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Introduction: Catnip (Nepeta cataria, L.) has well‐documented applications in arthropod repellency because of its bioactive iridoids. Long‐term stability of nepetalactones and other iridoids in N. cataria are needed to develop as effective pest repellents. Objectives: The present work intends to measure iridoid concentration over time in biomass, plant extracts, and extract solution while identifying degradative byproducts under different storage conditions. Methodology: Samples of desiccated biomass, ethanol extract, and extract in ethanol solution were stored in ambient light or darkness. Through UHPLC‐QTOF/MS or UHPLC‐QQQ/MS, the concentration of Z,E‐nepetalactone, E,Z‐nepetalactone, nepetalic acid, and dihydronepetalactone were examined over 2 years and statistically analyzed for determination of best storage practices. Degradation kinetics were applied to each analyte using graphical estimation. With targeted formula searching, degradative byproducts were identified and quantified. Results: Light exposure caused significant decreases in E,Z‐nepetalactone concentration in all sample types, while having no effect on Z,E‐nepetalactone as it decayed more rapidly. Extract samples lost nepetalactone content faster than biomass or extract solution. Dihydronepetalactone levels were low, but never declined over 2 years. Nepetalic acid increased over some periods, depending on sample type, indicating a relationship between the acid and nepetalactone. Four degradative byproducts—nepetonic acid, dehydronepetalactone, an anhydride, and an ethanolic ester—were identified, with variable responses to light exposure. Conclusions: Protecting catnip products from light is necessary to preserve nepetalactones, and a discernable difference in nepetalactone isomer stability was discovered. Identifying Nepeta chemotypes rich in dihydronepetalactone may provide more resilient botanicals as starting materials for processing. Catnip (Nepeta cataria, L.) sees use as a botanical product for arthropod repellency. In this study, the long‐term stability of its bioactive compounds was assessed over 2 years in three formulations and two lighting treatments. Light exposure significantly impacts the concentration of iridoids over time. The two primary isomers of nepetalactone have drastically different stabilities in all formulations tested. Dihydronepetalactone maintains a steady concentration over 2 years and offers a more stable alternative to nepetalactone. [ABSTRACT FROM AUTHOR]

BACKGROUND: Pheromones have unique advantages for pest control. Current aphid pheromone research focuses on alarm and sex pheromones. However, practical applications are limited so far, as (E)‐β‐farnesene has only been investigated to a small extent as an alarm pheromone and only male aphids are targeted by sex pheromones. Previous literature reports electrophysiological responses and repellent behavior of asexual aphids to nepetalactone (1B), therefore our objective was to modify nepetalactone's structure to identify key fragments responsible for repellent effects, as guidance for subsequent modifications and further investigation. RESULTS: In this study, seven derivatives were designed and synthesized based on nepetalactol (1A) and nepetalactone (1B) as lead compounds. Free‐choice tests, conducted using cowpea aphids (Aphis craccivora), revealed that the lactone moiety was crucial for the repellent activity, and the removal of the carbonyl group eliminated the repelling effect. Compound (±)1I, an analogue of nepetalactone (1B), demonstrated a significantly higher repellent value than nepetalactone (1B) at three different concentrations, and even at 0.1 mg/mL it maintained a considerable repellent effect (26.5%). Electrostatic potential and density functional theory calculations supported the importance of the carbonyl group for the repellent effects. CONCLUSION: The newly discovered para‐pheromone (±)1I shows improved repellent effects and potential for development as a novel biological control agent. Based on our innovative findings, analogues with improved efficacy and properties can be designed and prepared. Our research contributes to understanding the effects of structural modifications on pheromone activity and properties, which is crucial for exploring novel pheromone‐based products for crop protection. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Catnip (Nepeta cataria L.) plants produce a wide array of specialized metabolites with multiple applications for human health. The productivity of such metabolites, including nepetalactones, and natural insect repellents is influenced by the conditions under which the plants are cultivated. In this study, we assessed how field-grown catnip plants, transplanted after being propagated via either single-node stem cuttings or seeds, varied regarding their phytochemical composition throughout a growing season in two distinct environmental conditions (Pittstown and Upper Deerfield) in the state of New Jersey, United States. Iridoid terpenes were quantified in plant tissues via ultra-high-performance liquid chromatography with triple quadrupole mass spectrometry (UHPLC-QqQ-MS), and phenolic compounds (phenolic acids and flavonoids) were analyzed via UHPLC with diode-array detection (UHPLC-DAD). The highest contents of total nepetalactones in Pittstown were found at 6 weeks after transplanting (WAT) for both seedlings and cuttings (1305.4 and 1223.3 mg/100 g, respectively), while in Upper Deerfield, the highest contents for both propagules were at 11 WAT (1247.7 and 997.1 mg/100 g, respectively) for seed-propagated and stem cuttings). The highest concentration of nepetalactones was associated with floral-bud to partial-flowering stages. Because plants in Pittstown accumulated considerably more biomass than plants grown in Upper Deerfield, the difference in nepetalactone production per plant was striking, with peak productivity reaching only 598.9 mg per plant in Upper Deerfield and 1833.1 mg per plant in Pittstown. Phenolic acids accumulated in higher contents towards the end of the season in both locations, after a period of low precipitation, and flavone glycosides had similar accumulation patterns to nepetalactones. In both locations, rooted stem cuttings reached their maximum nepetalactone productivity, on average, four weeks later than seed-propagated plants, suggesting that seedlings have, overall, better agronomic performance. [ABSTRACT FROM AUTHOR]

Catnip (Nepeta cataria L.) plants produce a wide array of specialized metabolites with multiple applications for human health. The productivity of such metabolites, including nepetalactones, and natural insect repellents is influenced by the conditions under which the plants are cultivated. In this study, we assessed how field-grown catnip plants, transplanted after being propagated via either single-node stem cuttings or seeds, varied regarding their phytochemical composition throughout a growing season in two distinct environmental conditions (Pittstown and Upper Deerfield) in the state of New Jersey, United States. Iridoid terpenes were quantified in plant tissues via ultra-high-performance liquid chromatography with triple quadrupole mass spectrometry (UHPLC-QqQ-MS), and phenolic compounds (phenolic acids and flavonoids) were analyzed via UHPLC with diode-array detection (UHPLC-DAD). The highest contents of total nepetalactones in Pittstown were found at 6 weeks after transplanting (WAT) for both seedlings and cuttings (1305.4 and 1223.3 mg/100 g, respectively), while in Upper Deerfield, the highest contents for both propagules were at 11 WAT (1247.7 and 997.1 mg/100 g, respectively) for seed-propagated and stem cuttings). The highest concentration of nepetalactones was associated with floral-bud to partial-flowering stages. Because plants in Pittstown accumulated considerably more biomass than plants grown in Upper Deerfield, the difference in nepetalactone production per plant was striking, with peak productivity reaching only 598.9 mg per plant in Upper Deerfield and 1833.1 mg per plant in Pittstown. Phenolic acids accumulated in higher contents towards the end of the season in both locations, after a period of low precipitation, and flavone glycosides had similar accumulation patterns to nepetalactones. In both locations, rooted stem cuttings reached their maximum nepetalactone productivity, on average, four weeks later than seed-propagated plants, suggesting that seedlings have, overall, better agronomic performance.

