Variation in essential oil composition of Leonotis leonurus,an important medicinal plant in South Africa

Leonotis leonurus widely used by traditional healers in southern Africa for treatment of various ailments, is well known for its reported psychoactive properties. The present study was undertaken to investigate the variation in essential oil composition between geographically distinct populations of L. leonurus in South Africa using gas chromatography. Plant material (n = 50) was collected from three provinces of South Africa. Essential oils of the aerial parts were obtained by hydrodistillation and analysed using one and two dimensional gas chromatography. Twenty-six compounds accounted for more than 80% of the total composition of the oil. Eight major constituents in the oil, representing about 50% of the total oil composition, were identified by both GC–MS–FID and GCxGC–ToF–MS. These major compounds were trans-β-ocimene (0.1–5.0%), cis-β-ocimene (0.1–31.5%), β-caryophyllene (0.3–15.0%), caryophyllene oxide (0.1–5.0%), α-humulene (0.4–18.2%), γ-elemene (0.4–10.6%), α-cubebene (0.2–12.0%) and germacrene D (0.1–22.1%). Marked similarities exist in the essential oil composition between populations; differences are mostly quantitative when determined by GC–MS–FID, while GCxGC–ToF–MS data reveals both quantitative and qualitative differences.Untargeted multivariate analysis was performed using SIMCA-P + 14.0 PCA and OPLS-DA methods, identifying two distinct clusters, inland and coastal populations.     

Chemical Composition and In Vitro Evaluation of Antioxidant Effect of Free Volatile Compounds From Satureja montana L.

As a part of an investigation of natural antioxidants from Dalmatian aromatic plants, in this paper we report a study of the antioxidant activity related to the chemical composition of savory free volatile compounds. Twenty-one compounds were identified in the essential oil without fractionation, representing 97.4% of the total oil. The major compound was phenolic monoterpene thymol (45.2%). Other important compounds were monoterpenic hydrocarbons p-cymene (6.4%) and γ-terpinene (5.9%) and oxygen-containing compounds carvacrol methyl ether (5.8%), thymol methyl ether (5.1%), carvacrol (5.3%), geraniol (5.0%) and borneol (3.9%). The evaluation of antioxidant power was performed in vitro by the β-carotene bleaching and thiobarbituric acid (TBA) methods. As determined with both methods, the total savory essential oil as well as different fractions or pure constituents containing hydroxyl group exhibited relatively strong antioxidant effect. The hydrocarbons, when isolated as CH fraction, showed the poorest effectiveness in spite the fact that this fraction contained γ-terpinene, α-terpinene, p-cymene and terpinolene which previously were identified as potential antioxidants.     

Chemical compositions of Casuarina equisetifolia L., Eucalyptus toreliana L. and Ficus elastica Roxb. ex Hornem cultivated in Nigeria

Essential oils were obtained by separate hydrodistillation of three different plants cultivated in Nigeria and analysed comprehensively for their constituents by means of gas chromatography (GC) and gas chromatography-mass spectrometry (GC–MS). The leaf essential oil of Casuarina equisetifolia L. (Casuarinaceae) comprised mainly of pentadecanal (32.0%) and 1,8-cineole (13.1%), with significant amounts of apiole (7.2%), α-phellandrene (7.0%) and α-terpinene (6.9%), while the fruit oil was dominated by caryophyllene-oxide (11.7%), trans-linalool oxide (11.5%), 1,8-cineole (9.7%), α-terpineol (8.8%) and α-pinene (8.5%). On the other hand, 1,8-cineole (39.4%) and α-terpinyl acetate (10.7%) occurred in large quantities in the essential oils of the leaf of Eucalyptus toreliana L. (Myrtaceae). The oil also features high levels of sabinene (5.9%), caryophyllene-oxide (4.7%) and α-pinene (4.2%). The main compounds identified in the leaf oil of Ficus elastica Roxb. ex Hornem. (Moraceae) were 6,10,14-trimethyl-2-pentadecanone (25.9%), geranyl acetone (9.9%), heneicosene (8.4%) and 1,8-cineole (8.2%).     

