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The essential oil was obtained from the aerial parts of Pogostemon cablin by hydrodistillation. The chemical compounds of P. cablin essential oil were analyzed by gas chromatography-flame ionization detection and gas chromatography-mass spectrometry. Eight compounds were totally identified and accounted for 92.4% of the oil. Patchoulol was the major component (51.1%), followed by phloroacetophenone (23.5%) and β-patchoulene (7.3%). The essential oil and its two major compounds patchoulol and phloroacetophenone were evaluated for their contact and repellent activities against Tribolium castaneum, Lasioderma serricorne, and Liposcelis bostrychophila. Results of bioassays indicated that the essential oil and patchoulol had great contact toxicity against three species of insects. Meanwhile, the essential oil and patchoulol showed great repellent activities against T. castaneum and L. bostrychophila but were mildly repellent to L. serricorne. Phloroacetophenone exhibited neither contact nor repellent activity against any of these target insects. This work emphasized the promising potential of P. cablin to control insect pests during storage.

The essential oil extracted from roots and rhizomes of Ligusticum jeholense Nakai et Kitagawa was investigated for its chemical composition by GC-MS analysis, and evaluated for its contact toxicity and repellency against Tribolium castaneum and Lasioderma serricorne, along with some of its individual components. The essential oil was rich in aromatics (65.34%) with low molecular weight. Major components included sedanolide (33.95%), 3-butylidenephthalide (18.76%), spathulenol (8.90%) and myristicin (6.76%). The results of bioassays indicated that the essential oil of L. jeholense and 3-butylidenephthalide possessed significant repellent activities against T. castaneum at 2 and 4 h post-exposure. Meanwhile, 3-butylidenephthalide had potent contact toxicity against L. serricorne (LD50 = 13.64 µg/adult). The minor component n-butylbenzene in the oil was highly toxic to T. castaneum (LD50 = 23.99 µg/adult) and L. serricorne (LD50 = 7.86 µg/adult) in contact assays, but failed to repel these beetles at all testing concentrations. Spathulenol and myristicin exerted good insecticidal and repellent effects on the two target insects. This work suggests that the essential oil of L. jeholense has promising potential for development as natural insecticide or repellent to control pest damage in warehouses.

In this work, we investigated the chemical constituents of hydrodistillation essential oil from the aerial parts of Artemisia frigida Willd. All together 14 components were identified by GC-MS. Moreover, we tested the fumigant and contact activities of the essential oil and its five major individual compounds (terpinen-4-ol, verbenone, camphene, α-terpineol and α-terpinyl acetate) against Liposcelis bostrychophila, Lasioderma serricorne and Tribolium castaneum. In fumigant toxicity tests, α-terpineol possessed the strongest activity (LC50 = 3.27 mg/L air) against L. serricorne. Terpinen-4-ol exhibited the strongest activity (LC50 = 0.08 and 3.74 mg/L air respectively) against L. bostrychophila and T. castaneum. As for contact toxicity, terpinen-4-ol and α-terpinyl acetate exhibited fair toxicity against L. bostrychophila (LD50 = 33.10 and 31.80 µg/cm2 respectively) and L. serricorne (LD50 = 8.62 and 8.87 µg/adult respectively), and camphene possessed the strongest activity (LD50 = 5.13 µg/adult) against T. castaneum. The results indicated that A. frigida essential oil and its individual compounds had the potential to be developed as natural fumigants and insecticides for control of these three stored-product insects.

The natural and ecologically safe control of stored product insects has gained considerable attention in modern society. In this study of further searching for botanical pesticides from wild-growing plant, the contact toxicity and repellency towards Tribolium castaneum and Liposcelis bostrychophila were assessed for the essential oil (EO) from Ostericum viridiflorum. The EO was distilled from aboveground parts of O. viridiflorum and checked by gas chromatography-mass spectrometry. Twenty-two compounds were identified and the main components were β-caryophyllene (24.3%), α-humulene (21.0%), apiol (10.2%), and carotol (2.5%). For bioactivity tests, results indicated that the EO and its two main compounds (β-caryophyllene and α-humulene) all showed potent contact toxicity towards L. bostrychophila with LD50 values of 44.52 μg/cm2, 74.11 μg/cm2, and 118.56 μg/cm2, respectively. The EO and the two main compounds also exhibited comparable repellency towards T. castaneum and L. bostrychophila. The results evidenced the EO of O. viridiflorum aboveground parts and its major compounds could be considered for the development of eco-friendly botanical insecticides and repellents in controlling stored product insects.

Three lignans (1–3) and three butanolides (4–6) were isolated from the lipophilic extract of theCinnamomum camphorastem bark. The six compounds were identified as (-)-sesamin (1), 9α-hydroxysesamin (2), 9β-hydroxysesamin (3), obtusilactone A (4), isoobtusilactone A (IOA, 5), and isomahubanolide (6) from their spectroscopic data. Four (1, 2 and 5, 6) of them were evaluated for their repellent and feeding deterrent activities againstTribolium castaneum. In this work, the three butanolides (4–6) were confirmed to exist inC. camphorafor the first time. Results of bioassays indicated that (-)-sesamin (1), IOA (5), and isomahubanolide (6) displayed certain repellent activities againstT. castaneumat 78.63, 15.73, and 3.15 μg/cm2at 2 h after exposure. Among the three compounds, (-)-sesamin (1) and IOA (5) exerted stronger effects and maintained longer duration of repellency. Furthermore, IOA (5) and isomahubanolide (6) showed good feeding deterrent activity againstT. castaneum. IOA (5) was still potently active at low concentrations with the feeding deterrence index (FDI) ranging from 42.85% to 50.66% at 15–1500 ppm. This work provides some evidence for explaining antiinsect properties of the nonvolatile fraction of theC. camphorastem bark and helps promote the development and comprehensive utilization of this tree species.

In order to develop more environmentally benignant insecticides, the Ligusticum pteridophyllum Franch. rhizomes essential oil and supercritical fluid (SFE-CO

The extract from Cinnamomum cassia Presl bark was obtained with supercritical CO2 fluid extraction (SFE). Chemical components of the SFE extract were characterized by GC-MS spectrometry. The repellency and contact toxicity of the SFE extract were evaluated against the adults of Tribolium castaneum and Lasioderma serricorne along with those of its two main compounds. The results of GC-MS analysis indicated that 33 volatile constituents were identified from the extract. The main components included trans-cinnamaldehyde (32.1%), 3,3-dimethylhexane (10.6%) and 2,4-di-tert-butylphenol (7.9%). Testing results showed that the SFE extract had potent contact toxicity against T. castaneum and L. serricorne with LD50 values of 3.96 and 23.89 μg/adult, respectively. LD50 values of trans-cinnamaldehyde against T. castaneum and L. serricorne were 5.78 and 3.24 μg/adult, respectively. Additionally, percentage repellency values of the SFE extract and trans-cinnamaldehyde against T. castaneum and L. serricorne were rather high (PR = 100% and PR > 90%, respectively) at 78.63 and 15.73 nL/cm2 at 2 h post-exposure. 2,4-Di-tert-butylphenol showed some repellency against both beetle species. Considering its insecticidal and repellent effects, the SFE extract from C. cassia bark might be used in integrated pest management programs for T. castaneum and L. serricorne.

