Sesquiterpene lactones; Damsin and neoambrosin suppress cytokine-mediated inflammation in complete Freund's adjuvant rat model via shutting Akt/ERK1/2/STAT3 signaling.

ETHNOPHARMACOLOGIAL RELEVANCE: Although Damsissa (Ambrosia maritima) is traditionally used as anti-inflammatory and diuretic, the biological activity and mechanism of action of its major constituents are to be elucidated. AIM: to decipher the anti-arthritic potential of damsin (DMS) and neoambrosin (NMS) and to unfold their molecular signaling in complete Freund's adjuvant (CFA)-induced arthritis model. MATERIALS AND METHODS: the right hind paw was inoculated with CFA (0.1 ml) at day 0 and 7 while treatments were started from the 14th day and continued for 2 weeks. Rats were randomly assigned into 4 groups; normal group (NRML), CFA-induced arthritis group, CFA-induced arthritis treated with DMS and NMS (10 mg/kg/day) as 3rd and 4th group; respectively. RESULTS: Throughout experimental period, treatments ameliorated the increase of paw volume, knee joint diameter and nociception tests as reflected in open field arena. Also, DSM and NMS suppressed phosphorylation of Akt, STAT-3, ERK1/2 which was further mirrored by inactivation of GSK3ß and downregulation of MCP-1 together with CCN1 and NF-kß in hind paw tissue. Concomitantly, inflammation markers; TNF-α, IL-6, -12 were lowered as confirmed microscopically during examination of hind paw tissue. CONCLUSION: DSM and NMS-induced suppression of NF-kß subdues clinical features of RA most probably through repression of Akt/ERK1/2/STAT3 pathway. Therefore, DMS and NMS can serve as safe and effective treatment for rheumatoid arthritis, one of the most disabling chronic, inflammatory and painful autoimmune disease.

Isolation and Antifouling Activity of Azulene Derivatives from the Antarctic Gorgonian Acanthogorgia laxa.

Three azulenoid sesquiterpenes (1 - 3) were isolated from the Antarctic gorgonian Acanthogorgia laxa collected by bottom trawls at -343 m. Besides linderazulene (1), and the known ketolactone 2, a new brominated C16 linderazulene derivative (3) was also identified. This compound has an extra carbon atom at C(7) of the linderazulene framework. The antifouling activity of compounds 1 and 2 was assayed in the laboratory with Artemia salina larvae, and also in field tests, by incorporation in soluble-matrix experimental antifouling paints. The results obtained after a 45 days field trial of the paints, showed that compounds 1 and 2 displayed good antifouling potencies against a wide array of organisms. Compound 3, a benzylic bromide, was unstable and for this reason was not submitted to bioassays. Two known cembranolides: pukalide and epoxypukalide, were also identified as minor components of the extract.

Anti-cancer stem cell activity of a sesquiterpene lactone isolated from Ambrosia arborescens and of a synthetic derivative.

New regimens are constantly being pursued in cancer treatment, especially in the context of treatment-resistant cancer stem cells (CSCs) that are assumed to be involved in cancer recurrence. Here, we investigated the anti-cancer activity of sesquiterpene lactones (SLs) isolated from Ambrosia arborescens and of synthetic derivatives in breast cancer cell lines, with a specific focus on activity against CSCs. The breast cancer cell lines MCF-7, JIMT-1, and HCC1937 and the normal-like breast epithelial cell line MCF-10A were treated with the SLs damsin and coronopilin, isolated from A. arborescens, and with ambrosin and dindol-01, synthesized using damsin. Inhibitory concentration 50 (IC50) values were obtained from dose-response curves. Based on IC50 values, doses in the µM range were used for investigating effects on cell proliferation, cell cycle phase distribution, cell death, micronuclei formation, and cell migration. Western blot analysis was used to investigate proteins involved in cell cycle regulation as well as in the NF-κB pathway since SLs have been shown to inhibit this transcription factor. Specific CSC effects were investigated using three CSC assays. All compounds inhibited cell proliferation; however, damsin and ambrosin were toxic at single-digit micromolar ranges, while higher concentrations were required for coronopilin and dindol-01. Of the four cell lines, the compounds had the least effect on the normal-like MCF-10A cells. The inhibition of cell proliferation can partly be explained by downregulation of cyclin-dependent kinase 2. All compounds inhibited tumour necrosis factor-α-induced translocation of NF-κB from the cytoplasm to the nucleus. Damsin and ambrosin treatment increased the number of micronuclei; moreover, another sign of DNA damage was the increased level of p53. Treatment with damsin and ambrosin decreased the CSC subpopulation and inhibited cell migration. Our results suggest that these compounds should be further investigated to find efficient CSC-inhibiting compounds.

