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From Artemisia annua L., a new oxidoreductase (Red 1) was cloned, sequenced and functionally characterized. Through bioinformatics, heterologous protein expression and enzyme substrate conversion assays, the elucidation of the enzymatic capacities of Red1 was achieved. Red1 acts on monoterpenoids, and in particular functions as a menthone:neomenthol oxidoreductase. The kinetic parameter kcat/Km was determined to be 939-fold more efficient for the reduction of (−)-menthone to (+)-neomenthol than results previously reported for the menthone:neomenthol reductase from Mentha × piperita. Based on its kinetic properties, the possible use of Red1 in biological crop protection is discussed. [ABSTRACT FROM PUBLISHER]

The effects of alternative spray programs, NaHCO3/K2SiO3 + sulphur, KH2PO4/di - 1 - p - menthone, and a conventional spray program, penconazole/sulphur, as well as various levels of shoot toppings (to the 1st, 3rd, and 5th buds) on powdery mildew disease [Uncinula necator (Schw.) Burr.] and grape quality were investigated in this study. The study was carried out on grape variety Karasakız (Vitis vinifera L.) during 2003 and 2004 growing seasons. The effectiveness of NaHCO3/K2SiO3 + sulphur, KH2PO4/di - 1 - p - menthene alternate spray programs against powdery mildew was found as 74.8% and 70.7% on leaf and 65.7% and 62.1% on bunch in the 2003 vegetation period, which were close to the results (80.3% on leaf, 72.3% on bunch) obtained with the conventional control program (penconazole/sulphur). In 2004, NaHCO3/K2SiO3 + sulphur (44.7%) was more effective for the control of leaf powdery mildew than penconazole/sulphur (29.0%). In addition, it also exhibited a similar effect on bunches. NaHCO3/K2SiO3 + sulphur and penconazole/sulphur treatments showed positive effects on the yield and quality of grapes. All spray programs demonstrated a better performance in the vineyards where pruning was practiced from the 1st and 3rd buds after the last bunch of the grapes rather than from the 5th bud. According to the results of the study, NaHCO3/K2SiO3 + sulphur spray program could be used in combination with the green pruning from the 3rd bud to control the disease in organic and integrated wine grapes, while KH2PO4/di - 1 - p - menthene spray program is more effective with the same pruning practice in the areas where climatic conditions are less favourable for U. necator, and pathogen-resistant grape varieties are grown. [ABSTRACT FROM AUTHOR]

Formylation of ( - )-mcnthone (11) with LDA and HCCKCHCF, avoids loss of configurational integrity at the isopropyl group, giving hydroxymethylenemcnthonc 12. Lithium 2.2,6,6-tetramethyl-piperididc-induced intramolecular cyclopropanation of derived unsaturated terminal epoxide 17 (and chlorohydrin 16). efficiently generates a substituted tricyclol4.4.0.015]decan-4-ol 18. which is used in a concise synthesis of ( -)-cubebol (1). In contrast, isopropyl group inversion during formylation of menlhone with NaOMe and HCO2Et led, by a similar strategy, to syntheses of 7-epicubebol (33) and (from (+)-menthone) of naturally occurring (-)-10-epicubebol (39), confirming the original structural assignment. Computational studies support the origin of the inversion as being rate-determining formylation of cis-enolate 27 from a mixture of rapidly interconverting enolates. In the synthesis of 7-epicubebol (33), allylic tertiary C-H insertion is observed as a significant competing reaction in the intramolecular cyclopropanation of unsaturated terminal epoxide 22. [ABSTRACT FROM AUTHOR]

Stereoisomeric adducts, substituted ( R)-, ( S)-spiro[6-aryldioxin-4-ones] have been obtained by thermolysis of 5-arylfuran-2,3-diones in the presence of menthone and allobetulone. [ABSTRACT FROM AUTHOR]

