Bioassay-Guided Isolation of Antiproliferative Compounds from Limbarda crithmoides (L.) Dumort

In Vitro Anti-inflammatory Activity of Three Inula Species Essential Oils in Lipopolysaccharide-Stimulated RAW 264.7 Macrophages

In the face of the undesirable effects induced by anti-inflammatory drugs, there has been a return, nowadays, to the search for active ingredients based on plants. Herein, for the first time we study the anti-inflammatory activity of essential oils of three species of the genus Inula: Inula viscosa, Inula graveolens and Inula crithmoides in lipopolysaccharide (LPS)-activated macrophages. Essential oils have shown excellent preventive anti-inflammatory potential by causing inhibition of nitric oxide (NO) production in LPSactivated RAW264.7 macrophages with IC50s ranging between 15 and 35 µg  mL^− 1. On the other hand, the major acidic compounds, more precisely α- and β-costic acids, have been isolated from Inula viscosa and Inula graveolens essential oils and evaluated for their anti-inflammatory effect. These compounds appear to have a moderate preventive inhibitory effect on NO production relative to the significant effect generated by the neutral minority components present in the oils such as borneol, bornyl acetate, (E)-nerolidol, caryophyllene oxide, T-cadinol and eugenol. Therefore, we can deduce that the studied essential oils could be used as anti-inflammatory agents for the treatment of various inflammatory pathologies.

The chemical composition of the flowers essential oil of Inula crithmoides (Asteraceae) growing in aeolian islands, Sicily (Italy) and its biocide properties on microorganisms affecting historical art crafts

Essential oils have been used for a long time in several fields of interest. Recently, they have also been applied in the conservation of Cultural Heritage to contrast biodeterioration replacing the most current biocides toxic for humans and environment. Inula crithmoides L. (syn. Limbarda crithmoides (L.) Dumort) is a halophyte species distributed along the Mediterranean coasts and it is used as an edible vegetable since the young leaves or shoots are eaten raw or cooked. Several biological properties have been determined for this plant including antimicrobial activities. In this study the volatile composition of the aerial part of an accession from the Aeolian Islands, Sicily (Italy) is described. Furthermore, the in vitro antibacterial assay against four species of bacteria isolated from a XX century Tholu Bhommalu, a leather painted puppet from Andhra Pradesh (India), was showed by the Agar disc diffusion method.

Methodology for the Absolute Configuration Determination of Epoxythymols Using the Constituents of Piptothrix areolare

Since epoxythymols occur in Nature either as scalemic mixtures or as pure enantiomers, the knowledge of their chiral composition and of the absolute configuration (AC) of the dominant enantiomer turns out to be mandatory. This task has already been faced using 1,1-bis-2-naphthol (BINOL), as a chiral solvating agent in accurate ¹H NMR quantifications to determine the enantiomeric ratio, and vibrational circular dichroism (VCD) to evidence the AC of the dominant enantiomer. We now explore the use of electronic circular dichroism (ECD) to determine the AC of an epoxythymol for which time-expensive DFT calculations would be required unless the AC of a related molecule is already known, from either VCD studies or single-crystal X-ray diffraction analysis, since one could correlate the ECD Cotton effect with the AC because in ECD only chromophores and their neighborhoods are evidenced. This method is now applied by using the epoxythymols from Piptothrix areolare. Known areolal (1) and 10-cinnamoyloxy-8,9-epoxythymol isobutyrate (2) were isolated from the roots, while known 7-acetoxy-10-cinnamoyloxy-8,9-epoxythymol isobutyrate (3) and 10-cinnamoyloxy-7-hydroxy-8,9-epoxythymol isobutyrate (4), as well as the new enantiopure 7-acetoxy-10-cinnamoyloxy-6-hydroxy-8,9-epoxythymol isobutyrate (5) and 10-cinnamoyloxy-8,9-epoxy-6-hydroxy-7-northymol isobutyrate (6), were obtained from the extract of the flowers. Chemical correlation of epoxythymols 1 and 3 was achieved. Compounds 1-4 were obtained as scalemic mixtures, and 5 and 6 as the pure (8S) enantiomers. In addition, the new 10-cinnamoyloxy-7-oxo-8,9-dehydrothymol isobutyrate (7) was isolated from the roots. The structures of 5-7 followed from NMR and HRMS data, while enantiomeric compositions of 1-6 were determined by ¹H NMR-BINOL measurements. The AC determination for 2-6 was done by ECD using a sample of 1 to reference the ECD Cotton effect. In turn, the AC of 1 was determined by VCD and extensive DFT calculations. The ECD-BINOL methodology turned out to be some 500 times more sensitive than that combining VCD and ¹H NMR-BINOL.

Structural and Chemical Adaptations of Artemisia monosperma Delile and Limbarda crithmoides (L.) Dumort. in Response to Arid Coastal Environments along the Mediterranean Coast of Egypt

Arid coastal habitats are stressful regions subjected to the effects of biotic and abiotic factors. Vascular plants in these habitats display different responses to cope with these environmental fluctuations. This work addressed the morpho-anatomical features and chemical responses of two medicinal vascular plant species Artemisia monosperma Delile and Limbarda crithmoides (L.) Dumort., growing naturally along the Mediterranean coast of Egypt. Soil properties (physical and chemical), morpho-anatomical features and chemical constituents (secondary metabolites, antioxidant activity and essential oils) for the two species were performed. Our results displayed that both species are surviving where soils are alkaline, high saline with low moisture and organic carbon. The morphology of both species appeared woody low shrub with fleshy leaves. The most marked anatomical attributes were the thick cuticle of the epidermal layer in leaves and stems, compact palisade cells and abundant idioblasts (secretory ducts, phenolic compounds and calcium oxalate). Also, sclerenchymatous pericycle fibers in stem and glandular trichomes on the leaf had appeared in A. monosperma. Both plants exhibited a considerable content of phenolics, flavonoids, tannins, alkaloids and antioxidant activity with a higher level in A. monosperma than L. crithmoides. The leaf extracts of both plants showed higher values than the stem extracts. The sesquiterpenes group were the major identified compounds of the essential oils (EOs) in A. monosperma and L. crithmoides, and the majority were oxygenated sesquiterpenes with percentages of 42.63% and 51.49%, respectively. The second major group of EOs was monoterpenes, which were represented in A. monosperma in concentrations (34.04%) much higher than those recorded in L. crithmoides (4.97%). Exploring the local adaptation mechanism used by the target plants helps us to understand how these plants can acclimatize to harsh conditions, and this provides critical insights into the protection and survival strategy of species under extreme conditions.