Characteristic Changes in the Aroma Profile of Patchouli Depending on Manufacturing Process.

Patchouli is used as an incense material and essential oil. The characteristic odor of patchouli leaves results from the drying process used in their production; however, there have to date been no reports on the changes in the odor of patchouli leaves during the drying process. We investigated the aroma profile of dried patchouli leaves using the hexane extracts of fresh and dried patchouli leaves. We focused on the presence or absence of the constituents of the fresh and dried extracts, and the differences in the content of the common constituents. Fourteen constituents were identified as characteristic of dried patchouli extract odor by gas chromatography-olfactometry analysis. The structures of seven of the 14 constituents were determined by gas chromatography-mass spectrometry (α-patchoulene, seychellene, humulene, α-bulnesene, isoaromadendrene epoxide, caryophyllene oxide, and patchouli alcohol). The aroma profile of the essential oil obtained from the dried patchouli leaves was clearly different from that of dried patchouli. The aroma profile of the essential oil was investigated by a similar method. We identified 12 compounds as important odor constituents. The structures of nine of the 12 constituents were determined by gas chromatography-mass spectrometry (cis-thujopsene, caryophyllene, α-guaiene, α-patchoulene, seychellene, α-bulnesene, isoaromadendrene epoxide, patchouli alcohol, and corymbolone). Comparing the odors and constituents demonstrated that the aroma profile of patchouli depends on the manufacturing process.

Improving the productivity of a multidimensional chromatographic preparative system by collecting pure chemicals after each of three chromatographic dimensions.

The enhanced sample collection capability of a heart-cutting three-dimensional GC-prep system is reported. In its original configuration, a highly pure component can be usually collected after the last (3D) column outlet by means of a dedicated preparative station. The latter is located after the last chromatographic column, and this poses the requirement for multiple heart cuts even for those components showing satisfactory degree of purity after the first (or second) separation dimension. The feasibility to collect pure components after each chromatographic dimension is here described, employing a three-dimension MDGC system equipped with high-temperature valves, located inside the first and second GC ovens, with the aim to improve the productivity of the collection procedure. In addition to a commercial preparative collector located at the 3D outlet, two laboratory-made collection systems were applied in the first and second dimension, reached by the effluent to be collected trough a high-temperature valve switching the heart-cut fraction between either the detector (FID), or the collector. Highly pure sesquiterpene components were collected, namely: patchouli alcohol after the first column [poly(5% diphenyl/95% dimethylsiloxane)], α-bulnesene after a second column coated with high molecular weight polyethylene glycol, and α-guaiene after an ionic-liquid based column (SLB-IL60), used as the third dimension. Purity levels ranging from 85 to 95% were achieved with an average collection recovery of 90% (n=5). The following average amounts were collected per run: 160µg for α-guaiene, 295µg for α-bulnesene, and 496µg for patchouli alcohol.

Chemical composition and antimicrobial activity of the essential oils of Onychopetalum amazonicum R.E.Fr.

The essential oils from leaves, twigs and trunk bark of Onychopetalum amazonicum R.E. Fr. (Annonaceae), obtained by hydrodistillation, were analysed by GC and GC-MS, and also were evaluated for in vitro antimicrobial activity. Forty-one compounds, which correspond to 75.0-92.2% of the oil components, were identified. Major compounds were sesquiterpenes, including (E)-caryophyllene, caryophyllene oxide, spathulenol, α-gurjunene, allo-aromadendrene and α-epi-cadinol. The oils were evaluated for antimicrobial activities against four bacteria strains and five pathogenic fungi. The oil of the trunk bark exhibited good activity against Staphylococcus epidermidis ATCC 12228, Escherichia coli ATCC 10538 and Kocuria rhizophila ATCC 9341, with a minimal inhibitory concentration of 62.5 µg/mL. The essential oil composition and the antimicrobial evaluation are reported for the first time for the genus Onychopetalum.

