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The chloroform extract of the aerial parts of Centaurea musimomum exhibited significant activity against Plasmodium falciparum. The phytochemical study of this extract gave seven native and four acetylated sesquiterpene lactones.
Folklore reports from Afghanistan prior to the wars described the use of aqueous root extracts of Cichorium intybus (L.) as a light-sensitive plant remedy for malaria. Preparative isolation and bioassay against HB3 clone of strain Honduras-1 of Plasmodium falciparum identified the previously known light-sensitive sesquiterpene lactones Lactucin and Lactucopicrin to be antimalarial compounds.
The fresh spiny flowers of Centaurea solstitialis ssp. solstitialis (CSS) are used for the treatment of peptic ulcers in Turkey. Ethanol (80%) extract of CSS exhibited significant anti-ulcerogenic effect on the ethanol-induced ulcerogenesis model in rats. The ethanol extract was further fractionated by successive solvent extractions with n-hexane, chloroform, ethyl acetate and n-butanol. All fractions showed significant anti-ulcerogenic activity, however, the effect of the chloroform fraction was found to be more prominent with 99.5% ulcer inhibition. Bioassay-guided fractionation yielded sesquiterpene lactones as the active components. The main components responsible for the activity of the chloroform fraction were determined as chlorojanerin and 13-acetyl solstitialin A which were elucidated by HR-ESI and (1)H, (13)C and 2D NMR spectroscopic techniques.
Phytochemical analysis of the leaves of Vernonia amygdalina yielded two known sesquiterpene lactones: vernolide and vernodalol. The two compounds were tested by agar dilution method against 10 bacteria strains and 5 fungi species. Both compounds exhibited a significant bactericidal activity against five Gram positive bacteria while lacking efficacy against the Gram negative strains. In the antifungal test, while vernolides exhibited high activity with LC(50) values of 0.2, 0.3 and 0.4 mg/ml against Penicillium notatum, Aspergillus flavus, Aspergillus niger and Mucor hiemalis, respectively, vernodalol showed moderate inhibitions against Aspergillus flavus, Penicillium notatum and Aspergillus niger with LC(50) values of 0.3, 0.4 and 0.5 mg/ml, respectively. Both compounds were ineffective against Fusarium oxysporum, a microbe known to be highly resistant to chemical agents. However, the antimicrobial results of this study correspond positively with the claimed ethnomedical uses of the leaves of Vernonia amygdalina in the treatment of various infectious diseases.
Liquid chromatography/atmospheric pressure chemical ionization ion trap mass spectrometry (LC/APCI-ITMS) was applied to determine the concentration of terpene lactone in plasma of guinea pigs after chronic administration of Ginkgo biloba extract enriched in ginkgoterpenes in free form (IDN 5380) or complexed with soy phosphlipids (IDN 5381). Oral treatment of the animals with ginkgoterpenes resulted to inhibit the bronchoconstriction (ITP) and the concomitant increase of the levels of thromboxane B2 (TXB2) in the circulation caused by histamine (HIST) and platelet activating factor (PAF) in normal guinea pigs or by ovalbumin (OA) in actively sensitized guinea pigs. To compare the protective activities of G. biloba forms (IDN 5380 and IDN 5381), ED50 and dose ratio (DR) values for both parameters (ITP and TXB2) were evaluated. The phytosomic form (IDN 5381) significantly reduced (two- to four-fold as compared to free form, P < 0.001) the HIST, PAF or OA-induced airway changes and TXB2 release. In addition it has been observed that the absence of ginkgolide C (GC) in plasma samples (in human and animals) was due to its rapid methylation.
Preparations of Arnica montana L. are widely used for the topical treatment of inflammatory diseases. The anti-inflammatory activity is mainly attributed to their sesquiterpene lactones (SLs) from the helenalin and 11alpha,13-dihydrohelenalin type. To study the penetration kinetics of SLs in Arnica preparations, a stripping method with adhesive tape and pig skin as a model was used. For the determination of SLs in the stripped layers of the stratum corneum (SC), a gas chromatography/mass spectrometry method was developed and validated. Thereby the amount of helenalin derivatives was calculated as helenalin isobutyrate, and 11alpha,13-dihydrohelenalin derivatives as 11alpha,13-dihydrohelenalin methacrylate. This GC-MSD method is suitable also to determine low amounts of SLs in Arnica preparations. The penetration behaviour of one gel preparation and two ointment preparations was investigated. The SLs of all preparations show a comparable penetration in and a permeation through the stratum corneum, the uppermost part of the skin. Interestingly, the gel preparation showed a decrease of the penetration rate over 4h, whereas the penetration rate of ointments kept constant over time. Moreover, we could demonstrate that the totally penetrated amount of SLs only depends on the kind of the formulation and of the SLs-content in the formulation but not on the SLs composition or on the used extraction agent.