The stereoselective 1,3-dipolar cycloaddition between ( Z )-1,4-dichloro-2-butene and a menthone-derived nitrone led to the corresponding isoxazolidine. Regioselective azidation of a single chlorine atom followed by another Cu(I)-catalyzed azide–alkyne 1,3-dipolar cycloaddition (CuAAC) induced enantiopure 1,2,3-triazolyl-functionalized isoxazolidines. The subsequent acidic cleavage of the menthone chiral auxiliary and reductive cleavage of the isoxazolidine N–O bond triggered an intramolecular cyclization through the displacement of the second chlorine. This rapid and stereoselective synthetic strategy provided reliable access to a series of enantiopure 3-substituted 4-hydroxyproline derivatives. [ABSTRACT FROM AUTHOR]

Abstract: The Favorskii rearrangement of suitable α-chloro derivatives of commercially available (+)- and (−)-carvone, and (−)-menthone served efficiently to prepare the title compounds featuring delicious fruity, floral olfactory notes. [Copyright &y& Elsevier]

Abstract: The addition reaction of the sodium α-sulfinyl carbanion of a racemic aryl dichloromethyl sulfoxide to (−)-menthone in the presence of boron trifluoride diethyl etherate gave an adduct as a mixture of two easily separable diastereomers. After separation of the diastereomers, they were each treated with sodium hydride to afford enantiomerically pure aryl dichloromethyl sulfoxides and (−)-menthone both in high yields. This procedure provides a simple and efficient method for the resolution of racemic aryl dichloromethyl sulfoxides. [Copyright &y& Elsevier]

Abstract: A rapid HS-SPME–GC–MS (headspace solid-phase microextraction–gas chromatography–mass spectrometry) method has been developed for determination of menthone, isomenthone, neomenthol and menthol in serum samples with and without enzymatic cleavage. These flavour compounds are characteristic markers for consumption of peppermint liqueurs as well as certain digestif bitters, herbal and bitter liqueurs. This method enabled the detection of the four compounds with a limit of detection (LOD) of 2.1ngmL−1 (menthone and isomenthone), 2.8ngmL−1 (neomenthol) and 4.6ngmL−1 (menthol), and a limit of quantification (LOQ) of 3.1ngmL−1 (menthone and isomenthone), 4.2ngmL−1 (neomenthol) and 6.8ngmL−1 (menthol) in serum samples. The method shows good precision intraday (3.2–3.8%) and interday (5.8–6.9%) and a calibration curve determination coefficient (R 2) of 0.990–0.996. Experiments were conducted with a volunteer, who consumed peppermint liqueur on three different days under controlled conditions. At defined intervals, blood samples were taken, and the concentration–time profiles for serum menthone, isomenthone, neomenthol and menthol, as free substances as well as glucuronides, were determined. Both menthol and neomenthol underwent a rapid phase II metabolism, but minor amounts of free substances were also detected. Menthone and isomenthone were rapidly metabolised and were found in lower concentrations and over a shorter time span than the other analytes. In blood samples taken from 100 drivers who claimed to have consumed peppermint liqueur prior to the blood sampling, menthone, isomenthone, neomenthol and menthol were detected in the serum as free substances in concentrations between 3.1 and 7.0ngmL−1 in eight cases (menthone), 3.1 and 11.3ngmL−1 in eight cases (isomenthone), 5.3 and 57.8ngmL−1 in nine cases (neomenthol) and 8.0 and 92.1ngmL−1 in nine cases (menthol). The sum values of free and conjugated substances ranged between 4.2 and 127.8ngmL−1 in 35 cases for neomenthol and 11.0 and 638.2ngmL−1 in 59 cases for menthol. Menthone and isomenthone were not conjugated. These test results confirmed that the analysis of characteristic beverage aroma compounds, such as menthone, isomenthone, neomenthol and menthol, can be used for specific verification of post-offence alcohol consumption claims. [Copyright &y& Elsevier]