The essential oils (EOs) extracted from Evodia lenticellata Huang and Evodia rutaecarpa (Juss.) Benth. leaves are screened to evaluate their contact toxicity and repellency towards Tribolium castaneum (Coleoptera: Tenebrionidae), Lasioderma serricorne (Coleoptera: Anobiidae) and Liposcelis bostrychophila (Psocoptera: Liposcelididae) adults. The EOs are obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry (GC-MS). The principal components in the E. lenticellata EO are identified to be caryophyllene oxide (28.5%), β-caryophyllene (23.1%), β-elemene (14.5%), and β-cubebene (4.7%), while the main components of the E. rutaecarpa EO are α-pinene (39.4%), β-elemene (13.5%), α-ocimene (7.6%), and α-selinene (4.0%). These two kinds of EOs and their individual compounds all showed different levels of contact toxicity and repellent activity against three stored-product insects.

Essential oils obtained from many plants showed various kinds of insecticidal properties; some of them have been considered as alternative insecticides for pest control. The present study was aimed at determining the chemical composition of the essential oil from the roots of Bupleurum bicaule Helm, as well as evaluating the contact and repellent activities of the oil and four identified compounds against Lasioderma serricorne and Liposcelis bostrychophila adults. The essential oil was extracted by hydrodistillation, and its components were analyzed by gas chromatography-mass spectrometry (GC-MS). 26 components were determined and the main compounds included trans-2-isopropylbicyclo[4.3.0]non-3-en-8-one (25.9%), 4,5-dimethyl-1,2,3,6,7,8,8a,8b-octahydrobiphenylene (23.5%), and 1,4-dimethoxy-2-tert-butylbenzene (4.3%). It was found that the essential oil exhibited contact toxicity against L. serricorne (LD50 = 11.91 μg/adult), but the contact toxicity against L. bostrychophila could not be observed. The essential oil also showed strong repellent activity against L. serricorne with percent repellency of 100% at 78.63 nl/cm2. Four chemical compounds, 1,4-dimethoxy-2-tert-butylbenzene, bornyl acetate, (2E,4E)-2,4-nonadienal, and β-bisabolene, exhibited various levels of bioactivities. The experimental results indicated that the essential oil of B. bicaule and its individual compounds could be used in insecticidal and repellent strategies for stored product insects.

The Amomum villosum essential oil was obtained from hydrodistillation and was investigated by GC-MS. The main constituents were bornyl acetate (51.6%), camphor (19.8%), camphene (8.9%) and limonene (6.2%). Insecticidal toxicity of the essential oil was evaluated in this study. It showed that the essential oil possessed contact toxicity against Tribolium castaneum and Lasioderma serricorne (LD50 = 32.4 and 20.4 μg/adult). Three monoterpenoids camphor, camphene and limonene showed strong fumigant toxicity against T. castaneum (LC50 ＜ 2.3, LC50 ＝ 6.2 and 6.2 mg/L air). In addition, repellency of the essential oil was also evaluated. Data showed that the essential oil and all four compounds had repellent activity against T. castaneum and L. serricorne at high concentration (78.63 nL/cm2). But with the decrease of concentration, they showed a different degree of attractant properties.

Nineteen compounds were isolated from Ajania potaninii, including one sulfur paraffin (1), one monoterpene (6), one lactone (3), one aliphatic acid (15), two sterols (8 and 10), one triterpenes (13), one alkaloid (18), eleven flavonoids (2, 4, 5, 7, 9, 11, 12, 14, 16 and 17) and one cyclic amide (19). All of these compounds were obtained from A. potaninii for the first time. This is the first report of N-nonanemercaptan (1), 3-hydroxy-5-decanolide (3), cirsiliol (5), 1,2,4-trihydroxy-p-mentane (6), 6-methoxytricin (7), eriodictyol (11), pectolinarigenin (12), 3,3′-di-O-methylquercetin (14), tetradecanoic acid (15), lappaconitine (18) and 1,1′,1″,1‴,1‴'-tricontane lactam (19) from the genus Ajania. The occurrence of compounds 18 and 19 in A. potaninii warrants further study.

Five polyacetylenes (1-5) were isolated from Artemisia ordosica, one of the main arido-active shrubs growing in the arid areas in China. Their molecular structures were identified with NMR spectroscopy. The compounds were confirmed as capillene, capillin, capillinol, cis-dehydromatricaria ester and trans-dehydromatricaria ester. It was found that three compounds (1-3) had similiar structural skeleton of 2,4-hexadiyn-1-ylbenzene. The repellent and fumigant activities against Tribolium castaneum adults were investigated for compounds isolated and the essential oil. Bioassays showed that the essential oil extracted from the aerial parts of A. ordosica possessed fumigant toxicity of LC50 = 18.65 mg/L air, and compounds (1-4) had stronger activities from LC50 = 4.06 mg/L air to 6.16 mg/L air against T. castaneum adults. At the tested concentrations (62.91 and 12.58 nL/cm2), the crude essential oil and compounds (1, 2 and 4) showed the same repellent activity (p > 0.05) with DEET against T. castaneum adults at both 2 h and 4 h after exposure. Compound 2 showed strong repellence (PR = 100%) at tested concentrations of 62.91, 12.58 and 2.52 nL/cm2 at 2 h after exposure. Moreover, at tested concentration (62.91, 12.58, 2.52 and 0.5 nL/cm2), the PR value of compound 4 was all higher than 90% at both 2 h and 4 h after exposure. The results showed that the crude essential oil and the isolated polyacetylenes possessed fair repellent and fumigant activities. Furthermore, potential relationships between structure and bioactivity were also discussed. It might be found that the existence of acetylenic bonds was the principal factor of fumigant activity, and with the increase of acetylenic bonds, the fumigant activity would enhance. In addition, it was believed that oxygenous groups connected to the acetylenic bonds might contribute to fumigant toxicity against T. castaneum adults.

Murraya alata Drake is a shrub that is distributed in the underwood of sandy areas near sea level in China and Vietnam. Twenty-two compounds were isolated from the leaves and stems of M. alata, including six new coumarins (6, 8–10, 17, 19) named muralatins L–Q. The structures were identified on the base of NMR and MS spectral analysis. Furthermore, the repellent activity against Tribolium castaneum was tested for fourteen isolated compounds. A statistic model-grey relational analysis was introduced to evaluate repellent activity directly based on relative correlation degree. This statistical analysis was suitable for complex problems of multiple indexes. The testing compounds exhibited various repellent activities against T. castaneum. Among them, compounds 1 (meranzin), 2 (phebalosin) and 16 (muralatin K) showed significant repellent activity against T. castaneum with ri values of 0.7047, 0.6990 and 0.6884, respectively, comparable to that of the positive control, N, N-diethyl-3-methylbenzamide (DEET, ri = 0.7013). The optimal compounds might be considered as potential leading compounds for the development of natural repellents.

