Citronella Oil

In 1948 almost 3,500,000 pounds of this oil were exported by Indonesia, Ceylon, Guatemala and Formosa. The United States is normally the principal consumer, finding many uses for it in perfuming soap, insect sprays, perfume formulas, menthol production, and for the manufacture of certain important synthetic organic chemicals. The Western Hemisphere has achieved a material degree of progress in its efforts at independence from distant sources of the Java type.     

Ecotype Variation of Methyl Eugenol Content in Tea Tree (Melaleuca alternifolia and Melaleuca linariifolia)

Methyl eugenol is a natural phenylpropanoid compound found in a wide range of plants used for food, flavouring, cosmetics, and health‐care. As a suspected rodent carcinogen, methyl eugenol may also be harmful to humans when present in significant concentrations. Consequently, its level has been restricted in some foodstuffs and cosmetics for some markets. In order to assess the potential to breed uniformly low methyl eugenol cultivars for an essential oil crop, tea tree, the source of ‘Oil of Melaleuca, terpinene‐4‐ol type’, we examine levels in individual trees (n = 30) from two geographic regions and six terpene chemotypes. Overall, methyl eugenol levels were low in this species (Mean [SD] 354 [239] ppm, n = 30), much lower than levels predicted to be of toxicological concern. Within each chemotype, there was a lack of evidence for correlations between terpenoid constituents and methyl eugenol levels. Further support for the independence of methyl eugenol and terpene biosynthesis was evident from similar mean levels in selected (Mean [SD] 586 [339] ppm, n = 12) and undomesticated Melaleuca alternifolia trees (Mean [SD] 480 [299] ppm, n = 5) with terpinen‐4‐ol type oils. By contrast, methyl eugenol level varied by geographic origin and chemotype. Trees from the upland region, where there is a prevalence of terpinolene type trees, had lower average methyl eugenol levels than trees from the coastal region, where there is a prevalence of terpinen‐4‐ol and 1,8‐cineole type trees.     

Attraction of Bactrocera dorsalis (Diptera: Tephritidae) and nontarget insects to methyl eugenol bucket traps with different preservative fluids on Oahu Island, Hawaiian Islands

Attraction of oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), and nontarget insects to preservative fluids ethylene glycol antifreeze, propylene glycol antifreeze, or mineral oil in bucket traps that contained captured decaying male oriental fruit flies, a male lure (methyl eugenol), and a toxicant (DDVP vapor insecticidal strip) were compared with dry control traps. Significantly (P < 0.05) greater numbers of B. dorsalis were captured in propylene glycol antifreeze traps than in other attractant trap types. Among attractant trap types with lowest negative impacts on nontarget insects, control traps captured significantly lower numbers of three species and one morphospecies of scavenger flies, one species of plant-feeding fly, and one species each of sweet-and lipid-feeding ants. Mineral oil traps captured significantly lower numbers of two species of scavengers flies and one morphospecies of plant-feeding fly, and one species of sweet-feeding ant. Because of the fragile nature of endemic Hawaiian insect fauna, the propylene glycol antifreeze bucket trap is best suited for use in environments (e.g., non-native habitats) where endemic species are known to be absent and mineral oil traps are more suited for minimizing insect captures in environmentally sensitive habitats.     

Essential‐Oil Variability in a Collection of Ocimum basilicum L. (Basil) Cultivars

Ocimum basilicum L. (Lamiaceae) is an aromatic plant of great tradition in the Mediterranean area. Its economic importance is growing up determining an expansion of cultivation. This paper evaluated the morphological traits, the chemical profiles, and antibacterial activity of 21 cultivars of basil belonging to ?Genovese?, ?Napoletano?, and ?Purple basil? types. The cultivars were characterized by different growth rate and morphological traits. The chemical composition of the oils analyzed by GC and GC/MS analysis, supported by the PCA analysis, underlined the strong influence of chemotype. It is noteworthy that estragole, never present in Genovese and purple basil types, occurred in Napoletano type. The high presence of eugenol, methyl eugenol, and linalool in the majority of cultivars, belonging both to Genovese and to Napoletano types was registered. Of great interest resulted the composition of the purple basil ?Opal?. All the samples tested exhibited similar antibiotic profiles with moderate antibacterial activity. The results enhanced the importance of determination of essential‐oil profile in the selection of cultivars characterized by diverse morphological traits and are useful for different purposes.     