Nepeta crassifolia Boiss. & Buhse, from Lamiaceae family, is an aromatic species with medicinal properties which is endemic to Iran. The seeds and aerial parts of this plant were collected from six different regions of East Azerbaijan province. After drying, the plant aerial parts essential oil was obtained by hydrodistillation and their compounds were identified by GC and GC/MS. The collected seeds, after producing greenhouse seedlings, were planted in the field in a randomized complete block design with three replications. In the second year after planting, the flowering shoots were harvested, dried, and distilled. The results showed that there was significant differences among essential oil percentage of natural habitat samples which the highest amount belonged to "Marand" region, but the farm essential oil samples did not differ with each other significantly. The compounds nepetalactone I (4aα, 7α, 7aα) and II (4aα, 7α, 7aβ), globulol, germacrene B, caryophyllene oxide, and 1,8-cineole were identified as the main essential oil compounds of this species. The highest amount of nepetalactone I or II under the natural habitat (69% and 21.7%, respectively) and field (27.3% and 51.5%, respectively) conditions belonged to "Misho" region in "Marand". "Sarab" region also had the highest amount of nepetalactone II under the natural habitat and farm conditions compared to the other samples. The highest amount of 1,8-cineole (21.8%) in the oil was also obtained from the natural habitat of "Kharil" region. [ABSTRACT FROM AUTHOR]

Highlights By increasing the altitude, changes in growth and essential oil composition of the plant are observed Result of correlation analysis showed that essential oil yield was positively correlated with precipitation, and negatively with temperature. In the present study the populations with high-amount of nepetalactone and 1,8 cineole were identified, The populations of cluster 2 with higher amount of 1,8-cineole, were growing in the high altitude, cold, rainy and sloping areas

Abstract Background It has been known for centuries that cats respond euphorically to Nepeta cataria (catnip). Recently, we have shown that Lonicera tatarica (Tatarian honeysuckle), Actinidia polygama (silver vine), and Valeriana officinalis (valerian) can also elicit this “catnip response”. The aim of this study was to learn if the behavior seen in response to these plants is similar to the response to catnip. Furthermore, we studied if these responses are fixed or if there are differences between cats. While nepetalactone was identified decades ago as the molecule responsible for the “catnip response”, we know that this volatile is found almost exclusively in catnip. Therefore, we also aimed to identify other compounds in these alternative plants that can elicit the blissful behavior in cats. Bioassays with 6 cats were performed in a low-stress environment, where 5 plants and 13 single compounds were each tested for at least 100 and 17 h, respectively. All responses were video recorded and BORIS software was used to analyze the cats’ behavior. Results Both response duration and behavior differed significantly between the cats. While individual cats had preferences for particular plants, the behavior of individual cats was consistent among all plants. About half a dozen lactones similar in structure to nepetalactone were able to elicit the “catnip response”, as were the structurally more distinct molecules actinidine and dihydroactinidiolide. Most cats did not respond to actinidine, whereas those who did, responded longer to this volatile than any of the other secondary plant metabolites, and different behavior was observed. Interestingly, dihydroactinidiolide was also found in excretions and secretions of the red fox, making this the first report of a compound produced by a mammal that can elicit the “catnip response”. A range of different cat-attracting compounds was detected by chemical analysis of plant materials but differences in cat behavior could not be directly related to differences in chemical composition of the plants. Together with results of, among others, habituation / dishabituation experiments, this indicates that additional cat-attracting compounds may be present in the plant materials that remain to be discovered. Conclusions Collectively, these findings suggest that both the personality of the cat and genetic variation in the genes encoding olfactory receptors may play a role in how cats respond to cat-attracting plants. Furthermore, the data suggest a potential distinct mechanism of action for actinidine.

Introduction: Catnip (Nepeta cataria L.) produces volatile iridoid terpenes, mainly nepetalactones, with strong repellent activity against species of arthropods with commercial and medical importance. Recently, new catnip cultivars CR3 and CR9 have been developed, both characterized by producing copious amounts of nepetalactones. Due to its perennial nature, multiple harvests can be obtained from this specialty crop and the effects of such practice on the phytochemical profile of the plants are not extensively studied. Methods: In this study we assessed the productivity of biomass, chemical composition of the essential oil and polyphenol accumulation of new catnip cultivars CR3 and CR9 and their hybrid, CR9×CR3, across four successive harvests. The essential oil was obtained by hydrodistillation and the chemical composition was obtained via gas chromatography-mass spectrometry (GC-MS). Individual polyphenols were quantified by Ultra-High-Performance Liquid Chromatography-diode-array detection (UHPLC-DAD). Results: Although the effects on biomass accumulation were independent of genotypes, the aromatic profile and the accumulation of polyphenols had a genotype-dependent response to successive harvests. While cultivar CR3 had its essential oil dominated by E,Z-nepetalactone in all four harvests, cultivar CR9 showed Z,E-nepetalactone as the main component of its aromatic profile during the 1st, 3rd and 4th harvests. At the second harvest, the essential oil of CR9 was mainly composed of caryophyllene oxide and (E)-β-caryophyllene. The same sesquiterpenes represented the majority of the essential oil of the hybrid CR9×CR3 at the 1st and 2nd successive harvests, while Z,E-nepetalactone was the main component at the 3rd and 4th harvests. For CR9 and CR9×CR3, rosmarinic acid and luteolin diglucuronide were at the highest contents at the 1st and 2nd harvest, while for CR3 the peak occurred at the 3rd successive harvest. Discussion: The results emphasize that agronomic practices can significantly affect the accumulation of specialized metabolites in N. cataria and the genotype-specific interactions may indicate differential ecological adaptations of each cultivar. This is the first report on the effects of successive harvest on these novel catnip genotypes and highlights their potential for the supply of natural products for the pest control and other industries. [ABSTRACT FROM AUTHOR]

Nepeta binaludensis Jamzad is an endemic and rare perennial plant belonging to the Lamiaceae family, which grows in a limited area in Binaloud Mountain in northeast of Iran. In this study to evaluate the diversity of 20 populations (localities) of N. binaludensis and the influence of environmental factors on essential oil (EO) content and composition, the plant aerial parts were collected at the full flowering stage. The plant materials dried in shade and subjected to hydro-distillation for obtaining their EOs. Analysis of the EO was carried out using GC and GC/MS. The oil yields were varied from 1.2 to 4.9%. Classification of populations was made based on EO compounds. The results of mean comparison between populations belong to different habitats showed that the populations of Darood and Friezy with average values of 4.91 and 1.2% had the highest and lowest EO yield, respectively. Twenty-two compounds were identified in the oils with 1,8-cineol (25.4–59.0%), 4aα,7α,7aα-nepetalactone (13.8–55.1%), myrcene (2.3–5.5%) and p-cymene (1.1–5.7%) as the main components. Result of correlation analysis showed that the oil yield was positively correlated with precipitation and negatively with temperature. In addition, 1,8-cineole was positively and nepetalactone was negatively correlated with altitude. Cluster analysis by Ward method categorized the populations into two groups. The major compound of the oils in cluster 1 was nepetalactone (with an average of 37.9%), while the oils in cluster 2, contained higher percentage of 1,8-cineole (52–59%). Most of the populations in cluster 2, were originated from high, cold, rainy, and steep areas. Highlights: By increasing the altitude, changes in growth and essential oil composition of the plant are observed Result of correlation analysis showed that essential oil yield was positively correlated with precipitation, and negatively with temperature. In the present study the populations with high-amount of nepetalactone and 1,8 cineole were identified, The populations of cluster 2 with higher amount of 1,8-cineole, were growing in the high altitude, cold, rainy and sloping areas [ABSTRACT FROM AUTHOR]