From the ethanolic extract of stem bark of D. angustifolia three new compounds, a coumaroyl triterpene lactone, diospyrosooleanolide (1), a phenolic glycoside, diospyrososide (2) and a naphthalene glycoside, diospyrosonaphthoside (3) were isolated along with five known compounds (4-8). The structures of these compounds were established on the basis of spectroscopic and chemical evidences.
The costunolide lactone, a sesquiterpene compound isolated from Zaluzania triiloba species, reacted with several dihalocarbene sources produced by trihaloform-NaOH under successive phase transfer reactions yielding mono-, bis- and tris-dihalocyclopropane adducts. The structures, as well as the configurational assignments of the different derivatives, were established by (1)H and (13)C NMR spectroscopy and assisted by X-ray crystallographic and molecular modelling studies. The specific shielding of protons in the neighbourhood of different halogens on the cyclopropane moieties was correlated to the pseudocontact interactions.
In this paper we present a complete 1H and 13C NMR spectral analysis of three lignan lactones (methylpluviatolide, dimethylmatairesinol and hinokinin) by the use of techniques such as COSY, HMQC, HMBC and J-resolved. Complete assignment and all homonuclear hydrogen coupling constant measurements were performed, providing enough data also to the confirmation of the relative stereochemistry.
Treatment of Delta 4-3-ketosteroids with m-chloroperbenzoic acid at 0 degrees C produced the corresponding steroidal seven-membered A-ring epoxy lactones. The adopted procedure allowed for efficient recovery and separation of the products with definite stereochemistry.
We have developed a modified migration assay system in 96-well plate format which is able to detect resistance to the macrocyclic lactone group of drugs in Haemonchus contortus. The assay involves exposure of infective stage larvae to drug for a 24 h period, then counting the numbers of larvae that are able to migrate through an agar and filter mesh system over a further 48 h. The agar barrier greatly increased the sensitivity of the assay for resistance detection compared to use of filter mesh alone. The assay was able to detect the presence of 10% resistant worms in an otherwise susceptible background. However, the assay was ineffective with Trichostrongylus colubriformis and Ostertagia circumcincta indicating that its usefulness for field monitoring will be restricted to situations where H. contortus is of most significance. A small-scale drug screening exercise showed that the assay identifies some anthelmintic activities distinct from those identified by larval development assays. The assay therefore also has a potential role in drug discovery programmes in screening for new anthelmintics.
Costunolide, a germacranolide sesquiterpene lactone that exists in several medicinal plants, is known to be a possible anti-cancer and chemopreventive agent for tumorigenesis. In this report, we investigated the effect of costunolide on cellular differentiation in the human promyelocytic leukemia HL-60 cell culture system. Costunolide markedly increased the degree of HL-60 leukemia cell differentiation when simultaneously combined with 5nM 1,25-dihydroxyvitamin D(3) (1,25-(OH)(2)D(3)). Costunolide by itself had very weak effects on the differentiation of HL-60 cells. Cytofluorometric analysis and cell morphologic studies indicated that costunolide potentiated 1,25-(OH)(2)D(3)-induced cell differentiation predominantly into monocytes. Inhibitors for PKC, PI3-K, and ERK markedly inhibited HL-60 cell differentiation induced by costunolide in combination with 1,25-(OH)(2)D(3). In addition, pretreatment of HL-60 cells with costunolide before the 1,25-(OH)(2)D(3) addition also potentiated cell differentiation in a concentration- and time-dependent manner, and the enhanced levels of cell differentiation closely correlated with the inhibitory levels of NF-kappaB-binding activity by costunolide. These results indicate that PKC, PI3-K, ERK and NF-kappaB may be involved in 1,25-(OH)(2)D(3)-mediated cell differentiation enhanced by costunolide.