Abstract: A simple and enantioselective method for the determination of menthone enantiomers in peppermint essential oil samples is proposed. The method involves the initial supercritical fluid extraction (SFE) to clean-up and extraction of analytes and their preconcentration on C18 adsorption cartridges followed by achiral liquid chromatographic separation and direct circular dichroism (CD) detection. The calibration curve of the anisotropy factor (g) versus the enantiomeric excess was linear, with a correlation coefficient (R 2) of 0.9970. The precision evaluated by UV peak area and CD peak area was suitable both in terms of intra- and inter-day precision (RSD<5.1% in all cases). The usefulness of the proposed method was demonstrated by analyzing natural and spiked peppermint oil samples. This method has the advantages of being rapid and precise without using an expensive chiral column. It was demonstrated to be suitable for the simultaneous determination of both enantiomers and for assessing the chemical purity of menthone. [Copyright &y& Elsevier]

Abstract  Electroreduction of an equilibrium menthone-isomenthone mixture at a controlled potential in a diaphragm cell on various cathodes was studied. The influence exerted by the nature of a solvent and of an electrode, electrode material, and various additives on the reduction stereoselectivity of ketones was examined. Conditions for a predominant formation of the most stable of the four isomeric alcohols being formed, menthol, were found. [ABSTRACT FROM AUTHOR]

The oil of peppermint (Mentha x piperita L.) from the USA, a dementholized cornmint oil (M. canadensis L.), and a fraction of the dementholized cornmint oil were analyzed by GC-FID and GC/MS. The main constituents of the three samples analyzed were menthone (23.4%, 20.4% and 58.3%, respectively) and menthol (40.7%, 41.2% and 12.3%, respectively). The two oils, the cornmint oil fraction and seven mint oil compounds [(-)-menthol, (-)-menthone, (+/-)-menthyl acetate, 1,8-cineole, limonene, β-pinene and β-caryophyllene] were investigated for their antimicrobial effects against two Gram-positive bacteria (Staphylococcus aureus and Enterococcus faecalis), five Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa, Proteus vulgaris, Klebsiella pneumoniae and Salmonella sp.) and the yeast Candida aibicans using a modified agar dilution and agar diffusion method. Medium to high antimicrobial effects were found for both oils, the dementholized cornmint oil fraction, and the target-compounds against all Gram-positive bacteria, whereas against the Gram-negative bacteria and the yeast, one or more samples showed only weak or no activity. [ABSTRACT FROM AUTHOR]

Abstract  The biotransformation of several monoterpenes by the locally isolated unicellular microalga, Oocystis pusilla was investigated. The metabolites were identified by thin layer chromatography and GC/MS. The results showed that O. pusilla had the ability to reduce the C=C double bond in (+)-carvone to yield trans-dihydrocarvone and traces of cis-dihydrocarvone. O. pusilla also converted (+)-limonene to trans-carveol, as the main product, and yielded carvone and trans-limonene oxide. Furthermore, (−)-linalool was converted to trans-furanoid and trans-pyranoid linalool oxide, thymol was converted to thymoquinone, (−)-carveol was converted to carvone and trans-dihydrocarvone, (−)-menthone and (+)-pulegone were converted to menthol, (L)-citronellal was converted to citronellol, and (+)-β-pinene was converted to trans-pinocarveol. [ABSTRACT FROM AUTHOR]

