Essential oils (EOs), with their diverse bioactive compounds, are increasingly recognized as eco-friendly alternatives to synthetic pesticides. Species of Juniperus and Pinus are rich in EOs and represent valuable resources for natural pesticide development. This study evaluated the in vitro antifungal activities of EOs from two Juniperus species (J. sabina male and female; J. excelsa M. Bieb.) and four Pinus species (P. heldreichii, P. peuce, P. sylvestris, and P. nigra). The EOs were tested against mycelial growth of six phytopathogens: Alternaria alternata, Botrytis cinerea, Diaporthe nobilis (anamorph Phomopsis sp.), Fusarium oxysporum, Rhizoctonia solani, and the oomycete Phytophthora cryptogea. The strongest inhibition (95.1 %) was recorded against R. solani by J. sabina (female, F) EO, dominated by myrtenyl acetate (14.1 %), sabinene (20.3 %), δ-cadinene (9.2 %), and cis-sabinol (6.8 %). P. heldreichii EO effectively suppressed B. cinerea, D. nobilis, F. oxysporum, and P. cryptogea, outperforming other Pinus EOs. Pinus peuce EO was most active against A. alternata and R. solani, while P. nigra EO notably inhibited D. nobilis and F. oxysporum. Across all Pinus EOs, α-pinene was the dominant compound (38.2–46.9 % of the total EO); germacrene D was abundant in P. heldreichii (23.3 %), P. peuce (8.4 %), and P. nigra (16.2 %), while β-pinene was abundant in P. sylvestris (20.2 %) and P. peuce (10.3 %). Overall, J. sabina (F) and selected Pinus EOs exhibited strong antifungal activity, highlighting their potential as eco-friendly, botanical fungicides for managing economically important plant pathogens.

Capsinoids derived from Capsicum annuum have emerged as natural modulators of metabolic homeostasis. While capsiate is known to activate multiple nuclear receptors, its clinical utility is suspected by its inherent metabolic stability. In contrast, dihydrocapsiate (DHC) possesses a saturated side chain that confers greater metabolic stability, yet its specific pharmacological profile remains insufficiently characterized. To elucidate the DHC's metabolic effects and its underlying molecular mechanisms with a focus on glucose transport, adipocyte differentiation and nuclear receptor selectivity were investigated. In differentiated myocytes, DHC significantly upregulated glucose uptake, suggesting its potential role in improving peripheral insulin sensitivity. In adipocytes, DHC effectively antagonized rosiglitazone-induced adipogenic differentiation without modulating basal adipogenesis. These data indicate that DHC may mitigate the weight gain typically associated with PPARγ-targeted antidiabetic therapies. Transcriptional profiling revealed that DHC robustly induced NRF2 antioxidant signaling pathway and selectively activated PPARα while exerting negligible effects on PPARγ and LXR. The nuclear receptor-selective profile distinguishes DHC from the broader multi-nuclear receptor activation observed with capsiate. However, DHC was found to be similar to capsiate in enhancing AMPK phosphorylation. Owing to its enhanced metabolic stability and unique nuclear receptors' signature, DHC represents a promising natural alternative for the improved glucose uptake and selective adipogenesis. Hence it may play a significant role in management of metabolic syndrome and type2 diabetes.

