Mario Chessa

'Moringa oleifera: study of phenolics and glucosinolates by mass spectrometry' †

Moringa oleifera is a medicinal plant and an excellent dietary source of micronutrients (vitamins and minerals) and health-promoting phytochemicals (phenolic compounds, glucosinolates and isothiocyanates). Glucosinolates and isothiocyanates are known to possess anti-carcinogenic and antioxidant effects and have attracted great interest from both toxicological and pharmacological points of view, as they are able to induce phase 2 detoxification enzymes and to inhibit phase 1 activation enzymes. Phenolic compounds possess antioxidant properties and may exert a preventative effect in regards to the development of chronic degenerative diseases. The aim of this work was to assess the profile and the level of bioactive compounds in all parts of M. oleifera seedlings, by using different MS approaches. First, flow injection electrospray ionization mass spectrometry (FI-ESI-MS) fingerprinting techniques and chemometrics (PCA) were used to achieve the characterization of the different plants organs in terms of profile of phenolic compounds and glucosinolates. Second, LC-MS and LC-MS/MS qualitative and quantitative methods were used for the identification and/or determination of phenolics and glucosinolates in M. oleifera.

Variability of chemical composition and antioxidant activity of essential oils between Myrtus communis var. Leucocarpa DC and var. Melanocarpa DC

Essential oils (EOs) from several individuals of Myrtus communis L. (M. communis) growing in different habitats in Sardinia have been studied. The analyses were focused on four groups of samples, namely cultivated and wild M. communis var. melanocarpa DC, characterized by red/purple berries, and cultivated and wild M. communis var. leucocarpa DC, characterized by white berries. Qualitative and quantitative analyses demonstrated different EO fingerprints among the studied samples: cultivated and wild leucocarpa variety differs mainly from the melanocarpa variety by a high amount of myrtenyl acetate (>200 mg/mL and 0.4 mg/mL in leucocarpa and melanocarpa varieties respectively). Conversely, the wild group is characterized by a higher amount, compared with the cultivated species, of linalool (about 110 mg/mL and 20 mg/mL respectively), linalyl acetate (about 24 mg/mL and about 6 mg/mL respectively) whereas EOs of the cultivated plants were rich in pinocarveol-cis compared with wild plants (about 2 mg/mL and about 0.5 mg/mL respectively). Principal component analysis applied to the chromatographic data confirm a differentiation and classification of EOs from the four groups of M. communis plants. Finally, antioxidant activity of the studied EOs shows differences between the various categories of samples.

Genetic and metabolite diversity of Sardinian populations of Helichrysum italicum

Background Helichrysum italicum (Asteraceae) is a small shrub endemic to the Mediterranean Basin, growing in fragmented and diverse habitats. The species has attracted attention due to its secondary metabolite content, but little effort has as yet been dedicated to assessing the genetic and metabolite diversity present in these populations. Here, we describe the diversity of 50 H. italicum populations collected from a range of habitats in Sardinia. Methods H. italicum plants were AFLP fingerprinted and the composition of their leaf essential oil characterized by GC-MS. The relationships between the genetic structure of the populations, soil, habitat and climatic variables and the essential oil chemotypes present were evaluated using Bayesian clustering, contingency analyses and AMOVA. Key results The Sardinian germplasm could be partitioned into two AFLP-based clades. Populations collected from the southwestern region constituted a homogeneous group which remained virtually intact even at high levels of K. The second, much larger clade was more diverse. A positive correlation between genetic diversity and elevation suggested the action of natural purifying selection. Four main classes of compounds were identified among the essential oils, namely monoterpenes, oxygenated monoterpenes, sesquiterpenes and oxygenated sesquiterpenes. Oxygenated monoterpene levels were significantly correlated with the AFLP-based clade structure, suggesting a correspondence between gene pool and chemical diversity. Conclusions The results suggest an association between chemotype, genetic diversity and collection location which is relevant for the planning of future collections aimed at identifying valuable sources of essential oil.

Essential Oil Composition of Hypericum perforatum L. var. angustifolium DC Growing Wild in Sardinia (Italy)

Abstract The oil from inforescences of Hypericum perforatum var. angustifolium growing wild and harvested in Sardinia (Italy) was analyzed by GC and GC/MS. The major compounds in the oil were 2-methyloctane (21.1%), germacrene D (17.6%) and α-pinene (15.8%).

