Search

Salvia officinalis L. (Sage) is an important industrial plant used both for food and pharmaceutical purposes. The terpene fraction of this plant, which contains thujones and other mono and sesquiterpenoids, is responsible for many of its therapeutic and culinary properties. We used two extraction methods [hydrodistillation (HD) to obtain the essential oil (EO), and supercritical CO2 extraction (SFE)] to analyze by gas chromatography–mass spectrometry (GC–MS) the terpene fraction extracted from sage dried leaves. α-Thujone, β-thujone and other oxygenated monoterpenes (1,8-cineole, linalool, camphor, borneol and bornyl acetate) as well as hydrocarbon (β-caryophyllene and α-humulene) and oxygenated sesquiterpenes (caryophyllene oxide, viridiflorol, humulene epoxide II and III) were found. The EO contained a significantly (p < 0.05) higher percentage of 1,8-cineole (10.4%), α-thujone (17.3%) and camphor (29.2%), whereas supercritical fluid (SF) extracts contained a significantly higher percentage of borneol (8.4%), bornyl acetate (2.2%), α-humulene (6.4%), viridiflorol (22.1%), humulene epoxide II and III (2.4% and 0.4%), and some unidentified sesquiterpene alcohols. Both EO and SF extracts contained equal amounts of β-thujone (4.8%) and β-caryophyllene (~7%). Our results show that HD of EO is a more efficient and economic method for α- and β-thujone extraction. [ABSTRACT FROM AUTHOR]

Coevolution has been defined as the reciprocal genetic change in interacting species owing to natural selection imposed by each on the other. The process of coevolution between plants and the surrounding biota – including viruses, fungi, bacteria, nematodes, insects, and mammals – is considered by many biologists to have generated much of the earth's biological diversity. While much of the discussion on plant coevolution focuses on single plant–enemy interactions, a wide array of other micro and macro coevolutive processes co-occur in the same individual plant, posing the question whether we should talk about plant coevolutions. In this review article, I begin by briefly discussing the framework of coevolution theory and explore the complexities of studying coevolution in natural conditions. Then I analyze the difference between plants, microbes and animal coevolution, by exploring the above- and below-ground behaviors. [ABSTRACT FROM PUBLISHER]

Ocimum basilicum (sweet basil) is an important essential oil plant used for different purposes (from food flavoring to pharmaceutical applications) characterized by the presence of several chemotypes. Here we show a comparative analysis between hydrodistillation of essential oils (EO) and supercritical CO2 extraction (SFE) of an O. basilicum chemotype particularly rich in T-cadinol. SFE yielded a higher percentage of 1,8-cineole (10%; 4-fold), linalool (23.2%; 5.8-fold), eugenol (13.3%; 1.2-fold) and germacrene D (5.6%; 28-fold) with respect to EO. On the other hand, EO composition was characterized by higher percentages of T-cadinol (27.5%; 3-fold) and some other sesquiterpenes with respect to SFE. The presence of high percentages of T-cadinol in EO is of great importance owing to the biological activity of this compound in cancer therapy and as an antibiotic. [ABSTRACT FROM AUTHOR]

Essential oils (EOs) of chamomile contain several bioactive compounds, including monoterpenes, sesquiterpenes, triterpenes and fatty acids. Hydrodistillation of chamomile EO induces the formation of chamazulene, a bioactive compound. Chamazulene was isolated from the EO by column chromatography. The total antioxidant capacity confirmed a higher antioxidant activity of chamazulene (IC50 = 6.4 μg mL− 1) than of ascorbic acid (IC50 = 12.8 μg mL− 1), α-tocopherol (IC50 = 20.5 μg mL− 1) and of butylated hydroxytoluene (BHT) (IC50 = 30.8 μg mL− 1). Chamazulene was unable to react with DPPH√. However, when chamazulene was assayed with ABTS√, a strong and significantly (P < 0.05) higher free radical scavenging activity was observed (IC50 = 3.7 μg mL− 1), with respect to BHT (IC50 = 6.2 μg mL− 1) and α-tocopherol (IC50 = 11.5 μg mL− 1). The results of this work show that chamazulene is an important factor for the antioxidant power of chamomile oil. [ABSTRACT FROM PUBLISHER]

Little information is available on the interaction between herbivorous insects and plants storing terpenoids. In this work we describe the response of the essential oil plant Mentha aquatica to the specialist herbivore Chrysolina herbacea. Feeding from C. herbacea induced a significant increase of jasmonic acid (JA) in both local and systemic M. aquatica leaves, whereas the content of the JA precursor, cis-(+)-12-oxophytodienoic acid (OPDA), was increased in local leaves and decreased in systemic leaves. The JA conjugate, (3R,7S)-jasmonoyl-l-isoleucine (JA-Ile), was slightly increased in herbivore wounded (HW) local leaves, whereas its content significantly increased in systemic leaves. Herbivory by C. herbacea did not increase the content of salicylic acid (SA); however, SA showed a two-fold increase in HW systemic leaves. Our results indicate that also in plants producing direct defences, such as the essential oil plant M. aquatica, JA, and SA signalling is triggered by herbivory just like in plants that respond with indirect defence. [ABSTRACT FROM AUTHOR]