The contact toxicity and repellent activities of the essential oil extracted from the rhizomes of Zingiber zerumbet (L.) Smith (Zingiberaceae) was evaluated against cigarette beetles (Lasioderma serricorne). The essential oil obtained by hydrodistillation was investigated by GC-FID and GC-MS. The main constituents of the essential oil were zerumbone (40.2%), α-caryophyllene (8.6%), humulene epoxide II (7.3%), camphene (5.9%) and fenchene (4.7%). Zerumbone and its analogues totally are accounting for 60.3% of the essential oil. It was found that the essential oil possessed contact toxicity against L. serricorne adults with a LD50 value of 48.3 µg/adult. α-Caryophyllene (LD50 = 13.1 µg/adult) exhibited stronger contact toxicity against L. serricorne than humulene oxide (LD50 = 31.2 µg/adult), β-caryophyllene (LD50 = 35.5 µg/adult) and zerumbone (LD50 = 42.4 µg/adult). Moreover, α-caryophyllene possessed strong repellent activity (Class IV and V, respectively) against the beetles at 78.63 nL/cm2, after 2 and 4 h treatment. The results indicate that zerumbone and its analogues might be developed into natural insecticides or repellents for control of cigarette beetles, but their bioactivities are affected by their structures.

The objective of this study was to analyze six essential oils fromZanthoxylumgenus (family Rutaceae) in China and evaluate their repellent activities againstTribolium castaneumandLasioderma serricorneadults. Six essential oils fromZanthoxylumgenus, includingZ. armatum,Z. dimorphophyllum,Z. dimorphophyllumvar.spinifolium,Z. piasezkii,Z. stenophyllum,andZ. dissitum,were obtained by hydrodistillation and their yields were ranging from 0.02% to 0.53%. Totally, there were 39 chemical components revealed by GC-MS. Among them, some components with high relative content existed in more than threeZanthoxylumspecies. For instance, bothδ-cadinene (1.21%–17.15%) and spathulenol (0.36%–10.19%) appeared in essential oils ofZ. dimorphophyllum,Z. piasezkii,Z. stenophyllum,andZ. dissitumwhich were found to have higher content of sesquiterpenoids. The repellent activities of six essential oil samples againstT. castaneumandL. serricorneadults were investigated for the first time. Data demonstrated that sixZanthoxylumspecies had much stronger repellent activities againstT. castaneumthanL. serricorneadults, especially in 2 hours after exposure. The results indicate that these six essential oils fromZanthoxylumhave significant potential to be developed into natural repellents to control insects in grains, food, and traditional Chinese medicinal materials.

The chemical constituents of the essential oil extracted from Artemisia anethoides and the bioactivities of essential oil against Tribolium castaneum and Lasioderma serricorne were investigated. The main components of the essential oil were 1,8-cineole (36.54%), 2-isopropyl-5-methyl-3-cyclohexen-1-one (10.40%), terpinen-4-ol (8.58%), 2-isopropyltoluene (6.20) and pinocarveol (5.08%). The essential oil of A. anethoides possessed contact and fumigant toxicities against T. castaneum adults (LD50 = 28.80 μg/adult and LC50 = 13.05 mg/L air, respectively) and against L. serricorne (LD50 = 24.03 μg/adult and LD50 = 8.04 mg/L air, respectively). The crude oil showed repellent activity against T. castaneum and L. serricorne. Especially, the percentage repellency of essential oil was same level with DEET (positive control) against T. castaneum. The results indicated that the essential oil of A. anethoides had the potential to be developed as insecticide and repellent for control of T. castaneum and L. serricorne.

In this work, the essential oil (EO) and supercritical CO2 fluid extract (SF extract) of four Valerianaceae plants (Valeriana officinalis L., Valeriana officinalis L. var. latifolia Miq., Valeriana jatamansi Jones and Nardostachys chinensis Bat.) were chemically characterized. GC-MS analysis identified 74 compounds, representing 35.2%–82.4% of the total EOs and SF extracts. The EO was dominated by low-molecular-weight components while the SF extract was rich in fatty acids. Bornyl acetate and camphene were the characteristic compounds in EO and SF extracts. The efficacy of six extracts against three stored-product insects was investigated. In contact assays, V. officinalis exhibited strongest toxicity to red flour beetle (LD50 = 10.0 μg/adult), and V. jatamansi EO was the most active one against the cigarette beetle (LD50 = 17.6 μg/adult), while V. officinalis var. latifolia EO showed outstanding efficacy against the booklouse (LD50 = 40.2 μg/cm2). Binary mixtures of two major compounds (camphene and bornyl acetate) were assessed for the contact toxicity to the red flour beetle. Additive effect existed in the natural proportion of V. officinalis, and synergism was observed in that of V. officinalis var. latifolia. This work confirmed the insecticidal efficacy of the species of the Valerianaceae family, and it would offer some information for the development of botanical insecticide.

The essential oil extracted from roots and rhizomes of Ligusticum jeholense Nakai et Kitagawa was investigated for its chemical composition by GC-MS analysis, and evaluated for its contact toxicity and repellency against Tribolium castaneum and Lasioderma serricorne, along with some of its individual components. The essential oil was rich in aromatics (65.34%) with low molecular weight. Major components included sedanolide (33.95%), 3-butylidenephthalide (18.76%), spathulenol (8.90%) and myristicin (6.76%). The results of bioassays indicated that the essential oil of L. jeholense and 3-butylidenephthalide possessed significant repellent activities against T. castaneum at 2 and 4 h post-exposure. Meanwhile, 3-butylidenephthalide had potent contact toxicity against L. serricorne (LD

The essential oil was extracted from the roots of Valeriana officinalis L. by hydrodistillation. The qualitative and quantitative analysis of its chemical constituents was conducted on GC-MS and GC-FID in this study. Seventeen compounds were detected and the major constituents included bornyl acetate (48.2%) and camphene (13.8%). The toxic and repellent effects of the essential oil and its two major constituents were evaluated on Liposcelis bostrychophila and Tribolium castaneum. The results of bioassays indicated that the essential oil showed the promising fumigant and contact toxicity against L. bostrychophila (LC

As a medicinal plant, Artemisia annua is widely distributed in China. The purpose of this work was to analyze the chemical composition of essential oil from A. annua aerial portions, as well as to assess its repellent activity against Lasioderma serricorne and Tribolium castaneum adults. GC-FID and GC-MS analyses enabled the identification of 15 components representing 90.1% of the essential oil. The main components included artemisia ketone (70.6%), α-caryophyllene (5.1%) and germacrene D (3.8%). The essential oil was found to possess considerable ability to repel the two storage pests. This paper provided some evidence for the exploitation and utilization of A. annua resources as a natural repellent.