BACKGROUND:We report the bioassay-guided isolation and identification of phytotoxic compounds from an extract of the fungus Xylaria grammica (Ascomycota), isolated from leaf lesions of seedlings of Handroanthus serratifolius (Bignoniaceae), from the Atlantic Rain Forest in Brazil. From the fungal crude extract, grammicin (1) and xylaric acid methyl ester (2) were purified and identified using one- and two-dimensional nuclear magnetic resonance and high-resolution mass spectrometry analysis. RESULTS:Grammicin exhibited activity against Lactuca sativa (lettuce) and Agrostis stolonifera (bentgrass) at 1 mg mL-1, resulting in 100% inhibition of seed germination. Compound 2 had no activity against L. sativa but showed moderate activity against A. stolonifera, inhibiting seed germination at 1 mg mL-1. Against Lemna paucicostata (duckweed), grammicin inhibited growth by 50% (IC50) at 87.7 μM, while compound 2 had no activity. Neither compound had antifungal activity against the plant pathogen Colletotrichum fragariae. Grammicin is structurally similar to the natural compound patulin, which is reported to be phytotoxic by inhibition of photosystem II (PSII). Molecular modeling of the interaction of grammicin with the D1 protein of PSII predicts it to be a strong PSII inhibitor; however, in vivo testing indicated that it is a very weak PSII inhibitor. Patulin was highly cytotoxic to mammalian cells whereas grammicin was not cytotoxic. CONCLUSIONS:This is the first report unveiling the phytotoxicity of grammicin, which could serve as a scaffold for developing more potent herbicides with improved physicochemical properties and without any potential for cytotoxicity. © 2026 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.

This study investigated the phytochemical compositions of Pinus peuce (Balkan pine) essential oils (EO), total polyphenol, and flavonoid content from different plant parts: leaves, twigs, wood, and cones. Furthermore, this study evaluated the biological activities of the EO. The EO yield varied among different plant parts, and it was the highest in the wood of one to two-year-old twigs (1.08 % - 2.40 %). The predominant compounds of the EOs, a-pinene, (1-pinene, and limonene, were found in all analyzed trees from the five populations, but in different amounts. The concentration ranges for a-pinene were 32-56 % in leaves (L), 24-49 % in twigs (T), 26-48 % tips of twigs (TT), and 10.5-48 % in wood of one to two-year-old twigs. The concentrations of (1-pinene were 7.9-18.3 % in L, 5.9 %- 15.7 % in T, 7.9-13.2 % in TT, and 4.2-6.5 % in WT. The concentration of limonene was 2.9-12 % in L, 5.7-45 % in T, and 1.2-60 % in WT. Furthermore, camphene, (1-myrcene, bornyl acetate, germacrene D, and (1-caryophyllene were found in large quantities in some plant parts. The female cones had the highest concentration of polyphenolic compounds (56.03 mg GAE g-1), followed by the annual wood (24.56 mg GAE g-1) and leaves (22.86 mg GAE g-1). The EO of P. peuce had a high antimicrobial effect against Salmonella enterica subsp. enterica and Escherichia coli. Within 24 h of application, the EOs demonstrated 100 % efficacy against the aphid species Sitobion avenae and Rhopalosiphum padi. P. peuce EO from twigs demonstrated significant bioherbicidal activity against the seeds of weed species Anthemis arvensis and Papaver rhoeas effectively inhibiting sprout and root growth. These results demonstrated the potential of P. peuce EO as a novel ingredient in bioherbicides and plant protection products.

Wheat and barley are the two most important small-grain crops globally. A persistent challenge in their cultivation is pre-harvest sprouting (PHS), which occurs when seeds begin to germinate on the spike due to rainfall before harvest. Despite ongoing efforts, effective and environmentally friendly solutions for PHS control are limited. This study presents a novel approach by exploring the use of essential oils (EOs) as natural germination suppressants. This study hypothesized that essential oils (EOs) could suppress seed germination in wheat and barley, offering a potential avenue for developing products to mitigate PHS. The objective of the study was to evaluate the effects of 11 EOs on the germination rate (%), number of seminal roots, root length (mm), and seedling height (mm) of two grain crops: wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.). The EOs tested included Eucalyptus polybractea (blue mallee), Eucalyptus globulus (southern blue gum), Cinnamomum cassia (Chinese cassia), Abies sabirinensis (fir needle), Artemisia vulgaris (mugwort), Citrus paradisi (grapefruit), Commiphora myrrha (myrrh), Melaleuca viridiflora (Niaouli), Pinus strobus (Eastern white pine), Citrus reticulata (tangerine), and Cymbopogon martini (palmarosa). Essential oils were applied at rates of (0, 10, 30, and 90 mu L/ Petri dish) to study their inhibitory effect on seeds. The application of Cymbopogon martini and Cinnamomum cassia EOs reduced wheat and barley seed germination rate (%), number of seminal roots, root length (mm), and seedling height (mm) at 10 mu L. Therefore, they were further evaluated at reduced amounts (0, 1, 3, and 9 mu L/ Petri dish). Barley and wheat seed germination was suppressed by applying Cymbopogon martini and Cinnamomum cassia EOs at 1, 3 and 9 mu L; these EO significantly decreased all response variables relative to the non-treated control. Due to the effectiveness of the EOs, even at low amounts, a tetrazolium test (TZ) was conducted to test the viability of the seeds after they were exposed to EOs. The results of the TZ test showed that EOs had significant effects on seed viability. When the amount of EOs increased, the viability of the seed decreased. More research is necessary to confirm the findings in field conditions. This study was the first report to demonstrate that Cymbopogon martini and Cinnamomum cassia EO have promising potential as natural agents for controlling preharvest sprouting (PHS) in wheat and barley, offering a sustainable alternative to synthetic chemicals in grain production and storage systems.