Bioactivity and chemical characterisation of Lophostemon suaveolens--an endemic Australian Aboriginal traditional medicinal plant.

Lophostemon suaveolens is a relatively unexplored endemic medicinal plant of Australia. Extracts of fresh leaves of L. suaveolens obtained from sequential extraction with n-hexane and dichloromethane exhibited antibacterial activity in the disc diffusion and MTT microdilution assays against Streptococcus pyogenes and methicillin sensitive and resistant strains of Staphylococcus aureus (minimum bactericidal concentration < 63 µg/mL). The dichloromethane extract and chromatographic fractions therein inhibited nitric oxide in RAW264.7 murine macrophages (IC50 3.7-11.6 µg/mL) and also PGE2 in 3T3 murine fibroblasts (IC50 2.8-19.7 µg/mL). The crude n-hexane, dichloromethane and water extracts of the leaves and chromatographic fractions from the dichloromethane extract also showed modest antioxidant activity in the ORAC assay. GC-MS analysis of the n-hexane fraction showed the presence of the antibacterial compounds aromadendrene, spathulenol, ß-caryophyllene, α-humulene and α-pinene and the anti-inflammatory compounds ß-caryophyllene and spathulenol. Fractionation of the dichloromethane extract led to the isolation of eucalyptin and the known anti-inflammatory compound betulinic acid.

Exploitation of Artemisia arborescens as a Renewable Source of Chamazulene: Seasonal Variation and Distillation Conditions.

Tree Wormwood (Artemisia arborescens L.) is a Mediterranean medicinal herb known for its anti-inflammatory properties, mainly because of the high chamazulene content of its essential oil (EO). Herein are presented the results of an investigation concerning the seasonal variation in the chamazulene content of.the EOs of three Cretan natural populations of A. arborescens by combined GC-FID and GC-MS analysis. Results highlighted a population containing EO rich in chamazulene at amounts exceeding 50% of its quantitative composition at the full flowering stage, which is the more appropriate vegetative stage for harvesting. Hydro-distillation of the respective plant material in five different pH environments increased, in all cases, the chamazulene yield, with the most efficient pH value being 8.3, when the chamazulene amount increased 1.3 times compared with distillation under neutral conditions, reaching 65.1% of the total content of EO.

Bioactivity and chemical constituents of the essential oil from Dendranthema indicum (L.) Des Moul. against two stored insects.

Dendranthema indicum (L.) Des Moul. is a perennial herb commonly used as a traditional Chinese medicine for a long time. In this work, we took Dendranthema indicum as a target plant and two stored insects which include Tribolium castaneum and Stegobium paniceum adults as target insects. Essential oil obtained from Dendranthema indicum was analyzed by gas chromatography-mass spectrometry (GC-MS). A total of 31 components representing 92.44% of the oil were identified and the main compounds were found to be chamazulene (15.93%), ß-caryophyllene (13.78%), germacrene D (9.11%), and b-cis-farnesene (6.59%). With a further isolation, three constituents were obtained from the essential oil and identified as chamazulene, ß-caryophyllene and eucalyptol. Significantly, in the progress of assay, it showed that the essential oil and chamazulene exhibited stronger insecticidal and repellent activities against Stegobium paniceum than Tribolium castaneum. The results indicate that additional to its traditional use as Chinese medicinal herb, the essential oil of Dendranthema indicum aerial parts and isolated compounds have potential to be developed into natural insecticides or repellents for control of insects in stored grains.

Mechanistic studies on the autoxidation of α-guaiene: structural diversity of the sesquiterpenoid downstream products.

Two unstable hydroperoxides, 6b and 10a, and 13 downstream sesquiterpenoids have been isolated from the autoxidation mixture of the bicyclic sesquiterpene α-guaiene (1) on cellulose filter paper. One of the significant natural products isolated was rotundone (2), which is the only known impact odorant displaying a peppery aroma. Other products included corymbolone (4a) and its C-6 epimer 4b, the (2R)- and (2S)-rotundols (7a/b), and several hitherto unknown epimers of natural chabrolidione A, namely, 7-epi-chabrolidione A (3a) and 1,7-epi-chabrolidione A (3b). Two 4-hydroxyrotundones (8a/b) and a range of epoxides (9a/b and 5a/b) were also formed in significant amounts after autoxidation. Their structures were elucidated on the basis of spectroscopic data and X-ray crystallography, and a number of them were confirmed through total synthesis. The mechanisms of formation of the majority of the products may be accounted for by initial formation of the 2- and 4-hydroperoxyguaienes (6a/b and 10a/b) followed by various fragmentation or degradation pathways. Given that α-guaiene (1) is well known to exist in the essential oils of numerous plants, coupled with the fact that aerial oxidation to form this myriad of downstream oxidation products occurs readily at ambient temperature, suggests that many of them have been overlooked during previous isolation studies from natural sources.