In this work, the essential oils (EOs) of Alpinia zerumbet (Pers.) Burtt. et Smith were extracted from different organs (stems, leaves, flowers and fruits). The GC-MS analysis showed that two isomers m-cymene and o-cymene distributed totally diverse among different organs: m-cymene were relatively rich in the EOs from stems, flowers and fruits (7.1, 11.3 and 6.6%, respectively), but absent in the EO from leaves; o-cymene was predominant in the EO from leaves (14.9%), but missing in the EOs from other organs. A. zerumbet EOs from different organs, as well as seven characteristic compounds (m-cymene, o-cymene, camphene, eucalyptol, linalool, camphor, and borneol) showed varying degrees of insecticidal and repellent activities to Tribolium castaneum and Liposcelis bostrychophila. o-Cymene exhibited stronger fumigant and contact toxicity than m-cymene did to both insect species, suggesting that the relative position of methyl and isopropyl on benzene ring would influence the insecticidal activity. Positive correlation between relative content of camphor and LC50 value to T. castaneum was significant, while fumigant and contact toxicity of EOs appeared to be negatively correlated with the content of m-cymene.

A screening of Chinese medicinal herbs and wild plants for agrochemicals was carried out; the essential oil of Glycosmis lucida leaves was found to possess significant repellent activity against Tribolium castaneum and Liposcelis bostrychophila. It was found that the main components included elixene (19.81%), spathulenol (10.68%), anethole (12.05%), verbenone (10.32%) followed by β-caryophyllene (6.87%). The essential oil, anethole and verbenone were strongly repellent against T. castaneum (96, 86 and 94%, respectively, at 15.73 nL cm−2) and L. bostrychophila (100, 68 and 72%, respectively, at 31.58 nL cm−2) after a 2h treatment. The results indicate that anethole and verbenone had the potential to be developed as natural repellents for control of stored product insects.

The insecticidal activity and chemical constituents of the essential oil from Ajania fruticulosa were investigated. Twelve constituents representing 91.0% of the essential oil were identified, and the main constituents were 1,8-cineole (41.40%), (+)-camphor (32.10%), and myrtenol (8.15%). The essential oil exhibited contact toxicity against Tribolium castaneum and Liposcelis bostrychophila adults with LD50 values of 105.67 μg/adult and 89.85 μg/cm(2) , respectively. The essential oil also showed fumigant toxicity against two species of insect with LC50 values of 11.52 and 0.65 mg/l, respectively. 1,8-Cineole exhibited excellent fumigant toxicity (LC50 = 5.47 mg/l) against T. castaneum. (+)-Camphor showed obvious fumigant toxicity (LC50 = 0.43 mg/l) against L. bostrychophila. Myrtenol showed contact toxicity (LD50 = 29.40 μg/cm(2) ) and fumigant toxicity (LC50 = 0.50 mg/l) against L. bostrychophila. 1,8-Cineole and (+)-camphor showed strong insecticidal activity to some important insects, and they are main constituents of A. fruticulosa essential oil. The two compounds may be related to insecticidal activity of A. fruticulosa essential oil against T. castaneum and L. bostrychophila.

Two essential oil samples were obtained from the pericarp of Zanthoxylum bungeanum with the methods of hydrodistillation (HD) and supercritical fluid CO2 extraction (SFE), their chemical components were identified, and their bioactivities against Lasioderma serricorne adults were evaluated. In the process of testing, the two samples showed significant bioactivities against Lasioderma serricorne adults. For an example, the SFE-sample expressed relatively stronger fumigant toxicity on Lasioderma serricorne adults (LC50 = 3.99 μg/mL air) than that of the HD-sample (LC50 = 12.54 μg/mL air). According to GC-MS analysis, the chemical components between two samples were different. The major chemical components for HD included linalool (25.99%), limonene (19.34%), linalyl anthranilate (12.22%), 4-terpinenol (10.49%), eucalyptol (6.53%) and α-terpineol (5.02%), while for SFE included nonanoic acid (21.43%), γ-terpinene (14.51%), eucalyptol (13.45%), α-terpineol (5.83%) and caryophyllene oxide (5.48%). The results showed that different chemical components result in different bioactivities. This work provides theoretical basis for traditional Chinese concept of antagonistic storage, and it also provides important information for the development and comprehensive utilization of Zanthoxylum bungeanum.

In this work, we investigated the chemical constituents of the essential oil extracted from the leaves of Rhododendron thymifolium and their insecticidal and repellent activities against Liposcelis bostrychophila and Tribolium castaneum. 14 chemical components were identified from the essential oil and included germacrone (20.83%), γ-elemene (11.10%), selina-3,7(11)-diene (6.18%), α-oxobisabolene (5.39%), β-sesquiphellandrene (2.44%), β-elemenone (35.17%), Z,Z,Z-1,5,9,9-tetramethyl-1,4,7,-cycloundecatriene (3.64%) and 1-(4-ethylphenyl)-3-methyl-pyrazol-(4H)-one (2.91%). Among them, the first five components were isolated and identified. The results showed that the essential oil and five pure compounds possessed the obvious repellent activity and various levels of contact activities against the two species of stored insects. The essential oil possessed the contact toxicity (LD50 = 19.63 μg/cm2) which was quite close to the toxicity of positive control pyrethrins (LD50 = 18.72 μg/cm2) against L. bostrychophila. The five pure compounds might individually or together effect the contact toxicity of the essential oil against L. bostrychophila. The essential oil possessed the contact toxicity (LD50 = 29.82 μg/adult) against T. castaneum, but only germacrone revealed strong contact toxicity (LD50 = 0.97 μg/adult), which was comparable with the toxicity of pyrethrins (LD50 = 0.24 μg/adult) among five compounds against T. castaneum. The existence of germacrone might be one of the key elements which affected the contact toxicity of R. thymifolium essential oil against T. castaneum. The insecticidal and repellent activities of essential oil and five compounds were evaluated, the results provide a basis of the development and utilization in the future for control of insects.

The essential oil obtained by hydrodistillation from Alpinia kwangsiensis rhizomes was investigated by GC-MS. A total of 31 components representing 92.45% of the oil were identified and the main compounds in the oil were found to be camphor (17.59%), eucalyptol (15.16%), β-pinene (11.15%) and α-pinene (10.50%). These four compounds were subsequently isolated and the essential oil and four isolated compounds exhibited potent insecticidal activity against Lasioderma serricorne adults. During the assay, it was shown that the essential oil exhibited both potential contact (LD50 = of 24.59 μg/adult) and fumigant (LC50 = of 9.91 mg/L air) toxicity against Lasioderma serricorne. The study revealed that the insecticidal activity of the essential oil can be attributed to the synergistic effects of its diverse major components, which indicates that oil of Alpinia kwangsiensis and its isolated compounds have potential to be developed into natural insecticides to control insects in stored grains and traditional Chinese medicinal materials.

