Analgesic-like activity of essential oils constituents

Research on neuroactive drugs is a pharmaceutical sector of high interest and growth. The discovery of efficient drugs that can relieve pain is a subject of research in the pharmaceutical industry and academic field because pain is a symptom of many diseases. This review will summarize results on the discovery of essential oil constituents with analgesic-like activity from the chemical and pharmacological perspectives. Overall, 43 bioactive compounds were selected in nociception models. Among them, 62.8% were monoterpenes, 18.6% sesquiterpenes and other constituents represented 18.6%. The data show the potential of this group of natural product chemicals as analgesic drugs that may be useful for therapeutic purposes.     

Essential oils in combination and their antimicrobial properties

Essential oils (EOs) have been long recognized for their antibacterial, antifungal, antiviral, insecticidal and antioxidant properties. They are widely used in medicine and the food industry for these purposes. The increased interest in alternative natural substances is driving the research community to find new uses and applications of these substances. EOs and their components show promising activities against many food-borne pathogens and spoilage microorganisms when tested in vitro. In food systems, higher concentrations of EOs are needed to exert similar antibacterial effects as those obtained in in vitro assays. The use of combinations of EOs and their isolated components are thus new approaches to increase the efficacy of EOs in foods, taking advantage of their synergistic and additive effects. The purpose of this review is to provide an overview on the antimicrobial efficacy of these combinations. A survey of the methods used for the determination of the interactions and mechanisms involved in the antimicrobial activities of these combinations are also reported.     

Essential oils: SPE fractionation

Summary Essential oil analysis is often characterised by mixtures that are difficult to separate. The components belong to different classes of compounds that range widely in concentration. Hence, a pre-separation technique is often required, at least to evaluate the minor components. This paper reports an SPE method to overcome this problem. The method was developed with a standard solution that yielded 90% mean recovery of the analytes. It was then tested on two different essential oils: tarragon (Artemisia dracunculus) and rose (Rosa damascena). In this way, the essential oil components were pre-separated into three fractions: A, which contained hydrocarbons; B, which contained esters, ethers, oxides, carbonyl compounds and tertiary alcohols; and C, which contained other alcohols, acids and diols.     

Essential oils of Retama raetam from Libya: chemical composition and antimicrobial activity

Retama raetam (Forssk) Webb & Berthel is well known in the folk medicine of North and East Mediterranean regions for the treatment of microbial infections. The powdered leaves are used to heal circumcision wounds and used as an antiseptic for wounds, skin rash and pruritus. In this study, to validate this antiseptic property, the chemical composition and antimicrobial activity of the essential oil from the flowers of R. raetam was evaluated. The oil was obtained using hydrodistillation and was analysed by gas chromatography-mass spectrometry. The antibacterial activity was achieved using disc diffusion and broth dilution assay against six bacteria species. Analysis of the essential oil revealed the presence of β-linalool (51%), 2-decen-1-ol (6.6%) and limonene (7.4%) as the major components. The results showed significant activity against microorganisms, especially Staphylococcus aureus, with inhibition zones and minimal inhibitory concentration values in the range of 5.0 mm and 3.0 mg mL?1, respectively. The results on the antibacterial activity provide scientific support for the use of these plants in traditional herbal preparations.     

Chemical constituents of Eugenia catharinae and their antioxidant activity

Nine compounds were isolated from the leaves of Eugenia catharinae, namely monomethyl olivetol (1), β-sitosterol (2), stigmasterol (3), uvaol (4), erythrodiol (5), rotundic acid (6), quercetin (7), catechin (8) and myricitrin (9). The structures of 1–9 were established through analysis of their spectroscopic (¹H and ¹³C NMR) and spectrometric (MS) data. Compounds 1 and 6 are reported the first time in the Eugenia genus. In addition, these data were compared with those reported in the literature. The antioxidant activity of plant samples and compounds was measured using the DPPH radical scavenging assay. Flavonoids 7, 8, 9 and the ethanolic extract showed the best results, with IC₅₀ values of 20.94 μM, 44.20 μM, 30.01 μM and 58.82 μg/mL, respectively.     