Essential oil composition of Eryngium rosulatum P.W. Michael ined.: A new undescribed species from eastern Australia

The essential oil composition from the aerial parts of a new Eryngium species from Australia, Eryngium rosulatum P.W. Michael ined., has been analysed by GC and GC/MS. A total of 34 compounds have been identified representing around 80% of the total oil. The main constituents of the oil were found to be β-elemene (16.0%) and bicyclogermacrene (12.5%). Other representative compounds were identified as δ-elemene (7.0%) and (E)-caryophyllene (5.9%). The sesquiterpene fraction (75.0%) was predominant in the essential oil of this species, most of these were hydrocarbons (53.8%). This paper represents the first study on this new, undescribed Australian species and its chemical composition.     

Screening the essential oil composition of wild Sicilian fennel

Fifty-six samples of wild fennel (Foeniculum vulgare Mill.) have been collected in different localities of Sicily and analysed for their content in seed essential oils. The GC-FID-MS analyses allowed identifying 78 compounds, representing more than 98% of the oils. Phenylpropanoids are the most highly represented components – 55 samples show estragole as the main compound ranging between 34 and 89%, while (E)-anethole is the other phenylpropanoid ranging between 0.1 and 36%, although it only reaches appreciable values in a few samples, largely being present below 1%. The oxygenated monoterpene, fenchone, a typical fennel oil component, has been found in all samples, in the 2–27% range; α-pinene (1–21%), limonene (1–17%) and γ-terpinene (<1–4%) were the monoterpene hydrocarbons found in all samples. Only one sample showed piperitenone oxide and limonene as main components, with 42 and 34%, respectively, and with the lack of any phenylpropanoid. Sesquiterpenes and others compounds class had only negligible values or were not detected in all samples. Statistical analyses allowed to single out five groups, reflecting the compositional differences of the essential oil profiles of the wild Sicilian fennel.     

The ethnobotany,leaf anatomy,essential oil variation and biological activity of Pteronia incana (Asteraceae)

The only available ethnobotanical information on Pteronia incana has been recorded by the Montagu Museum in the Western Cape Province of South Africa. It was reported that the plant is used to treat influenza, fever, kidney ailments and backache. In common with other species of Pteronia, the plant contains an essential oil reminiscent of pine turpentine oil with β-pinene, limonene, 1,8-cineole, myrcene, spathulenol, p-cymene and methyleugenol as main compounds present in all or most of the samples, with smaller amounts of α-pinene, sabinene, γ-terpinene, terpinen-4-ol, biclogermacrene, globulol and α-bisabolol in some of the distillates. We investigated the oil composition of 11 individual plants collected at three geographically distant localities but found limited variation, both within and between populations. Leaf sections of P. incana showed that it is anatomically similar to P. divaricata in the presence of a secretory duct associated with the main vascular bundle (and often other bundles as well), in addition to glandular and non-glandular trichomes on both leaf surfaces. One yeast (Cryptococcus neoformans), two Gram-negative bacteria (Moraxella catarrhalis and Klebsiella pneumoniae) and one Gram-positive bacterium (Mycobacterium smegmatis) were selected for antimicrobial activity studies using the minimum inhibitory concentration (MIC) microtitre plate method. The results showed that methanol:dichloromethane (MeOH:CH₂Cl₂) extracts were active against M. smegmatis (lowest MIC values of 0.5–0.8 mg/ml) and C. neoformans (lowest MIC values of 0.5–2.0 mg/ml). The essential oil was most active against C. neoformans (lowest MIC value of 0.3 mg/ml). These results provide a scientific rationale for the use of P. incana in Cape herbal medicine.     