Murraya genus (family Rutaceae) has been widely used as local traditional medicines in East Asia. The chemical composition of essential oils extracted from six Murraya species and their repellent activity against Tribolium castaneum was investigated. From the samples of Murraya tetramera , Murraya euchrestifolia , Murraya koenigii , Murraya kwangsiensis , Murraya exotica , and Murraya alata , essential oils were obtained by hydrodistillation and their yields were various from 0.03 to 0.23%. All together 36 components were identified by GC–MS from the essential oils samples. The constituents with relatively higher contents included α-cedrene (4.22–21.82%), β-caryophyllene (8.15–27.73%), γ-elemene (4.38–12.65%), γ-selinene (3.80–21.09%), α-selinene (2.60–10.68%), α-zingiberene (2.08–12.68%), spathulenol (3.08–11.80%), caryophyllene oxide (1.58–10.59%), β-eudesmol (1.33–25.32%), etc. Moreover, eight compounds, which were recognized as significant components in the essential oils of M. tetramera , and M. kwangsiensis , were isolated and they were identified as α-terpinene, β-caryophyllene, α-caryophyllene, alloaromadendrene, spathulenol, β-eudesmol, camphene and caryophyllene oxide. The repellent activity against T. castaneum was tested for all the six samples of essential oils and eight isolated compounds. The testing samples exhibited a variety of repellent activity against T. castaneum . Among them, the essential oils of two species ( M. tetramera and M. kwangsiensis ) and three isolated compounds (alloaromadendrene, spathulenol and caryophyllene oxide) showed the fair repellent activity with relatively higher yields of contents. They might be considered as potential materials for the development of natural repellents for control of insects in stored products. Meanwhile, cluster analysis was performed using the collectives of data which were obtained in the process of the experiments. It was found that the characteristics of the repellent activity against T. castaneum could be related to the chemical composition of the essential oils. There were some interesting senses brought out as well. Such as, the repellent activity of the essential oils would not be depend on the contents of individual bioactive compound, and the existence of some compounds might affect the repellent activity of the essential oils.

Antifeedant activities of the methanol extracts from Zanthoxylum bungeanum , Zanthoxylum schinifolium , Zanthoxylum armatum and Zanthoxylum dissitum were assessed on Tribolium castaneum adults. It was found that the methanol extract of stem bark of Z. schinifolium had the highest antifeedant activity at 41.12% (antifeedant index). Based on bioactivity-guided fractionation, six benzophenanthridines norchelerythrine ( 1 ), decarine ( 2 ), 8-hydroxy-9-methoxy-2,3-(methylenedioxy) benzophenanthridine ( 3 ), 6-hydroxydihydrochelerythrine ( 4 ), 6-methoxy-7-hydroxydihydrochelerythrine ( 5 ) and oxychelerythrine ( 6 ) were isolated from the stem barks of Z. schinifolium . And their antifeeding activities were also evaluated against T. castaneum . All of them exhibited strong antifeeding activity in a concentration-dependant manner with EC 50 of 62.67, 66.97, 151.39, 96.72, 141.61 and 192.32 ppm, respectively. The six bioactive compounds from the stem bark of Z. schinifolium might be used as antifeedants against T. castaneum .

Five new sulphur-containing amides (2, 5–8) and three known analogue compounds (1, 3–4) were isolated from the leaves of Glycosmis lucida which were collected in Yunnan province, China. Their structures were elucidated with NMR spectroscopy and mass spectrometry. The compounds were identified as N-(p-hydroxyphenethyl)-3-(methylsulfonyl)-propenamide (1), N-[2-(4- hydroxyphenyl)-ethyl]-3-methanesulfonyl-N-methyl-propionamide (2), methylgerambullin (3), methylisogerambullone (4), methylgerambullindiol (5), N-{2-[4-(6,7-hydroxy-3,7-dimethyl-oct- 2-enyloxy)-phenyl]-ethyl}-3-methanesulfonyl-N-methyl-acrylamide (6), N-{2-[4-(6,7-dihydroxy- 3,7-dimethyl-oct-2-enyloxy)-phenyl]-ethyl}-3-methanesulfonyl-N-methyl-propionamide (7), (E)-N-{2-[4-(6-hydroxy-7-dimethyl-oct-2-enyloxy)-phenyl]-ethyl}-3-methanesulfinyl-N-methyl- acrylamide (8). Feeding deterrent activities of these surphur-containing derivatives against Tribolium castaneum were assayed for the first time. Compound 2, 3, 6 possessed significant feeding deterrent activities against T. castaneum adults (EC50 = 311.6, 244.9 and 108.3 ppm, respectively). These results demonstrated that some sulphur-containing amides are promising candidates as insect antifeedant agents.

Zanthoxylum species and volatile oils have shown to have insect resistance. The present work was conducted to find alternative botanical source with significant activity on storage pests control. Chemical examination of Zanthoxylum dimorphophyllum Hemsl. var. spinifolium Rehder et E. H. Wilson stem bark has led to fifteen coumarins, which including two were novel compounds named 6-(2′,3′-dihydroxy-3′-methylbutyl)-7-hydroxyl-8-(3″-methyl-2″-butenyl)-2H-1-benzopyran-2-one (7) and 6-(2′-hydroxyl-3′-methyl-3′-butenyl)-7-methoxyl-8-(3″-methyl-2″-butenyl)-2H-1-benzopyran-2-one (8). All the chemical structures were elucidated on the basis of nuclear magnetic resonance spectroscopy and high resolution electrospray ionization mass spectrometry analysis. Additionally, dose-dependent feeding deterrent activities of fifteen coumarins against Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) were evaluated scientifically. Among them, compound 12 (phellopterin) exhibited stronger feeding deterrent activity (EC50 = 64.00 ppm) than the positive control, toosendanin. While, compound 11 (imperatorin) displayed the same level of feeding deterrent activity as the positive control with median effect concentration of 73.10 ppm. The relationship between chemical structure and effectiveness showed that compounds with epoxy structure or isopentenyl group exhibited higher feeding deterrent activities and might have potential to be developed into novel feeding deterrent reagents or potential lead compounds on storage insect prevention and control.

Spices are popular commodities with highly edible and medicinal values. At ancient times, people took advantage of spices to prevent insect infestation and mold erosion in stored-products. The Lauraceae family offers abundant raw materials as spices and plants from this family have widely biological activities. Here, the essential oils (EOs) of four spice plants from the Lauraceae, namely Cinnamomum burmannii, Cinnamomum migao, Litsea pungens and Laurus nobilis were analyzed for their chemical composition by GC–MS. The EOs and some of their individual components mainly monoterpenoids were evaluated for their bioactivities against stored-product insects. Three modes of action were selected: fumigant, contact toxicity and repellent activity. Target insects were adults of Tribolium castaneum and Liposcelis bostrychophila. Results of GC–MS analysis denoted that the chemical composition of EOs from these spice plants had certain similarity and diversity. All the EOs were rich in monoterpenoids, and the major components were limonene, sabinene, linalool, eucalyptol, borneol, α-terpineol, 4-terpinenol, α-terpinyl acetate, β-caryophyllene, spathulenol and 1,2,3,4-tetramethylbenzene. The results of bioassays indicated that all the EOs were toxic and repellent to T. castaneum and L. bostrychophila. Common monoterpenoids limonene, sabinene, linalool, eucalyptol, borneol, α-terpineol, 4-terpinenol and α-terpinyl acetate showed different levels of insecticidal or repellent activities against the two insect species. Among these monoterpenoids, borneol had no fumigant toxicity, but possessed contact toxicity and beneficial repellency at the concentration range of 63.17-2.53 nL/cm2 against L. bostrychophila. Sabinene and α-terpineol were significantly repellent to T. castaneum within the testing concentration range of 78.63-3.15 nL/cm2. Furthermore, β-caryophyllene (sesquiterpenoids) and 1,2,3,4-tetramethylbenzene (aromatics) were also assessed. β-caryophyllene exhibited contact toxicity and repellency against T. castaneum and L. bostrychophila. 1,2,3,4-tetramethylbenzene was toxic to these target insects in fumigant and contact assays. This work provides some evidence for explaining insecticidal and repellent activities of several spices from the Lauraceae based on individual active substances. It suggests that these spice EOs have promising potential to serve as bio-insecticides and green repellents for controlling pest damage in warehouses and grain stores.

