Essential oil variation in Calyptranthes spruceana

Two chemical races in Calyptranthes spruceana were examined. One of them contains limonene, geranial and perillaldehyde as the main constituents of its essential oil. The other is shown to contain α-pinene, β-pinene, neral and geranial as its major oil components.     

Chemotaxonomic Investigations of Peel and Petitgrain Essential Oils from 17 Citron Cultivars

Chemical compositions of essential oils from 17 citron cultivars were studied using GC and GC/MS. To the best of our knowledge, chemical compositions of peel and petitgrain oils from seven of them were reported for the first time. Combined analysis of peel and petitgrain essential oils led to the identification of 37 components (amounting to 98.2–99.9% of the total oil) and 42 components (97.0–99.9%), respectively. Statistical analysis was applied to identify possible relationships between citron cultivars. The levels of seven components, i.e., limonene, β‐pinene, γ‐terpinene, neral, geranial, nerol, and geraniol, indicated that the cultivars could be classified in four main chemotypes for peel and petitgrain oils. Chemotaxonomic investigations were carried out to establish relations between the morphological characteristics of citron cultivars and their corresponding oil compositions.     

The antimicrobial activity of essential oil from Dracocephalum foetidum against pathogenic microorganisms

A number of essential oils from Mongolian aromatic plants are claimed to have antimicrobial activities. The essential oil of Dracocephalum foetidum, a popular essential oil used in Mongolian traditional medicine, was examined for its antimicrobial activity. Eight human pathogenic microorganisms including B. subtilis, S. aureus, M. lutens, E. hirae, S. mutans, E. coli, C. albicans, and S. cerevisiae were examined. The essential oil of Dracocephalum foetidum exhibited strong antimicrobial activity against most of the pathogenic bacteria and yeast strains that were tested; by both the agar diffusion method and the minimum inhibitory concentration (MIC) assay (MIC range was 26-2592 microg/ml). Interestingly, Dracocephalum foetidum even showed antimicrobial activity against methicillin-resistant Staphylococcus aureus (MRSA) strains. We also analyzed the chemical composition of the oil by GC-MS and identified several major components, including n-Mentha-1,8-dien-10-al, limonene, geranial, and neral.     

Changes in volatile constituents of Zingiber officinale rhizomes during storage and cultivation

The essential oil from the fresh rhizome of Zingiber officinale was characterized by the presence of acyclic oxygenated monoterpenes mainly composed of neral, geraniol, geranial and geranyl acetate. During storage the content of neral and geranial in the rhizome increased to ca 60% of the essential oil, while the content of geraniol and geranyl acetate decreased to an undetectable amount. The change resulted from the conversion of geranyl acetate into geraniol, geranial and neral, successively. The content of geranial and neral decreased to a small extent through cultivation of the stored rhizome, whereas a large quantity of geraniol and geranyl acetate occurred in the newly propagated fresh rhizome.     

A Study on the Chemical Components of the Essentialoi from Peel of Citrus medica L. var. muhensis W. D. et Y.

The chemical components of the essential oil from peel of Citrus medica L. var. muliensis W. D. et Y. has been studied by means of the GC-MS-DS, the retention index of eapillarly gas chromatography and the Authentic sample addition process. Twenty-nine constituents has been identified from sixty-four seperated peaks. The main constituents is d-limonene (68.2%), geranial (9.5%), neral (5.37%), nerol (2.72%), β-ocimen (2.47%) and (+)-Carvone.     

THE CHEMICAL CONSTITUENTS OF THE ESSENTIAL IIL FR0M THE LEAVES 0F CITRUS MADICA

In order to find the aroma cbaracteristics of Citrus madica L.,the chemical compositions of the cssential oil of C.madica have been examined. The cssentia] oil was prepared from fresh leaves by steam disti1lation. The plants was collccted at Ying-giang district of Yunnan province in August, 1983. Tho properties of the essential oil were determined as following:the yield of oil 0.22-0.3%, d21/21 0.8826, n23/D 1.4800, [α]21.5/D + 36.9'.This essential oil was analysed by GC-MS on the Finnigan 4510 instrument. As rcsult (see Table 1 and Fig. 1 ) 22 compounds were identified. The major components are limonene (56.63%), neral (8.1%), geranial (13.52%), P-cy- mene (3.92%), geranyl acetate (2.34%), 6 -methyl- 5 -hepten- 2 -one and myrcene (3.26%) etc. This essential oil having a characteristic lemon-citrus fruitful aroma shows to be suitable for compounding perfumes of food flavour and cosmetic.     

