Analisi dei costituenti volatili emessi in vivo da specie del genere Salvia facenti parte di una collezione dell'Orto Botanico di Pisa mediante la tecnica SPME in GC-MS.

Trenta specie del genere Salvia, facenti parte di una collezione dell’Orto Botanico di Pisa, sono state analizzate in vivo tramite la tecnica della Head-Space Solid Phase Micro-Extraction (HS-SPME) abbinata alla GC-MS (gas-cromatografia accoppiata alla spettrometria di massa). Sono stati identificati oltre 300 composti organici volatili (VOC). Il profilo di emissione di tali composti è stato sottoposto ad analisi statistica mediante il clustering gerarchico, effettuato sia sui singoli VOC, sia sulle classi chimiche dei composti. È emersa una discreta correlazione tra le similitudini rilevate dal clustering gerarchico e la provenienza geografica delle specie raccolte. In ragione dell’habitat originario delle diverse specie, infatti, il profilo di emissione in vivo dei VOC muta: piante provenienti da una stessa area geografica tendono ad avere pattern di emissione simili tra loro, sia in termini di prevalenza di composti individuali sia di classi chimiche. Non ho rintracciato nella letteratura studi effettuati su un numero così esteso di Salvie, né studi sulle emissioni volatili spontanee da parte di campioni analizzati in vivo, non sottoposti ad alcun trattamento di essiccamento, macinazione o distillazione

Comparison of the Chemical and Sensorial Evaluation of Dark Chocolate Bars

As it mimics olfactory perception, headspace analysis is frequently used for examination of products like chocolate, in which aroma is a key feature. Chemical analysis by itself, however, only provides half the picture, as final consumer's perception cannot be compared to that of a Gas Chromatography-Mass Spectrometry (GC-MS) port, but rather to a panel test assessment. The aim of the present study was the evaluation of combined chemical (by means of headspace solid-phase microextraction and GC-MS) and panel test data (by means of a sensory evaluation operated by 6 untrained panelists) obtained for 24 dark chocolate bars to assess whether these can discriminate between bars from different brands belonging to different commercial segments (hard discount, HD; supermarket, SM; organic bars, BIO). In all samples, with the only exception of one supermarket bar (in which esters exhibited the highest relative abundance), pyrazines were detected as the most abundant chemical class (HD: 56.3–74.2%; BIO: 52.0–76.4%; SM: 31.2–88.9%). Non-terpene alcohols, aldehydes, and esters followed as quantitatively relevant groups of compounds. The obtained data was then subjected to hierarchical cluster (HCA) and principal component (PCA) analysis. The statistical distribution of samples obtained for the chemical data did not match that obtained with panelists' sensorial data. Moreover, although an overall ability of grouping samples of the same commercial origin was evidenced for hard discount and supermarket bars, no sharp grouping was possible

Survival in different habitats: extreme ultramafic and calcareous soils influence on Stachys recta essential oils composition

Ultramafic soils contain large amounts of magnesium and iron; they are also frequently rich in chromium, cobalt and nickel. They represent a difficult environment for plants to grow on, as they often contain toxic amounts of magnesium and nickel, whilst lacking mineral nutrients (like silicon, phosphorus, potassium and calcium); their dark colour attracts sunlight, which leads to higher temperature and drought conditions (1). On these soils, edaphic adaptation of plants is strongly evident: plants adapted to ultramafic soils exhibit morphological traits that often differ from correlated species growing on different substrates. They are often significantly smaller and show xeromorphic foliage, with reduced leaf size as the most apparent character (2). The aim of this study was to assess the influence of edaphic adaptation to ultramafic soils on a non- morphological level, investigating its role in the composition of the essential oil produced by plants growing on these kind of soils. We investigated the composition of the essential oil (EO) of Stachys recta L. subsp. subcrenata (Vis.) Briq. collected between Nibbiaia and Gabbro (province of Livorno, Italy), grown on an ultramafic soil mainly deriving from the alteration of serpentinites. We compared the yield and the composition of this EO to the one we hydrodistilled from Stachys recta L. subsp. recta L., which had been collected in the same phenological state in La Gruzza, near Montemarcello (province of La Spezia, Italy), on calcareous substrate. Whilst the yields of the two species were comparable, the composition profiles were very different: the EO extracted from S. recta subsp. recta was mainly rich in terpene compounds, which accounted for 93.8%; the species grown on the ultramafic soils, instead, had a volatile profile dominated by non-terpene derivatives, which accounted for 55.7%. In the species grown on the calcareous soil, the main constituents were germacrene D (18.8%), b-caryophyllene (17.7%), 1,8-cineole (15.9%) and a-pinene (14.2%). The EO from S. recta subsp. subcrenata was mainly dominated by 1-octen-3-ol (38.2%), a-cadinol (6.1%), (E)-3- hexen-1-ol (5.9%) and cadinene (5.6%). Considering the extent of the differences shown by the two EOs, it is reasonable to assume that the ultramafic soil plays a central role in the plants’ secondary metabolism, leading to a very different product