The essential oils (EOs) extracted from Evodia lenticellata Huang and Evodia rutaecarpa (Juss.) Benth. leaves are screened to evaluate their contact toxicity and repellency towards Tribolium castaneum (Coleoptera: Tenebrionidae), Lasioderma serricorne (Coleoptera: Anobiidae) and Liposcelis bostrychophila (Psocoptera: Liposcelididae) adults. The EOs are obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry (GC-MS). The principal components in the E. lenticellata EO are identified to be caryophyllene oxide (28.5%), β-caryophyllene (23.1%), β-elemene (14.5%), and β-cubebene (4.7%), while the main components of the E. rutaecarpa EO are α-pinene (39.4%), β-elemene (13.5%), α-ocimene (7.6%), and α-selinene (4.0%). These two kinds of EOs and their individual compounds all showed different levels of contact toxicity and repellent activity against three stored-product insects.

The speciation of a methanolic extract of Zanthoxylum armatum stem bark has enabled the isolation and characterization of 11 known lignans. Among them, five compounds (6, 8–11) are reported in this plant for the first time. All of the chemical structures were elucidated on the basis of NMR spectral analysis. Additionally, their antifeedant activities against Tribolium castaneum were evaluated scientifically. Among them, asarinin (1), with an EC50 of 25.64 ppm, exhibited a much stronger antifeedant activity than the positive control, toosendanin (EC50 = 71.69 ppm). Moreover, fargesin (2), horsfieldin (3), and magnolone (10), with EC50 values of 63.24, 68.39, and 78.37 ppm, showed almost the same antifeedant activity as the positive control. From the perspective of structure-effectiveness relationship, compounds with the chemical group of methylenedioxy exhibited higher antifeedant activities and have potential to be developed into novel antifeedants or potential lead compounds to protect food and crops in storage.

To develop natural product resources to control cigarette beetles (Lasioderma serricorne), the essential oil from Artemisia lavandulaefolia (Compositae) was investigated. Oil was extracted by hydrodistillation of the above-ground portion of A. lavandulaefolia and analyzed using gas chromatography-mass spectrometer (GC-MS). Extracted essential oil and three compounds isolated from the oil were then evaluated in laboratory assays to determine the fumigant, contact, and repellent efficacy against the stored-products' pest, L. serricorne. The bioactive constituents from the oil extracts were identified as chamazulene (40.4%), 1,8-cineole (16.0%), and β-caryophyllene (11.5%). In the insecticidal activity assay, the adults of L. serricorne were susceptible to fumigant action of the essential oil and 1,8-cineole, with LC50 values of 31.81 and 5.18 mg/L air. The essential oil, 1,8-cineole, chamazulene, and β-caryophyllene exhibited contact toxicity with LD50 values of 13.51, 15.58, 15.18 and 35.52 μg/adult, respectively. During the repellency test, the essential oil and chamazulene had repellency approximating the positive control. The results indicated that chamazulene was abundant in A. lavandulaefolia essential oil and was toxic to cigarette beetles.

A nuclear magnetic resonance- (NMR-) based metabolomics method was used to identify differential metabolites of methanol extracts obtained from six parts of Peganum harmala L. (P. harmala), namely, the root, stem, leaf, flower, testa, and seed. Two multivariate statistical analysis methods, principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA), were combined to clearly distinguish among the P. harmala samples from the six different parts. Eleven differential components were screened by the PLS-DA loading plot, and the relative contents were calculated by univariate analysis of variance. Chemometric results showed significant differences in the metabolites of the different parts of P. harmala. The seeds contained large amounts of harmaline, harmine, and vasicine compared to other organs. The acetic acid, proline, lysine, and sucrose contents of the roots were significantly higher than those of the other parts. In the testa, the vasicine, asparagine, choline, and 4-hydroxyisoleucine contents were clearly dominant. The obtained data revealed the distribution characteristics of the metabolomes of the different P. harmala parts and provided fundamental knowledge for the rational development of its medicinal parts.

To develop natural product resources from the Clausena genus (Rutaceae), the essential oils (EOs) from four Clausena plants (Clausena excavata, C. lansium, C. emarginata, and C. dunniana) were analyzed by GC-MS. Their lethal (contact toxicity) and sublethal effects (repellency) against Liposcelis bostrychophila (LB) adults were also evaluated. Santalene sesquiterpene was the precursor substance of santalol, a valuable perfumery. It was found that plenty of α-santalol (31.7%) and α-santalane (19.5%) contained in C. lansium from Guangxi Province and α-santalene (1.5%) existed in C. emarginata. Contact toxicity of the four EOs was observed, especially C. dunniana (LD50 = 37.26 µg/cm2). Santalol (LD50 = 30.26 µg/cm2) and estragole (LD50 = 30.22 µg/cm2) were the two most toxic compounds. In repellency assays, C. excavate, C. lansium, and C. emarginata exhibited repellent effect at the dose of 63.17 nL/cm2 2 h after exposure (percentage repellencies were 100%, 98%, and 96%, respectively). Four Clausena EOs and santalol had an excellent potential for application in the management of LB. Clausena plants could be further developed to find more resources of natural products.

In this work, the essential oil (EO) was extracted from the fruits of Evodia lenticellata, and the fumigant toxicity, contact toxicity and repellency against three stored-product insect species were evaluated for the obtained EO and several of its chemical components. The target insects were the adults of Tribolium castaneum (Coleoptera: Tenebrionidae), Lasioderma serricorne (Coleoptera: Anobiidae) and Liposcelis bostrychophila (Psocoptera: Liposcelididae). The EO was obtained with hydrodistillation and its chemical components were analyzed with the gas chromatography-mass spectrometry (GC-MS). Twenty-seven compounds, accounting for 83.1% of the total amount of the oil, were identified from the EO sample. The main compounds included linalool (12.0%), β-pinene (11.5%), 3-carene (9.6%), caryophyllene oxide (8.7%) and β-caryophyllene (7.9%). Among them, the amounts of monoterpenes and sesquiterpenes were as high as 52.7% and 22.7% to the total amount of EO respectively. The results of bioactivity test showed that the EO and its testing compounds had interspecific toxicity and repellent activity. So that, it might be expected that the EO extracted from the fruits of E. lenticellata could be developed to a new type of eco-friendly natural insecticide or repellent for the control of stored-product insects.