Chemical constituents from Gueldenstaedtia verna and their anti-inflammatory activity

A new triterpenoid glycoside (1) and 15 known compounds (2–16) were isolated from the whole plants of Gueldenstaedtia verna. The new compound (1) was identified as complogenin 22-O-β-d-glucopyranoside by extensive spectroscopic techniques including 1D (¹H and ¹³C) and 2D NMR experiments (HSQC, HMBC and NOESY), HR-DART-MS and chemical methods. Most of the isolates were evaluated for their inhibitory activities on LPS-induced NO production in RAW 264.7 cells. The inhibitory effects of the active compounds, sulphuretin (8) and (22E,24S)-5α,8α-epidioxy-24-methyl-cholesta-6,9(11),22-trien-3β-ol (13), on the production of pro-inflammatory mediators (including IL-6, IL1β and PGE₂) were further estimated in vitro by ELISA in RAW 264.7 macrophages.     

Essential oils of mongolian plants

1. The following compounds have been isolated by gas-liquid chromatography from the essential oil ofArtemisia rutifolia Steph. ex Spreng. growing in the Mongolian People's Republic and have been identified by their IR spectra: 1,8-cineole (35%), α-thujone andβ-thujone (11%), (+)-camphor (18%), (−)-α-terpineol (5%), and (−)-terpinen-4-ol (7%). By analytical gas chromatography α-pinene,β-pinene, camphene, limonene,β-phellandrene, and p-cymene have been identified in the hydrocarbon fraction. It has been shown that apart from compounds of a terpene nature the oil contains 4-phenylbutan-2-one, (±)-4-phenyl-butan-2-ol, and (±)-4-phenylbut-2-yl acetate. This is the first time that (±)-4-phenylbutan-2-ol and its acetate has been found in plant material.     

Essential oils of Pimpinella aromatica

V. L. Komarov Institute of Botany, Academy of Sciences of the Azerbaidzhan SSR, Baku. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 288–291, March–April, 1991.     

Essential and fatty oils of Agastache rugosa

Northern Caucasus Zonal Experimental Station of VILR [All-Union Scientific Research Institute of Medicinal and Aromatic Plants], Vasyurinskaya, Krasnodar Territory. Translated from Khimiya Prirodnykh Soedinenii. No. 3, pp. 449–450, May–June, 1988.     

Major constituents and anthelmintic activity of volatile oils from leaves and flowers of Cymbopogon martini Roxb

The major volatile constituents of leaves and flowers of Cymbopogon martini from the volatile oil obtained by steam distillation were identified by GC/MS. Five constituents were identified from the volatile oil of leaves and flowers, which constituted about 82.49 and 75.63% of the total amount, respectively. A monoterpene, piperitone (6.00%), was identified in the flowers of C. martini; in addition, flowers were found to contain more olefinic terpenes, namely geraniol (69.63%), compared with leaves (53.41%). Leaves contain bicyclic monoterpene, nerol (24.76%) and alpha-pinene (4.32%). Anthelmintic activity of these oils was evaluated on adult Indian earthworms Pheretima posthuma and results showed that the volatile oil of C. martini flower required less time to cause paralysis and death of the earthworms.     

Boiling temperatures and enthalpy changes of Essential oils

A capillary long neck glass sample holder is proposed for the determination of boiling temperatures of essential oils containing a majority component. Essential oils from Aniba dukei K. and Pimenta dioica L. containing linalool and eugenol, respectively, as major constituents were used after optimization of parameters such as scan rate, sample mass and starting temperature. Best performance in the determination of boiling temperatures was obtained with the proposed sample holder in comparison with commercial aluminum pans. Good agreement was obtained for the boiling temperature and enthalpy for the essential oil samples with the linalool and eugenol standards. This revised version was published online in August 2006 with corrections to the Cover Date.     

Phytochemical constituents of the pericarps of Illicium difengpi and their anti-inflammatory activity

Abstract

Phytochemical investigation on the pericarps of Illicium difengpi lead to the isolation and structure elucidation of a new sesquiterpene, sesquicaranoic acid C (1), a new neolignan, difengpiol C (2), and 10 known compounds. The structures and absolute configurations of two new compounds were determined by a combination of NMR and CD spectroscopic analyses. All isolates were evaluated for their inhibitory effects on lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW264.7 cells.