Geographical patterns of in vivo spontaneously emitted volatile organic compounds in Salvia spp.

The genus Salvia is part of the family of the Lamiaceae, comprising almost 1000 different species that make it the largest one in this family; it includes annual, biennial and perennial specimens. It shows a wide variety of characteristics in the specimens, both in the external appearance and the volatile organic compounds (VOCs) profiles. Such a wide number of species is due to the almost ubiquitous origin of this genus, but also to the cultivars selection carried out by botanists and private collectors during centuries. In this work, we analysed the spontaneous volatile emission profiles of living samples to evaluate the existence of possible patterns and to find out possible parameters that lead to such patterns. We carried out the analysis on living samples of leaves taken from 30 species of Salvia obtained from a large collection, which has been bestowed the title of “collection of national relevance” by the Italian Botany Society, located at the Botanical Garden of the University of Pisa. Within the collected samples, 14 are specimens whose natural habitat is the Mediterranean Europe and Middle East regions, 14 species have their native environment in the Central and Southern America, and 2 come from South Africa. The sampling was carried out using the Head Space - Solid Phase Micro Extraction technique. The captured volatile organic compounds were then characterized by GC-MS. We carried out a Multivariate Statistical Analysis on the results to show possible relevant patterns: we found out that the spontaneous volatile emission profiles differ significantly accordingly to the geographical origin of the various species. This permitted to hypothesize that the environment plays a fundamental role in Salvia secondary metabolites production: the volatile fraction, in particular, represents the reaction of the specimen to the particular local environment (temperature, humidity, latitude, altitude, pollinators, enemies…), making it a very specific chemotaxonomical marker. These results, once improved with a wider number of specimens analyses, could be used as a method to identify the origins of unknown cultivars and wild Salvia species. At present, the dietary and pharmacological use of Salvia is restricted to a small number of species. This genus exhibits a largely variable thujones (α- and β-thujone) content, which determines the edibility and the potential human toxicity if used in dietary and pharmacological supplements or in essential oil form. Thujone toxicity has been widely studied and its intake can result in neurotoxicity, both acute and chronic: it inhibits GABAA receptors, inducing dose-dependent excitation and convulsions. This becomes especially important in assessing the safety of use in children: in 2011 a report showed the case of a child and a newborn who experienced generalized tonic-clonic seizures after an accidental exposure to sage essential oil. In this study, we also investigated the collected leaves samples to assess the presence (or the lack of) thujone in the spontaneously emitted volatile fraction. We found specimens without thujone, thus making them suitable possible candidates for food and pharmacological use. Furthermore, the different aromatic profiles could suggest different uses of the various species as spices

Cannabis sativa and Humulus lupulus essential oils as novel control tools against the invasive mosquito Aedes albopictus and fresh water snail Physella acuta