Background: It has been known for centuries that cats respond euphorically to Nepeta cataria (catnip). Recently, we have shown that Lonicera tatarica (Tatarian honeysuckle), Actinidia polygama (silver vine), and Valeriana officinalis (valerian) can also elicit this "catnip response". The aim of this study was to learn if the behavior seen in response to these plants is similar to the response to catnip. Furthermore, we studied if these responses are fixed or if there are differences between cats. While nepetalactone was identified decades ago as the molecule responsible for the "catnip response", we know that this volatile is found almost exclusively in catnip. Therefore, we also aimed to identify other compounds in these alternative plants that can elicit the blissful behavior in cats. Bioassays with 6 cats were performed in a low-stress environment, where 5 plants and 13 single compounds were each tested for at least 100 and 17 h, respectively. All responses were video recorded and BORIS software was used to analyze the cats' behavior. Results: Both response duration and behavior differed significantly between the cats. While individual cats had preferences for particular plants, the behavior of individual cats was consistent among all plants. About half a dozen lactones similar in structure to nepetalactone were able to elicit the "catnip response", as were the structurally more distinct molecules actinidine and dihydroactinidiolide. Most cats did not respond to actinidine, whereas those who did, responded longer to this volatile than any of the other secondary plant metabolites, and different behavior was observed. Interestingly, dihydroactinidiolide was also found in excretions and secretions of the red fox, making this the first report of a compound produced by a mammal that can elicit the "catnip response". A range of different cat-attracting compounds was detected by chemical analysis of plant materials but differences in cat behavior could not be directly related to differences in chemical composition of the plants. Together with results of, among others, habituation / dishabituation experiments, this indicates that additional cat-attracting compounds may be present in the plant materials that remain to be discovered. Conclusions: Collectively, these findings suggest that both the personality of the cat and genetic variation in the genes encoding olfactory receptors may play a role in how cats respond to cat-attracting plants. Furthermore, the data suggest a potential distinct mechanism of action for actinidine. [ABSTRACT FROM AUTHOR]

Plant based natural products have been widely used as antibacterial and insect repellent agents globally. Because of growing resistance in bacterial plant pathogens and urban pests to current methods of control, combined with the long- and short-term negative impact of certain chemical controls in humans, non-target organisms, and the environment, finding alternative methods is necessary to prevent and/or mitigate losses caused by these pathogens and pests. The antibacterial and insect repellent activities of essential oils of novel cultivars of catnip (Nepeta cataria L. cv. CR9) and oregano (Origanum vulgare L. cv. Pierre) rich in the terpenes nepetalactone and carvacrol, respectively, were evaluated using the agar well diffusion assay and petri dish repellency assay. The essential oils exhibit moderate to high antibacterial activity against three plant pathogens, Pseudomonas cichorii, Pseudomonas syringae and Xanthomonas perforans of economic interest and the individual essential oils, their mixtures and carvacrol possess strong insect repellent activity against the common bed bug (Cimex lectularius L.), an urban pest of major significance to public health. In this study, the essential oils of catnip and oregano were determined to be promising candidates for further evaluation and development as antibacterial agents and plant-based insect repellents with applications in agriculture and urban pest management.

IntroductionCatnip (Nepeta cataria L.) produces volatile iridoid terpenes, mainly nepetalactones, with strong repellent activity against species of arthropods with commercial and medical importance. Recently, new catnip cultivars CR3 and CR9 have been developed, both characterized by producing copious amounts of nepetalactones. Due to its perennial nature, multiple harvests can be obtained from this specialty crop and the effects of such practice on the phytochemical profile of the plants are not extensively studied.MethodsIn this study we assessed the productivity of biomass, chemical composition of the essential oil and polyphenol accumulation of new catnip cultivars CR3 and CR9 and their hybrid, CR9×CR3, across four successive harvests. The essential oil was obtained by hydrodistillation and the chemical composition was obtained via gas chromatography-mass spectrometry (GC-MS). Individual polyphenols were quantified by Ultra-High-Performance Liquid Chromatography- diode-array detection (UHPLC-DAD).ResultsAlthough the effects on biomass accumulation were independent of genotypes, the aromatic profile and the accumulation of polyphenols had a genotype-dependent response to successive harvests. While cultivar CR3 had its essential oil dominated by E,Z-nepetalactone in all four harvests, cultivar CR9 showed Z,E-nepetalactone as the main component of its aromatic profile during the 1st, 3rd and 4th harvests. At the second harvest, the essential oil of CR9 was mainly composed of caryophyllene oxide and (E)-β-caryophyllene. The same sesquiterpenes represented the majority of the essential oil of the hybrid CR9×CR3 at the 1st and 2nd successive harvests, while Z,E-nepetalactone was the main component at the 3rd and 4th harvests. For CR9 and CR9×CR3, rosmarinic acid and luteolin diglucuronide were at the highest contents at the 1st and 2nd harvest, while for CR3 the peak occurred at the 3rd successive harvest.DiscussionThe results emphasize that agronomic practices can significantly affect the accumulation of specialized metabolites in N. cataria and the genotype-specific interactions may indicate differential ecological adaptations of each cultivar. This is the first report on the effects of successive harvest on these novel catnip genotypes and highlights their potential for the supply of natural products for the pest control and other industries.

Main conclusion: Using virus-induced gene silencing, we demonstrated that the enzymes GES, ISY, and MLPL are responsible for nepetalactone biosynthesis in Nepeta cataria. Nepetalactone is the main iridoid that is found in the Nepeta genus and is well-known for its psychoactive effect on house cats. Moreover, there is a burgeoning interest into the effect of nepetalactone on insects. Although the enzymes for nepetalactone biosynthesis have been biochemically assayed in vitro, validation of the role that these enzymes have in planta has not been demonstrated. Virus-induced gene silencing (VIGS) is a silencing method that relies on transient transformation and is an approach that has been particularly successful when applied to a variety of non-model plants. Here, we use a recently designed visual-marker dependent VIGS system to demonstrate that the nepetalactone biosynthetic enzymes GES, ISY, and MLPL impact nepetalactone biosynthesis in Nepeta cataria. [ABSTRACT FROM AUTHOR]

The red palm weevil, Rhynchophorus ferrugineus (Olivier) (Coleoptera: Curculionidae) is a key pest of palms in diverse agro-systems worldwide. We carried out four field trials in a date palm, Phoenix dactylifera L plantation in Al-Ghowaybah village of Alahsa, Saudi Arabia to screen 45 known insect repellents categorized based on boiling point into four groups (very low, low, medium and high) against R. ferrugineus by ascertaining the extent of reduction in weevil captures in food baited R. ferrugineus pheromone traps (trap shutdown) additionally emitting candidate repellents. Results indicate that the four high boiling repellents tumerone, vanillin, nepetalactone and cinnamic acid can collectively induce a high degree of stimulo-deterrence against R. ferrugineus, with a trap shutdown of 83.8%. These findings offer the possibility of using R. ferrugineus repellents to protect fresh injury sites on palms especially after frond and offshoot removal and also in devising a broader R. ferrugineus semiochemical mediated control strategy by deploying the above repellents as non-host volatiles in the field in conjunction with pheromone (ferrugineol) traps in area-wide push–pull R. ferrugineus control programs. [ABSTRACT FROM AUTHOR]