The chemical composition of the essential oil obtained by hydrodistillation from the aerial parts of Mentha haplocalyx was investigated by GC-FID and GC/MS analyses. In sum, 23 components, representing 92.88% of the total oil composition, were identified, and the main compounds were found to be menthol (59.71%), menthyl acetate (7.83%), limonene (6.98%), and menthone (4.44%). By bioassay-guided fractionation (contact toxicity), three compounds were obtained from the essential oil and identified as menthol, menthyl acetate, and limonene. The essential oil and the three isolated compounds exhibited potent contact toxicity against Lasioderma serricorne adults, with LD50 values of 16.5, 7.91, 5.96, and 13.7 μg/adult, respectively. Moreover, the oil and its isolated compounds also exhibited strong repellency against L. serricorne adults. At the lower concentrations tested and at 2 h after exposure, menthol showed even significantly stronger repellency than the positive control DEET. The study revealed that the bioactivity properties of the essential oil can be attributed to the synergistic effects of its diverse major and minor components, which indicates that the M. haplocalyx oil and its isolated compounds have potential for the development as natural insecticides and/or repellents to control insects in stored grains and traditional Chinese medicinal materials.

During a screening program for new agrochemicals from Chinese medicinal herbs and local wild plants, the petroleum ether (PE) extract of Atractylodes lancea (Thunb.) rhizomes was found to possess repellent and contact activities against Tribolium castaneum adults. Bioactivity-directed chromatographic separation of PE extract on repeated silica-gel columns led to the isolation of two polyacetylenes, atractylodin and atractylodinol (1 and 2, resp.), and two lactones, atractylenolides II and III (3 and 4, resp.). The structures of the compounds were elucidated based on NMR spectra. The four isolated compounds were evaluated for their insecticidal and repellent activities against T. castaneum. Atractylodin exhibited strong contact activity against T. castaneum adults with a LD50 value of 1.83 μg/adult. Atractylodin and atractylenolide II also possessed strong repellenct activities against T. castaneum adults. After 4-h exposure,90% repellency was achieved with atractylodin at a low concentration of 0.63 μg/cm(2) . The results indicated that atractylodin (1) and atractylenolide II (3) have a good potential as a source for natural repellents, and 1 has the potential to be developed as natural insecticide.

The insecticidal and repellent activities of the essential oil extracted from Zingiber purpureum Roscoe rhizomes were evaluated against Tribolium castaneum (Herbst) and Lasioderma serricorne (L.) adults. During our screening program for agrochemicals from Chinese medicinal herbs and wild plants, the essential oil of Z. purpureum rhizomes was found to possess strong contact toxicity against T. castaneum and L. serricorne adults, with LD50 values of 39.0 and 16.3 µg per adult, respectively, and also showed strong fumigant toxicity against the two grain storage insects with LC50 values of 13.6 and 9.3 mg/liter of air, respectively. The essential oil obtained by hydrodistillation was investigated by gas chromatography-mass spectrometry. The main components of the essential oil were identified to be sabinene (48.1%), terpinen-4-ol (25.1%), and γ-terpinene (6.7%), followed by α-terpinene (4.3%), β-thujene (3.4%), and α-phellandrene (2.7%). Sabinene, terpinen-4-ol, and γ-terpinene were separated and purified by silica gel column chromatography and preparative thin-layer chromatography. Terpinen-4-ol showed the strongest contact toxicity against T. castaneum and L. serricorne (LD50=19.7 and 5.4 µg per adult, respectively) and also the strongest fumigant toxicity against T. castaneum and L. serricorne (LC50=3.7 and 1.3 mg/liter of air, respectively). Otherwise, sabinene and terpinen-4-ol were strongly repellent against T. castaneum as well as the essential oil, while γ-terpinene exhibited weaker repellency against T. castaneum compared with the positive control, DEET (N, N-diethyl-3-methylbenzamide). Moreover, only the essential oil exhibited strong repellency against L. serricorne, the three compounds exhibited weaker repellency against L. serricorne relative to DEET.

This work aimed to investigate benzophenanthridine from the roots of Zanthoxylum nitidum (Roxb.) DC. var. fastuosum How ex Huang for the first time. Thirteen benzophenanthridines were isolated, and our results of the cytotoxic activities indicated that compound 6 exhibited the best potency against A549, Hela, SMMC-7721 and EJ, with the IC50 values of 27.50, 37.50, 16.95 and 60.42 μM, respectively. Compounds 7 and 11 also showed strong cytotoxicity when tested against the four human cancer cell lines (A549, Hela, SMMC-7721 and EJ), while only compounds 12 and 13 displayed cytotoxicity in inhibiting BALL-1 proliferation among all the compounds. These results suggested that benzophenanthridines may become a valid alternative of potential basis for new anti-proliferative agents.

In order to find and develop new botanical pesticides against tobacco storage pests, bioactivity screening was performed. The essential oil obtained from the aerial parts of Liriope muscari was investigated by GC/MS and GC/FID. A total of 14 components representing 96.12% of the oil were identified and the main compounds in the oil were found to be methyl eugenol (42.15%) and safrole (17.15%), followed by myristicin (14.18%) and 3,5-dimethoxytoluene (10.60%). After screening, the essential oil exhibit potential insecticidal activity. In the progress of assay, it showed that the essential oil exhibited potent contact toxicity against Tribolium castaneum, Lasioderma serricorne and Liposcelis bostrychophila adults, with LD50 values of 13.36, 11.28 µg/adult and 21.37 µg/cm2, respectively. The essential oil also exhibited strong repellency against the three stored product insects. At the same concentrations, the essential oil was more repellent to T. castaneum than to L. serricorne adults. The results indicate that the essential oil of Liriope muscari has potential to be developed into a natural insecticide or repellent for controlling insects in stored tobacco and traditional Chinese medicinal materials.

The toxic and repellent activities of the essential oil extracted from the leaves of Atalantia guillauminii Swingle were evaluated against three stored product insects, red flour beetles (Tribolium castaneum), cigarette beetles (Lasioderma serricorne) and booklice (Liposcelis bostrychophila). The essential oil obtained by hydrodistillation was investigated by GC-MS. The main constituents of the essential oil were β-thujene (27.18%), elemicin (15.03%), eudesma-3, 7(11)-diene (9.64%), followed by (-)-4-terpeniol (6.70%) and spathulenol (5.25%). The crude oil showed remarkable contact toxicity against T. castaneum, L. serricorne adults and L. bostrychophila with LD50 values of 17.11, 24.07 µg/adult and 55.83 µg/cm(2) respectively and it also displayed strong fumigant toxicity against T. castaneum, L. serricorne adults with LC50 values of 17.60 and 12.06 mg/L respectively, while weak fumigant toxicity against L. bostrychophila with a LC50 value of 16.75 mg/L. Moreover, the essential oil also exhibited the same level repellency against the three stored product insects, relative to the positive control, DEET. At the same concentrations, the essential oil was more repellent to T. castaneum than to L. serricorne. Thus, the essential oil of A. guillauminii may be potential to be developed as a new natural fumigant/repellent in the control of stored product insects.

