Chemical Composition and in Vitro Antimicrobial Activities of the Essential Oils from Endemic Psiadia Species Growing in Mauritius

Abstract

Essential oils are among the secondary metabolites of higher plants. These fragrant compounds comprise volatile terpenes, sesquiterpenes as well as their derivatives. The antimicrobial attributes of essential oils have been recognized long ago but only recently it has been established scientifically. 1,2) Among the essential-oil bearing families are the Asteraceae (Compositae). This family is one of the largest plant family with over 1000 genera and 25000 species and growing in several different habitats. Many of the plants from this family are reputed to have medicinal properties and enter the local pharmacopeias of countries and for example, several Tagetes species have been found to possess anti-microbial activity.3,4) The anti-microbial activity of Tagetes minuta is well established against organisms such as Bacillus subtilis, Escherichia coli, Staphylococcus aureus, S. epididermis and Pseudomonas aerugunisa. This property has been ascribed to the presence of flavonoids in the leaf extract. 5)Several species of the genus Psiadia also belonging to the Asteraceae family are used in the traditional pharmacopoeia of Africa to treat several ailments such as abdominal pains and colds in the head, 6) as expectorant for bronchitis and asthma, 7) a poultice for rheumatoid arthritis, 8) and as a plaster cast for broken bones by the Bedouin. 9)In Mauritius, Psiadia species have been reported to be used medicinally. The species are: P. viscosa, P. terebinthina, P. arguta, P. lithospermifolia and P. penninervia. They are all known under one common vernacular name, which is "Baume de l'Ile Plate". In the local pharmacopeia, leaves of Psiadia plants are usually employed as poultice or in herbal teas to treat pulmonary infections and minor wounds and burns. 10) In the literature, there exists limited information on the essential oil composition of Psiadia species. P. arabica from Saudi Arabia has been reported to contain b-pinene as most abundant constituent (37%).11) Other components are present albeit as trace amounts. P. salviifolia has been reported to contain b-pinene, limonene, g-terpinene, p-cymene, a-copaene, linalool, b-bourbonene, a-himachalene, g-cadinene, d-cadinene, g-elemene and a hydroxy derivative of calarene while P. altissima contains sesquiterpenoids such as Tmuurolol and b-eudesmol (2.2%) and d-cadinol (1.2%). 12,13) The Psiadia species which grow on Mauritius have also been studied and the compositon of the leaf oil of three of them has already been reported in the literature.10,14,15) P. lithospermifolia has been reported to contain (E)-isoasarone as the major component (51.55%). P. viscosa has been reported to contain pentyl-4-(1-methylethyl benzoate) (25.86%), and (Z)-isoasarone (13.35%) as major components. The leaf oil of P. arguta, the most endangered species locally, is characterized by the presence of isoeugenol (56.5%) as the major component. 14,15) It can already be observed that the composition of the Psiadia species varies extensively. This may be attributed to several factors and one of the...

Synergistic bactericidal activity of Eremanthus erythropappus oil or β-bisabolene with ampicillin against Staphylococcus aureus

“…It is noteworthy that the antibacterial activity of b-bisabolene described in the present study is in agreement with results reported by other groups showing that the activity of essential oils of other Asteraceae species against S. aureus is also due to this compound (Gouvinden-Soulange et al 2004;Simic et al 2005).…”

Postharvest Highbush Blueberry Fruit Antimicrobial Volatile Profiles in Relation to Anthracnose Fruit Rot Resistance

“…There was no clear relationship across all highbush blueberry cultivars studied for volatiles emitted (both quantitative and qualitative differences) and resistance to anthracnose fruit rot. Except for 8-hydroxylinalool, all of the aldehydes and terpenes identified as evolving from the highbush blueberry samples in this study have been reported to have antifungal properties, although not necessarily against C. acutatum (Archbold et al, 1997;Azaz et al, 2002;Carson and Riley, 1995;Cavaleiro et al, 2006;Corbo et al, 2000;Fraternale et al, 2004;Govinden-Soulange et al, 2004;Himejima et al, 1992;Lanciotti et al, 1999;Peana et al, 1999;Plotto et al, 2003;Raintree Nutrition Inc., 2004;Song et al, 2007;Tabanca et al, 2006Tabanca et al, , 2007Tepe et al, 2004;Wilson et al, 1997). Thus, the compounds we identified, although not correlated with anthracnose fruit rot resistance, may play a role in resistance to other highbush blueberry fruit diseases.…”

“…The incorporation of high concentrations of various antimicrobial volatiles, including hexanal and trans-2-hexenal, into the storage atmosphere of fresh produce has been shown to reduce postharvest decay (Corbo et al, 2000;Lanciotti et al, 1999). Most, if not all, terpenes emitted from highbush blueberry have antifungal activities and include 1,8cineole Wilson et al, 1997), caryophyllene (Raintree Nutrition Inc., 2004), cadinene (Song et al, 2007), a-farnesene (Govinden-Soulange et al, 2004), 2-and 3carene (Archbold et al, 1997;Cavaleiro et al, 2006;Himejima et al, 1992), limonene (Archbold et al, 1997;Himejima et al, 1992;Wilson et al, 1997), linalool (Carson and Riley, 1995;Fraternale et al, 2004;Plotto et al, 2003), terpinolene (Himejima et al, 1992), a-terpineol (Carson and Riley, 1995;Tepe et al, 2004), and a-terpinyl acetate (Peana et al, 1999). 8-Hydroxylinalool, another volatile emitted from highbush blueberry fruit, may have antifungal activity because oxygenated terpenes generally have more antifungal activity than nonoxygenated ones (Caccioni and Guizzardi, 1994;Knobloch et al, 1989).…”

Aromatic Plants from Reunion Island (France)

“…In contrast, considerable differences were found to exist in the composition of essential oils of P. boivinii. The occurrence of these unusual terpenoids in these four species supposes that the latter have the same biosynthetic pathway and it may also suggest that the two new molecules could be used as a chemotaxonomic tool for the characterization of some Psiadia species (Gurib-Fakim et al, 1995Gauvin et al, 2004b;Govinden-Soulange et al, 2004;Gauvin and Smadja, 2005;Gauvin-Bialecki and Smadja, 2007).…”