Highly hydroxylated guaianolides of Achillea asiatica and Middle European Achillea species

Germacranolide- and guaianolide-type sesquiterpenoids from Achillea alpina L. reduce insulin resistance in palmitic acid-treated HepG2 cells via inhibition of the NLRP3 inflammasome pathway

Chemical investigation on the aerial part of Achillea alpina L. led to the isolation of twenty sesquiterpenoids. The structures of the undescribed achigermalides A-H were determined by extensive spectroscopic analysis, including NMR, HRESIMS, UV and IR, and their absolute configurations were established by computational electronic circular dichroism (ECD) method. The X-ray crystal structure for 8α-angeloxy-1β,2β:4β,5β-diepoxy-10β-hydroxy-6βH,7αH,11βH-12,6α-guaianolide was reported for the first time. Glucose consumption was analyzed to investigate the effect of all compounds on palmitic acid (PA)-mediated insulin resistance (IR) in HepG2 cells, and achigermalides D-F, desacetylherbohde A, and 4E,10E-3-(2-methylbutyroyloxy)-germacra-4,10(1)-diene-12,6α-olide appreciably enhanced the glucose consumption at low concentrations of 1.56-6.25 μM. Moreover, achigermalide D decreased the expression of IL-1β and the generation of reactive oxygen species (ROS), and also down-regulated the protein levels of TXNIP, NLRP3, caspase-1 and NF-κB in the Western blot analysis, suggesting achigermalide D mediated IR via the suppression of NLRP3 inflammasome pathway.

UHPLC-MS Characterization and Biological Insights of Different Solvent Extracts of Two Achillea Species (A. aleppica and A. santolinoides) from Turkey

In the current study, Achillea santolinoides and Achillea aleppica aeral parts and root were extracted with ethyl acetate, methanol, and water. Detailed phytochemical profiles were obtained using UHPLC-MS, yielding the identification of hydroxybenzoic and hydroxycinnamic acids, phenolic acid glycosides and sugar esters, acylquinic acids, O-glycosyl flavones and flavonols, and flavonoid aglycons, among others. The antioxidant properties and enzyme inhibitory activities of the extracts were assayed with in vitro tests. The phenolic content of the water extracts was significantly higher as compared to the ethyl acetate and methanol ones. A. aleppica aerial parts methanol extract possessed highest flavonoid content (49.18 mg rutin equivalent/g). Antioxidant properties assessment revealed that the methanol extract of A. santolinoides roots actively scavenged DPPH (54.11 mg TE/g) and ABTS radicals (112.53 mg TE/g) and possessed highest reducing potential (183.55 and 129.92 mg TE/g, for CUPRAC and FRAP, respectively). The ethyl acetate extracts of aerial parts and roots of both species showed highest inhibition against BuCHE (6.07–6.76 mg GALAE/g). The ethyl acetate extract of A.santolinoides aerial part showed highest inhibition against tyrosinase (73.00 mg KAE/g). These results showed that the tested Achillea species might represent novel phytotherapeutic avenues for the management of Alzheimer’s disease and epidermal hyperpigmentation conditions, which are both associated with oxidative stress. This paper could shed light into future potential industrial applications using the tested Achillea species.

Protective effect of Chresta martii extract against indomethacin-induced gastric lesions in mice