In this work, we investigate the changes in Mentha aquatica var. citrata (bergamot-mint) characteristics and essential oil composition regarding the modification of the amended dose of Olive Mill Wastewater (OMW) in pots at three different doses; D 1 = 9 ml/100 g, D 2 = 22.5 ml/100 g and D 3 = 54 ml/100 g of soil, seven months before plantation of bergamot-mint cuttings. OMW application didn't affect plant biomass production (leaves, stems, roots) and chlorophylls in the leaf, while the amount of leaf phenols showed a dose dependent increase. Bergamot-mint essential oil major compound is linalool acetate for control, trans-pulegol when OMW is applied at 9 ml/100 g, isopulegyl acetate when OMW is applied at 22.5 ml/100 g, and verbenone when OMW is applied at 54 ml/100 g. When OMW was applied to soil at doses D 1 , D 2 and D 3 , some of bergamot-mint essential oil compounds such as decanone, citronellol, piperitone epoxide, guaiacol acetate, methyl cinnamate and citronellyl propanoate, totally disappeared. OMW spreading at 9 ml/100 g allowed appearance of menthone in Mentha aquatica var. citrata essential oil while menthol and terpineol appeared only when OMW was applied at the high dose 54 ml/100 g. • Olive Mill Wastewater amendment didn't affect bergamot-mint biomass production. • Olive Mill Wastewater amendment significantly increased leaf phenols. • Olive Mill Wastewater amendment changed bergamot-mint essential oil composition. • At amended dose 9 ml/100 g, menthone appears in bergamot-mint essential oil. • At amended dose 54 ml/100 g, menthol and terpineol appears in bergamot-mint essential oil. [ABSTRACT FROM AUTHOR]

Clinopodium pulegium (Rochel) Bräuchler (Lamiaceae) is an endangered species endemic to the Southern Carpathians. It is characterized by the production of high amounts of essential oils, which emit volatile organic compounds (VOCs) that have an essential role in biotic and abiotic stress responses and in plant–plant and plant–insect interactions. The present study was initiated to phytochemically examine the influence of different carbon sources in the nutrition medium on VOC emissions of micropropagated C. pulegium plants, using gas chromatography–mass spectrometry analysis of headspace VOCs. The volatile profiles were subjected to multivariate analysis with respect to the presence, concentration and type of carbon source in the nutrient medium. In addition, the effect of different carbohydrates on the density and size of the leaf glandular trichomes, the main structures involved in the emission of VOCs, was determined. A total of 19 VOCs, primarily belonging to mono- and sesquiterpenes previously described in plants, were tentatively identified. Six VOCs were produced at levels higher than 2% of the total VOC emission, dominated by pulegone, ß-pinene and menthone. Inclusion of the carbohydrates in the culture media affected the production of the main leaf trichome-associated volatile allelochemicals although the qualitative composition of the volatiles changed only slightly. Multivariate analysis showed that the concentration, rather than the carbohydrate type, influenced the VOC profile. [ABSTRACT FROM AUTHOR]

Abstract: The heterogeneously catalysed epimerisation of neomenthol and isomenthol is a key step in the synthesis of menthol in the Symrise process (formerly know as Haarmann & Reimer process). A reaction model based on the experimentally determined kinetic and thermodynamic parameters was derived for industrial relevant conditions of 150–210°C and 0.8–7.5MPa hydrogen pressure. Results of experiments and modelling show a good agreement and thus the derived kinetic parameters can be used for the optimisation of batch slurry processes as well as of continuous fixed bed processes. [Copyright &y& Elsevier]

• Peppermint and Japanese catnip accumulate monoterpenoids with identical functionalization patterns but opposite stereochemistry. • Multiple peppermint enzymes exhibited enantioselectivity toward intermediates of the pathway that proceeds through (-)-4S-limonene. • Multiple Japanese catnip enzymes preferred intermediates of the pathway that proceeds through (+)-4R-limonene. Peppermint (Mentha x piperita L.) and Japanese catnip (Schizonepeta tenuifolia (Benth.) Briq.) accumulate p -menthane monoterpenoids with identical functionalization patterns but opposite stereochemistry. In the present study, we investigate the enantioselectivity of multiple enzymes involved in monoterpenoid biosynthesis in these species. Based on kinetic assays, mint limonene synthase, limonene 3-hydroxylase, isopiperitenol dehydrogenase, isopiperitenone reductase, and menthone reductase exhibited significant enantioselectivity toward intermediates of the pathway that proceeds through (-)-4 S -limonene. Limonene synthase, isopiperitenol dehydrogenase and isopiperitenone reductase of Japanese catnip preferred intermediates of the pathway that involves (+)-4 R -limonene, whereas limonene 3-hydroxylase was not enantioselective, and the activities of pulegone reductase and menthone reductase were too low to acquire meaningful kinetic data. Molecular modeling studies with docked ligands generally supported the experimental data obtained with peppermint enzymes, indicating that the preferred enantiomer was aligned well with the requisite cofactor and amino acid residues implicated in catalysis. A striking example for enantioselectivity was peppermint (-)-menthone reductase, which binds (-)-menthone with exquisite affinity but was predicted to bind (+)-menthone in a non-productive orientation that positions its carbonyl functional group at considerable distance to the NADPH cofactor. The work presented here lays the groundwork for structure-function studies aimed at unraveling how enantioselectivity evolved in closely related species of the Lamiaceae and beyond. [ABSTRACT FROM AUTHOR]

