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At least 19 recordsLinked to original sources
PubMed2001

Composition of the essential oil of two Nepeta species and in vitro evaluation of their activity against Helicobacter pylori.

The chemical composition of the essential oils obtained from the aerial parts of Nepeta camphorata and Nepeta argolica ssp. dirphya were analysed by GC-MS. A total of 52 components were identified and significant differences (qualitative and quantitative) were observed between the two samples. 1,8-Cineol and two nepetalactones were found to be the major components of the oil of N. camphorata and N. argolica ssp. dirphya respectively. The in vitro activity, of the two oils and the three above mentioned isolated compounds, against 25 clinically isolated and commercial strains of Helicobacter pylori was investigated and some activity was found.

Cyclohexanols↗
PubMed2005

Simplified isolation procedure and interconversion of the diastereomers of nepetalactone and nepetalactol.

Three nepetalactones were isolated from Nepeta racemosa (mussinii) by traditional methods. An improved method was developed to isolate nepetalactones from N. faassénii. An epimerization procedure was used to prepare the fourth 7S-nepetalactone diastereomer. The cis-fused nepetalactols were prepared by reduction of the corresponding nepetalactones, while the trans-fused nepetalactols were unstable and found to undergo ring-opening reactions yielding iridodials. The characterizations and structural assignments by means of NMR agree with quantum chemical density functional calculations.

Animals↗
PubMed2002

Characterization of (1'R,4S,4aR,7S,7aR)-dihydronepetalactol as a semiochemical for lacewings, including Chrysopa spp. and Peyerimhoffina gracilis.

The enantiomerically pure diastereoisomers (1R,4S,4aR,7S,7aR)- (1) and (1R,4R,4aR,7S,7aR)-dihydronepetalactol (2) were synthesized diastereoselectively from a renewable resource, (4aS,7S,7aR)-nepetalactone (3), isolated as the main constituent of the essential oil of the catmint plant Nepeta cataria. The stereochemistry of the compounds was determined by NMR spectroscopy and X-ray crystallography, and the compounds were identified, respectively, as neomatatabiol and isoneomatatabiol, natural products from Actinidia polygama, for which the lactol stereochemistry was previously incompletely defined. Compound 1 was found to catch significant numbers of three species of lacewing in the field: in Korea. Chrysopa cognata, and in the United Kingdom, Nineta vittata and most notably Peverimhoffina gracilis. All species caught in significant numbers were found more frequently in traps releasing 1 than 2, while more C. cognata, C. formosa, and C. phyllochroma were found in traps releasing (1R,4aS,7S,7aR)-nepetalactol (4). The catch of P. gracilis with 1 is of particular interest as this lacewing has only recently been recorded in the United Kingdom. Where sexed, the lacewings of all species trapped were found to be male, implying a possible pheromonal role for these or structurally related compounds.

Animals↗
PubMed2004

Identification of two sex pheromone components of the potato aphid, Macrosiphum euphorbiae (Thomas).

Females of the potato aphid Macrosiphum euphorbiae exhibit typical calling behavior, with virgin female oviparae raising their back legs off the substrate to release sex pheromone from glands on the tibia. Airborne collections from calling oviparae were analyzed by GC and GC-MS to determine if, like the majority of aphids examined to date, they produced (1R,4aS,7S,7aR)-nepetalactol (1) and (4aS,7S,7aR)-nepetalactone (2). Both components were present and produced in ratios that varied with age from 4:1 to 2:1. The relative stereochemical configurations of these components were determined by GC-coinjection of the aphid-derived sample with synthetic standards on both HP-1 and DB-Wax GC columns. The absolute stereochemical configuration of the nepetalactol (determined from approximately 15 microg of material in an air entrainment sample) was determined as (1R,4aS,7S,7aR)-1 by derivatization of the aphid sample with (S)-(+)-alpha-methoxy-alpha-(trifluoromethyl)phenylacetyl chloride (Mosher's acid chloride) to generate a diastereoisomer that was compared to synthetic samples by NMR spectroscopy and GC. In bioassays in the wind tunnel, M. euphorbiae males responded to potato plants with oviparae but not to unattacked plants or those infested with parthenogenetically reproducing apterae. In no-choice laboratory bioassays, the same level of male response was observed to virgins and to the 3:1-5:1 synthetic blends of nepetalactol (1):nepetalactone (2). However, the time taken to reach the source was significantly less to virgin females than to the synthetic pheromone blends. In all cases, males walked rather than flew to the source. Males showed lower responses to a 1:1 synthetic mixture and did not respond to either of the components when presented alone. Under field conditions, few M. euphorbiae males were captured in traps baited with different ratios of the synthetic pheromone. Possible reasons for the different responses under laboratory and field conditions are discussed.