Antifungal screening identified Pogostemon cablin essential oil (EO) as a potent fungicide against Colletotrichum fragariae, prompting bioassay-directed fractionation. This process identified patchoulol and pogostone as antifungal constituents. Pogostone exhibited strong activity with IC50 values of 8.5 ± 0.5, 2.34 ± 0.13, 7.74 ± 0.23, and 6.34 ± 0.85 μg mL-1 against C. fragariae, C. gloeosporioides, C. acutatum, and Botrytis cinerea, respectively, at 48 h. Due to its structural similarities to β-triketone herbicides, its phytotoxicity was assessed. It exhibited herbicidal activity against Lemna paucicostata (IC50 = 0.9 μM) comparable to atrazine (IC50 = 1.1 ± 0.23 μM), and Amaranthus palmeri in postemergence trials, showing similar efficacy to glyphosate. Despite its herbicidal effect, photosystem II disruption is unlikely, suggesting a novel mechanism. Molecular modeling also supported the idea that it may act through a distinct mode from known HPPD inhibitors. These results indicate pogostone's potential as a dual-function agrochemical with both antifungal and herbicidal properties.

Background1,4-Naphthoquinone compounds have shown pesticidal activity against Aedes aegypti larvae, a key vector of diseases such as dengue and Zika. However, limited knowledge of their structure-activity relationships has hindered their optimization for pesticide development. This study investigates the structure-activity relationships of 1,4-naphthoquinone, particularly 2-hydroxy-1,4-naphthoquinone and its derivatives.ResultsA series of 1,4-naphthoquinones with modifications at the C-2, C-5, and C-8 positions were synthesized and tested for larvicidal activities against Ae. aegypti. The presence of chlorine substituents at the C-2 position significantly increased mosquito larval mortality. In contrast, 2-hydroxy and 2-methoxy groups were less effective, highlighting the importance of the C-2 substituent in determining larvicidal activity. The compounds were tested on both pyrethroid-susceptible Orlando 1952 (ORL1952) and permethrin-resistant Puerto Rico (PR) strains of Ae. aegypti. While compound 1d exhibited the lowest median lethal concentration (LC50) against ORL1952 larvae, it showed minimal activity against the PR strain, which is resistant. The most promising compounds, 1 and 4a, showed LC50 values of 2.764 and 4.916 ppm in the ORL strain, and 2.548 and 4.878 ppm in the PR strain, respectively.ConclusionChlorine substitution at the C-2 position of 1,4-naphthoquinones enhances larvicidal activity against Ae. aegypti, while 2-hydroxy and 2-methoxy substitutions reduce efficacy. Certain compounds, such as 1 and 4a, show potential as broad-spectrum agents effective against both susceptible and resistant strains of Ae. aegypti, highlighting their promise for further development as mosquito control agents. (c) 2025 Society of Chemical Industry.