Evaluation of Characteristic Aroma Compounds of Citrus natsudaidai Hayata (Natsudaidai) Cold-Pressed Peel Oil

The characteristic aroma compounds of Citrus natsudaidai Hayata essential oil were evaluated by a combination of instrumental and sensory methods. Sixty compounds were identified and quantified, accounting for 94.08% of the total peel oil constituents. Limonene was the most abundant compound (80.68%), followed by γ-terpinene (5.30%), myrcene (2.25%) and α-pinene (1.30%). Nineteen compounds which could not be identified in the original oil were identified in the oxygenated fraction. Myrcene, linalool, α-pinene, β-pinene, limonene, nonanal, γ-terpinene, germacrene D, and perillyl alcohol were the active aroma components (FD-factor > 3⁶), whereas β-copaene, cis-sabinene hydrate and 1-octanol were suggested as characteristic aroma compounds, having a Natsudaidai-like aroma in the GC effluent. Three other compounds, heptyl acetate, (E)-limonene oxide and 2,3-butanediol, which each showed a high RFA value (>35) were considered to be important in the reconstruction of the original Natsudaidai oil from pure odor chemicals. The results indicate that 1-octanol was the aroma impact compound of C. natsudaidai Hayata peel oil.     

Volatile constituents in leaves of parsley

Volatile chemicals obtained from the leaves of parsley, Petroselinum sativum by steam distillation, isopentane extraction, and head-space analysis were identified by GLC-MS. The presence in leaf oil of α-pinene, β-pinene, myrcene, β-phellandrene, trans-β-ocimene, γ-terpinene, 1-methyl-4-isopropenyl benzene, and 1,3,8-p-menthatriene as shown by earlier investigators was confirmed. In the present studies, the number of volatile chemicals detected in the leaves was extended by an additional 42. Sniffing tests of effluent from a gas chromatograph of a concentrate from parsley leaves showed that 1,3,8-p-menthatriene was only one of several compounds that gave a parsley-like aroma.     

Essential oil variability within and among populations of Cunila incisa Benth.

To evaluate the intra- and interpopulational variability of volatile compounds in Cunila incisa, 72 samples representing 12 populations, were collected all over the distribution area of the species in Rio Grande do Sul State. The samples were extracted by steam distillation and analyzed using GC and GC–MS. A total of 19 volatile compounds were detected and identified. In average, the main compounds were 1,8-cineole, α-terpineol, p-cymene, sabinene, terpinene-4-ol, and γ-terpinene. Negative correlation was detected between the concentrations of 1,8-cineole and α-terpineol. Significant variation in the concentration of volatile compounds was detected within and among populations. Multivariate analysis of volatile oil composition identified three groups. Most populations exhibited low intra-populational variation indicating foundation effect. Relation between geographic distribution and chemical composition was observed.     

Essential oil variability in Thymbra capitata (L.) Cav. growing wild in Southern Apulia (Italy)

Essential oils of Thymbra capitata (Thymus capitatus) collected from Southern Apulia (Italy) were analysed using gas chromatography and gas chromatography–mass spectrometry techniques, to check for chemical variability. The study showed that among the 75 components of the oils the most recurrent ones were thymol and carvacrol, which always constituted more than 50% of the oils, as well as γ-terpinene, borneol and p-cymene. Cluster analysis led to the identification of three chemotypes: thymol, carvacrol and thymol/carvacrol; this was presumably a crossbreed between the other two chemotypes. Principal component analysis showed the direct correlation among myrcene, α-terpinene and γ-terpinene; anti-correlation between thymol and carvacrol, and the inverse correlation between linalool and myrcene. Moreover, lower thymol concentrations were accompanied by an increase in myrcene, α-terpinene and γ-terpinene.     

A revision of the continental species of Copa Simon, 1885 (Araneae,Corinnidae) in the Afrotropical Region

The cryptic ground-dwelling castianeirine genus Copa Simon, 1885 (Araneae: Corinnidae) is revised in the continental Afrotropical Region. The type species of the genus, Copa flavoplumosa Simon, 1885, is redescribed and considered a senior synonym of Copa benina Strand, 1916 syn. n. and Copa benina nigra Lessert, 1933 syn. n. It is widespread throughout the Afrotropical Region but has not been introduced to any of the associated regional islands. A new species, Copa kei sp. n., is described from South Africa. Copa agelenina Simon, 1910, originally described from a subadult female from southern Botswana, is considered a nomen dubium. Copa flavoplumosa is a characteristic species of leaf litter spider assemblages and is particularly prevalent in savanna habitats on the continent, but also occurs in various forest types, grasslands, fynbos and semi-arid Nama Karoo habitats. In contrast, Copa kei sp. n. has only been recorded from Afromontane and coastal forests in south-eastern South Africa.     