Production of the pepper aroma compound, (-)-rotundone, by aerial oxidation of α-guaiene.

The aroma link between pepper and wine has recently been elucidated to be due to the important aroma compound rotundone. To date, rotundone is the only known impact odorant with a peppery aroma. Although the concentration found in products of natural origin is small, the odor detection threshold is among the lowest of any natural product yet discovered. We report herein the identification of the first known precursor to rotundone, namely, α-guaiene, and that one mechanism of transformation is simple aerial oxidation.

Rupestonic acids B-G, NO inhibitory sesquiterpenoids from Artemisia rupestris.

Six new guaiane sesquiterpenoids, rupestonic acids B-G (1-6), have been isolated from the whole plants of Artemisia rupestris together with six known compounds (7-12). The structures of the new isolates (1-6) were elucidated on the basis of extensive 1D and 2D NMR analysis, and the absolute configurations were established by electronic circular dichroism (ECD) in combination with density functional theory calculations. In in vitro bioassays, compounds 2 and 6 exhibited significant inhibitory effects on LPS-stimulated NO production in BV-2 microglial cells with IC50 values of 2.6 and 2.2 µM, respectively.

Essential oil alloaromadendrene from mixed-type Cinnamomum osmophloeum leaves prolongs the lifespan in Caenorhabditis elegans.

Cinnamomum osmophloeum Kaneh. is an indigenous tree species in Taiwan. The present study investigates phytochemical characteristics, antioxidant activities, and longevity of the essential oils from the leaves of the mixed-type C. osmophloeum tree. We demonstrate that the essential oils from leaves of mixed-type C. osmophloeum exerted in vivo antioxidant activities on Caenorhabditis elegans. In addition, minor (alloaromadendrene, 5.0%) but not major chemical components from the leaves of mixed-type C. osmophloeum have a key role against juglone-induced oxidative stress in C. elegans. Additionally, alloaromadendrene not only acts protective against oxidative stress but also prolongs the lifespan of C. elegans. Moreover, mechanistic studies show that DAF-16 is required for alloaromadendrene-mediated oxidative stress resistance and longevity in C. elegans. The results in the present study indicate that the leaves of mixed-type C. osmophloeum and essential oil alloaromadendrene have the potential for use as a source for antioxidants or treatments to delay aging.

Multiple anticancer effects of damsin and coronopilin isolated from Ambrosia arborescens on cell cultures.

Terpenoids in plants are important sources for drug discovery. In this study, we extracted damsin and coronopilin, two sesquiterpene lactones, from Ambrosia arborescens and examined their anticancer effects on cell cultures. Damsin and coronopilin inhibited cell proliferation, DNA biosynthesis and formation of cytoplasmic DNA histone complexes in Caco-2 cells, with damsin being more potent than coronopilin. Further studies using the luciferase reporter system showed that damsin and coronopilin also inhibited expressions of nuclear factor-κB (NF-κB) and signal transducer and activator of transcription-3 (STAT3), indicating that these sesquiterpenes can interfere with NF-κB and STAT3 pathways. Finally, we examined the effects of two synthetic dibrominated derivatives of damsin, 11α,13-dibromodamsin and 11ß,13-dibromodamsin. While bromination appeared to weaken the antiproliferative effects of damsin, the ß epimer had strong inhibitory effects on STAT3 activation. In conclusion, the sesquiterpene lactones damsin and coronopilin have inhibitory effects on cell proliferation, DNA biosynthesis and NF-κB and STAT3 pathways, thus being potentially important for discovery of drugs against cancer.

Three new guaiane sesquiterpene lactones from rhizomes of Curcuma wenyujin.