BACKGROUND: Olfactory stimulation is an often overlooked method of environmental enrichment for cats in captivity. The best known example of olfactory enrichment is the use of catnip, a plant that can cause an apparently euphoric reaction in domestic cats and most of the Pantherinae. It has long been known that some domestic cats and most tigers do not respond to catnip. Although many anecdotes exist of other plants with similar effects, data are lacking about the number of cats that respond to these plants, and if cats that do not respond to catnip respond to any of them. Furthermore, much is still unknown about which chemicals in these plants cause this response. METHODS: We tested catnip, silver vine, Tatarian honeysuckle and valerian root on 100 domestic cats and observed their response. Each cat was offered all four plant materials and a control, multiple times. Catnip and silver vine also were offered to nine tigers. The plant materials were analyzed by gas chromatography coupled with mass spectrometry to quantify concentrations of compounds believed to exert stimulating effects on cats. RESULTS: Nearly all domestic cats responded positively to olfactory enrichment. In agreement with previous studies, one out of every three cats did not respond to catnip. Almost 80% of the domestic cats responded to silver vine and about 50% to Tatarian honeysuckle and valerian root. Although cats predominantly responded to fruit galls of the silver vine plant, some also responded positively to its wood. Of the cats that did not respond to catnip, almost 75% did respond to silver vine and about one out of three to Tatarian honeysuckle. Unlike domestic cats, tigers were either not interested in silver vine or responded disapprovingly. The amount of nepetalactone was highest in catnip and only present at marginal levels in the other plants. Silver vine contained the highest concentrations of all other compounds tested. CONCLUSIONS: Olfactory enrichment for cats may have great potential. Silver vine powder from dried fruit galls and catnip were most popular among domestic cats. Silver vine and Tatarian honeysuckle appear to be good alternatives to catnip for domestic cats that do not respond to catnip.

Introduction Catnip (Nepeta cataria L.) is one of the most important medicinal plants belonged to the Lamiaceae family that referred to considerable pharmacological, antimicrobial, antibacterial and pesticides activities of its essential oil in most of the literatures. The harmful effects of chemical fertilizers on the environment and human health and lack of soil organic matter in arid and semi-arid regions have resulted in an increase in the use of chemical fertilizers in these areas.Excessive use of these fertilizers has led to serious environmental pollutions during the last decades. With respect to the hazards of chemical fertilizers and the importance of medicinal plants, researchers have recently considered the application of biofertilizers and organic materials. According to literatures, the application of biofertilizers and organic fertilizers can be recommended as a proper alternation for the improvement of the quantity and quality of essential oil in Catnip. Material and Methods This research was conducted as factorial layout based on a randomized complete block design (RCBD) with three replications at the research farm of the faculty of agriculture, Shahid Chamran University of Ahvaz, Iran. The first factor was included fertilizer treatments in five levels (Control (C), Azetobarvar-1 (Az), Phosphatbarvar-2 (Ph), Combination of Az and Ph (M), chemical fertilizer (Ch) included 150 kg.ha-1 granular urea (46% N) and 100 Kg.ha-1 triple superphosphate (46% p < sub>2O5)) and the second factor was comprised humic acid in two levels (0 and 20 Kg.ha-1). The studied traits in this research included soil microbial respiration and biomass carbon and soil organic matter contents, leaf nitrogen and phosphorus amounts, number and size of secretory trichomes, essential oil content, yield and composition. Leaf nitrogen and phosphorus concentrations were measured at the beginning of reproductive stage by Kjeldahl method and colorimetric method using a UV-2100-Unico spectrophotometer, respectively. Moreover, the soil microbial respiration and soil biomass carbon were determined by alkali absorption and the fumigated extraction, respectively, and soil organic matter was estimated by the modified Walkly and Blackʼs methods. Furthermore, the number and size of secretory trichomes was registered using Binocular microscope and essential oil was extracted by Clevenger-type apparatus and analyzed using GC and GC-MS at full bloom stage. Results and Discussion According to the results, the sole application of fertilizer treatment was positively affected on soil microbial respiration and biomass carbon, leaf nitrogen and phosphorus contents. The number and size of secretory trichomes, essential oil content and yield and essential oil composition were significantly influenced when fertilizer treatments and humic acid were applied simultaneously. The highest amount of soil microbial respiration as well as biomass carbon was detected in M and the lowest was observed in control. The application of Ch and humic acid was significantly improved the soil organic matter. However, no significant difference was found between these treatments and biofertilizers treatments. The lowest amount of soil organic matter was detected in control. The maximum content of leaf nitrogen element was observed in plant treated by Ch and minimum was registered in control. The highest level of leaf phosphorus element, the size of secretory trichomes and essential oil content were obtained when Ph was applied while there was no significant difference between this biofertilizer and Ch and M. The maximum number of secretory trichomes and essential oil yield was detected in plant treated with M. The most amounts of isomers 1 and 2 of nepetalactone and caryophyllene oxide was observed in Az, Ch and control, respectively, and least was in control, Ph and Ch, respectively. The highest level of trans- caryophyllene and (E,E)–Farnesene was obtained in the oil of plant treated with M+ and Ch+ and lowest detected in Az+ and Ch-. Conclusion According to the results, to improve the quantity and quality of Catnip essential oil, the application of biological fertilizers instead of chemical fertilizers is recommended and further research is also required to investigate both the effects of applying humic acid alone and in combination with biofertilizers on some traits.

Nepetalactones belongs to the group of iridoid monoterpenoids, which are present in the aerial parts of nepeta plants. Nepetalactone is an attractant to feline animals causing euphoric effects, while it is a repellent to mosquitoes and cockroaches. It is also a pheromone for several insect aphid species. The main objective of this research was to study the electronic and spectral properties of nepetalactones. We investigated its structural properties using hybrid density-functional theory of B3LYP and WB97XD functional with the 6-311++G(d,p) basis set to optimize the geometry, and then computed the electronic structure, HOMO–LUMO, natural bond orbitals, molecular electronic potential and its contour map. We also obtained spectral signatures of NMR, IR and UV–Vis, and compared them with experimental data from the literature. The DFT study provided different electronic and spectral information that will be of value for further research on making new derivatives of nepetalactones for commercial purposes. Nepetalactones have a promising future in the development of novel mosquito repellents for the control of malaria and arboviral diseases. [ABSTRACT FROM AUTHOR]

Phytochemical analysis, antioxidant and antifungal activity of Nepeta species (N. racemosa, N. saccharata, N. congesta, and N. cataria) were assessed. The amount of essential oil yield ranged from 0.31 (N. racemosa) to 1.76 % (N. congesta). The 4aα,7α,7aβ-nepetalactone was the major compound in the essential oil of the N. racemosa (91.0 %), N. cataria (81.3 %) and N. saccharata (75.4 %). Also, in essential oil of N. congesta, 1,8-cineol (25.4 %) was the main component. The major phenolic acid was ferulic acid (8.03–26.08 g kg−1). The highest concentrations of ferulic acid, chlorogenic acid, caffeic acid, and coumaric acid were obtained in N. cataria. The most abundant flavonoid was rutin (0.02–0.51 g kg−1). The highest amounts of rutin, quercetin, and kaempferol were obtained in N. racemosa, N. saccharata, and N. cataria, respectively. As well as, the highest total phenolic (87.40 g GAE kg−1 DW powder), flavonoid contents (1.99 g Qu/kg DW powder), and antioxidant capacity by DPPH (77.26 %) and FRAP (2.23 µmol Fe++ g−1 DW powder) were obtained in N. cataria. The antifungal assay showed that the use of ≥ 600 ppm of essential oil resulted in a fungicidal effect against funguses tested (Botrytis cinerea, Cladosporium fulvum, and Pyricularia oryzae). In the case of Stemphylium botryosum, their mycelial growth completely inhibited at concentrations like or superior than 600 ppm essential oil of N. saccharata and N. racemosa. The obtained results of present study can provide new safe resources to the development of new products for the food, agriculture, and pharmaceutical industries. [ABSTRACT FROM AUTHOR]