Cercopithecidae from the Pliocene Chiwondo beds, Malawi-rift

There are a total of 16 fossil cercopithecid specimens, representing at least 10 individuals, from the Chiwondo Beds of northern Malawi. The majority of this material is derived from the Middle Pliocene Unit 3A, but one specimen is from the Early Pliocene Unit 2. This latter specimen is from a papionin of indeterminate genus similar in size to Parapapio ado and Pliopapio alemui. Among the specimens from Unit 3A, two species can be diagnosed: an indeterminate species of Theropithecus, and a species of Parapapio similar in dental size to P. broomi. Neither of the genera from Unit 3A are exclusive to either East Africa or South Africa. Their relative abundances, however, are more similar to Middle Pliocene South African sites where Parapapio is the most common primate genus, and Theropithecus is comparatively rare. This is in contrast to similarly-aged East African sites where Theropithecus is by far the most abundant genus.     

Essential oils of Cupressus funebris, Juniperus communis, and J. chinensis (Cupressaceae) as repellents against ticks (Acari: Ixodidae) and mosquitoes (Diptera: Culicidae) and as toxicants against mosquitoes

Juniperus communis leaf oil, J. chinensis wood oil, and Cupressus funebris wood oil (Cupressaceae) from China were analyzed by gas chromatography and gas chromatography-mass spectrometry. We identified 104 compounds, representing 66.8-95.5% of the oils. The major components were: α-pinene (27.0%), α-terpinene (14.0%), and linalool (10.9%) for J. communis; cuparene (11.3%) and δ-cadinene (7.8%) for J. chinensis; and α-cedrene (16.9%), cedrol (7.6%), and β-cedrene (5.7%) for C. funebris. The essential oils of C. funebris, J. chinensis, and J. communis were evaluated for repellency against adult yellow fever mosquitoes, Aedes aegypti (L.), host-seeking nymphs of the lone star tick, Amblyomma americanum (L.), and the blacklegged tick, Ixodes scapularis Say, and for toxicity against Ae. aegypti larvae and adults, all in laboratory bioassays. All the oils were repellent to both species of ticks. The EC(95) values of C. funebris, J. communis, and J. chinensis against A. americanum were 0.426, 0.508, and 0.917 mg oil/cm(2) filter paper, respectively, compared to 0.683 mg deet/cm(2) filter paper. All I. scapularis nymphs were repelled by 0.103 mg oil/cm(2) filter paper of C. funebris oil. At 4 h after application, 0.827 mg oil/cm(2) filter paper, C. funebris and J. chinensis oils repelled ≥80% of A. americanum nymphs. The oils of C. funebris and J. chinensis did not prevent female Ae. aegypti from biting at the highest dosage tested (1.500 mg/cm(2) ). However, the oil of J. communis had a Minimum Effective Dosage (estimate of ED(99) ) for repellency of 0.029 ± 0.018 mg/cm(2) ; this oil was nearly as potent as deet. The oil of J. chinensis showed a mild ability to kill Ae. aegypti larvae, at 80 and 100% at 125 and 250 ppm, respectively.     

