these seven compounds, 2 and 3 showed cytotoxicity against HSC-T6, SK-Hep1 and A549 cell lines.     

Isolation and characterisation of three new anthraquinone secondary metabolites from Symplocos racemosa

Three new anthraquinone secondary metabolites were isolated from Symplocos racemosa, a small tree of family symplocaceae. The structures of compounds (1–3) were elucidated to be 1,4-dihydroxy-6-(ethoxymethyl)-8-propylanthracene-9,10-dione (1), 1,4-dihydroxy-6-(hydroxymethyl)-8-butylanthracene-9,10-dione (2) and 1,4-dihydroxy-6-(hydroxymethyl)-8-propyl anthracene-9,10-dione (3) using their spectral data, i.e. through IR, UV, ¹H NMR, ¹³C NMR and two-dimensional (2D) NMR techniques including heteronuclear multiple quantum coherence, heteronuclear multiple bond correlation and correlation spectroscopy.     

Two new benzolactones from the leaves of Nicotiana tabacum and their anti-tobacco mosaic virus activities

Two new benzolactones, 5-methyl-6-prenyl-isobenzofuran-1(3H)-one (1), 5-hydroxymethyl-6-prenyl-isobenzofuran-1(3H)-one (2), together with four known phenolic compounds (3–6), were isolated from the leaves of Nicotiana tabacum. Their structures were elucidated by spectroscopic methods, including extensive 1D and 2D NMR techniques. Compounds 1–6 were evaluated for their anti-tobacco mosaic virus (anti-TMV) activities. The results showed that compounds 1–6 exhibited high anti-TMV activities with inhibition rates in the range of 16.9–26.2%, respectively.     

Isolation and identification of a new neo-clerodane diterpenoid from Teucrium chamaedrys L.

Teucrium chamaedrys L. is an aromatic and medicinal plant used as traditional medicine. Aerial parts of the plant material were dried and extracted with hexane–dichloromethane (extract 1), ethyl acetate–dichloromethane (extract 2) and methanol–dichloromethane (extract 3) in a ratio of 1:1 at rt successively. The solvents were evaporated to give crude extracts. Extract 1 was suspended in water at 60°C then partitioned successively with hexane and ethyl acetate to give hexane and ethyl acetate portions. After the column chromatography (silica gel) of ethyl acetate extract, one new and four known compounds were isolated. The new compound was named as 1(12S,18R)-15,16-epoxy-2β,6β-dihydroxy-neo-cleroda-13(16),14-dien-20,l2-olide-l8,l9-hemiacetal (teuchamaedryn D) (4). The known compounds were teucrin A (1), dihydroteugin (2), teucroxide (3), syspirensin A (5). The chromatographic methods were also applied for extract 3 to isolate verbascoside (6) and teucrioside (7). The structure of isolated compounds was elucidated by spectroscopic methods including LC-TOF/MS, 1D NMR and 2D NMR.     

A new sesquiterpene from the entomogenous fungus Phomopsis amygdali

A new sesquiterpene, (+)-S-1-methyl-abscisic-6-acid (1), together with five known compounds, (+)-S-abscisic acid (2), fusicoccin J (3), 3α-hydroxyfusicoccin J (4), (R)-5-hydroxymethylmellein (5) and 4-hydroxyphenethyl acetate (6) was isolated from the fermentation extract of Phomopsis amygdali, an entomogenous fungus isolated from Call midge. Their structures were determined mainly by analysis of MS and NMR spectroscopic data. Compounds 1–6 were tested for antimicrobial activity against three plant pathogenic fungi: Gibberella zeae, Verticillium albo-atrum, and Fusarium nivale, and two bacteria: Escherichia coli and Pseudomonas aeruginosa 2033E. As a result, compounds 1–4 displayed antibacterial activity against Gram-negative P. aeruginosa 2033E, and the minimum inhibition concentration (MIC value) of 1–4 is 30 μg/mL, 58 μg/mL, 26 μg/mL, and 26 μg/mL, respectively.     

A new anthraquinone and eight constituents from Hedyotis caudatifolia Merr. et Metcalf: isolation,purification and structural identification

Hedyotis caudatifolia Merr. et Metcalf. (HC), a folk medicine in Yao nationalities areas in China, was used to investigate the chemical constituents. Through silica gel and Sephadex LH-20 column chromatography, nine compounds were isolated and purified. By physical and chemical properties, IR, MS (EI-MS, high resolution EI-MS), 1D NMR (¹H NMR, ¹³C NMR) and 2D NMR (HSQC, ¹H–¹H COSY, HMBC), their structures were identified as β-sitosterol (1), stigmasterol (2), scopolin (3), 2-hydroxy-1,7,8-trimethoxyanthracene-9,10-dione (4), oleanolic acid (5), ursolic acid (6), methyl barbinervate (7), β-daucosterol (8) and p-Hydroxybenzoic acid (9). These compounds were isolated from HC for the first time, and 4 a new anthraquinone whose biological activities are worth to be investigated in future. These compounds may contribute to the HC’s pharmacological effects on treating diseases, and may be used as candidates for control index in establishing the quality control standard of HC.     

A new di-C-prenylated coumarin from Sophora interrupta

A new di-C-prenylated coumarin, 7-methoxy-6,8-bis-(2,3-dihydroxy-3-methylbutyl)-coumarin (1), together with seven known compounds, isopimpinellin (2), an arylbenzofuran (3), three flavonoids (4–6), (+)-maackianin (7) and echinoisoflavanone (8), were isolated from the leaves of Sophora interrupta Bedd. The structure of the new compound 1 as well as known compounds was elucidated by extensive 1D and 2D NMR spectral studies.     