Sesquiterpene lactones (SLs) are natural products responsible for the anti-inflammatory activity of a variety of medicinal plants, mainly from the Asteraceae family. Here, we investigated whether they also influence the process of exocytosis of pro-inflammatory enzymes, such as the human neutrophil elastase (HNE). Altogether, eight structurally different SLs from the eudesmanolide, guaianolide, pseudoguaianolide, and germacranolide type were studied. Neutrophils were isolated from fresh human blood. After pre-incubation with different concentrations of the respective SL and cytochalasin B, the exocytosis of elastase was initiated either by platelet activating factor or N-formyl-methionyl-leucyl-phenylalanine. Inhibition of HNE release was measured by p-nitroaniline formation. The SLs exhibited an inhibitory effect on elastase release from neutrophils challenged either by platelet activating factor or N-formyl-methionyl-leucyl-phenylalanine. Concentration-response curves were recorded and the IC(50) values ranged from 2 to 30 microM. Studies on isolated HNE showed that a selective direct inhibition on HNE can be excluded. Interestingly, the inhibitory activity did not correlate with the number of alpha,beta-unsaturated carbonyl functions. The structure-activity relationship and the molecular mechanism are discussed.
The X-ray diffraction and high-resolution 1H and 13C NMR spectral data are reported for 2,4,7,8-tetra-O-acetyl-3-deoxy-alpha-D-manno-2-octulopyranosono-1,5-lactone.
2,3,4,5-tetra-O-methyl-D-glucono-1,6-lactone has been prepared as a crystalline compound in acceptable yield by two different routes. An initial assay of copolymerization with L-lactide by ring-opening polymerization was carried out. The incorporation of the carbohydrate monomer into the polymer chain was about 2%.
5-Thio-D-arabinopyranose (5) and 5-thio-D-xylopyranose (10) were synthesized from the corresponding D-pentono-1,4-lactones. After regioselective bromination at C-5, transformation into 5-S-acetyl-5-thio derivatives, reduction into lactols and deprotection afforded the title compounds in 49 and 42% overall yield, respectively.
We investigated in vitro anti-inflammatory effects of cynaropicrin, a sesquiterpene lactone from Saussurea lappa, on tumor necrosis factor (TNF)-alpha and nitric oxide (NO) release, and lymphocyte proliferation. Cynaropicrin strongly inhibited TNF-alpha release from lipopolysaccharide-stimulated murine macrophage, RAW264.7 cells, and differentiated human macrophage, U937 cells, proved to produce notable amount of TNF-alpha. It also potently attenuated the accumulation of NO released from lipopolysaccharide- and interferon-gamma-stimulated RAW264.7 cells in a dose-dependent manner. In addition, the immunosuppressive effects of the compound on lymphocyte proliferation in response to mitogenic stimuli were examined. Cynaropicrin also dose-dependently suppressed the proliferation of lymphocytes from splenocytes and interleukin-2-sensitive cytotoxic T lymphocyte, CTLL-2 cells, stimulated by lipopolysaccharide, concanavalin A, phytohemagglutinin and interleukin-2. However, treatment with sulphydryl compound, L-cysteine, abrogated all these inhibitory effects. These results suggest that cynaropicrin may participate in the inflammatory response by inhibiting the production of inflammatory mediators and the proliferation of lymphocytes and its inhibitory effect is mediated through conjugation with sulphydryl groups of target protein(s).
A group of eleven sesquiterpene lactones isolated from different Asteraceae species from north-western Argentina were investigated for their inhibitory action on the estrogen biosynthesis. Seven of them, of different skeleton types, were found to inhibit the aromatase enzyme activity in human placental microsomes, showing IC50 values ranging from 7 to 110 microM. The most active were the guaianolides 10-epi-8-deoxycumambrin B (compound 1), dehydroleucodin (compound 2) and ludartin (compound 3). These compounds were competitive inhibitors with an apparent Ki = 4 microM, Ki = 21 microM and Ki = 23 microM, respectively. Compounds 1 and 2 acted as type II ligands to the heme iron present in the active site of aromatase cytochrome P450 (P450arom). Besides, all of them failed to affect the cholesterol side-chain cleavage enzyme activity on human placental mitochondrias. This is the first report on the aromatase inhibitory activity of this group of natural compounds.