Essential oil in Betula spp. leaves naturally growing in Estonia

The essential oils of the leaves of Betula pendula Roth., Betula pubescens Ehrh., Betula humilis Schrank and Betula nana L. (Betulaceae), and B. pendula buds were obtained using hydrodistillation and their chemical compositions were analyzed using gas chromatography and gas chromatography – mass spectrometry. The yield of essential oil was the highest (0.27%) in leaves of. B. humilis and the lowest in the leaves of B. pendula (0.11%), B. pubescens (0.05%) and B. nana (traces). Overall, 35–60 compounds were identified representing more than 92% of the total volume of the oils investigated. The bicyclical sesquiterpenoids found in the essential oils extracted from the leaves of B. pendula, B. pubescens and B. humilis and from the buds of B. pendula where α-betulenol (20.4–33.1%), α-betulenol acetate (5,6–28.9%), β-betulenal (5.5–6.2%) and β-betulenol (2.0–5.8%). The buds of B. pendula contained more birkenal, (E)-β-caryophyllene, δ-cadinene and caryophyllene oxide, but less α-betulenol acetate, β-betulenal and aliphatic compounds than the oils extracted from the leaves investigated. The oil composition of B. humilis and B. nana leaves was studied for the first time. The content of essential oil of B. nana leaves was much more varied: the oil contained less bicyclical sesquiterpenoids and more aliphatic compounds than the other Betula species investigated. The findings of our study could be used in chemosystematics of birch species, especially for B. nana.     

Identification des constituants de l'essence des aiguilles de Pinus pinaster

The chromatographic analysis of the volatile leaf oil of Pinus pinaster Ait. showed 42% of monoterpene hydrocarbons (α-pinene, camphene, β-pinene, myrcene, 3-carene, limonene, cis-ocimene, terpinolene, para-cymene, 35% of sesquiterpene hydrocarbons (cubebene, copaene, caryophyllene, humulene, germacrene D, α- and γ-muurolenes, δ- and γ-cadinenes) and 23% of oxygenated compounds including esters (linalyl, bornyl, geranyl, neryl and farnesyl acetates), alcohols (cis-hexenol, linalool, α-fenchol, trans-pinocarveol, terpinen-4-ol, α-terpineol, dihydrocarveol, guaiol, junenol and α-cadinol), one aldehyde (hexenal) and one ketone (piperitone). Three non terpenoid phenylethyl esters were also identified: phenylethyl isovalerate, methyl-2 burtyate and 3-3 dimethylacrylate. Some alcohols and mainly α-terpineol and linalool seemed to be formed during the steam distillation process, they were absent when the leaf oil was obtained by maceration of small portions of leaves in the usual solvents of terpenes.     

Studies on Leaf Oils of Citrus Species

Leaf oil samples of four Japanese citrus species were analysed by gas chromatography to determine the detailed composition of each leaf oil. The following components were identified: α-pinene, α-thujene, camphene, β-pinene, sabinene, β-myrcene, α-terpinene, limonene, β-phellandrene, trans-2-hexen-1-al, γ-terpinene, p-cymene, terpinolene, cis-2-penten-1-ol, n-hexyl alcohol, cis-3-hexen-1-ol, trans-2-hexen-1-ol, p-α-dimethylstyrene linalool, linalyl acetate, β-elemene, terpinen-4-ol, caryophyllene, humulene, α-terpineol, neryl acetate, geranyl acetate, β-selinene, geraniol and thymol. Most components were contained in common in leaf oils of the four citrus species, but relative contents of some of the components; such as γ-terpinene, linalyl acetate, and thymol differed from species to species. For example, γ-terpinene was the major component (33.8%) of Hassaku, whereas it was only a minor component in Daidai. Daidai is characterized by a very high content of linalyl acetate (35%) which is only a trace in the other three species. Kishu-mikan is characterized by a high content of thymol (15%).     

Composition of essential oil of <Emphasis Type="Italic">Artemisia scoparia</Emphasis> Waldst. et Kit. from Buryatia and Mongolia