Antimicrobial Activity against Beneficial Microorganisms and Chemical Composition of Essential Oil of Mentha suaveolens ssp. insularis Grown in Sardinia

UNLABELLED The aim of this work was to determine the chemical constituents and in vitro antimicrobial activity of the essential oil (EO) of the aerial parts of Mentha sueveolens spp. insularis grown in Sardinia (Italy) against probiotic and starter microorganisms. The gas chromatography-mass spectrometry (GC-MS) analysis allowed to identified 34 compounds, most of oxygenated monoterpene compounds (82.5%) and among them, pulegone was found as major compound (46.5%). The agar diffusion test carried out employing the EO of Mentha suaveolens spp. insularis showed a low antibacterial activity, in particular no action was noticed for probiotic bacteria belonging to lactic acid bacteria groups, whereas almost all yeasts strains tested were inhibited. The automated microtitter dilution assay showed a clear effect at increasing concentration of EO on the specific growth rate (μ) and extension of the lag phase (λ) only for S. xylosus SA23 among bacteria and for Saccharomyces cerevisiae, Tetrapisispora phaffii CBS 4417, Metschnikowia pulcherrima, and Candida zemplinina among yeasts. Results obtained in this work allow us to broaden the knowledge on the effect of EOs on probiotic and food-related microorganisms. PRACTICAL APPLICATION Mentha suaveolens spp. insularis may be used in combination with probiotic bacteria into the food matrix or encapsulated in coating and edible films for food preservation.

Chemical and biological study on the essential oil of Artemisiacaerulescens L. ssp. densiflora (Viv.)

Artemisia caerulescens L. ssp. densiflora (Viv.) is a wild shrub that grows in the archipelago of La Maddalena, Sardinia, Italy. The antifungal activity of the volatile oil of this sub-species has not been evaluated earlier. This study aimed to identify the main components of the essential oil of A. caerulescens L. ssp. densiflora and to investigate its antifungal activity. Identification of the different components of the essential oil obtained by hydrodistillation from A. caerulescens L. ssp. densiflora was done by both techniques: GC-MS and NMR analyses (1H, 13C, HSQC-NMR). Antifungal activity was evaluated by agar disc diffusion technique against environmental isolates of fungal strains: two yeasts (Rhodotorula spp., Candida spp.), three moulds (Aspergillus spp., Alternaria spp., Fusarium spp.) and a mixture of moulds. GC-MS analysis of the essential oil yielded 42 compounds, out of which, 26 compounds were identified. The main compound was identified as terpinen-4-ol (22%) followed by p-cymene (7.6%) and α-terpineol (3.02%). The significant inhibition spectrum of the essential oil of A. caerulescens L. ssp. densiflora can be considered as an alternative to common disinfectants.

Chemical composition and fungicidal activity of the essential oil of Laserpitium garganicum from Italy