Achillea thracica Velen. Sec. Achillea s.l. [=Sect. Filipendulinae (DC.) Afan.] is a Bulgarian endemic species found in a single population within the country. Endemic species like A. thracica are often under-studied, yet they hold significant potential for the discovery of novel compounds. The goal of this study was to assess the reproductive capacity of A. thracica (pollen and seeds viability) and its reproductive structures, and to characterize the chemical profile and the antimicrobial activity of its essential oil (EO). The male and female generative spheres show that A. thracica reproduces via sexual reproduction. Furthermore, the normal progression of processes leading to pollen and seed formation is essential for fully realizing reproductive capacity. Despite the high fertility observed in the pollen of the target species, seed viability was found to be very low. Further, the female gametophyte of A. thracica is highly influenced by environmental conditions, which directly affect the quality of the seeds produced. Moreover, the lack of alternative reproductive mechanisms, such as apomixis, limits the plasticity of A. thracica populations, reducing their adaptability to environmental changes. Overall, the composition of A. thracica EO was notably different from that of other Achillea species within Sec. Filipendulinae. Santolina and yomogi alcohols and (l-eudesmol were the most abundant compounds found in the EO. The strongest antimicrobial activities of A. thracica EO in our study were found against Clostridium perfringens followed by Yersinia enterocolitica and Listeria monocytogenes. With its vigorous growth, unique essential oil (EO) composition, and strong antimicrobial activity, A. thracica demonstrates significant potential for cultivation and development as a high-value crop. Additionally, A. thracica EO can serve as a promising natural source of (l-eudesmol, creating opportunities for diverse commercial applications.

We evaluated the diversity and biotechnological potential of culturable fungi from sediments of Florencia and Katerina lakes, James Ross Island, maritime Antarctica. A total of 57 fungal isolates, belonging to 24 taxa (16 from Florencia and 8 from Katerina) were identified. Ascomycota was the dominant phylum, followed by Mortierellomycota and Basidiomycota. The main genera included Cladosporium, Dactylaria, Glaciozyma, Graphium, Leucosporidium, Mortierella, Penicillium, Pseudeurotium, Pseudogymnoascus, Tetracladium and Thelebolus. Pseudogymnoascus sp. 1 and Thelebolus species were the most frequent. Florencia Lake showed greater taxonomic richness and diversity than Katerina Lake. Of all taxa, 12 were exclusive to Florencia, 4 to Katerina, and 4 were shared. All fungal isolates were screened for the production of 11 industrially relevant enzymes; inulinase was the most common, followed by protease, invertase, gelatinase and pectinase. Eight isolates (Pseudogymnoascus and Thelebolus) produced biosurfactants and 50 contained intracellular lipid bodies. A Penicillium palitans isolate fully inhibited germination of Allium schoenoprasum seeds, and NMR analysis confirmed (-)-palitantin as the active compound. These results confirm that Antarctic lake sediments harbor diverse fungi with potential for producing enzymes, biosurfactants, lipids and bioactive metabolites, reinforcing the value of studying extremophilic fungi as a source of bioproducts in the context of fragile ecosystems affected by climate change.

Abstract Our study focused on the phytotoxic and antifungal activities of metabolites isolated from Fusarium sp., an endophyte associated with the medicinal plant Piper sp. Chromatographic separations of the Fusarium sp. crude extract led to the isolation of three analogous compounds: anhydrofusarubin (1), 5,10-dihydroxy-1,7-dimethoxy-3-methyl-1H-benzo[g]isochromene-6,9-dione (2), and javanicin (3). The structures of the isolated compounds were determined by high-resolution mass spectrometry (HRMS) analysis and direct comparison of 13C NMR data with that reported in the literature. The isolated compounds were evaluated for phytotoxic activity against Lactuca sativa and Agrostis stolonifera. All compounds exhibited strong phytotoxic activity on both plant species, completely inhibiting seed germination at a concentration of 1 mg mL-1. Additionally, the isolated compounds were evaluated against Lemna paucicostata, achieving a 50% growth inhibition (IC50) at concentration of 64, 28, and 31 μM for compounds 1, 2, and 3, respectively. The antifungal activity of these compounds was evaluated using a bioautography assay targeting the agricultural pathogen Colletotrichum fragariae. Among them, compound 2 demonstrated significant antifungal activity. Our results showed that tropical medicinal plants harbor an interesting endophyte that has a potential reservoir of bioactive compounds. Moreover, the structures of these compounds could serve as scaffold for the development of new pesticides.