Essential oil from the epigeal portion of Artemisia scoparia Waldst. et Kit. collected in different regions of Buryatia and Mongolia has been isolated using steam distillation. The yield of essential oil from the stems and leaves of A. scoparia collected in different regions of Buryatia and in the Selenga aymag of Mongolia ranged from 0.06 to 0.40%, that is, the variation was rather high. The composition of the oil was analyzed using chromatography with mass spectrometric detection on a gas chromatography device Agilent Packard HP 6890 N with a quadrupole mass spectrometric detector HP MSD 5973. The total number of compounds detected exceeded 100. The major components of Artemisia scoparia oil were the following: p-cymene (0.6–15.2%), limonene (0.1–6.3%), α-pinene (0.2–10.1%), β-pinene (0.4–8.9%), trans-β-ocimene (0.3–5.4%), caryophyllene (4.6–13.8%), germacrene D (11.5–40.3%), spathulenol (4.0–11.7%), and caryophyllene oxide (4.3–15.6%). Several chemotypes of essential oil from A. scoparia were identified according to the nature of the major components: 1) oil that contained acetylene hydrocarbons (from plants collected in Gilan, Mazandaran, Kashan, and Tigran provinces of Iran, Tajikistan, and the European part of the CIS); 2) oil that contained monoterpenes and aromatic compounds (from plants collected in the Khorasan province of Iran, India, and South Korea); and 3) oil that contained monoterpenes or aromatic and sesquiterpene compounds (from plants collected in Kazakhstan and Mongolia). The major components of A. scoparia essential oil obtained from Buryatian plants belonged to the classes of mono- and sesquiterpene compounds, and thus the oil can be assigned to the third chemotype characteristic of A. scoparia from geographically close regions.     

A new species of Combretum section Ciliatipetala (Combretaceae) from southern Africa, with a key to the regional members of the section

Combretum stylesii O.Maurin, Jordaan & A.E.van Wyk, a liana or slender tree with scrambling branches from the Tugela River Valley (KwaZulu-Natal), South Africa, is described. Molecular data supports its placement in subgenus Combretum section Ciliatipetala with its closest relative Combretum edwardsii. The new species differs from C. edwardsii in having, amongst others, a single mature leaf form, leaves softly textured, with whitish hairs, often with drooping habit, shorter leaf petioles (less than 5 mm), and less complex 8-celled leaf scales. A key to the species and infraspecific taxa of section Ciliatipetala in the Flora of southern Africa region is provided.     

Essential‐Oil Composition of the Tunisian Endemic Cypress (Cupressus sempervirens L. var. numidica Trab.)

The essential oils isolated from leaves, wood, and cones of the Tunisian endemic cypress Cupressus sempervirens L. var. numidica Trab. collected from three natural populations were characterized by GC‐FID and GC/MS analyses. In the wood, leaf, and cone oils, 38, 35, and 26 constituents, representing 94.4, 97.8, and 98.5% of the total oil composition, respectively, were identified. Monoterpenes constituted the major fraction of the oils from all organs and for all populations. The oils were found to be of an α‐pinene (64.2%)/δ‐car‐3‐ene (11.1%) chemotype with considerable contents of α‐humulene (3.4%) in the leaf oil, cedrol (2.8%) in the wood oil, and sabinene (3.2%) in the cone oil, respectively. α‐Pinene, δ‐car‐3‐ene, limonene, carvacrol methyl ether, α‐humulene, and α‐amorphene were the main components that differentiated the oils of the three organs in the cypress of Makthar.     

Antigonococcal activity of Ximenia caffra Sond. (Olacaceae) and identification of the active principle

The “large sour plum” tree Ximenia caffra Sond. (Olacaceae) is the only African representative of the genus Ximenia L., with a distribution covering East Africa, from Tanzania in the north to South Africa, as well as parts of Botswana and Namibia. It has many uses in traditional medicine, including treatment of wounds and infections as well as diarrhea, which have been verified through various pharmacological studies. Furthermore, the plant is also known for its nutritional and cosmetic value. Its edible fruits are known to be high in protein, potassium and vitamin C, while the seed oil, also referred to as “Ximenia oil” is rich in long chain unsaturated fatty acids and finds use as a domestic biofuel, with characteristics amenable to cosmetic development as topical applicants. Extracts of the plants are also widely used for treating sexually transmitted infections (STIs), which has been verified through ethnobotanical surveys and pharmacological screens. Based on these observations, X. caffra var. caffra was examined for its phytochemical composition and activity against the gonorrheal pathogen Neisseria gonorrhoeae. Initially, the leaf ethanolic extract was seen to be active (43.9% inhibition). The DCM partition of this extract (with 78.8% inhibition) was subjected to bioassay guided fractionation leading to the identification of the bisnorsesquiterpene vomifoliol which exhibited significant activity (63.1%) against N. gonorrhoeae.