The antimicrobial activities of (Z,E)- and (E,Z)-nepetalactones, 2 major compositional compounds from the essential oil of catnip (Nepeta cataria), were first discovered from fly larval development media studies with over 98% inhibition of bacterial growth. Further investigation demonstrated inhibition of the growth of various bacterial species of public health significance. Catnip oil showed antibacterial activity against 5 Gram-positive and 9 Gram-negative bacteria. The antimicrobial activity varied among the original essential oil from the plant and its major compositional compounds as a blended mixture or an individual compound. Growth inhibition was observed against 5 Neisseria species, with particularly strong inhibition against Neisseria sicca (with MICs ranging from 0.5 to 5 mg/mL) that provided comparable or increased levels of growth control produced by 2 antibiotics (Ceftiofur and Cephalothin). The development of plant-based antibacterial agents to prevent or delay the emergence of antimicrobial resistance in bacteria is discussed. [ABSTRACT FROM AUTHOR]

Two species Nepeta cataria L. and Nepeta bracteata Benth. (fam. lamiaceae) are native to Iran. To study the quantity and quality of the two species essential oil in the field, the seeds of eight populations from these two species were collected from natural habitats and planted in a randomized complete block design in Alborz Research Station of Research Institute of Forests and Rangelands (Karaj, Alborz province). The flowering branches were harvested at the full flowering stage and after room temperature-drying, their essential oils were extracted by hydrodistillation, and analyzed and identified by GC and GC/MS. The essential oil yield of N. cataria populations varied between 0.02 (Karaj) and 0.50% (Arak). Twenty-three compounds were identified in the essential oil of this species, and the main compound in all populations was from nepetalactone isomers. NepetalactoneIII (4aα,7β,7aα-nepetalactone) and nepetalactoneI (4aα,7α,7aα-nepetalactone) constituted 44.4 (Karaj) to 91.6% (Arak) and 0.8 (Karaj) to 15.9% (Bafgh1) of the essential oil, respectively. NepetalactoneII (4aα,7α,7aβ-nepetalactone) was observed only in the population Bafgh2 (21.2%). The amount of 1,8-cineole in the essential oil of different N. cataria populations varied from 0.4 (Taft1) to 12.8% (Karaj). The essential oil yield of N. bractaeta populations was obtained between 0.02 (Ardakan) and 0.70% (Taft2). Twenty-seven compounds were identified in the essential oil of this species, and the main compounds were 1,8-cineole (1.0, 9.6, and 41.0% in Tabas, Ardakan, and Taft2, respectively) and geranyl acetate (0.9, 3.4, and 39.8% in Tabas, Taft2, and Ardakan, respectively). In general, the results showed that the N. cataria populations were all from the same chemotype, but N. bracteata populations were from two chemotypes (ct. geranyl acetate and ct. 1,8-cineole). [ABSTRACT FROM AUTHOR]

This study was designed to evaluate, for the first time, the antioxidant and antimicrobial activities of Nepeta × faassenii essential oil (NEO). Twenty-six compounds were identified by gas chromatography and mass spectrometry analysis, of which 4a alpha,7alpha,7a alpha-nepetalactone (34.12%), elemol (23.23%), spiro(5,6)dodecane (13.73%), and 3,4 alpha-dihydro-4a alpha, 7 alpha, 7a alpha-nepetalactone (7.93%) were the major compounds. The NEO exhibited broad-spectrum antibacterial effects, and possesses potent antifungal activity on Candida albicans and Candida parapsilosis. NEO's antioxidant activity was evaluated against cold-pressed sunflowers oil by peroxide, thiobarbituric acid, 1,1-diphenyl- 2-picrylhydrazyl radical, and β-carotene/linoleic acid bleaching methods. The NEO showed strong scavenging (IC50: 0.032 ± 0.005 mg/mL) and relative antioxidative activity (RAA%: 92.31 ± 0.17%) in 1,1-diphenyl- 2-picrylhydrazyl radical and β-carotene/linoleic acid bleaching assays, respectively. Moreover, during 24 days of the incubation period, the oil inhibits the primary lipid oxidation significantly better (p < 0.05) than butylated hydroxyanisole (BHA). In the case of secondary lipid oxidation, the oil performed significantly better (p < 0.001) than BHA from day 8 to day 12 of the incubation period. The biological activities recorded suggest that NEO may represent an antioxidant and antimicrobial agent with applications in medicine or the food industry. [ABSTRACT FROM AUTHOR]

Nepeta binaludensis Jamzad is an endemic and rare perennial plant belonging to the Lamiaceae family which grows in a limited area in Binaloud Mountain in northeast of Iran. In order to study the effect of drying methods on its essential oil content and composition, the aerial parts were collected in flowering stage from its habitat at altitude of 2650 m above sea level in July 2018. Seven drying methods as sun drying, shade drying, oven drying at 30oC, 40oC and 50oC and microwave drying (180W and 360W) were applied in three replications. The essential oils of all samples were obtained using a Clevenger type apparatus during 3 h. The essential oils were analyzed using gas chromatography (GC) and gas chromatography/mass spectrometry (GC-MS). Data statistically analyzed using one way ANOVA (CRD) with three replications and mean comparison were made using the Tukey method. The highest oil yield was obtained in oven drying 50 °C (2.16%) followed by shade drying (1.96%). In contrast, the lowest values of essential oil content, 1.09 and 0.65%, were obtained in sun drying and microwave 360W, respectively. Twenty-four compounds were identified in the essential oils of N. binaludensis with various drying methods with neptalactone (23.1-54.0%), 1,8-cineol (25.5-51.0%) and myrcene (2.0-4.0%) as major components. The highest percentage of 1,8-cineole (51%) was obtained from sample dried in oven 50 °C, while, the highest amount of neptalactone (54.0%) was obtained from sample dried by the microwave 180 W. The results demonstrated that drying the aerial parts of N. binaludensis in the shade and oven 50oC are the best optimal methods to obtain the highest oil yield, while drying in microwave at 180 W is recommended to enhance higher neptalactone content in the oil. [ABSTRACT FROM AUTHOR]

Methanol extracts of three endemic Nepeta species were analyzed for their main secondary metabolites, terpenes and phenolics, and further investigated for antioxidant capacity and embryonic toxicity in zebrafish. UHPLC/DAD/(±) HESI-MS/MS analysis showed that the dominant compound in N. rtanjensis was trans,cis-nepetalactone, the cis,trans isomer of this monoterpene lactone was dominant in N. sibirica, while nepetalactone was detected only in traces in N. nervosa. In all investigated species, rosmarinic acid was the dominant phenolic compound, while other identified phenolic acids (chlorogenic, neochlorogenic and caffeic) were present in considerably lower amounts. ABTS and DPPH assays showed that the methanol extracts of N. rtanjensis, N. sibirica and especially N. nervosa possessed strong antioxidant activities, with the FRAP assay revealing high ferric-reducing abilities for all three tested species. Such a strong antioxidant potential, especially as manifested in the DPPH and FRAP assays, can be attributed to phenolic acids, and in the first place to rosmarinic acid. Increased lethality of zebrafish embryos in any of the treatments was not observed, but several toxic effects on embryonic development were recorded, such as pericardial and yolk sac edema. As in other Nepeta species, the three studied endemic species possessed a great potential for food conservation or as medicinal supplements if applied in optimized concentrations; however, alternative sources of plant material (e.g. field cultivation) should be established bearing in mind their vulnerability in nature.