Three new guaiane sesquiterpene lactones (4S)-4-hydroxy-gweicurculactone (1), zedoalactone G (2), and (1R, 4R, 5S, 10S)-zedoalactone B (3), and three known guaiane sesquiterpene lactones, including zedoarolide B (4), zedoalactone B (5), and a new natural product (+)-zedoalactone A (6), were isolated from the rhizomes of Curcuma wenyujin Y.H. Chen et C. Ling. The structures were elucidated by spectroscopic methods including 1D and 2D NMR and HR-ESI-MS. The absolute configuration of 2 was determined via the calculated electronic circular dichroism (ECD), whereas the absolute configurations of 1 and 3 were determined via the ECD data of the [Rh2(OCOCF3)4] complex and [Mo2(OAc)4] complex, respectively. The inhibitory effects of compounds 1-6 on nitric oxide production in lipopolysaccharide-activated macrophages were evaluated. All of them exhibited weak anti-inflammatory activity.

Isolation and structure elucidation of three new dolastanes from the brown alga Dilophus spiralis.

Three new dolastane diterpenes (1-3) and five previously reported perhydroazulenes were isolated from the organic extracts of the brown alga Dilophus spiralis. The structure elucidation and the assignment of the relative configurations of the isolated natural products were based on extensive analyses of their spectroscopic data, whereas the absolute configuration of metabolite 2 was determined through its chemical conversion to a previously isolated compound of known configuration.

Quantification of sesquiterpene lactones in Parthenium hyterophorous by normal-phase HPLC.

This paper describes the development of a normal-phase liquid chromatography ultraviolet-diode array detection method for the simultaneous quantification of parthenin and coronopilin in the leaves and flowers of Parthenium hysterophorous. The compounds were analyzed on a Merck Si60 silica column (5 µm, 250 × 4 mm) using an isocratic 15:85 mixture of isopropyl alcohol and hexane. The calibration curves resulting from the reference compounds in the concentration range of 200-2,000 ng exhibited acceptable linearity (r > 0.999). The method was developed to study the levels of parthenin and coronopilin in the leaves and flowers of P. hysterophorous collected during different seasons, and the method was validated by analyzing the spiked samples.

Advances in studies on the rupestonic acid derivatives as anti-influenza agents.

Rupestonic acid (isolated from the Chinese traditional medicine Artemisia rupestris L.) is a sesquiterpene with multifunctional groups and possess higher activity against influenza virus B. In order to improve the biological activity of rupestonic acid, many derivatives have been synthesized and their anti-influenza activity was screened. This review describes the rupestonic acid derivatives and their anti-influenza activity studied by our researching group.

Chemical composition of essential oil and in vitro antioxidant activities of the essential oil and methanol extracts of Eucalyptus loxophleba.

This study was designed to examine the chemical composition of the essential oil and the antioxidant activity of the essential oil and methanol extracts of Eucalyptus loxophleba Benth. subsp. The chemical composition of the essential oil of the leaves of E. loxophleba was analysed by GC and GC/MS. The main constituents of the oil were found to be 1,8-cineole (39.4%), methyl amyl acetate (19.8%) and aromadendrene (10%). Antioxidant activities of the samples were determined by two different test systems namely DPPH and ß-carotene/linoleic acid. In the DPPH system, the highest radical-scavenging activity was shown by the polar subfraction of the methanol extract (15.2 ± 1.7 µg mL⁻¹). Also, in the second case, the inhibition capacity (%) of the polar subfraction (94.1 ± 1.3) was found to be stronger. In addition, the amounts of total phenol components in the polar subfraction (273.0 ± 2.6 µg mg⁻¹) and nonpolar subfraction (146.3 ± 2.5 µg mg⁻¹) were determined.

Anthogorgienes A-O, new guaiazulene-derived terpenoids from a Chinese gorgonian Anthogorgia species, and their antifouling and antibiotic activities.

Fifteen new guaiazulene-based terpenoids designated anthogorgienes A-O (1-15) were isolated from a Chinese gorgonian Anthogorgia sp., together with eight known analogues (16-23). The structural patterns were classified into monomers, dimers, and trimers, which were supposed to be generated from a precursor guaiazulene and followed by side-chain and nucleus oxidation and oxidative rearrangement. The structures of new compounds were elucidated on the basis of extensive spectroscopic (IR, MS, and 1D and 2D NMR) data analysis. A possible biogenetic relationship of the isolated compounds was postulated. Some of the compounds showed potent antifouling activities against the larval settlement of barnacle Balanus amphitrite , whereas their antibiotic activities were also evaluated.