Chresta martii (Asteraceae) is a plant found in the Xingó region (semi-arid area) in Northeastearn Brazil, and is recognized by the local population as a traditional herb used to treat gastric diseases. This is the first report of the chemical composition, acute toxicity, and gastroprotective effect in mice of the hydroalcoholic extract (HAE) from the aerial parts (leaves and flowers) of Chresta martii. Animals received HAE doses from 10 to 2000 mg/kg, i.p. or 50 to 3000 mg/kg, p.o.) and were observed over 48 h for toxicity signs and mortality; sub-chronic toxicity was evaluated through 14 days treatment with once-daily HAE doses (400 mg/kg, p.o.). The gastroprotective effect of HAE was demonstrated on the indomethacin-induced gastric ulcer model after the administration of extracts. Data comparison of ulcer index averages between saline and HAE (100 or 400 mg/kg, p.o.) groups showed significant (P < 0.01) inhibition (71.73 and 76.72 %, respectively) of indomethacin-induced gastric lesions. Histological analyses showed significant (P < 0.05) inhibition of leukocyte migration in HAE-treated groups. A fingerprint of the HAE obtained by HPLC/UV/MS analysis showed major peaks characteristic of sesquiterpene lactones. Compound 1 was isolated and elucidated as a new natural product. Its capacity to prevent leukocyte chemotaxis was demonstrated in vitro, corroborating the pharmacological effects observed for C. martii HAE.

Dimeric guaianolides and sesquiterpenoids from Artemisia anomala

A new dimeric guaianolide (8) and a new glaucolide (3), a seco-guaiaretic acid (4), two guaianolides (6 and 7), and five known sesquiterpene lactones (1, 2, 5, 9, and 10) were isolated from the aerial part of Artemisia anomala. Their structures were determined on the basis of chemical and spectroscopic analysis. In addition, their cytotoxic activities against five human cancer cell lines and anti-COX-2 effects in vitro were evaluated.

Natural sesquiterpenoids

This review covers the isolation, structural determination, synthesis and chemical and microbiological transformations of natural sesquiterpenoids. 423 references are cited.

Chemotypes in Achillea collina based on sesquiterpene lactone profile

The lactone profile of six origins of Achillea collina growing in Bulgaria was studied and significant variability was observed. The reasons for the differences in the lactone composition are discussed. Twenty-five components in total were isolated and identified, while the presence of ten lactones was proved by intensive TLC analysis in comparison with reference compounds. The structures of the components 17, 20, 25-30 were established by spectroscopic methods. The structure of 7, a cyclization product of 6, was also discussed. The anti-inflammatory activity of some extracts, fractions and individual compounds was tested in vitro by determining the inhibitory effects on induced human neutrophils.

Composition, enantiomeric distribution, and antibacterial activity of the essential oil of Achillea ligustica All. from Corsica

The essential oil of Achillea ligustica from Corsica was investigated by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). A total of 82 compounds representing 94.0% of the oil were tentatively identified. The main constituents were the camphane derivatives, representing >30% (camphor, 21.3%; borneol, 6.2%; bornyl acetate, 3.5%) of the whole oil, and santolina alcohol (19.3%). The enantiomeric distribution of 8 chiral constituents was determined by GC-MS using two enantioselective stationary phases (DIME-beta-CD and Lipodex-E). Racemic santolina alcohol, required for optimization of the enantioselective GC conditions, was prepared by an original two-step synthesis from 2,5-dimethylhexa-2,4-diene. The whole essential oil was tested for its antibacterial activity against a wide range of bacteria using a paper disk method. The results show a promising activity against Streptomyces species.

Analysis of aroma and phenolic components of selected Achillea species

Dried flowers and leaves of four different Achillea species grown wild in several provinces of Iran, including one species collected from three different locations of Isfahan province were analyzed for the headspace volatile components, total phenolics (TP) and tartaric esters (TE). Capillary gas chromatography/mass spectrometry (GC/MS) combined with a purge and trap method was used for quantification of aroma components. Over 70 compounds were determined in the samples. Flower samples from all species contained 2-methyl butanal, alpha-pinene, alpha-thujene, camphene, hexanal, beta-pinene and 1,8-cineole; however, the major constituents of the aerial parts were determined as alpha-pinene, camphene, DL-limonene and 1,8-cineole. The largest number of aroma components were found in Achillea tenuifolia Lam. and Achillea millefolium L. In all species, except A. millefolium, the leaves contained more TP and TE than flowers. However, A. wilhelmsii from Semirom in Isfahan province showed the highest values for TP and TE.