Anticonflict effects of rose oil and identification of its active constituents

The present study investigates the pharmacologically active constituents of rose oil, which possesses anti-conflict effects. Analysis using GC/MS revealed that rose oil contains 9 substances that were identified as myrcene, benzyl alcohol, 2-phenethyl alcohol, citronellol, geraniol, citronellyl acetate, eugenol, geranyl acetate and methyl eugenol. We examined the effects of each of these substances using the Geller and Vogel conflict tests in ICR mice. Myrcene, benzyl alcohol and citronellyl acetate did not produce any effects in either tests. Geranyl acetate and methyl eugenol produced no effect in the Geller conflict test. Geraniol and eugenol decreased the response rate during the safe period of the Geller conflict test, but did not affect the response rate during the alarm period. In contrast, 2-phenethyl alcohol and citronellol, like rose oil, produced an increasing effect on the response rate during the alarm period in the Geller conflict test. In addition, both chemicals increased the number of electric shocks mice received in the Vogel conflict test in a manner similar to that of rose oil. Given that 2-phenethyl alcohol and citronellol produced the same anti-conflict effects in both tests as rose oil, we concluded that they are the pharmacologically active constituents of anti-anxiety-like effect of rose oil.     

Frequencies of chromosome polymorphism in pairs no. 1, 9, and 13 in three geographical variants of black rats,Rattus rattus

Frequencies of the acrocentric and subtelocentric polymorphism in pairs no. 1, 9 and 13 chromosomes have been examined in 358 black rats, Rattus rattus, distributed over several countries of Asia, Australia and United States. The black rats are divided into three geographical types by the different chromosome numbers, such as Asian (2n=42), Ceylon (2n=40) and Oceanian types (2n=38). Pairs no. 13 polymorphism was found widely in these all types, but the pair no. 1 and 9 polymorphisms were found in only Asian type black rats. In the Asian type rats, however, those distributed in northern India and Pakistan showed always the subtelocentric pairs no. 1 and 9 like as those in Ceylon and Oceanian type black rats. This finding supports that the Ceylon and Oceanien type rats have developed in India or Pakistan from the Asian type. The present study also suggests that inversion of the pair no. 13 could have occurred in earlier period than those of the pairs no. 1 and 9.     

Lijndenia, a re–established paleotropical genus of the Melastomataceae–Memecyleae

The genus Lijndenia Zoll. & Mor. is re–established and emended to include four species, L. laurina Zoll. & Mor. from W Malesia and Java, L. capitellata (Arn.) Bremer from Ceylon, L. gardneri (Thw.) Bremer from Ceylon, and L. barteri (Hook. f.) Bremer from tropical W Africa. The latter three names are new combinations.     

Variability in essential oil composition of Turkish basils (Ocimum basilicum L.)

Sweet basil (Ocimum basilicum L.), one of the most popular aromatic plants, shows great variation in both morphology and essential oil components. In this study, the composition of 18 Turkish basil essential oils was investigated by GC and GC–MS. Variation of essential oils in the landraces was subjected to cluster analysis, and seven different chemotypes were identified. They were (1) linalool, (2) methyl cinnamate, (3) methyl cinnamate/linalool, (4) methyl eugenol, (5) citral, (6) methyl chavicol (estragol), and (7) methyl chavicol/citral. Methyl chavicol with high citral contents (methyl chavicol/citral) can be considered as a “new chemotype” in the Turkish basils. Because methyl eugenol and methyl chavicol have structural resemblance to carcinogenic phenylpropanoids, chemotypes having high linalool, methyl cinnamate or citral contents and a mixture of these is suitable to cultivate for use in industry.     

北细辛超临界萃取物挥发性成分的GC-MS分析

采用超临界流体萃取法(SFE)和水蒸气蒸馏法分别对北细辛根及根茎进行提取分离,分别得5.5%SFE萃取物和2.8%挥发油。应用GC-MS分析,从北细辛SFE萃取物中鉴定出7种化学成分,占萃取物总量的72.70%,其中甲基丁香酚为44.62%;从细辛挥发油中鉴定出19种化学成分,占挥发油总量的88.53%,其中甲基丁香酚为43.02%。两种方法有6种成分完全相同,其中致癌物质黄樟油素SFE法比蒸馏法低2.8倍。北细辛根及根茎超临界萃取物与水蒸汽蒸馏挥发油主要成分相同,但其化学组成存在较大差异,提示药效亦不相同。超临界流体萃取法是剂型改革的有效方法之一。     