Seasonal variation in chemical constituents of Santolina rosmarinifolia L. ssp. rosmarinifolia

The seasonal variation of the essential oil extracts from the aerial parts of a Santolina rosmarinifolia population has been studied. Oil yields increased in the months of March, April, May and June. Oil concentration showed significant correlations with both precipitation (positive) and temperature (negative). Essential oil main components were sabinene, beta-pinene, myrcene, beta-phellandrene, limonene, 1,8-cineole, artemisia ketone, terpinen-4-ol, capillene, ar-curcumene and beta-eudesmol. Monoterpenes like beta-phellandrene, limonene and 1,8-cineole showed a significant negative correlation with temperature, while capillene presented a strong positive correlation with precipitation. The rest of the essential oil components did not show any noticeable trend.     

云南柠檬草油化学成份研究

采用气—质—计算机联用法对云南柠檬草油进行定性定量分析,分离出22种成份,占全精油含量的98.23%,鉴定了其中的15种成份,其中主要成份是:月桂烯(14.61％),顺-β-罗勒烯(0.61％),芳樟醇(1.98％),香茅醛(0.65％),柠檬烯氧化物(6.43％),反-柠檬醛b(35.24％),顺-柠檬醛a(36.69％)。     

Studies on the Leaf Oils of Citrus Species

Leaf oil samples of four different citrus species were prepared from young leaves and the detailed composition of each leaf oil was investigated using gas chromatography, thin-layer chromatography and infrared spectrometry. The following components were identified: α-pinene, α-thujene, β-pinene, limonene, γ-terpinene, p-cymene, p-α-dimethylstyrene, β-humulene, β-selinene, trans-2-hexen-l-al, cis-3-hexen-l-ol, trans-2-hexen-l-ol, linalool terpinen-4-ol and α-terpineol. In addition, camphene, sabinene, β-myrcene, α-terpinene, β-elemene, caryophyllene, neral, geranial, nerol and geraniol were tentatively identified. Most of the components were found to be contained in common in the leaf oils of four different citrus species, but the relative contents of some of the components such as limonene, γ-terpinene, p-cymene, linalool, neral and geranial were distinctly different from species to species. Thus, gas chromatographic analyses of leaf oils seemed to be useful for the identification of citrus species.     

Spatial releasing properties and mosquito repellency of cellulose-based beads containing essential oils and vanillin

Porous cellulose beads (Viscopearl) manufactured from wood pulp can provide gradual-release action for aromatic substances. Here we immersed lemongrass oil, xanthoxylum oil, and vanillin to apply mosquito repellents. The volatiles from this Viscopearl were analyzed to obtain information for quality control (QC) or specification using a GC–MS, and its standard compounds were determined as linalool, geranial, neral, and vanillin. In a test using a 20 L chamber, it was confirmed that their constant amounts were released continuously and they did not be affected by light. In another monitoring test for 47 days on the Viscopearl equipped with a commercialized air conditioner operated for 8 h every day under indoor conditions, the amounts of all released components increased in proportion to the open number of the pores on the module, which is a housing case containing the Viscopearl. In addition, the concentration of 8 major components including 3 standard QC compounds (linalool, geranial, and neral) in a repellency test room depended on both the ventilation and elapsed time. The vapor from the module did not affect main 7 plastic units of the air conditioner, whereas the Viscopearl equipped with an air conditioner showed good mosquito repellency under test chamber and room conditions that temperature, relative humidity, and carbon dioxide concentration were controlled at 24.8–25.4 °C, 63.8–65.7%, and 708–1383 ppm, respectively. Therefore, the plant essential oil-based repellent Viscopearl has high potential to be used as human protective agent against indoor mosquitoes by applying it to air conditioners.     

Composition of the essential oil from the lemon balm growing in the neighborhood of Krasnoyarsk as indicated by gas chromatography–mass spectrometry data

Essential oil has been isolated from the above-ground part of the lemon balm growing in the neighborhood of Krasnoyarsk by the method of exhaustive water and steam distillation. Forty seven components, each with a content of more than 0.1% of whole oil, have been identified by GC-MS. The main oil components are citronellol (36.71%) and geraniol (27.20%). The oil also contains ten components with a content of more than 1% of the sum of all oil components: benzyl alcohol (1.67%), linalool (1.75%), citronellal (1.44%), neral (3.33%), geranial (4.39%), caryophyllene (3.73%), caryophyllene oxide (1.40%), dibutyl phthalate (1.36%), butylisobutyl ester of phthalic acid (2.45%), and phytol (2.55%). The composition of lemon balm oils from different regions of the world has been compared.     

Constituents of the essential oil of a new chemotype of Elsholtzia strobilifera Benth.