Cyclodextrin inclusion complexes have been successfully used to encapsulate essential oils, improving their physicochemical properties and pharmacological effects. Besides being well-known for its effects on cats and other felines, catnip (Nepeta cataria) essential oil demonstrates repellency against blood-feeding pests such as mosquitoes. This study evaluates the tick repellency of catnip oil alone and encapsulated in β-cyclodextrin, prepared using the co-precipitation method at a 1:1 molar ratio. The physicochemical properties of this inclusion complex were characterized using GC-FID for encapsulation efficiency and yield and SPME/GC-MS for volatile emission. Qualitative assessment of complex formation was done by UV-Vis, FT-IR, 1H NMR, and SEM analyses. Catnip oil at 5% (v/v) demonstrated significant tick repellency over time, being comparable to DEET as used in commercial products. The prepared [catnip: β-CD] inclusion complex exerted significant tick repellency at lower concentration of the essential oil (equivalent of 1% v/v). The inclusion complex showed that the release of the active ingredient was consistent after 6 h, which could improve the effective repellent duration. These results demonstrated the effective tick repellent activity of catnip essential oil and the successful synthesis of the inclusion complex, suggesting that β-CDs are promising carriers to improve catnip oil properties and to expand its use in repellent formulations for tick management.

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Nepeta is one of the biggest geniuses of Lamiaceae family which N. pungens, N. binaludensis, N. isphanica, N. pogonosperma and N. bracteata has been used traditionally in Iran. Nepeta pogonesperma is one of the endemic Nepeta species in Alamut region (Qazvin Province ). So in this research the aerial parts of Nepeta pogonesperma in full flowering stage were collected from Kheshchal altitudes of Alamut (2400, 2600 and 2800 m). Some main morphological characters of plant were measured. Essential oil were obtained by hydro distillation (Clevenger apparatus) and were analyzed by GC/MS. Results were showed that in high altitude (2800m) the yield and quantity of the essential oil components of plant were increased and the 1,8-cineole had the highest content (80.7%). 19 compounds were identified in the essential oil of this plant, Such as α-Pinene, Sabinene, β-Pinene, Myrcene, δ-3-Carene, ρ-Cymene, Limonene, 1,8-Cineole, Cis-Sabinene hydrate, Terpinolene, Linalool, Cis-p-Menth-2-en-1-ol, Pinocarvone, Borneol, Terpinen-4-ol, α-Terpineol, 4aα-7α-7aβ-Nepetalactone, α-Humulene and Viridiflorol. Variance analysis revealed that there was a significant difference between altitudes in the weight of leaf, stem and flower and total plant weight and oil percentage (α≤0.01). According to the means comparison of the highest leaf and flower weight were belonged to 2400 and 2600 m with 63.7 and 35.7g, respectively. The maximum amount of oil percentage and 1,8-Cineole were observed in 2400 m with 0.55 and 80.7%, respectively. In this research, there were many changes in altitudes in essential oil combinations, which can be increased the production and performance of Nepetalactone, by applying nature-generated modeling factors.

Background: Drying is the most common way to preserve quality of aromatic and medicinal plants. Chosen drying methods can affect on the essential oil content and composition of medicinal plants. Objective: This study aimed to assess the changes in essential oil constitutes of catnip aerial part under various drying methods. Methods: The experiment was performed as the randomized complete block design (RCBD) with 10 treatments and 3 replications. The treatments were included the freshly harvested plants, sun-drying, shade-drying, oven-drying at 35, 45, and 55 °C, microwave-drying at 100 and 200 W, and initial sun-drying followed by subsequent shade-drying and oven-drying at 45 °C. Results: The result indicated that the various drying methods had a significant effect (p ≤ 0.01) on the essential oil content and compositions. The highest amount of essential oil was observed in the oven-drying at 55°C. GC-MS analysis revealed the presence 9 compounds in the essential oil of catnip, which three isomers of nepetalactone with a predominance of 4a-α, 7-α, 7a-β-nepetalactone were major essential oil components. Although, the amount of 4a-α, 7-α, 7a-β-nepetalactone were reduced by oven-drying at 55 °C, but other the isomers of nepetalactone were increased. However, the total content of three isomers of nepetalactone were equal in the fresh catnip with the dried plants by the oven drier at 55°C. Conclusion: In general, the oven-drying at 55°C is recommended as an effective method to dry the catnip.

Two Balkan Peninsula endemics, Nepeta rtanjensis and N. argolica subsp. argolica, both characterized by specialized metabolite profiles predominated by iridoids and phenolics, are differentiated according to the stereochemistry of major iridoid aglycone nepetalactone (NL). For the first time, the present study provides a comparative analysis of antimicrobial and immunomodulating activities of the two Nepeta species and their major iridoids isolated from natural sources—cis,trans-NL, trans,cis-NL, and 1,5,9-epideoxyloganic acid (1,5,9-eDLA), as well as of phenolic acid rosmarinic acid (RA). Methanol extracts and pure iridoids displayed excellent antimicrobial activity against eight strains of bacteria and seven strains of fungi. They were especially potent against food-borne pathogens such as L. monocytogenes, E. coli, S. aureus, Penicillium sp., and Aspergillus sp. Targeted iridoids were efficient agents in preventing biofilm formation of resistant P. aeruginosa strain, and they displayed additive antimicrobial interaction. Iridoids are, to a great extent, responsible for the prominent antimicrobial activities of the two Nepeta species, although are probably minor contributors to the moderate immunomodulatory effects. The analyzed iridoids and RA, individually or in mixtures, have the potential to be used in the pharmaceutical industry as potent antimicrobials, and in the food industry to increase the shelf life and safety of food products.