Genetic diversity of Ocimum gratissimum L. based on volatile oil constituents, flavonoids and RAPD markers

Morphological, chemical and genetic differences of 12 tree basil (Ocimum gratissimum L.) accessions were studied to determine whether volatile oils and flavonoids can be used as taxonomical markers and to examine the relationship between RAPDs to these chemical markers. Eugenol, thymol, and geraniol were the major volatile oil constituents found in Ocimum gratissimum. Xantomicrol and cirsimaritin were the major external flavones. The accessions morphologically described as O. gratissimum var. gratissimum contained eugenol as the major volatile oil constituent, and cirsimaritin as the major flavone. Ocimum gratissimum var. macrophyllum accessions contained thymol as the major volatile oil constituent, and xantomicrol as the major flavone. A distinct essential oil and flavone chemotype (producing geraniol and a mixture of the flavones cirsimaritin, isothymusin, xanthomicrol, and luteolin) was found in an accession genetically more distant from the other two groups when analyzed by molecular markers. The accessions could be divided based on volatile oil constituents into six groups: (1) thymol: alpha-copaene (ot24, ot25, ot26, and ot28); (2) eugenol:spathulenol (ot17, ot63, and ot52); (3) thymol:p-cymene (ot65); (4) eugenol:gamma-muurolene (ot27 and ot29); (5) eugenol:thymol: spathulenol (ot85); and (6) geraniol (ot84). Cluster analysis of RAPD markers showed that there are three groups that are distinct genetically and highly correlated (r=0.814) to volatile oil constituents.     

Effects of two sodium salts on fatty acid and essential oil composition of basil (Ocimum basilicum L.) leaves

The effects of two sodium salts on growth, fatty acids, and essential oil compositions were investigated in a medicinal and aromatic plant, Ocimum basilicum cultivated in hydroponic medium. Plants were subjected to an equimolar concentration of Na₂SO₄ (25 mM) and NaCl (50 mM) for 15 days. Our results showed that leaf growth rate was more depressed by 25 mM Na₂SO₄ than by 50 mM NaCl. The total fatty acid contents did not show any change in plants. α-Linolenic, palmitic, and linoleic acids were the major fatty acids. The identification of basil leaf fatty acids has not been previously studied and this work revealed the predominance of polyunsaturated fatty acids. Under both salts, leaf fatty acid composition remained unchanged. Regarding the essential oil yield, it decreased significantly by 28 % under 25 mM Na₂SO₄ and showed an increase by 27 % under 50 mM NaCl. The major volatile compound in leaves was linalool with 34.3 % of total essential oil constituents, followed by eugenol (19.8 %), 1.8-cineole (14.4 %) and methyl eugenol (5.2 %). Further, levels of eugenol and methyl eugenol were most modulated by salt, and the negative correlation between these two compounds reflects the stimulation of O-methyltransferase activity under both salts.     

The Essential Oil Compositions of Ocimum basilicum from Three Different Regions: Nepal,Tajikistan, and Yemen

The aerial parts of Ocimum basilicum L. were collected from four different geographical locations, Sindhuli and Biratnagar (Nepal), Chormaghzak village (Tajikistan), and Sana'a (Yemen). The essential oils were obtained by hydrodistillation and analyzed by gas chromatography/mass spectrometry. A cluster analysis of 179 essential oil compositions revealed six major chemotypes: Linalool, eugenol, estragole, methyl eugenol, 1,8‐cineole, and geraniol. All four of the basil oils in this study were of the linalool‐rich variety. Some of the basil oils were screened for bioactivity including antimicrobial, cytotoxicity in human cancer cells, brine shrimp lethality, nematicidal, larvicidal, insecticidal, and antioxidant. The basil oils in this study were not notably antibacterial, cytotoxic, antioxidant, nor nematicidal, but were active in the brine shrimp lethality test, and did show larvicidal and insecticidal activities.     

The Small Ribosomal Subunit RNA Isoforms in Plasmodium Cynomolgi

We report the isolation, characterization and analysis of the small subunit rRNA genes in Plasmodium cynomolgi (Ceylon). As in other Plasmodium species, these genes are present in low copy number, are unlinked and form two types that are distinct in sequence and are expressed stage specifically. The asexually expressed (type A) genes are present in four copies in the Ceylon(-) and in five copies in the Berok(-) strain. Surprisingly, the sexually expressed (type B) gene is present in a single copy. The vast majority of the differences between gene types is confined to the variable regions. The pattern of divergence is different from that observed in Plasmodium berghei or in Plasmodium falciparum. Analysis of the small subunit rRNA sequences of P. cynomolgi, P. berghei and P. falciparum, indicates that the two gene types do not evolve independently but rather interact (through gene conversion or some form of recombination) to such an extent as to erase whatever stage-specific sequence signatures they may have had in the last common ancestor.     

