Guido Flamini

Composition and antimicrobial properties of essential oils of four Mediterranean Lamiaceae

Essential oils from Satureja montana L., Rosmarinus officinalis L., Thymus vulgaris L., and Calamintha nepeta (L.) Savi, were chemically analysed and their antimicrobial and fungicide activities evaluated on the basis of their minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). All four oils have a biotoxic effect, the most active being those from Calamintha and Thymus.

Two flavonoids and other compounds from the aerial parts of Centaurea bracteata from Italy

The flowering aerial parts of Centaurea bracteata Scop. (Asteraceae) have been studied for the first time. Nineteen compounds were isolated and identified, namely a sterol glucoside, two phenolic acids, three quinic acid derivatives, and 13 flavonoids, two of which, are new natural products. Structural elucidation was performed mainly by mean of FABMS, 1D and 2D NMR spectroscopy.

GC–MS analysis of essential oil of some commercial Fennel teas

Abstract Fennel teas were prepared by classical infusion or microwave decoction of unbroken and crushed fruits, three pre-packaged teabags and two instant teas. Their volatile constituents were obtained by extraction with n-hexane and analysed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC–MS), using two columns with stationary phases of different polarity. Of the constituents 85–95% were identified on the basis of their GC retention times and their mass spectra in relation to authentic compounds. No volatile constituents were detected in one sample of instant tea. Conventional teas from crushed fruits and teas prepared from the other instant tea showed the highest levels of volatile constituents. Anethole (30–90%) and/or anisaldehyde (0.7–51%) were the main constituents of all the samples. Methychavicol (0.8–4.1%), eugenol (1.5–11.3%) and fenchone (0.5–47%) were detected in most samples. Carvone (2.1–6.1%) was presenting only some teabags and camphor (2.3–2.6%) in others. The volatile constituents of only one instant tea included limonene (1.4%) and α-terpineol (0.4%).

Use of solid-phase micro-extraction as a sampling technique in the determination of volatiles emitted by flowers, isolated flower parts and pollen☆

The volatiles emitted by fresh whole flowers or isolated flower parts of mandarin, Citrus deliciosa Ten. (Rutaceae), were sampled using solid-phase micro-extraction (SPME). This technique offers several advantages over dynamic headspace sampling techniques used in previous investigations. In particular, SPME requires smaller sample sizes and very short sampling times, which can minimize the formation of artifacts due to damage to the plant, and contaminations or loss of compounds. This was especially applicable to the collection of volatiles from pollen.

Antimicrobial activity of the essential oil of Calamintha nepeta and its constituent pulegone against bacteria and fungi.

The chemical composition of the essential oil of Calamintha nepeta and its antimicrobial activity against Listeria monocytogenes, Bacillus cereus, Salmonella veneziana, S. paratyphi B, S. typhimurium, Fusarium moniliforme, Botrytis cinerea, Aspergillus niger and Pyricularia oryzae have been studied. Moreover the main constituents of the oil (limonene, menthone, pulegone, menthol) have been tested against the same microorganisms. Only pulegone showed antimicrobial activity, particularly against all the Salmonella species. Copyright

Volatile constituents of two endemic Centaurea species from Turkey: C. pseudoscabiosa subsp. pseudoscabiosa and C. hadimensis

The essential oils obtained from two endemic Centaurea species (Compositae) from Turkey, C. pseudoscabiosa subsp. pseudoscabiosa Boiss. et Buhse (Sect. Acrocentron) and C. hadimensis Wagenitz, K. Ertugrul et H. Dural (Sect. Psephelloideae), have been studied. Germacrene D was the major component (36.0 and 44.3%, respectively), followed by β-caryophyllene, bicyclogermacrene and β-sesquiphellandrene.