A new caffeic acid tetramer from the Dracocephalum moldavica L.

A new caffeic acid tetramer compound, named (+) methyl rabdosiin (4), together with seven known caffeic acid multimers (1–3, 5–8) and one caffeic acid monomer (9), were isolated from the aerial parts of Dracocephalum moldavica L. The structures of these compounds were assigned on the basis of 1D and 2D NMR spectroscopic and mass spectrometry analyses. The protective effects of compounds 2–4 against hydrogen peroxide (H₂O₂)-induced apoptosis were evaluated in primary cardiomyocytes of SD neonatal rats in vitro by the MTT method. Three compounds exhibited potent protective activities at 12.5 μg/mL.     

Secondary metabolites from Triclisia gilletii (De Wild) Staner (Menispermaceae) with antimycobacterial activity against Mycobacterium tuberculosis

Triclisinone (2), a new ochnaflavone derivative, was isolated from the aerial parts of Triclisia gilletii, along with known drypemolundein B (1) and eight other known compounds. The chemical shifts of drypemolundein B (1) have been partially revised based on reinterpretation of NMR spectroscopic data. The eight other secondary metabolites are composed of: (+)-nonacosan-10-ol (3); stigmasterol (4), 3-O-β-D-glucopyranosylsitosterol (5), 3-O-β-D-glucopyranosylstigmasterol (6); oleanic acid (7); myricetin (8), quercetin (9) and 3-methoxyquercetin (10). Their structures were elucidated using IR, MS, NMR 1D and 2D, ¹H and ¹³C and comparison with literature data. Furthermore, compounds 1, 2, 5, 6, 8, 9 and the crude extract were tested against Mycobacterium tuberculosis. Compounds 1, 2, 8 and 9 displayed moderate to very good activity against resistant strain (codified AC 45) of M. tuberculosis with minimum inhibitory concentrations MICs ranging from 3.90 to 62.5 μg/mL.     

Further New Cembrane Diterpenes from the Hainan Soft Coral Sarcophyton latum

Two new cembranoid diterpenes, diepoxysarcophytonene ( 1 ) and sarconphytonol ( 2 ), were isolated from the Hainan soft coral Sarcophyton latum. Their structures including relative stereochemistry were established by 1D and 2D NMR spectroscopic techniques. Compound 1 showed weak inhibitory activity against COX‐2 in vitro at the concentration of 10^?5 µmol·L^?1 with the inhibitory rate of 55%.     

Further eleganolone-derived diterpenes from the brown alga Bifurcaria bifurcata

Four new diterpenes (1–4) together with six known members of this family were isolated from the brown alga Bifurcaria bifurcata collected off the coast near Roscoff, France. The structures of the new compounds were established in a comprehensive study on the basis of 1D and 2D NMR spectroscopic and mass spectrometric (ESI-MS) analyses. Our assignment is supported by a comparison of the ¹³C NMR chemical shifts to known compounds and predicted values. The new diterpenes are derivatives of the diterpene eleganolone (5). The structural relation and hypothetical metabolic pathway of the new diterpenes (1–4) with the co-isolated known diterpenes are discussed.     

New furostanol glycosides from Polygonatum multiflorum (L.) All.

The phytochemical investigation of the whole plant of Polygonatum multiflorum resulted in the isolation of two new steroidal glycosides, polmultoside A (4) and polmultoside B (5), along with three known glycosides protobioside (1), protodeltonin (2) and huangjiangsu A (3). The structures of the isolated compounds have been elucidated by extensive 1D (¹H, ¹³C) and 2D (COSY, HSQC, HMBC) NMR spectral data analysis, as well as high-resolution mass determinations.     

A new benzofuran from Artemisia halodendron Turcz. ex Bess.

A new benzofuran, methyl (2S,2″S,3′E)-[2-(1″-acetoxypropan-2-yl)-2,3-dihydrobenzofuran-5-yl]acrylate (1), and 13 known compounds (2–14) were isolated from an ethanol extract of Artemisia halodendron Turcz. ex Bess. The chemical structures of these compounds were determined by 1D and 2D NMR (¹H-¹H COSY, HMBC, HMQC and NOESY) and HR-ESI-MS spectra, and results were compared with data from the literature. The effects of compounds 1–14 were measured on NF-κB activation, with compounds 2 and 3 exhibiting inhibitory activities against TNF-α-induced NF-κB reporter gene expression in HeLa cells from 10 to 100 μM.     

Furofuran lignans from the bark of <Emphasis Type="Italic">Magnolia kobus</Emphasis>

A new furofuran lignan (1) along with four knownones (2-5) were isolated from the bark of Magnolia kobus. Their structures were elucidated as (+)-2α-(3’,4’-dimethoxyphenyl)-6α-(3″-hydroxy-4″,5″-dimethoxyphenyl)-3,7-dioxabicyclo[3.3.0]octane (1), (+)-sesamin (2), (+)-yangambin (3), (+)-kobusin (4), and (+)-eudesmin (5) on the basis of their comprehensive spectroscopic analysis, including 2D NMR, and by comparison of their spectral data with those of related compounds. Published in Khimiya Prirodnykh Soedinenii, No. 4, pp. 338–341, July–August, 2008.