Animals↗
PubMed2004

Semiochemistry of the goldeneyed lacewing Chrysopa oculata: attraction of males to a male-produced pheromone.

Gas chromatographic-electroantennographic detection (G3C-EAD) experiments showed that antennae of males and females of the goldeneyed lacewing, Chrysopa oculata Say (Co. = Chrysopa), consistently responded to four compounds extracted from the abdominal cuticle of males:nonanal, nonanol, nonanoic acid, and (1R*,2S*,5R*,8R*)-iridodial. These compounds were not detected from abdominal cuticle of females. Thoracic extracts of both sexes contained antennal-stimulatory 1-tridecene and EAD-inactive skatole. Chrysopa oculata adults were most sensitive to (1R,2S,5R,8R)-iridodial standard at an EAD-response threshold between 0.1 and 1 pg, which was 10-100 times lower than thresholds for nonanal and nonanoic acid, and up to 10,000 times lower than thresholds for other compounds tested. A similar EAD response pattern was also found in another Chrysopa sp. (Co. quadripunctata Burmeister). In field-trapping experiments, (1R,2S,5R,8R)-iridodial was the only male-specific compound that attracted Co. oculata males. Males also were weakly attracted to (1R,4aS,7S,7aR)-nepetalactol (an aphid sex pheromone component), probably due to the 5% (1R,2S,5R,8R)-iridodial present in the synthetic sample as an impurity. A herbivore-induced plant volatile, methyl salicylate, increased attraction of males to (1R,2S,5R,8R)-iridodial, whereas 1-tridecene was antagonistic. No females were caught in the entire study. Scanning electron micrographs revealed numerous male-specific, elliptical epidermal glands on the 3rd-8th abdominal sternites of Co. oculata, which are likely the pheromone glands. Another lacewing species, Chrysoperla rufilabris (Burmeister) (Cl. = Chrysoperla), did not produce male-specific volatiles or possess the type of gland presumed to produce pheromone in Co. oculata males, but (Z)-4-tridecene was identified as a major antennal-stimulatory compound from thoracic extracts of both sexes of Cl. rufilabris. Thus, (1R,2S,5R,8R)-iridodial (or its enantiomer) is now identified as a male-produced male aggregation pheromone for Co. oculata, the first pheromone identified for lacewings.

Aldehydes↗
PubMed1998

Nepetalactone: a new opioid analgesic from Nepeta caesarea Boiss.

The essential oils of Nepeta species including Nepeta phyllochlamys P. H. Davis, N. nuda L. ssp. nuda, and N. caesarea Boiss. have been screened by use of the tail-flick and tail immersion (52.5 degrees C) methods. Of the species studied, only N. caesarea showed significant analgesic activity, besides marked sedation, which was also blocked by naloxone, indicating involvement of opioid receptors. Moreover, it was only active on mechanical, not thermal, algesic response which suggests specificity for specific opioid receptor subtypes, excluding mu-opioid receptors. Because 4a alpha,7alpha,7a alpha-nepetalactone is the main component of the essential oil of N. caesarea, and is present at very high levels (92-95%), it is concluded that 4a alpha,7alpha,7a alpha-nepetalactone is the active principle and has a specific opioid receptor subtype agonistic activity.

Analgesia↗
PubMedDate not supplied

Chemical composition and biological activity of Nepeta parnassica oils and isolated nepetalactones.

Essential oils of Nepeta parnassica, collected at different developmental stages, were analyzed by means of GC/MS. From the fifty-five identified constituents in samples A and B, representing 94.8% and 98.7% of the oils respectively, 4a(alpha),7alpha,7alpha(beta)-nepetalactone (22.0%), 1,8-cineole (21.1%), alpha-pinene (9.5%) and 4a(alpha),7,beta,7alpha(beta)-nepetalactone (7.9%) were the major components of sample A (vegetative stage), whereas in sample B (flowering stage) the main contributors were 1,8-cineole (34.6%), 4a(alpha),7alpha,7a(alpha)-nepetalactone (17.3%), alpha-pinene (11.4%) and 4a(alpha),7alpha,7alpha(beta)-nepetalactone (8.9%). The oils were tested on human health important insects such as the Pogonomyrmex sp. ants and the Culex pipiens molestus mosquitoes with promising results on insect repellency/toxicity.

Animals↗
PubMed2002

Behavioral activity of catnip (Lamiaceae) essential oil components to the German cockroach (Blattodea: Blattellidae).