A potential field suppression system for Bactrocera dorsalis Hendel

Development of an effective and safe detection or control system is important for pest management. Attractants for male fruit flies, e.g., methyl eugenol (ME), are currently being used in fruit fly control in combination with insecticides. A single formulation that possesses both attraction and killing properties would improve control methods and cost effectiveness. We previously observed the attraction of oriental fruit flies to a basil plant in a yard and confirmed the attraction of male fruit flies to basil oil (BO) in the laboratory. Subsequently, we identified insecticidal compounds from BO that killed three species of tephritid fruit flies in the laboratory, and we also discovered physiological interactions between BO constituents and male attractants. Based on these observations, we developed a single package of basil oil and methyl eugenol (BO + ME) formulation that possesses “attract and kill” properties in combination with a modified AWPM standard trap for field application. The effectiveness of this system is dependent on the type of trap and weather conditions (sunny or not sunny). Any attracted flies were killed within 2 h after entering the BO + ME trap. The combination of BO, ME, and a clear bucket trap may be a novel alternative for a cost effective and environmentally friendly fruit fly management system.     

Screening of chemical composition, antimicrobial and antioxidant activities of Artemisia essential oils

The chemical composition of essential oils isolated from aerial parts of seven wild sages from Western Canada – Artemisia absinthium L., Artemisia biennis Willd., Artemisia cana Pursh, Artemisia dracunculus L., Artemisia frigida Willd., Artemisia longifolia Nutt. and Artemisia ludoviciana Nutt., was investigated by GC–MS. A total of 110 components were identified accounting for 71.0–98.8% of the oil composition. High contents of 1,8-cineole (21.5–27.6%) and camphor (15.9–37.3%) were found in Artemisia cana, A. frigida, A. longifolia and A. ludoviciana oils. The oil of A. ludoviciana was also characterized by a high content of oxygenated sesquiterpenes with a 5-ethenyltetrahydro-5-methyl-2-furanyl moiety, of which davanone (11.5%) was the main component identified. A. absinthium oil was characterized by high amounts of myrcene (10.8%), trans-thujone (10.1%) and trans-sabinyl acetate (26.4%). A. biennis yielded an oil rich in (Z)-beta-ocimene (34.7%), (E)-beta-farnesene (40.0%) and the acetylenes (11.0%) (Z)- and (E)-en-yn-dicycloethers. A. dracunculus oil contained predominantly phenylpropanoids such as methyl chavicol (16.2%) and methyl eugenol (35.8%). Artemisia oils had inhibitory effects on the growth of bacteria (Escherichia coli, Staphylococcus aureus, and Staphylococcus epidermidis), yeasts (Candida albicans, Cryptococcus neoformans), dermatophytes (Trichophyton rubrum, Microsporum canis, and Microsporum gypseum), Fonsecaea pedrosoi and Aspergillus niger. A. biennis oil was the most active against dermatophytes, Cryptococcus neoformans, Fonsecaea pedrosoi and Aspergillus niger, and A. absinthium oil the most active against Staphylococcus strains. In addition, antioxidant (beta-carotene/linoleate model) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities were determined, and weak activities were found for these oils.     

Simultaneous determination of cinnamaldehyde, eugenol and piperine by HPTLC densitometric method

An HPTLC densitometric method for the simultaneous determination of cinnamaldehyde and eugenol as well as trace amounts of piperine in pepper-contaminated cinnamon was developed. The applicability of the method was tested with cinnamon bark powder adulterated with pepper powder, cinnamon oil, clove powder, clove oil and a commercial preparation containing cinnamaldehyde and eugenol. The method was validated for specificity, precision, accuracy and robustness. The method was found to be precise for different concentrations of cinnamaldehyde, eugenol and piperine. The accuracy of the method was checked by conducting a recovery study at three different levels. The linearity was found to be in the ranges 52.54-735.56, 533.2-8531.2 and 50-300 ng/spot, respectively, with correlation coefficients of 0.9985 +/- 0.04, 0.9982 +/- 0.06 and 0.9937 +/- 0.11 for cinnamaldehyde, eugenol and piperine.     

