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Artemisia songarica Schrenk is a dominant sand fixation plant growing in the People's Republic of China. At present, there are rare studies on the chemical composition and biological activity of A. songarica. The chemical composition of the original oil was analyzed by gas chromatography-mass spectrometry, and 16 compounds were determined. The main compounds were bisabolol oxide II (28.7%), nerolidol (18.6%), bisabolol (12.9%), bisaboloxide A (10.0%), and spathulenol (6.0%). The contact toxicity and repellent activity of A. songarica essential oil and four selected compounds (bisabolol, geranyl butyrate, nerolidol, and santalol) were assessed against Tribolium castaneum Herbst and Liposcelis bostrychophila Badonnel. Bioassays showed that the crude essential oil exhibited strong insecticide and repellent activities against both pests. Santalol possessed the strongest contact toxicity (50% lethal dose [LD50] = 1.29 μg per adult) against T. castaneum. Nerolidol, santalol, and geranyl butyrate showed fair contact activity against L. bostrychophila. In particular, geranyl butyrate exhibited outstanding activity (LD50 = 11.53 μg/cm2). In addition, all of the four compounds did not detect a difference between compounds and the positive control (P0.05) against two pests at five tested concentrations. These results indicated that A. songarica and its selected compounds could be used as prospective insecticidal and repellent agents for further development and use.

Continuous use of synthetic insecticides increases environmental contamination and resistance in many species. Botanical insecticides, such as essential oil, were considered to be suitable alternatives due to multiple modes of action and low mammalian toxicity. Haplophyllum dauricum is a overlooked plant for the control of stored-product insects. Five essential oils (EOs) from Haplophyllum dauricum collected in October and November, rich in pinene, were extracted and evaluated on anti-insect activity against two stored-product insects, Tribolium castaneum (Coleoptera: Tenebrionidae) and Lasioderma serricorne (Coleoptera: Anobiidae). The lethal doses (LD50 and LD90), lethal concentrations (LC50 and LC90) and percentage repellency (PR) were evaluated. The GC-MS analysis showed that pinene (α-pinene and β-pinene) were major constituent of the EOs (54.61% and 57.33% in fruits, 46.80% in stems + leaves, and 30.57% in leaves), followed by β-phellandrene (14.49% and 21.34% in fruits and leaves), 3-carene (26.84% in leaves) and limonene (15.77%, 11.09%, 12.40%, 7.59%, and 6.24% in five EOs, respectively). Five EOs and selected major compounds provided promising fumigant, contact and repellent activity against T. castaneum and L. serricorne. The EO of stems + leaves collected in October showed the strongest contact toxicity on T. castaneum (LD50 = 20.21μg/adult), as well as fumigant and contact toxicity on L. serricorne (LC50 = 17.17 mg/L air, LD50 = 25.46 μg/adult). All the five EOs exhibited effective repellent activity (PR>80%) against T. castaneum. The results highlight that the EOs from H. dauricum have a promising potential as eco-friendly botanical insecticides.

In this work, the essential oils (EO) were extracted from seven typical Chinese herbs, and their repellent and contact toxicities against Tribolium castaneum adults (red flour beetles) were evaluated. The experimental results showed that the above EOs presented the various levels of repellent and contact toxicities. The EOs extracted from A. lancea and A argyi of the Compositae (Asteraceae) family presented obvious repellent effects (Repellency Percentage > 90% at 3.15 nL/cm2 after 4 h exposure) and strong contact toxicity with LD50 values of 5.78 and 3.09 μg/adult respectively. Based on literature researches and screening results, the EO from A. lancea was analyzed by GC-MS and chosen for further identification of bioactive components. Altogether 59 chemical components were identified and 17 of them were recognized as sesquiterpene compounds, accounting for 57.8% of the total weight of the EO. From the identified sesquiterpenes, three individual compounds (β-eudesmol, hinesol, valencene) were selected for the laboratory bioassays of the toxicity against red flour beetles. It was found that all the three compounds expressed some repellent effects. Although β-eudesmol (31.2%) and hinesol (5.1%) were identified as main constituents and had been considered to be symbolic characteristics of high medicinal value, valencene (0.3%) showed strong repellent property which could be comparable to that of DEET (N, N‑diethyl‑3‑methylbenzamide), a powerful commercial pesticides, and it had best toxicity with LD50 values of 3.25 (μg/adult) in the contact test. This work may provide toxicity evidence of seven common herbs against red flour beetles, add the information for the development and comprehensive utilization of A. lancea, and will contribute to the application of grain preservation.