Leptospermone, a natural β-triketone and major constituent of manuka oil (Leptospermum scoparium), is an established inhibitor of plant HPPD and was identified to induce rapid knockdown and induce high toxicity to Aedes aegypti adults via topical and tarsal contact exposure with LD50 values of 150 ng/mg of mosquito and 357 ng/cm2, respectively. Although toxic to mosquitoes, leptospermone was non-toxic to ticks, the honey bee, or the fruit fly indicating a high degree of insect specificity. Importantly, leptospermone was equally toxic to non-blood fed and blood-fed mosquitoes suggesting the mode of action is not via HPPD inhibition. Molecular modeling suggested high structural similarities between leptospermone and mammalian sulfonamide carbonic anhydrase (CA) inhibitors. In vitro potency assays with mosquito midgut homogenate or purified CA verify leptospermone inhibits Ae. aegypti CA, but not mammalian CAs. CAs are metalloenzymes that regulate the pH of tissues and ubiquitously expressed throughout insect tissues but are abundantly expressed in the mosquito midgut and, thus, we tested leptospermone to alter pH regulation in the mosquito midgut. Indeed, leptospermone significantly reduced the pH of Ae. aegypti midguts when compared to control mosquitoes which further supports the notion that leptospermone mode of action in insects is via inhibition of CA. These data verify leptospermone is an effective mosquitocide that induces rapid knockdown and toxicity to Ae. aegypti at doses that approach natural pyrethrins against pyrethroid-resistant mosquito strains. Further, the data indicate leptospermone mode of action is CA inhibition, which is a novel mosquitocide target and is different when compared to the mode of action in plants.

Therapeutic hypothermia (TH) has demonstrated neuroprotection in instances of cardiac arrest and neonatal hypoxia/ischemia but faces different challenges in application to stroke due to the activation of cold defense mechanisms in conscious patients. This study examined the efficacy and specificity of capsinoids (a purified mixture of capsiate and dihydrocapsiate) to induce a sustained fall in core body temperature in conscious mice. Capsinoids function as TRPV1 agonists. However, unlike capsaicin, capsinoids are vulnerable to esterase-mediated breakdown, thus significantly restricting their action to the site of delivery. We showed that capsinoids delivered intraperitoneally (IP) to mice induced a TRPV1-dependent drop in core body temperature into the mild hypothermia range (32-34 °C). Core temperatures dropped without triggering observable cold defense mechanisms (e.g. shivering). The response to capsinoids was dose-dependent and effective in young and aged mice of both sexes. Repeated administration of capsinoids maintained mild hypothermia for up to 6 h, supporting the potential for applying this cooling procedure for promoting post-stroke TH. Capsinoid-induced hypothermia was linked to an activation of heat defense mechanisms, as evidenced by the rapid induction of cutaneous vasodilation and subsequent drop in core body temperature. We showed that IP capsinoids activate vagal afferents, as demonstrated by an increase in c-Fos positive neurons in the nodose ganglion. Finally, we provide proof-of-principle showing that capsinoid-induced hypothermia is neuroprotective in an experimental model of ischemic stroke.

Hostile and harsh environments to most organisms represent more than 80% of the earth’s surface. These extreme environments shelter interesting microbial communities that can live in habitats that combine polyextremophile conditions, including cold, hot, dry, oligotrophic conditions, and high solar radiation over the year. Microorganisms inhabiting extreme ecosystems can have specialized metabolism to adapt to physicochemical conditions different from those that most organisms can withstand. These microbes are called extremophiles. For this reason, extreme regions represent a natural laboratory to study different aspects of its resident extremophile microorganisms, including fungi able to produce bioactive compounds. In this context, extremophile fungi present in environments such as Antarctica, the Artic, and alpine regions such as the Alps may have unusual biochemical metabolic pathways that produce secondary metabolites that can be used as possible prototypes for pharmaceuticals in medicine and pesticides for use in agriculture, as well as for industrial uses. Recent studies with these fungal extremophiles have searched for new compounds with biological functions such as cytotoxicity, antimicrobial, lipid-lowering ability, antioxidant, nematocidal, anti-inflammatory, antimalarial, antitumor, herbicidal, and antifouling activities. This review summarizes recent literature on extremophile fungi that are sources of metabolites for use in medicine, agriculture, and industry.