Mass Propagation and Essential Oil Analysis of Artemisia vulgaris

Artemisia vulgaris L. (Mugwort) is a threatened and valuable medicinal plant. Attempts have been made in this research to mass propagate its plantlets through in vitro liquid culture technology using Murashige and Skoog (MS) basal medium supplemented with 6-benzyl adenine (BA) (0.44-8.88 microM). Initially, 22.6 shoots (99.9% shooting frequency) developed from shoot tip explants cultured in MS with 4.44 microM BA at 100 ml flask capacity. This was further subcultured at increasing flask capacity (150, 250, and 500 ml) for shoot proliferation. Of the different concentrations of BA and flask capacities tested, 4.44 microM BA and 500 ml flask capacity were found to produce a maximum of 85.5 shoots after 30 d of culture. Shoot proliferation was found to increase with increasing flask capacity whereas shoot number decreased with increasing BA concentration (>4.44 microM). Individual shoots were isolated and rooted on MS medium containing 8.56 microM indole-3-acetic acid (IAA). Then the plantlets were acclimatized under standard laboratory conditions and later under greenhouse conditions. Fresh leaves were collected from greenhouse-grown plants and subjected to essential oil analysis by the simultaneous distillation and extraction method. GC-MS results revealed the presence of 88 components and the extracted oil was rich in camphor (16.8%), alpha-thujone (11.3%), germacrene D (7.2%), camphene (6.5%), 1,8-cineole (5.8%) and beta-caryophyllene (5.4%). This in vitro strategy can be a reliable method for the steady production of a large number of plants for essential oil production, which is reported for the first time for A. vulgaris.

Isoflavonoids and chalcones from Anthyllis hermanniae

From the aerial parts of Anthyllis hermanniae two new prenylated chalcones, 1-(2,4-dihydroxyphenyl)-3-[2,2-dimethyl-8-(3-methyl-2-butenyl)-2H-1-benzopyran-6-yl]-2-propen-1-one (anthyllisone) and 1-(2,4-dihydroxyphenyl)-3-[4-hydroxy-3-(2-hydroxy-3-methyl-3-butenyl)-5-(3-methyl-2-butenyl)phenyl]-2-propen-1-one (anthyllin), have been isolated, along with the known chalcones isobavachalcone and abyssinone VI and the prenylated isoflavonoids wighteone, lupiwighteone and lupalbigenin. Their structures were elucidated by spectroscopic methods, including 2D NMR techniques. d-Pinitol was also isolated.

ESSENTIAL OIL COMPOSITION OF TWO ENDEMIC CENTAUREA SPECIES FROM TURKEY CENTAUREA MUCRONIFERA AND CENTAUREA CHRYSANTHA COLLECTED IN THE SAME HABITAT

The essential oils of two endemic Centaurea species from Turkey, C. mucronifera and C. chrysantha, collected in the same habitat, have been studied. The main compounds of the former were germacrene D (29.3%), β-eudesmol (17.4%) and β-caryophyllene (7.3%), while in the latter germacrene D (27.4%), caryophyllene oxide (9.5%) and bicyclogermacrene (5.4%) were detected among its major constituents. The two species produced many similar compounds in their essential oils that could be justified by the similar ecological conditions of their habitat, but also many differences were found that could confirm their taxonomic separation.

Mentha spicata Essential Oil: Chemical Composition, Antioxidant and Antibacterial Activities against Planktonic and Biofilm Cultures of Vibrio spp. Strains.

Chemical composition, antioxidant and anti-Vibrio spp. activities of the essential oil isolated from the aerial parts of Mentha spicata L. (spearmint) are investigated in the present study. The effect of the essential oil on Vibrio spp. biofilm inhibition and eradication was tested using the XTT assay. A total of 63 chemical constituents were identified in spearmint oil using GC/MS, constituting 99.9% of the total identified compounds. The main components were carvone (40.8% ± 1.23%) and limonene (20.8% ± 1.12%). The antimicrobial activity against 30 Vibrio spp. strains (16 species) was evaluated by disc diffusion and microdilution assays. All microorganisms were strongly affected, indicating an appreciable antimicrobial potential of the oil. Moreover, the investigated oil exhibited high antioxidant potency, as assessed by four different tests in comparison with BHT. The ability of the oil, belonging to the carvone chemotype, to inhibit or reduce Vibrio spp. biofilm warrants further investigation to explore the use of natural products in antibiofilm adhesion and reinforce the possibility of its use in the pharmaceutical or food industry as a natural antibiotic and seafood preservative against Vibrio contamination.