In the course of our search for natural bioactive chemicals and investigations on their insecticidal activities from some medicinal plants growing in China, the essential oil derived from the twigs of Zanthoxylum armatum (Rutaceae) was found to possess strong insecticidal activities against two stored-product insects, Lasioderma serricorne and Tribolium castaneum. A total of 32 constituents of the essential oil were identified by GC and GC-MS analysis, and it revealed (E)-anethole (20.5%), 1,8-cineole (14.0%), 2-tridecanone (12.5%), limonene (9.0%) and piperitone (8.0%) as major components, followed by β-phellandrene (6.3%), β-pinene (5.1%) and 4-terpineol (4.4%). From the essential oil, five compounds were isolated and identified as (E)-anethole, 1,8-cineole, 2-tridecanone, limonene and piperitone. The results of insecticidal bioassays showed that the essential oil of Z. armatum exhibited strong fumigant toxicity towards L. serricorne and T. castaneum with LC50 values of 13.83 and 4.28 mg/L air, respectively, and also possessed contact toxicity against two insect species with LD50 values of 18.74 and 32.16 μg/adult, respectively. Among the active compounds, piperitone performed the strongest fumigant toxicity against L. serricorne (LC50 = 1.21 mg/L air) and contact toxicity against T. castaneum (LD50 = 3.16 μg/adult). 1,8-Cineole, limonene and piperitone showed similar fumigant toxicity against T. castaneum with LC50 values of 5.47, 6.21 and 7.12 mg/L air, respectively. Meanwhile, L. serricorne was the most sensitive to 2-tridecanone (LD50 = 5.74 μg/adult) in the progress of contact toxicity assay.

The aim of this research was to determine the chemical constituents and toxicities of essential oil derived from Alpinia blepharocalyx rhizomes against the cigarette beetle, Lasioderma serricorne (Fabricius). Essential oil of A. blepharocalyx rhizomes was obtained from hydrodistillation and was investigated by Gas Chromatography-Mass Spectrometry (GC-MS). A total of 46 components of the essential oil of A. blepharocalyx rhizomes were identified. The principal compounds in A. blepharocalyx essential oil were camphor (23.13%), sabinene (11.27%), ?-pinene (9.81%) and eucalyptol (8.86%) followed by camphene (8.05%), sylvestrene (5.61%) and ?-phellandrene (5.00%). Among them, the four active constituents, predicted with a bioactivity-test, were isolated and identified as camphor, sabinene, ?-pinene and eucalyptol. The essential oil of A. blepharocalyx possessed strong contact toxicity against the cigarette beetle with LD50 value of 15.02 ?g adult-1, and also exhibited strong fumigant toxicity against L. serricorne adults with LC50 value of 3.83 mg L-1 air. The results indicate that the essential oil of A. blepharocalyx shows potential in terms of contact and fumigant toxicities against stored product insects.

Dendranthema indicum (L.) Des Moul. is a perennial herb commonly used as a traditional Chinese medicine for a long time. In this work, we took Dendranthema indicum as a target plant and two stored insects which include Tribolium castaneum and Stegobium paniceum adults as target insects. Essential oil obtained from Dendranthema indicum was analyzed by gas chromatography-mass spectrometry (GC-MS). A total of 31 components representing 92.44% of the oil were identified and the main compounds were found to be chamazulene (15.93%), β-caryophyllene (13.78%), germacrene D (9.11%), and b-cis-farnesene (6.59%). With a further isolation, three constituents were obtained from the essential oil and identified as chamazulene, β-caryophyllene and eucalyptol. Significantly, in the progress of assay, it showed that the essential oil and chamazulene exhibited stronger insecticidal and repellent activities against Stegobium paniceum than Tribolium castaneum. The results indicate that additional to its traditional use as Chinese medicinal herb, the essential oil of Dendranthema indicum aerial parts and isolated compounds have potential to be developed into natural insecticides or repellents for control of insects in stored grains.

Amomum maximum Roxb. is a perennial herb distributed in South China and Southeast Asia. The objective of this work was to analyze the chemical constituents and assess insecticidal and repellent activities of the essential oil from Amomum maximum fruits against Tribolium castaneum (Herbst) and Liposcelis bostrychophila (Badonnel). The essential oil was obtained by hydrodistillation and analyzed by gas chromatography-flame ionization detector and gas chromatography-mass spectrometry. The main components of the essential oil were identified to be β-pinene (23.39%), β-caryophyllene (16.43%), α-pinene (7.55%), sylvestrene (6.61%) and c-cadinene (4.19%). It was found that the essential oil of A. maximum fruits possessed contact and fumigant toxicities against T. castaneum adults (LD50 = 29.57 μg/adult and LC(50) = 23.09 mg/L air, respectively) and showed contact toxicity against L. bostrychophila (LD(50) = 67.46 μg/cm(2)). Repellency of the crude oil was also evaluated. After 2 h treatment, the essential oil possessed 100% repellency at 78.63 nL/cm(2) against T. castaneum and 84% repellency at 63.17 nL/cm(2) against L. bostrychophila. The results indicated that the essential oil of A. maximum fruits had the potential to be developed as a natural insecticide and repellent for control of T. castaneum and L. bostrychophila.

Artemisia stolonifera, a perennial herb, is widely distrbuted in China. The aim of this study was to analyze the essential oil from the aerial parts of Artemisia stolonifera, as well as to evaluate the bioactivity of the oil and its main constituents. The essential oil was analyzed by gas chromatography-flame ionization detector and gas chromatography-mass spectrometry that allowed characterizing 22 compounds. The main components were eucalyptol (32.93%), β-pinene (8.18%), camphor (6.12%) and terpinen-4-ol (6.11%), and obtained from the essential oil after a further isolation. During the contact toxicity tests, the essential oil (LD50 = 8.60 μg/adult) exhibited stronger toxicity against Tribolium castaneum adults than those isolated constituents, however, camphor and terpinen-4-ol showed 1 and 2 times toxicity against Lasioderma serricorne adults than the essential oil (LD50 = 12.68 μg/adult) with LD50 values of 11.30 and 5.42 μg/adult, respectively. In the fumigant toxicity tests, especially on Tribolium castaneum, the essential oil (LC50 = 1.86 mg/L air) showed almost the same level toxicity as positive control, methyl bromide (LC50 = 1.75 mg/L air). Moreover, the essential oil and its four isolated constituents also exhibited strong repellency against two stored-product insects.

A new myrsinol-type diterpene (1), three myrsinol-type diterpenes (2–4), three ent-abietane-type diterpenes (5–7), one tigliane-type diterpene (8), two cycloartane-type triterpenes (9–10), and two tirucallane-type triterpenes (11–12) were isolated from the roots of Euphorbia nematocypha Hand.-Mazz. Their structures were identified by spectroscopic analyses and by comparison of their spectral data with those reported in the literature. Compound 12 was isolated and reported from plants for the first time. All compounds were isolated from E. nematocypha for the first time.