Abstract: The present study examines the mechanism that underlies the ability of menthone (MTN), a constituent of peppermint oil, to promote mouse ambulation. Since bupropion (BUP), a dopamine (DA) uptake inhibitor, promotes mouse ambulation, the effect of MTN combined with BUP on ambulation was investigated. The results showed that BUP with MTN produced an additive interaction on mouse ambulation. The effects of DA antagonists chlorpromazine, fluphenazine, haloperidol, SCH12679 and spiperone on the ability of MTN to promote ambulation were then examined. All of these antagonists attenuated the effects of MTN. Prior exposure to the tyrosine hydroxylase inhibitor α-methyl-p-tyrosine, which inhibits catecholamines synthesis, decreased subsequent sensitivity to the effect of MTN. These results suggest that DA is involved in the ability of MTN to promote ambulation in mice. [Copyright &y& Elsevier]

meta-Chloroperoxybenzoic acid ( m-ClPBA) was shown to be an oxidant for two stereoisomers of menthone oxothiolane. The effect of steric factors on the ability to oxidize the sulfide group was found. Oxidation of (5 S,6 S,9 R)-6-isopropyl-9-methyl-1-oxo-4-thiaspiro[4.5]-decane to the sulfone was prevented by the steric proximity of an isopropyl group to the S atom in the oxothiolane ring. [ABSTRACT FROM AUTHOR]

Antimicrobial properties and chemical composition of eight exotic and indigenous Argentinean essential oils to control American Foulbrood (AFB) were determined. The oils tested were extracted from Artemisia absinthium, Artemisia annua, Lepechinia floribunda, Aloysia polystachya, Verbena officinalis, Wedelia glauca, Satureja odora and Hetherothalamus alienus. The components of the essential oils were identified by SPME-GC/MS analysis. The antimicrobial activity of the oils against Paenibacillus larvae were determined by broth microdilution method. Two-way ANOVA for minimum inhibitory concentrations (MICs) data and minimal bactericide concentrations (MBCs) data, indicated no significant differences between the thirteen P. larvae strains tested and highly significant differences between the oils. The antimicrobial assays showed that the oils of A. absinthium, A. annua and L. floribunda inhibited the bacterial strains at the lowest concentrations tested, MICs and MBCs averages of 393.6 mg/L to 416.7 mg/L and 517.9 mg/L to 624.4 mg/L respectively, indicating the highest inhibitory capacities. Their antimicrobial activities were attributed to the kind and the variation in percentage of the components. α-Thujone (62.3%) was largely predominant in the oil of the A. absinthium meanwhile artemisia ketone (36.3%) and 1,8-cineole (31.5%) constituted the bulk of the oil of A. annua. 1,8-Cineole (27.5%) was also very important in the composition of the oil of L. floribunda, which also possessed camphene (16.6%) and camphor (12.9%). [ABSTRACT FROM AUTHOR]

Asymmetrical oxidation was performed of menthone dithiolane obtained in 95–98% yield by condensation of menthone with 1,2-ethanedithiol in the presence of boron trifluoride etherate. 6-Isopropyl-9-methyl-1,4-dithiaspiro[4,5]decane-1,4-dioxide (yield 5–55%) and 6-isopropyl-9-methyl-1,4-dithiaspiro[4,5]-decane-1,1,4-trioxide (yield 65–70%) were synthesized. Chemical structures of compounds obtained were proved by XRD analysis, NMR and IR spectroscopy. [ABSTRACT FROM AUTHOR]