The essential oil of catnip, Nepeta cataria L., contains two isomers of nepetalactone, E,Z-and Z,E-nepetalactone, and was tested for repellent activity to adult male German cockroaches, Blattella germanica (L.), in a choice-test arena. The two isomers of nepetalactone were purified by using preparative thin-layer chromatography and tested for behavioral activity in the choice-test arena. Significant differences due to concentration were detected by analysis of variance, and the responses were compared by least-squared means analysis. The activities of the essential oil and purified isomers were compared with N,NA-diethyl-3-methylbenzamide (DEET) by a paired t-test. E,Z-Nepetalactone was the most active of the compounds tested, being significantly more active to this species than equivalent doses of DEET, the essential oil, or Z,E-nepetalactone. Antennectomized insects showed no response to concentrations that were active against intact insects.

Animals↗
PubMed2003

Catnip essential oil as a barrier to subterranean termites (Isoptera: Rhinotermitidae) in the laboratory.

The essential oil of catnip, Nepeta cataria (Lamiacae) was evaluated for behavioral effects on two populations of subterranean termite, Reticulitermes flavipes (Kollar) and R. virginicus (Banks) (Isoptera: Rhinotermitidae). The catnip essential oil contained approximately 36:64 E,Z-nepetalactone and Z,E-nepetalactone, respectively. The time to 50% dissipation (DT50) of the isomers in sand was dependent on dose, and ranged from 5.7 to 12.6 d for the E,Z-isomer and 7.7-18.6 d for the Z,E-isomer. For R. flavipes, the 24-h topical LD50 value was approximately 8200 microg/g termite. The 24-h fumigation LC50 value for R. flavipes was between 36 and 73 microg/ml air, and the 7-d fumigation LC50 value was between 14 and 36 microg/ml air. Exposure of R. virginicus to treated sand resulted in a 24-h LC50 value (95% F.L.) of 84 (67.6, 112) microg/cm2 and a 7-d LC50 value of 21.1 (16.4, 26.8) microg/cm2; for R. flavipes these values were 63.2 (53.7, 73.9) and 44.4 (34.6, 58.1) microg/cm2, respectively. Vertical tunneling through treated sand was eliminated at 500 ppm for R. virginicus and at 250 ppm for R. flavipes. Horizontal tunneling was stopped at 250 ppm for R. virginicus and reduced at doses above 250 ppm for R. flavipes. Although tunneling ceased in these tests, mortality was not high, indicating that the termites avoided the treated sand. Efficacy of catnip oil was equivalent to other monoterpenoids reported in the literature.

Animals↗
PubMed2005

Feeding deterrent effects of catnip oil components compared with two synthetic amides against Aedes aegypti.

Recently, catnip, Nepeta cataria L. (Lamiaceae), essential oil has been formulated and marketed as an alternative repellent for protection against biting arthropods by several vendors. We isolated the major active components of catnip oil, E,Z- and Z,E-nepetalactone, and quantitatively measured their antibiting efficacy compared with the repellents N,N-diethyl-3-methylbenzamide (deet) and chiral (1S,2'S)-2-methylpiperidinyl-3-cyclohexene-1-carboxamide (SS220) against the yellowfever mosquito, Aedes aegypti (L.), by using an in vitro assay and human volunteers at 24 nmol compound/cm2 (cloth or skin). Of all compounds tested in an in vitro assay, SS220 ranked as the most effective, whereas catnip oil and the nepetalactone compounds did not differ significantly from each other or from deet. However, in human volunteer bioassays, neither E,Z and Z,E-nepetalactone nor racemic nepetalactone deterred mosquito biting as effectively as SS220 or deet. All compounds differed significantly from the control. We conclude that catnip oil and nepetalactone isomers are significantly less effective than deet or SS220 in deterring the biting of Ae. aegypti.

Aedes↗
PubMed1964

CATNIP: ITS RAISON D' ETRE.

Catnip (nepetalactone) is closely related chemically to certain cyclopentanoid monoterpenes recently isolated from insects, and it shares with some of these terpenes an ability to repel insects. It is suggested that the adaptive function of catnip is to protect the plants that produce it against phytophagous insects.

Animals↗
PubMed2001

Effect of ring size in R-(+)-pulegone-mediated hepatotoxicity: studies on the metabolism of R-(+)-4-methyl-2-(1-methylethylidene)-cyclopentanone and DL-camphorone in rats.