Transport of methyl eugenol-derived sex pheromonal components in the male fruit fly, Bactrocera dorsalis

Males of Bactrocera dorsalis (Diptera: Tephritidae) are attracted strongly to and feed compulsively on methyl eugenol (1,2-dimethoxy- 4 -(2-propenyl)benzene), a highly potent male attractant. Pharmacophagy of methyl eugenol results in the production of phenylpropanoids 2-allyl-4,5-dimethoxyphenol and (E)-coniferyl alcohol that are sequestered and stored in the rectal gland prior to release as sex pheromonal components during mating at dusk. While these pheromonal components have also been detected in the hemolymph and crop of methyl eugenol-fed males, there is currently little information on the transport of these compounds from the crop to rectal gland in male B. dorsalis. Therefore, using physiological techniques such as parabiosis, rectal gland transplantation and hemolymph transfusion coupled with gas chromatography-mass spectrometry (GC-MS) analyses, we were able to ascertain and confirm the role of the hemolymph in the transport of these sex pheromonal components from the crop to the rectal gland. Further, the temporal profile of these methyl eugenol-derived bioactive compounds in the hemolymph also shows an increase with time post-methyl eugenol-feeding, i.e., 2-allyl-4,5-dimethoxyphenol attaining maximum amounts 15 min after ME consumption and decreasing thereafter, while for (E)-coniferyl alcohol-the increase and decrease are more gradual. These results further demonstrate the ability of insect hemolymph to transport many diverse forms of bioactive molecules including attractant-derived sex pheromonal components.     

Inhibition of oxidation of unsaturated fatty acid methyl esters by essential oils

The essential oils from 16 various spice plants were studied as natural antioxidants for the inhibition of autooxidation of polyunsaturated fatty acids methyl esters isolated from linseed oil. The content of methyl oleate, methyl linoleate, and methyl linolenoate after 1, 2, and 4 months of autooxidation were used as criteria to estimate the antioxidant efficiencies of essential oils. In 4 months, 92% of the methyl linolenoate and 79% of the methyl linoleate were oxidized in a control sample of a model system. It was found that the most effective antioxidants were essential oils from clove bud, cinnamon leaves, and oregano. They inhibited autooxidation of methyl linolenoate by 76–85%. The antioxidant properties of these essential oils were due to phenols— eugenol, carvacrol, and thymol. Essential oil from coriander did not contain phenols, but it inhibited methyl linolenoate oxidation by 38%. Essential oils from thyme, savory, mace, lemon, and tea tree inhibited methyl linolenoate oxidation by 17–24%. The other essential oils had no antioxidant properties.     

The multiple phenylpropene synthases in both Clarkia breweri and Petunia hybrida represent two distinct protein lineages

Many plants synthesize the volatile phenylpropene compounds eugenol and isoeugenol to serve in defense against herbivores and pathogens and to attract pollinators. Clarkia breweri flowers emit a mixture of eugenol and isoeugenol, while Petunia hybrida flowers emit mostly isoeugenol with small amounts of eugenol. We recently reported the identification of a petunia enzyme, isoeugenol synthase 1 (PhIGS1) that catalyzes the formation of isoeugenol, and an Ocimum basilicum (basil) enzyme, eugenol synthase 1 (ObEGS1), that produces eugenol. ObEGS1 and PhIGS1 both utilize coniferyl acetate, are 52% sequence identical, and belong to a family of NADPH-dependent reductases involved in secondary metabolism. Here we show that C. breweri flowers have two closely related proteins (96% identity), CbIGS1 and CbEGS1, that are similar to ObEGS1 (58% and 59% identity, respectively) and catalyze the formation of isoeugenol and eugenol, respectively. In vitro mutagenesis experiments demonstrate that substitution of only a single residue can substantially affect the product specificity of these enzymes. A third C. breweri enzyme identified, CbEGS2, also catalyzes the formation of eugenol from coniferyl acetate and is only 46% identical to CbIGS1 and CbEGS1 but more similar (>70%) to other types of reductases. We also found that petunia flowers contain an enzyme, PhEGS1, that is highly similar to CbEGS2 (82% identity) and that converts coniferyl acetate to eugenol. Our results indicate that plant enzymes with EGS and IGS activities have arisen multiple times and in different protein lineages.