Abstract: The essential oils obtained by hydrodistillation from the aerial parts of Tunisian native Hypericum perfoliatum L. (sect. Drosocarpium Spach.) and Hypericum tomentosum (sect. Adenosepalum Spach.) were analyzed by GC and GC–MS. Thirty-two compounds were identified in the essential oils of H. perfoliatum with α-pinene (13.1%), allo-aromadendrene (11.4%), germacrene-D (10.6%), n-octane (7.3%), α-selinene (6.5%) and β-selinene (5.5%) as main constituents. Sixty-seven components were identified in the oil of H. tomentosum with menthone (17.0%), n-octane (9.9%), β-caryophyllene (5.3%), α-pinene (5.2%), lauric acid (4.1%) and β-pinene (3.7%) as the most abundant components. Both oils were characterized by the presence of many components which could have numerous applications in food, pharmaceutical and perfume industries. [Copyright &y& Elsevier]

The co-occurrence of individual Calamintha glandulosa (Req.) Bentham plants of two different chemotype within the same population is reported. The main constituents of the essential oil of plants of Chemotype I, were, cis- and trans-piperitone oxide, limonene and piperitenone oxide and of Chemotype II, were, menthone, pulegone, piperitenone and piperitone The chemotypes were conserved in cultivated plants. The end-products of monoterpene biosynthesis in April (vegetative stage) were trans-piperitone oxide and menthone in Chemotype I and II, respectively while in early September (flowering) there was an increase in precursory intermediates and their related biosynthetic products, i.e. limonene and piperitenone oxide in Chemotype I and pulegone, piperitenone and piperitone in Chemotype II. Differences in the percentage composition of the main oil constituents were observed between the oils from the different organs of plants in the same developmental stage and between the same organs in different developmental stages. [ABSTRACT FROM AUTHOR]

An evidence-based systematic review including written and statistical analysis of scientific literature, expert opinion, folkioric precedent, history, pharmacology, kinetics/dynamics, interactions, adverse effects, toxicology and dosing. [ABSTRACT FROM AUTHOR]

Abstract: The effects of various methods of drying on the content and chemical quality of the essential oil of Mentha longifolia was studied. The most prominent component in both the air-dried and sun-dried leaf oils was menthone (47.9% and 38.3%, respectively), while oven-dried leaf oil had limonene as the major compound (40.8%), whereas pulegone was the major compound from the original fresh leaf oil. Menthone and pulegone were not detected in the oven-dried leaf oil. The essential oil underwent significant chemical transformation in its monoterpenoids when the leaves were dried by the three different methods. Due to the significant reduction of the potentially harmful pulegone and menthone by oven-drying, it is suggested that this herb should be oven-dried or cooked before consumption in order to reduce toxicity. [Copyright &y& Elsevier]

An oil of Minthostachys verticillata (Griseb.) Epling was analyzed by GC. The main constituents identified were pulegone (63.0%) and menthone (16.4%). It was found that the oil inhibited β-hexosaminidase release from basophils. Forty-two percent of the cells present in lymphocyte cultures stimulated by the oil were CD8(+) T cells and showed higher IFN-γlevels than non-stimulated cultures (p < 0.05). According to these results, the oil was considered to be a Th1 deviation inducer, inhibiting the immediate-type allergic reaction. [ABSTRACT FROM AUTHOR]