Two species of Nepeta genus, N. kotschyi var. persica and N. glomerulosa, are native medicinal plants of Iran, containing medicinal compositions such as Nepetalactones. This study was conducted for plant domestication under field condition during years 2017 and 2018. The experiment was carried out under completely randomized block design with three replications. Morphological and yield traits besides essential oil content and composition were measured. Results showed that total fresh and dry weight in N. kotshyi (9954 and 3152 kg ha-1, respectively), were higher than N. glomerulosa (2858 and 990 kg ha-1, respectively). Essential oil content and yield in N. kotschyi were 2.12% and 48.35 kg ha-1, respectively, while these traits in N. glomerulosa were 1.42% and 7.39 kg ha-1, respectively. Essential oil composition analysis determined that the sum of Nepetalactone isomers in N. kotschyi were higher than N. glomerulosa, 94.57% and 38.68%, respectively. On the whole, according to the aerial parts and essential oil yield, and Nepetalactone content in the oil, the N. kotschyi var. persica showed the higher performance, though, in order to produce Nepetalactone for medicinal industries, N. kotschyi var. persica cultivation is recommended under similar field condition. [ABSTRACT FROM AUTHOR]

Abstract This study aimed at characterizing the modulation of skeletal muscle contraction and cardiorespiratory response of tambaqui, Colossoma macropomum submitted to baths using anaesthetic concentrations (capable of inducing fast, i.e. < 5 min, and full body immobilization) of propofol (PRP) and essential oil of Nepeta cataria (EON). For the evaluation of electromyography, electrocardiographic data, and opercular beat intensity (OBI) and rate (OBR), fish (5.6 ± 1.8 g, 8.0 ± 0.3 cm, total length) were assigned to the following groups: a) control (basal recording), b) ethanol-exposed fish (vehicle control), c) fish submitted to induction with EON at 175 μL L−1 and subsequent recovery, and d) fish submitted to induction with PRP at 4 μL L−1 and subsequent recovery. Eight fish (n = 8) per group were used. Both products induced full body immobilization and suppressed (99.9%) dorsal muscle contraction power, determining a general anaesthesia-like state. During exposure to either anaesthetic, cardiac function was transiently affected, with decreased heart rates (42–43%) and a mild arrhythmia in PRP recovering fish. Moreover, ventilatory capacity was reduced with this drug (85.3% and 59.6% decrease in OBI and OBR, respectively), yet without mortality. On the other hand, EON did not alter ECG tracings, allowing for the maintenance of normal ventilation intensity during exposure, albeit a slight increment in OBR occurred during deep anaesthesia. This study confirms propofol anaesthesia in fish and presents N. cataria essential oil as a novel and safe natural anaesthetic for juvenile Colossoma macropomum and potentially for other teleost species. Highlights • This is the first study using Nepeta cataria essential oil as an anaesthetic for fish. • Propofol and N. cataria essential oil blunted muscle contraction power in Colossoma macropomum. • Exposure to short-term baths using propofol and N. cataria essential oil did not compromise cardioventilatory function. [ABSTRACT FROM AUTHOR]

This study was designed to evaluate, for the first time, the antioxidant and antimicrobial activities of Nepeta × faassenii essential oil (NEO). Twenty-six compounds were identified by gas chromatography and mass spectrometry analysis, of which 4a alpha,7alpha,7a alpha-nepetalactone (34.12%), elemol (23.23%), spiro(5,6)dodecane (13.73%), and 3,4 alpha-dihydro-4a alpha, 7 alpha, 7a alpha-nepetalactone (7.93%) were the major compounds. The NEO exhibited broad-spectrum antibacterial effects, and possesses potent antifungal activity on Candida albicans and Candida parapsilosis. NEO’s antioxidant activity was evaluated against cold-pressed sunflowers oil by peroxide, thiobarbituric acid, 1,1-diphenyl- 2-picrylhydrazyl radical, and β-carotene/linoleic acid bleaching methods. The NEO showed strong scavenging (IC50: 0.032 ± 0.005 mg/mL) and relative antioxidative activity (RAA%: 92.31 ± 0.17%) in 1,1-diphenyl- 2-picrylhydrazyl radical and β-carotene/linoleic acid bleaching assays, respectively. Moreover, during 24 days of the incubation period, the oil inhibits the primary lipid oxidation significantly better (p < 0.05) than butylated hydroxyanisole (BHA). In the case of secondary lipid oxidation, the oil performed significantly better (p < 0.001) than BHA from day 8 to day 12 of the incubation period. The biological activities recorded suggest that NEO may represent an antioxidant and antimicrobial agent with applications in medicine or the food industry.

Iridoids are monoterpenes that are produced by various plants as chemical defense molecules. Lichman et al. recently described the timeline of molecular events that underpin the re-emergence of iridoid biosynthesis in an independent lineage of aromatic plants (catnip). This study represents a benchmark for studying enzyme and metabolite evolution in different clades across the tree of life. [ABSTRACT FROM AUTHOR]

The asymmetric synthesis of a compound with the cyclopentan[c]pyran core of iridoid natural products in four steps and 40% overall yield is reported. Our methodology includes a one-pot tandem domino reaction which provides a trisubstituted cyclopentane with five new completely determined stereocenters, which were determined through 2D homo and heteronuclear NMR and n.O.e. experiments on different compounds specially designed for this purpose, such as a dioxane obtained from a diol. Due to their pharmaceutical properties, including sedative, analgesic, anti-inflammatory, CNS depressor or anti-conceptive effects, this methodology to produce the abovementioned iridoid derivatives, is an interesting strategy in terms of new drug discovery as well as pharmaceutical development.

Nepeta is one of the largest genera of the Lamiaceae family, and Iran is one of the main centers of origin of the genus. There are lots of reports related to biological activities of secondary metabolites of Nepeta that shows the importance of the genus. Quantity and quality of essential oil (EO) components of 12 accessions of three Iranian Nepeta species, N. cataria, N. menthoides and N. crassifolia, cultivated in West of Tehran, were studied. Also, EO components capability on intra and inter-specific relationships was investigated. Plant aerial parts were harvested at full bloom stage. EO was extracted by hydrodistillation method from shade-dried plant materials. EO was quantitatively and qualitatively analyzed by GC and GC/MS, respectively. Principal component analysis was used in order to determine the role of each EO components in intra and inter-specific diversity. The most part of EO yield (w/w) belonged to "Markazi" accession of N. cataria (2.5%). Main EO component(s) of species were NepII (4aα,7α,7aβ-nepetalactone) in N. cataria, 1,8-cineole and NepII in N. menthoides and NepI (4aα,7α,7aα-nepetalactone), 1,8-cineole and NepII in N. crassifolia. N. crassifolia and N. cataria species, respectively, allocated on the first positions based on the quantity of NepI and II. N. cataria had the most total quantity of nepetalactone (97.8-99.1%). Results indicated that EO components were able to distinguish species, and to identify intra and inter-specific relationships. N. crassifolia and N. cataria species were separated from N. menthoides by cluster and PCA analysis based on EO components. [ABSTRACT FROM AUTHOR]

Nepetalactones are accumulated as the main secondary metabolites in the majority of Nepeta species; however, their biosynthetic pathway remains to a great extent unknown, as well as their relationship to the overall physiology of these plants. Nepetalactones most certainly arise through general iridoid biosynthetic pathway leading to nepetalactol, a common precursor of all plant-derived iridoids that is formed in a reaction catalysed by iridoid synthase ( IS , EC 1.3.1.99). In this paper, we aimed to localize the sites of nepetalactone biosynthesis and accumulation by comparatively analysing the nepetalactones content and the expression of putative iridoid synthase ( NrIS ) in leaves of Nepeta rtanjensis Diklić & Milojević, a trans,cis -nepetalactone and dehydronepetalactone rich species. Another aim was to give an insight into the developmental regulation of nepetalactone biosynthesis in leaves of cultivated N. rtanjensis plants. Knowledge on the spatial-, and developmental- regulation of nepetalactone metabolism could greatly benefit potential growers by enabling them to adequately plan and manage plant cultivation, harvesting, and handling and thus increase yield of bioactive compounds. The expression profile of putative NrIS1 is highly correlated with trans,cis -nepetalactone and dehydronepetalactone content/ratio in leaves of different developmental stages. The results strongly indicate that developmental regulation of nepetalactone biosynthesis in leaves resides largely at the level of gene expression, and suggest an important role of NrIS1 . Young leaves exhibited the most intensive nepetalactone biosynthesis and accumulation, but also its conversion to dehydronepetalactone. Thus, the pattern of NL accumulation in leaves can be explained by both the rate of its biosynthesis and metabolic degradation. The gene expression patterns of NrIS1 and NrIS2 transcripts in trichomes and abraded leaves revealed trichomes as the main site of their activity. UHPLC/qqqMS profiling of nepetalactones in trichomes and abraded leaves, complemented with Raman spectroscopy and dichloromethane dipping experiment, supported glandular trichome-specific localization of nepetalactone biosynthesis and accumulation. [ABSTRACT FROM AUTHOR]