Over the past several decades, there has been a resurgence of interest in industrial hemp (Cannabis sativa L., Cannabaceae) cultivation. Besides fibre, seeds and oil, hemp contains high quantity of essential oil (EO). Hop (Humulus lupulus L., Cannabaceae) is a high-climbing, perennial vine, largely utilized in the brewing industry to add flavour and bitterness to beer. While it is known that hop also contains α- and ß-acids, and terpenes that have been found to be toxic, anti-feedant, and repellent for insects and mites, little is known about the bioactivity against problematic species of the hemp EO. In this study, the chemical composition of the EOs from C. sativa and H. lupulus was evaluated by GC-MS, and their acute toxicity was assessed against the Asian tiger mosquito Aedes albopictus (Skuse) (Diptera Culicidae) and, the freshwater bladder snail Physella acuta (Draparnaud) (Mollusca Physidae), two problematic invasive species. Furthermore, we evaluated the toxicity of both EOs against a non-target insect, the mayfly Cloeon dipterum L. (Ephemeroptera Baetidae). Both EOs were toxic against the three tested species. The most effective EO was the C. sativa, able to kill 100% of P. acuta snails starting from 100 μL L-1. C. sativa LC50 were 301.560, 282.174 and, 35.370 μL L-1, while H. lupulus LC50 were 330.855, 219.787 and, 118.653 μL L-1 against A. albopictus, C. dipterum and P. acuta, respectively. Relative median potency analysis showed that the C. sativa EO was more toxic than H. lupulus against A. albopictus and P. acuta, while H. lupulus was more toxic than C. sativa EO against C. dipterum. The most susceptible species to the two EOs was P. acuta, while A. albopictus resulted the least susceptible one

Repellency of anethole- and estragole-type fennel essential oils against stored grain pests: the different twins

Aromatic plants essential oils (EOs) are promising alternatives to chemical insecticides and insect repellent for the post-harvest protection of crops. Fennel (Foeniculum vulgare Mill.) is a highly aromatic plant, cultivated worldwide of which several chemotypes can be distinguished on the basis of the relative content of its main compounds (E)-anethole and estragole. Fennel is well known for its pharmacological, antioxidant antimicrobial and acaricidal activities, and several studies showed its effectiveness as insecticidal and repellent against insects. In this study the repellency of the EOs extracted from two chemotypes, anethole- and estragole-type of F. vulgare fruits, against Rhyzopertha dominica (F.), Sitophilus zeamais Motschulsky and Tribolium confusum Jaqcquelin du Val, three of the major worldwide post-harvest grains insects was assessed by in vitro bioassays. Along with the EOs, we also tested the repellency of their major chemical components (E)-anethole, estragole, limonene and, fenchone and we evaluated the co-repellency effect of (E)-anethole and estragole. Finally, the repellence of the fennel EOs in the presence of maize was tested by a two-choice pitfall bioassay. (E)-anethole and estragole content in the anethole-type was 78.4 and 8.0%, respectively while in the estragole-type fennel EO anethole and estragole content was 0.9 and 85.5%, respectively. RD50 values showed that the estragole-type EO was the most effective repellent against the three insect species with values of 0.007, 0.051 and 1.124 mg cm-2 for R. dominica, T. confusum and S. zeamais, respectively. Consistently, relative median potency analysis showed that estragole was significantly more repellent to the three pest insect species than (E)-anethole. Interestingly, in the EOs, (E)-anethole and estragole showed a synergistic co-repellent effect. The strongest synergy was observed against R. dominica (CRC = 634.51). The repellency of fennel EOs also in the presence of maize was confirmed by a two-choice bioassay. Also in this case, the most overall effective EO resulted to be the estragole-type. The results highlight the importance of a chemical standardization based on the bioactivity of the fennel EOs and indicate the estragole-type fennel EO as suitable for the development of eco-friendly repellents for the post-harvest protection of grain crops

chemical constituents anti nociceptive and anti inflammatory activities of essential oil of phyllanthus muellerianus

The aim of the present study was to characterize the chemical composition and to evaluate the anti-inflammatory and anti-nociceptive properties of the essential oil from the leaves of Phyllanthus muellerianus (Kuntze) Exell. The essential oil was hydrodistilled and characterized by gas chromatography-flame ionization detection and gas chromatography coupled with mass spectrometry analyses. The anti-inflammatory activity was evaluated on carrageenan-induced rat paw edema while the anti-nociceptive test was based on hot plate analysis. The hydrodistillation afforded 0.09% (dry weight basis) of pale yellow oil. Thirty-eight compounds representing 94.8% were identified in the oil. The major components of the oil were hexahydrofarnesyl acetone (11.6%), isocaryophyllene (9.8%), and limonene (9.4%). The oils of P. muellerianus displayed anti-nociceptive effect at a rate independent of reaction time and dose (P < 0.001). The rate of inhibition increased exponentially as the dose increases with optimum activity at..