Essential oil components of 20 Indian peppermint accessions were analyzed through GC and GC/MS and compared with the reported components found in oil samples of different countries (22 locations of 19 countries) to check the commercial potential of the germplasm collection. The comparative oil component analyses revealed the close relation of P4 and P5 (Indian collections) with Chinese and P9 to Japanese peppermint. Some of the analyzed samples (P6, P8, P11 and P17) were close to American, Canadian, European and South African oils. Essential oil profiles of Indian accessions P10, P14, P19 and P20 were quite different from others as revealed by component plot analysis. In addition to the similarities, distinct chemotypes in the germplasm were detected with unique essential oil component profiles, which have been discussed in details in this investigation. Further, Amplified fragment length polymorphism (AFLP) analysis of these 20 Indian accessions differentiated them genetically with a diversity ranging between 17-95%. [ABSTRACT FROM AUTHOR]

Abstract: Plant defensive mechanisms against herbivores include chemical changes following damage. Effects of feeding punctures produced by Liriomyza huidobrensis (pea leafminers) adult females on the plant''s dominant monoterpenes, pulegone and menthone were assessed by monitoring essential oil composition at 24, 48, and 120h; emission of volatiles was also measured 24 and 48h after wounding. We studied such changes in Minthostachys mollis, a Lamiaceae species native to Central Argentina with medicinal and aromatic uses. Leaf puncturing resulted in reduced menthone throughout the experiment and increased pulegone concentration in M. mollis essential oil during the first 48h. The adjacent undamaged leaves showed similar changes, suggesting a systemic response. Composition of volatiles released from damaged leaves was also altered, most noticeably by increasing pulegone and diminishing menthone emissions. Such herbivore-induced chemical changes in aromatic plants are economically relevant, since the quality of essential oils and volatile emissions are altered. [Copyright &y& Elsevier]

Plant essential oils from 21 plant species were tested for their insecticidal activities against larvae of Lycoriella ingenua Dufour (Diptera: Sciaridae) by using a fumigation bioassay. Good insecticidal activity against larvae of L. ingenua was achieved with essential oils of Acorns gramineus Solander, Schizonepeta tenuifolia Briquet, and Zanthoxylum piperitum De Candolle at 25 µg/ml air. S. tenuifolia oil showed the most potent insecticidal activity among the plant essential oils. At 12.5 µg/ml air concentration, S. tenuifolia oil caused 96.6% mortality, but mortality decreased to 60% at 3.125 µg/ml air. Analysis by gas chromatography-mass spectrometry led to identification of three major compounds from S. tenuifolia oil. These three compounds were tested individually for their insecticidal activities against larvae of L. ingenua and compared with the toxicity of dichlorvos. Pulegone was the most toxic, followed by menthone and limonene with LC50 values of 1.21, 6.03, and 15.42 µg/ml, respectively. LC50 of dichlorvos was 8.13 µg/ml. Effects of S. tenuifolia and its components on growth of Pleurotus ostreatus (Jacq. ex Fr.) Kummer also were investigated. [ABSTRACT FROM AUTHOR]