Green lacewings (Chrysopidae) are predators of soft-bodied pest insects and are among the most important biological control agents in crop protection. Chrysopa spp. are of special importance since, unlike most green lacewing species, adults are also predatory. The current study was undertaken in search of Chrysopa formosa compounds with semiochemical activity. Using coupled gas chromatography-electroantennography (GC-EAG), head and thorax extracts of C. formosa elicited EAG responses to a compound subsequently identified by coupled GC/mass spectrometry, microchemistry, chemical synthesis and GC peak enhancement as (Z)-4-tridecene. In field experiments, this compound decreased attraction of adult C. formosa to (1R,4aS,7S,7aR)-nepetalactol and that of Chrysoperla carnea species-complex to a ternary floral lure, with the inhibitory effect found to be dose-dependent. Our results suggest that (Z)-4-tridecene may serve as a general warning signal among multiple green lacewing species. Perspectives for potential practical applications are discussed. [ABSTRACT FROM AUTHOR]

Nepetalactones are iridoid monoterpenes with a broad range of biological activities produced by plants in the Nepeta genus. However, none of the genes for nepetalactone biosynthesis have been discovered. Here we report the transcriptomes of two Nepeta species, each with distinctive profiles of nepetalactone stereoisomers. As a starting point for investigation of nepetalactone biosynthesis in Nepeta , these transcriptomes were used to identify candidate genes for iridoid synthase homologs, an enzyme that has been shown to form the core iridoid skeleton in several iridoid producing plant species. Iridoid synthase homologs identified from the transcriptomes were cloned, heterologously expressed, and then assayed with the 8-oxogeranial substrate. These experiments revealed that catalytically active iridoid synthase enzymes are present in Nepeta, though there are unusual mutations in key active site residues. Nevertheless, these enzymes exhibit similar catalytic activity and product profile compared to previously reported iridoid synthases from other plants. Notably, four nepetalactone stereoisomers with differing stereochemistry at the 4α and 7α positions – which are generated during the iridoid synthase reaction – are observed at different ratios in various Nepeta species. This work strongly suggests that the variable stereochemistry at these 4α and 7α positions of nepetalactone diastereomers is established further downstream in the iridoid pathway in Nepeta . Overall, this work provides a gateway into the biosynthesis of nepetalactones in Nepeta . [ABSTRACT FROM AUTHOR]

Methanol extracts of three endemic Nepeta species were analyzed for their main secondary metabolites, terpenes and phenolics, and further investigated for antioxidant capacity and embryonic toxicity in zebrafish. UHPLC/DAD/(±) HESI-MS/MS analysis showed that the dominant compound in N. rtanjensis was trans, cis-nepetalactone, the cis, trans isomer of this monoterpene lactone was dominant in N. sibirica, while nepetalactone was detected only in traces in N. nervosa. In all investigated species, rosmarinic acid was the dominant phenolic compound, while other identified phenolic acids (chlorogenic, neochlorogenic and caffeic) were present in considerably lower amounts. ABTS and DPPH assays showed that the methanol extracts of N. rtanjensis, N. sibirica and especially N. nervosa possessed strong antioxidant activities, with the FRAP assay revealing high ferric-reducing abilities for all three tested species. Such a strong antioxidant potential, especially as manifested in the DPPH and FRAP assays, can be attributed to phenolic acids, and in the first place to rosmarinic acid. Increased lethality of zebrafish embryos in any of the treatments was not observed, but several toxic effects on embryonic development were recorded, such as pericardial and yolk sac edema. As in other Nepeta species, the three studied endemic species possessed a great potential for food conservation or as medicinal supplements if applied in optimized concentrations; however, alternative sources of plant material (e.g. field cultivation) should be established bearing in mind their vulnerability in nature. [ABSTRACT FROM AUTHOR]

Essential oils from the aerial parts of three populations of Nepeta crassifolia (Lamiaceae), which are Iranian endemic species and four populations of N. nuda grown in northwestern Iran were obtained by hydro-distillation and examined by gas chromatography (GC) and GC-mass spectrometry (GC/ MS). Overall, 37 compounds were identified in the essential oils from different populations of N. crassifolia and N. nuda. The essential oils consisted mainly of oxygenated monoterpenes and sesquiterpene aldehydes. The major components in the oils of three populations of N. crassifolia were 4aβ, 7α, 7aβ-nepetalactone (16.46-27.45%), 4aα, 7α, 7aβ-nepetalactone (13.45-17.54%), 1,8-cineole (8.15-9.70%) and elemol (14.38-22.14%), while 7aβ-nepetalactone (61-72.21%), 4aα, 7α, 7aβ-nepetalactone (8.72-12.63%), pulegone (7.36%) and piperitenone oxide (4.12%) were identified as the main constituents in the oils of four populations of N. nuda. The essential oils from the aerial parts of two species of Nepeta sourced in northwestern Iran were rich in oxygenated monoterpenes. In conclusion, the present study indicated the essential oil components of wild populations of both Nepeta species varied with chemotypes, environmental conditions, and geographic origin. [ABSTRACT FROM AUTHOR]

Nepeta dschuparensisBornm. is an endemic plant from Iran. Little information is available on this endemic medicinal plant. The aim of the present study was to identify the essential oil compositions in stems, leaves and flowers ofN.dschuparensisusing GC-MS analysis. The essential oil yields of stems, leaves and flowers fromN. dschuparensiswere 0.2, 1.2 and 0.7%, respectively. The main components in the essential oil of stems were 1,8-cineole (26.8%) and nepetalactone (66.9%), in the essential oil of leaves were α-terpineol (8.9%) and nepetalactone (80.3%) and in the essential oil of flowers were 1,8-cineole (22.8%), α-terpineol (7.5%) and nepetalactone (63.3%). The results showed that nepetalactone was the main component in the essential oil of this medicinal plant. To the best of our knowledge, this is the first report revealing the essential oil components inN. dschuparensis. [ABSTRACT FROM PUBLISHER]

This paper describes the seasonal variations of volatile compounds from stems, leaves and flowers ofNepeta cataria. The essential oils obtained by hydrodistilation were analyzed by GC and GS-MS. Sixty-five constituents were identified in the flower oil, with sesquiterpenes as dominant components (54.8%). The leaf oils before and during flowering were dominated by monoterpenes (54.6% and 94%, respectively), withcis,trans-nepetalactone as the most abundant constituent. As for the stem oils obtained before and during flowering, the dominant class were acids (60.4% and 72.1%, respectively). Antibacterial activity, evaluated by using microbroth dilution method, revealed that all five essential oils were active against tested bacteria. Oil obtained from stems before flowering showed the strongest activity againstY. eneterococlitica(MIC50and MIC90values; 7.5 mL/mL and 8.0 mL/mL, respectively). [ABSTRACT FROM AUTHOR]