Juniperus sabina L., commonly known as Savin, is an evergreen shrub from Cupressaceae family, grown as an ornamental all over the world. J. sabina contains two valuable metabolites: essential oil (EO) and podophyllotoxin. The EO is known for various bioactivities, while podophyllotoxin, is currently used as a precursor for anticancer drugs. The hypothesis of this work was that J. sabina plants from natural populations in Bulgaria would have desirable EO profiles and bioactivity. Furthermore, accessions with high concentrations of podophyllotoxin may be discovered. The objectives were: (1) Assessment of the EO profile and podophyllotoxin variability, including seasonal, within populations, and between populations of J. sabina in Bulgaria; (2) Evaluation of the potential biopesticidal effect of J. sabina EO from natural populations; and (3) Assessment of antioxidant and enzymatic activities of J. sabina EO. Overall, the EO content and composition varied between natural populations, within a population, between female (F) and male (M) plants, and between different seasons (months) of the year. Sabinene (10.1-66.8% of the total EO), myrtenyl acetate (0-57.2%), alpha-pinene (2.6-8.6%), myrcene (2.85-4.5%), alpha-thujone (0-10.9%), beta-thujone (0-9.9%), and germacrene-4-ol (3.0-10.3%) were the major EO constituents. Monoterpenes represented 89.5-92.8% and sesquiterpenes were 6.7-7.1% of the EO. The EO yield was 0.61-3.8% in dried biomass, while the concentration of podophyllotoxin varied from undetected to 0.19%. Antioxidant activity was higher in EOs from female (F) plants in DPPH assay; in the FRAP assay, some EOs from male (M) plants collected in January, March, May, and July were the most active. Moreover, EO from F plants exhibited good activity on alpha-amylase and alpha-glucosidase enzymes. The tested EOs from both M and F plants at 5 mu L, 10 mu L, and 20 mu L significantly reduced or completely suppressed the germination and sprout length of seeds of five weed species. Eight chemotypes of J. sabina were identified and the EO of these were tested for suppression of soft white winter wheat, SWWW ( Triticum aestivum L.) germination and root and shoot growth. About half of the chemotypes suppressed wheat seed germination, root, and shoot growth. J. sabina EO could potentially be further explored for the development of biopesticides to be utilized for weed control in organic production systems and possibly for control of pre-harvest sprouting in wheat.

As part of a program to discover novel succinate dehydrogenase inhibitor fungicides, a series of new pyrazole acyl-(thio)-urea compounds containing a diphenyl motif were designed and synthesized. Their structures were confirmed by 1H NMR, HRMS, and single X-ray crystal diffraction analysis. Most of these compounds possessed excellent activity against 10 fungal plant pathogens at 50 mu g mL(-1), especially against Rhizoctonia solani, Alternaria solani, Sclerotinia sclerotiorum, Botrytis cinerea, and Cercospora arachidicola. Interestingly, compounds 3-(difluoromethyl)-1-methyl-N-((3',4',5'-trifluoro-[1,1'-biphenyl]-2-yl)-carbamoyl)-1H-pyrazole-4-carboxamide (9b, EC50 = 0.97 +/- 0.18 mu g mL-1), 1,3-dimethyl-N-((3',4',5'-trifluoro-[1,1'-biphenyl]-2-yl)-carbamoyl)-1H-pyrazole-4-carboxamide (9a, EC50 = 2.63 +/- 0.41 mu g mL(-1)), and N-((4'-chloro-[1,1'-biphenyl]-2-yl)-carbamoyl)-1,3-dimethyl-1H-pyrazole-4-carboxamide (9g, EC(5)0 = 1.31 +/- 0.15 mu g mL(-1)) exhibited activities against S. sclerotiorum that were better than the commercial fungicide bixafen (EC50 = 9.15 +/- 0.05 mu g mL-1) and similar to the positive control fluxapyroxad (EC50 = 0.71 +/- 0.11 mu g mL-1). These compounds were not significantly phytotoxic to monocotyledonous and dicotyledonous plants. Structure-activity relationships (SAR) are discussed by substituent effects/molecular docking, and density functional theory analysis indicated that these compounds are succinate dehydrogenase inhibitors.