Laserpitium garganicum subsp. garganicum (Ten.) Bertol.(= Laserpitium siler L. subsp. garganicum (Ten.) Arcangeli) is a perennial herb belonging to the Apiaceae family. The distribution is limited to the southern area of the Balkan peninsula and Italy [1]. In Italy this plant is found in the central Apennines, Sicily and Sardinia [2]. This plant is described as a subspecies of L. siler or a species of Laserpitium in the Flora Europaea [1] and the Flora d’Italia [2] respectively. A few studies have reported the biologically active components isolated from L. siler, mainly sesquiterpene lactones [3–8], and one refers to sesquiterpene lactones from the roots of L. garganicum [9]. The essential oil composition of L. siler was also reported [10–13], but to the best of our knowledge, this is the first report on the GC/MS determination of the essential oil composition of the L. garganicum subsp. garganicum (Ten.) Bertol. Since the biological activity of this plant has not been studied, we focused our investigation on the antifungal activities of this essential oil against some phytopathogens and opportunistic human fungi. Fifty-six compounds were identified in L. garganicum essential oil, representing 92.3% of the total oil [14–19]. Table 1 shows the list of components identified and their percentages and retention indices. Compounds are listed in order of their elution from an HP-5. The most abundant compounds were myrcene (15.7%), β-phellandrene (14.4%), sabinene (9.7%), and γ-muurolene (7.8%). Monoterpene hydrocarbons made up 47.0% of the total oil; myrcene (15.7%) was the most abundant compound. Significant amounts of sesquiterpene hydrocarbons (25.0%) were found, with γ-muurolene (7.8%) being the main component. The oxygenated sesquiterpene fraction made up 9.8% of the total oil, with spathulenol (4.0%) having the highest content. The oxygenated monoterpenes (7.7%) also contributed with a similar content to the essential oil. This fraction was dominated by terpinen-4-ol (4.3%). Esters and ketones represented 1.8% and 0.6% of the total oil, respectively. The oil of L. garganicum differs markedly from the fruit oil of L. siler from southern France [13]; the later is characterizated by perillaldehyde (75.0%) and limonene (22.0%), compounds that were not found in L. garganicum oil. The oil from fruits of L. siler analyzed by Motl [10] contained perillaldehyde (89.5%) and limonene (10.5%). According to Adcock and Betts [11] the lack of perillaldehyde and limonene in L. garganicum is reason to consider these plants as a species of Laserpitium instead of a subspecies of L. siler despite the morphological similarities. Based on chemical composition, the plants analyzed in the present work were more similar to the other Laserpitium species reported by Adcock and Betts [11] (L. prutenicum L., L. hispidum Bieb., L. glaucum L., L. halleri Crantz, L. krapfii Crantz, L. archangelica Wulfen, L. latifolium L., and L. gallicum L.) than to L. siler. The antimycotic activity of essential oils depends on their chemical composition and may play a fundamental role in the host/pathogen relationship. Systemic fungal infections are important problems in medicine. Infections caused by fungal species are common in immunocompromised patients and result in significant treatment costs and mortality. Table 2 shows the antimicrobic activity of the essential oil of L. garganicum.

Antioxidant and antiproliferative activity of Stachys glutinosa L. ethanol extract

Ethanol extracts of Stachys glutinosa L. (Lamiaceae) were investigated for antioxidative properties, as well as antiproliferative action on various cell lines. The antioxidant activities were investigated by ABTS (2,2′-azinobis-3-ethylbenzothiazoline-6-sulphonic acid) assay, DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging, β-carotene/linoleic acid assay, scavenging of hydrogen peroxide (horseradish peroxidase test), superoxide anion scavenging, and hypochlorous acid scavenging (taurine test). The antioxidant activity was reported as IC50 and reveals antioxidant effects. Antiproliferative effects were measured in vitro on three cell lines: HepG2 (human hepatocarcinoma), MCF7 (breast human adenocarcinoma) and C2C12 (mouse myoblast) cell lines by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. The ethanol extract induced variations in cell viability on all cell lines tested. At 200 μg/mL, the effects on cell viability were − 23%, − 27% and − 37%, respectively, for C2C12, MCF7 and HepG2.

Essential Oil Composition of Tordylium apulum L. from Italy

Abstract The essential oil composition of aerial parts of Tordylium apulum L. from Italy was analyzed by GC and GC/MS. Sixty-seven compounds were identified representing 96.5% of the oil. The most abundant compounds were (E)-β-ocimene (17.3), α-humulene (11.4%) and octyl octanoate (8.8%).

Chemical, biological, morphoanatomical and antimicrobial study of Ocotea puchury-major Mart.

Ocotea puchury-major Mart. is a tree native to the Brazilian rain forest, where it is popularly known as puxurì. In local folk medicine the leaves are used for their sedative, gastroenteric and antireumatic properties. The morphoanatomical study determined those features useful in distinguishing this species from other closely related taxa. Chemical analysis was focused on the study of the volatile oil. Gas chromatography-mass spectrometry analyses indicated safrol as the main compound of the volatile oil (39%). The results confirm and authenticate the use of its leaves in folk medicine. Furthermore, safrol is economically important as the starting material for hemisynthesis of several products. The antimicrobial activity of the essential oil was studied which showed promising activity against environmental microorganisms as well as anti-inflammatory activity.