R-(+)-Pulegone, a monoterpene ketone, is a potent hepatotoxin. The present study was designed to evaluate whether the reduction of the ring size in R-(+)-pulegone would affect its mode of metabolism and its hepatotoxic potential. Metabolic fate of R-(+)-4-methyl-2-(1-methylethylidene)-cyclopentanone (I) and 5-methyl-2-(1-methylethylidene)-cyclopentanone (DL-camphorone; II) were examined in rats. Compounds I and II were administered orally (250 mg/kg of b.wt./day) to rats for 5 to 7 days. The following metabolites were isolated and identified from the urine of rats dosed with I: 3-methyl-5-(1-methylethylidene)-cyclopent-2-enone (Ie), Z-4-methyl-2-(1-hydroxymethylethylidene)-cyclopentanone (Ib), E-4-methyl-2-(1-hydroxymethylethylidene)-cyclopentanone (Ia), 3-hydroxy-4-methyl-2-(1-methylethylidene)-cyclopentanone (If), 4-hydroxy-4-methyl-2-(1-methylethylidene)-cyclopentanone (Ic), and E-4-methyl-2-(1-carboxyethylidene)-cyclopentanone (Id). Phenobarbital (PB)-induced rat liver microsomes in the presence of NADPH transformed compound I into metabolites, which were identified as Ia, Ib, Ic, Ie, and If. The following urinary metabolites were isolated and identified from compound II: 5-hydroxy-5-methyl-2-(1-methylethylidene)-cyclopentanone (IIc), 5-hydroxy-5-methyl-2-(1-methylethyl)-cyclopentanone (IIg), Z-5-methyl-2-(1-hydroxymethylethylidene)-cyclopentanone (IIb), 5-methyl-2-(1-hydroxymethylethyl)-cyclopentanone (IIf), E-5-methyl-2-(1-hydroxymethylethylidene)-cyclopentanone (IIa), E-5-methyl-2-(1-carboxyethylidene)-cyclopentanone (IId), and 5-methyl-2-(1-carboxyethyl)-cyclopentanone (IIe). PB-induced rat liver microsomes in the presence of NADPH were shown to transform compound II to IIa, IIb, and IIc. Studies carried out in vitro demonstrated that hydroxylation at the tertiary carbon atom or oxidation of the isopropylidene methyl groups in II can be specifically blocked through structural modifications as seen in compounds 2,2-dimethyl-5-(1-methylethylidene)-cyclopentanone (III) and 5-methyl-2-(1-ethyl-1-propylidene)-cyclopentanone (IV). Similar observation was also made when isopropylidene methyl groups in R-(+)-pulegone were replaced by ethyl groups. Intraperitoneal administration of a single dose (250 mg/kg) of I and II to rats did not elicit hepatotoxicity as judged by serum alanine aminotransaminase levels and liver microsomal drug metabolizing enzyme activities.

Animals↗
PubMed1997

Antimutagenicity of Tochu tea (an aqueous extract of Eucommia ulmoides leaves): 1. The clastogen-suppressing effects of Tochu tea in CHO cells and mice.

The suppressing effect of crude extracts of Tochu tea, an aqueous extract of Eucommia ulmoides leaves and a popular beverage in Japan, on the induction of chromosome aberrations in CHO cells and mice was studied. When CHO cells were treated with Tochu tea crude extract after MMC treatment, the frequency of chromosome aberrations was reduced. Out of 17 Tochu tea components, 5 irridoids (geniposidic acid, geniposide, asperulosidic acid, deacetyl asperulosidic acid, and asperuloside) and 3 phenols (pyrogallol, protocatechuic acid, and p-trans-coumaric acid) were found to have anticlastogenic activity. Since the anticlastogenic irridoids had an alpha-unsaturated carbonyl group, this structure was considered to play an important role in the anticlastogenicity. The anticlastogenic effect of Tochu tea extracts was examined in mice using a micronucleus assay. When mice received 1.0 ml 4% Tochu tea extract by oral gavage 6 h before intraperitoneal injection of MMC, a decrease in the frequency of micronuclei was observed. This decrease was not due to a delay in the maturation of micronucleated reticulocytes.

Animals↗
PubMed2006

A simple high-performance liquid chromatography method for the determination of throat-burning oleocanthal with probated antiinflammatory activity in extra virgin olive oils.

A high-performance liquid chromatography (HPLC) method was developed to quantitatively analyze oleocanthal in extra virgin olive oils. Oleocanthal, a deacetoxy ligstroside aglycone, is known to be responsible for the back of the throat irritation of olive oils and to have probated antiinflamatory activity. Oleocanthal was isolated from small amounts of olive oil sample (1 g) by liquid-liquid extraction. Hexane-acetonitrile was found to be the best solvent system to extract oleocanthal from the oil matrix. The solvent extract was analyzed by reversed-phase HPLC with UV detection at 278 nm. Chromatogaphic separation of oleocanthal from other extracted compounds and of the two geometric isomers of oleocanthal was achieved by an elution gradient with acetonitrile and water. Both the external standard calibration curve and the internal standard calibration curve were established, and quantitation using both calibration curves gave essentially the same result. The reproducibility (RSD = 4.7%), recovery (> 95%), and limit of quantitation (< 1 microg/g) were also determined. Concentrations of oleacanthal in 10 selected throat-burning extra virgin olive oils were determined using the method (ranged from 22 to 190 microg/g) with external standard calibration.

Aldehydes↗