The sand fly, Phlebotomus papatasi (Scopoli, 1786), is a major vector for Leishmania major in the Middle East, which has impacted human health and US military operations in the area, demonstrating the need to develop effective sand fly control and repellent options. Here, we report the results of spatial repellency and avoidance experiments in a static air olfactometer using the female P. papatasi testing essential oils of Lippia graveolens (Mexican oregano), Pimenta dioica (allspice), Amyris balsamifera (amyris), Nepeta cataria (catnip), Mentha piperita (peppermint), and Melaleuca alternifolia (tea tree); the 9–12 carbon saturated fatty acids (nonanoic acid, decanoic acid, undecanoic acid, and dodecanoic acid); and the synthetic repellents DEET and IR3535. The materials applied at 1% exhibited varying activity levels but were not significantly different in mean repellency and avoidance from DEET and IR3535, except in regards to nonanoic acid. Some materials, particularly nonanoic and undecanoic acids, produced sand fly mortality. The observed trends in mean repellency over exposure time included the following: (1) P. dioica oil, M. alternifolia oil, decanoic acid, undecanoic acid, DEET, and IR3535 exhibited increasing mean repellency over time; (2) oils of N. cataria, A. balsamifera, M. piperita, and dodecanoic acid exhibited relatively constant mean repellency over time; and (3) L. graveolens oil and nonanoic acid exhibited a general decrease in mean repellent activity over time. These studies identified the essential oils of N. cataria and A. balsamifera as effective spatial repellents at reduced concentrations compared to those of DEET. Additional research is required to elucidate the modes of action and potential synergism of repellents and essential oil components for enhanced repellency activity.

Worldwide, potatoes are an essential food crop; however, substantial post-harvest losses due to sprouting during storage have been a significant issue. Chemical sprout suppressants have been widely used to extend potato dormancy and reduce or eliminate sprouting in storage. However, chlorpropham (CIPC), the most effective and the most widely used chemical suppressant worldwide has been banned in the European Union and other countries due to potential health and environmental risks. Essential oils (EOs) from various plants have been investigated and are being used as environmentally friendly alternatives to synthetic chemical suppressors. This study aimed to investigate EOs that were not previously tested for preventing potato sprout suppression at room temperature. The objective of this study was to evaluate the effects of twenty EOs in three potato cultivars, Ranger Russet, Terra Rosa, and TrailBlazer minitubers, on the suppression of sprouts at room temperature. The results showed that Cinnamomum camphora (L.) J. Presl and Origanum majorana L. EOs suppressed sprouting in all potato cultivars throughout the storage period while maintaining potato quality during storage. Furthermore, Lavandula x intermedia Emeric ex Loisel. EO showed the ability to shorten and restrict sprouts relative to the controls. The GC analysis of C. camphora EO identified eight constituents with linalool being the dominant one at 95.5 %, whereas the main EO constituents of O. majorana were terpinen-4-ol (40.3 %), gamma-terpinene (14.6 %), sabinene (7.2 %), alpha-terpinene (6.9 %), para cymene (6.2 %), and limonene (4.1 %) in addition to other compounds. 1,8-Cineole and linalool were the major compounds in L. x intermedia EO. This work is the first report on these specific EOs as sprout suppressors. These EOs offer a potential for environmentally safe substitutes to conventional sprout inhibitors for potato storage and could be utilized in the development of commercial products for potato sprout control at room temperature.