A plethora of information is available on the essential oil composition of commercially grown Pelargoniums namely P. capitatum, P. graveolens and P. radens and their hybrids, while only a few chemical investigations have been carried out on the other aromatic Pelargonium species indigenous to South Africa. The hydrodistilled leaf oils of 13 South African Pelargonium species of the genus Pelargonium (family Geraniaceae) were analyzed by means of GC and GC/MS and a total of 315 compounds were identified. The oil data was chemotaxonomically informative confirming taxonomic relationships i.e. between P. graveolens and P. radens, P. papilionaceum and P. vitifolium and between P. panduriforme and P. quercifolium. The oil compositions of P. citronellum, P. papilionaceum and P. vitifolium were different with respect to those of the other analyzed species in this study. Geranic acid was the most abundant oil constituent (36.0%) in P. citronellum (provenance NBG), which was the only species in which neral (17.4%) and geranial (27.2%) were detected. Citronellic acid dominated in the oils of P. papilionaceum (provenance NBG) and P. vitifolium (provenance SBG), occurring in amounts of 96.2% and 74.7%, respectively. The major monoterpene identified in P. radens (provenance NBG) and in the samples of P. graveolens (provenances SBG and WSBG) was isomenthone (84.5%, 65.8% and 83.3%, respectively). The P. tomentosum oil samples produced an essential oil rich in menthone (36.1-41.1%) and isomenthone (49.3-56.6%). The latter monoterpenic ketone was responsible for the chemical affinity demonstrated among P. graveolens, P. radens and P. tomentosum. p-Cymene was the principle component (37.6-45.4%) in both samples of P. panduriforme. It was also the major compound (54.9%) in P. quercifolium (provenance WSBG) followed by lesser amounts of viridiflorol (13.0%) and spathulenol (5.9%). Pelargonium quercifolium (provenance SBG) and P. capitatum (provenance WSBG) were characterized by a high viridiflorol content (24.0-36.6%). Pelargonium glutinosum (provenance SBG) was closely associated with the latter species; its oil was typified by oxygenated sesquiterpenes namely caryophyllene oxide (6.3%), spathulenol (6.9%) and viridiflorol (8.9%). Citronellyl formate (31.1%), citronellol (9.9%) and furopelargone B (6.1%) were most abundant in P. capitatum (provenance Strand). Pelargonium hispidum oil (provenance SBG) was characterized by decanoic acid (47.0%) and 2-decenoic acid (31.3%). Pelargonium scabrum produced an oil rich in 14-hydroxy-β-caryophyllene (27.9%). Pelargonium scabrum was associated with P. betulinum (provenance NBG) which was characterized by the oxygenated sesquiterpene T-cadinol (18.9%). [ABSTRACT FROM AUTHOR]

The essential oil composition, antimicrobial, anti-inflammatory and cytotoxic activities of 17 indigenous Agathosma species (18 samples) were investigated in order to validate their use in traditional healing. The results were related to the chemical composition of the essential oils as determined by GC and GC/MS. The antimicrobial activity was evaluated using the minimum inhibitory concentration (MIC) method on four pathogens: Staphylococcus aureus (ATCC 12600), Bacillus cereus (ATCC 11778), Klebsiella pneumoniae (NCTC 9633) and Candida albicans (ATCC 10231). The anti-inflammatory activity was evaluated using the 5-lipoxygenase assay while the cytotoxic activity was determined using the MTT (3-[4,5-dimethyl-2-thiazol-yl]-2,5-diphenyl-2H-tetrazolium bromide) cellular viability assay. The antimicrobial assay revealed that the most active oil against C. albicans was A. collina (MIC value of 3 mg/mL) whilst the most active oils against B. cereus were A. crenulata and A. pungens (MIC values of 3 mg/mL). Nine of the species had MIC values of 4 mg/mL against the Gram-positive pathogen S. aureus. The oils showed less activity against the Gram-negative pathogen K. pneumoniae. All the oils exhibited good in vitro anti-inflammatory activity with A. collina being the most potent (IC50 value of 25.98 ± 1.83 µg/mL). The results show that the oils were strong inhibitors of the enzyme 5-lipoxygenase. The oils proved to be toxic in the MTT assay displaying IC50 values of < 0.0001 µg/mL, which were relatively toxic when compared to a plant-derived compound such as quinine (IC50 value of 0.08 ± 0.03 µg/mL). The results revealed some relationships between the major components, some bioactivities and toxicities. The oils were found to differ qualitatively and quantitatively in compositions and their analysis resulted in the identification of a total of 322 compounds in 18 of the samples. [ABSTRACT FROM AUTHOR]

The effect of harvesting time on the quality and quantity of mint oils produced from plants grown in short summer and long-day climatic conditions of northern Finland (64°40′N and 25°E) was examined to determine what growth stage is best for cutting to obtain the highest possible biomass (herb yield), oil content and suitable oil composition. In the field experiment, plants cut only once at the end of August were compared with those of two cuttings. The first cut was at the beginning of August and the second cut in the middle of September. The mint species were Mentha piperita L."peppermint", M. canadensis "cornmint", M. canadensis "Sakhalin mint" and M. spicata L. "spearmint." [ABSTRACT FROM AUTHOR]