The composition of the essential oil from a new chemotype of Elsholtzia strobilifera Benth. collected from sub-alpine region of central Himalaya, India, has been investigated by Gas Chromatography and Gas Chromatography–Mass Spectrometry. The GC of the oil revealed the presence of more than 50 constituents, of which neral (18.3%) and geranial (29.9%) were found to be the major compounds and an absence of monoterpene hydrocarbons. Acylfuran derivatives, the specific chemical markers of the essential oils from the genus Elsholtzia were not detected.     

Chemical composition and antigenotoxic properties of Lippia alba essential oils

The present work evaluated the chemical composition and the DNA protective effect of the essential oils (EOs) from Lippia alba against bleomycin-induced genotoxicity. EO constituents were determined by Gas Chromatography/Mass Spectrometric (GC-MS) analysis. The major compounds encountered being citral (33% geranial and 25% neral), geraniol (7%) and trans-β-caryophyllene (7%) for L. alba specimen COL512077, and carvone (38%), limonene (33%) and bicyclosesquiphellandrene (8%) for the other, COL512078. The genotoxicity and antigenotoxicity of EO and the compounds citral, carvone and limonene, were assayed using the SOS Chromotest in Escherichia coli. The EOs were not genotoxic in the SOS chromotest, but one of the major compound (limonene) showed genotoxicity at doses between 97 and 1549 mM. Both EOs protected bacterial cells against bleomycin-induced genotoxicity. Antigenotoxicity in the two L. alba chemotypes was related to the major compounds, citral and carvone, respectively. The results were discussed in relation to the chemopreventive potential of L. alba EOs and its major compounds.     

Chemical composition and antimicrobial activity of <Emphasis Type="Italic">Thymus pannonicus</Emphasis> All. (<Emphasis Type="Italic">Lamiaceae</Emphasis>) essential oil

This paper presents the results of a study on chemical composition and antimicrobial activity of Thymus pannonicus All. (Lamiaceae) essential oil from Vojvodina province (north of Serbia). The investigated oil was hydrodistilled from a flowering plant and analysed by GC and GC-MS. Fifty-three constituents were identified (>97% of total oil), with geranial (41.42%, w/w) and neral (29.61%, w/w) as the most prominent. The antimicrobial activity of the oil was evaluated using agar disc diffusion and broth microdilution method against Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa, Escherichia coli, two strains of Klebsiella pneumoniae and two strains of Candida albicans. The essential oil exhibited antimicrobial activity to varying degrees against all tested strains. The maximum activity of T. Pannonicus oil was observed against E. coli, S. aureus and both tested strains of C. Albicans (MIC = 50 μ/ml, each). Moderate activity was observed against P. aeruginosa and one of the tested strains of K. Pneumoniae (MIC = 200 μ/ml), while E. faecalis and the other strain of K. Pneumoniae expressed a higher degree of resistance (MIC > 200 μ/ml). This study confirms that essential oil of T. pannonicus possesses remarkable in vitro antimicrobial activity against several medicinally important pathogens. This is attributable to lemon-scented citral, a mixture of geranial and neral, which has well-documented antimicrobial activity against a range of bacteria and fungi.     

The essential oil of ginger from Fiji

The essential oil of ginger (Zingiber officinale) from Fiji was analysed by GC-MS and a number of sesquiterpenes not reported previously in ginger oil were identified including α-copaene, β-bourbonene, α-bergamotene, α-selinene, calamenene and cuparene. The composition of the oil was unusual in having a much higher neral and geranial content than oils reported from India, Australia, Japan and Africa.     

Strigolactone and Methyl Jasmonate-Induced Antioxidant Defense and the Composition Alterations of Different Active Compounds in Dracocephalum kotschyi Boiss Under Drought Stress

Strigolactone (SL) and methyl jasmonate (MeJA) are one of the most important plant hormones that exert biological activity in plant responses to environmental stresses. Considering the undetected role of SL in drought tolerance and essential oil yield of medicinal plants as well as conceivable interaction among MeJA and SL, a factorial experiment was performed as a complete randomized design with three replications. Experimental factors including two irrigation regimes such as irrigation to 80% field capacity (control) and 40% field capacity (drought stress) and spraying treatments include MeJA (0 and 0.5 mM) and SL (0 and 10 μM) were applied. Treatment of plants with SL and MeJA resulted in higher tolerance to drought stress due to higher fresh and dry weights as well as lower electrolyte leakage, malondialdehyde, H₂O₂, total phenol content, total antioxidant activity and antioxidant power assay. The most important essential oil constituents of D. kotschyi included geranyl acetate (41.1–48.6%), α-pinene (16.2–18.9%), geranial (7.9–10.1%), limonene (5.5–7.0%), neral (3.5–4.1%), methyl geranate (2.3–3.3%) and geraniol (1–2.2%), the least of which was found in non-MeJA- and SL-treated plants under drought and the highest in MeJA- and SL-treated plants under drought stress. Drought tolerance of D. kotschyi became more intense and the amount of essential oil components of water stressed plants was the highest (99.2%) when these plant hormones were used together. These results suggest a cross-link between MeJA and SL in improving drought resistance and optimizing the production of essential oil of D. kotschyi.