Bioactivity of Different Chemotypes of Oregano Essential Oil against the Blowfly Calliphora vomitoria Vector of Foodborne Pathogens

Blowflies play a substantial role as vectors of microorganisms, including human pathogens. The control of these insect pests is an important aspect of the prevention of foodborne diseases, which represent a significant public health threat worldwide. Among aromatic plants, spices essential oils (EOs) are the most suitable to protect food from insect pests. In this study, we determined the chemical composition of three oregano EOs and assessed their toxicity and deterrence to oviposition against the blowfly Calliphora vomitoria L. The chemical analyses showed that the EOs belonged to three chemotypes: one with a prevalence of carvacrol, the carvacrol chemotype (CC; carvacrol, 81.5%), and two with a prevalence of thymol, the thymol/p-cymene and thymol/-terpinene chemotypes(TCC and TTC; thymol, 43.8, and 36.7%, respectively). The bioassays showed that although all the three EOs chemotypes are able to exert a toxic activity against C. vomitoria adults (LD50 from 0.14 to 0.31 L insect1) and eggs (LC50 from 0.008 to 0.038 L cm2) as well as deter the oviposition (Oviposition Activity Index, OAI, from 0.40 0.04 to 0.87 0.02), the bioactivity of oregano EOs significantly varies among the chemotypes, with the thymol-rich EOs (TCC and TTC) overall demonstrating more effectiveness than the carvacrol-rich (CC) EO

Ferulago campestris Essential Oil as Active Ingredient in Chitosan Seed-Coating: Chemical Analyses, Allelopathic Effects, and Protective Activity against the Common Bean Pest Acanthoscelides obtectus

Ferulago campestris is an aromatic plant, distributed in Mediterranean Europe, and a source of essential oils (EOs) regarded as promising alternatives to synthetic herbicides and pesticides. F. campestris EO, hydrodistilled and analyzed, was tested for its antigerminative activity and for its effect on radicle elongation, hydrogen peroxide concentration, and lipid peroxidation on four infesting weed species (Papaver rhoeas, Taraxacum campylodes, Poa annua, and Setaria verticillata) and on Phaseolus vulgaris. Its repellent ability was also tested against Acanthoscelides obtectus, a pest commonly affecting P. vulgaris during storage. Moreover, a chitosan coating layer was developed with the addition of F. campestris EO and tested for its toxic and oviposition-deterring effects against A. obtectus. Myrcene, -pinene, and -terpinene were detected as the main compounds in F. campestris EO. The EO demonstrated a selective in vitro antigerminative activity towards the weed species, without affecting the bean seeds. Moreover, the chitosan coating layer exerted a dose-dependent repellent effect against A. obtectus adults, thus effectively protecting the bean seeds, while preserving their germinative ability. To the best of our knowledge, this is the first report on a chitosan–EO coating proposed with the aim of protecting bean seeds for sowing from insect attack

Constituents of essential oil from the leaf of Alternanthera sessilis (L.) R. Br. ex DC. (Amaranthaceae) from Nigeria

This study was designed to determine the chemical constituents of essential oil from the leaves of Alternanthera sessilis (L.) R. Br. Ex DC. (Amaranthaceae) grown in Nigeria. The essential oil was isolated using hydrodistillation method. The constituents of A. sessilis oil were characterized using gas chromatography-flame ionization detector (GC-FID) and gas chromatography-mass spectrometry (GC-MS). The yield of the essential oil was 0.21% (v/w), calculated on a dry weight basis. A total of seventeen compounds accounting for 95.6% of the oil content were identified. The oil was devoid of any of the monoterpene compounds. The main constituents of the oil were hexahydrofarnesyl acetone (35.6%), β-caryophyllene (16.1%) and n-heptadecane (10.7%). Terpenoid compounds were being reported for the first time in A. sessilis