     

Nematicidal activity of essential oils and volatiles derived from Portuguese aromatic flora against the pinewood nematode, Bursaphelenchus xylophilus

Twenty seven essential oils, isolated from plants representing 11 families of Portuguese flora, were screened for their nematicidal activity against the pinewood nematode (PWN), Bursaphelenchus xylophilus. The essential oils were isolated by hydrodistillation and the volatiles by distillation-extraction, and both were analysed by GC and GC-MS. High nematicidal activity was achieved with essential oils from Chamaespartium tridentatum, Origanum vulgare, Satureja montana, Thymbra capitata, and Thymus caespititius. All of these essential oils had an estimated minimum inhibitory concentration ranging between 0.097 and 0.374 mg/ml and a lethal concentration necessary to kill 100% of the population (LC(100)) between 0.858 and 1.984 mg/ml. Good nematicidal activity was also obtained with the essential oil from Cymbopogon citratus. The dominant components of the effective oils were 1-octen-3-ol (9%), n-nonanal, and linalool (both 7%) in C. tridentatum, geranial (43%), neral (29%), and β-myrcene (25%) in C. citratus, carvacrol (36% and 39%), γ-terpinene (24% and 40%), and p-cymene (14% and 7%) in O. vulgare and S. montana, respectively, and carvacrol (75% and 65%, respectively) in T. capitata and T. caespititius. The other essential oils obtained from Portuguese flora yielded weak or no activity. Five essential oils with nematicidal activity against PWN are reported for the first time.     

Systematic Evolutional Relation of Chemical Components of the Essential Oils from 11 Taxa of Citrus Leaves

With fused silica capillary column for GC, according to Kovats retention index ITP of GC and GC-MS-DS double identification, chemical components of the essential oils from 11 taxa in Citrus leaves were studied. It has been found that the characteristic component of Papeda seedon is citronellal; that of ilurantiurn section is “myrcene and linalool” or “sabinene and liaalool”; that of Microacrumen subsection is linalool; that of Macroacrumen subsection is Z-, E-liaalooloxide and that the characteristic components of Citrophorum section are neral and geranial and those of Cephalocitrus section are neral, geranial and carvone. Our study indicates that there are different GC configurations for various taxonomic units. The differences narrow from sections to species and from species to cultivars. The differences are greatest among sections and remarkable among different species of the same section. Different culativars of the same species of the same section have similar Gig patterns. All these differences or similarities reflect their close or distant relationships, which are the important bases for setting up natural classification. The systematic evolution of the sections of genus Citrus may correlate well with the characteristic components, the biosynthesis pathways and the morphological characters.     

Micropropagation and in vitro production of secondary metabolites of Croton floribundus Spreng.

Croton floribundus Spreng., a native plant from South America, was utilized for in vitro micropropagation and phytochemical analyses. The effects of the addition of naphthaleneacetic acid and indole butyric acid, on the production of shoots and leaves, as well as volatile constituent production, were determined. The combination of naphthaleneacetic acid and indole butyric acid at a ratio of 1:1 led to the production of the maximum number of leaves and longest shoots after a 60-d subculture period. Analyses of leaf dichloromethane extracts using gas chromatography–mass spectrometry showed that monoterpenes and sesquiterpenes were the main chemical classes present in both in vivo and in vitro conditions. Use of these plant growth regulators in the medium-induced quantitative changes in the major monoterpenes (neral, geranial, limonene, and carvone). In vitro leaf extracts produced compounds such as carvone as well as a large amount of trans-β-farnesene, with the highest production of carvone (16.8%) being produced on medium supplemented with 1.0 mg?L^?1 naphthaleneacetic acid. These results suggested the occurrence of biotransformation reactions of limonene and farnesyl cations in culture.     

小蓬草精油的提取及GC-MS分析

水蒸馏和水蒸气蒸馏分别提取鲜小蓬草精油的气相色谱-质谱分析结果表明:水蒸馏提取的鲜小蓬草精油挥发性组分较多且柠檬烯质量分数最高(15.36%),香芹酮(10.15%)次之.而水蒸气蒸馏分别提取鲜和干小蓬草精油的气相色谱-质谱分析表明干小蓬草有利于提取更多精油香料成分,且柠檬烯质量分数最高(57.68%),反式-α-佛手...