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.

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.

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.

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.

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.

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.

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.

Purple Perilla (Perilla frutescens (L.) Britt.) is an annual herb commonly used as a traditional Chinese medicine for more than 1000 years. This work investigated the chemical composition, insecticidal and repellent activities of the essential oil of Purple Perilla aerial parts against Lasioderma serricorne (Fabricius). Moreover, we also isolated active constituents from the essential oil. The experiment was investigated in 2013 in Beijing. The essential oil of Purple Perilla was obtained by hydrodistillation and a total of 47 components in the essential oil were identified with GC–MS. It was found that the main compounds included carvone (32.55%), perilla aldehyde (20.52%), caryophyllene (9.85%), 2-furyl methyl ketone (7.53%), 2,6-dimethyl-6-(4-methyl-3-pentenyl)-2-norpinene (5.17%), and β-terpinyl acetate (3.41%). With a further isolation, four active constituents were obtained from the essential oil and identified as R-(+)-carvone, perilla aldehyde, 2-furyl methyl ketone, and β-caryophyllene. In the progress of assay, it showed that the essential oil, R-(+)-carvone, perilla aldehyde, and 2-furyl methyl ketone exhibited stronger insecticidal and repellent activities against L. serricorne than β-caryophyllene. The results indicate that the essential oil of Purple Perilla aerial parts and isolated compounds have potential for development into natural insecticides or repellents for control of insects in stored products.

During our screening program for agrochemicals from Chinese medicinal herbs and wild plants, the essential oil of Litsea cubeba fruits was found to possess strong contact toxicity against the cigarette beetle Lasioderma serricorne adults and the booklouse Liposcelis bostrychophila , with LD 50 values of 27.33 μg/adult and 71.56 μg/cm 2 , respectively, and also showed strong fumigant toxicity against the two stored product insects with LC 50 values of 22.97 and 0.73 mg/L, respectively. The essential oil obtained by hydrodistillation was investigated by GC MS. The main components of the essential oil were identified to be E-citral (geranial) (27.49%), Z-citral (neral) (23.57%) and d -limonene (18.82%) followed by β-thujene (3.34%), β-pinene (2.85%), α-pinene (2.57%), 6-methyl-5-hepten-2-one (2.40%) and linalool (2.36%). Citral (Z/E-citral), d -limonene, β-pinene, α-pinene and linalool were separated and purified by silica gel column chromatography and preparative thin layer chromatography, and further identified by means of physicochemical and spectrometric analysis. Citral and linalool showed strong contact toxicity against L. serricorne and L. bostrychophila (LD 50 = 11.76, 12.74 μg/adult and 20.15, 99.97 μg/cm 2 , respectively) and fumigant toxicity against L. serricorne and L. bostrychophila (16.54, 18.04 mg/L air and 0.14, 0.71 mg/L air, respectively). Otherwise, citral, d -limonene and linalool were strongly repellent against the cigarette beetle L. serricorne as the essential oil whereas β-pinene and α-pinene exhibited weaker repellency against the cigarette beetle compared with the positive control, DEET. Moreover, except α-pinene and linalool, the other three compounds as well as the essential oil exhibited comparable repellency against the booklouse relative to DEET.

Two new compounds 6-methoxy-9H-carbazole-3-carboxylic acid ( 1 ) and 9-[3-methyl-4-(4-methyl-5-oxo-tetrapydro-furan-2-yl)-but-2-enyloxy]-furo[3,2-g]chromen-7-one ( 5 ) along with four known compounds clausine D ( 2 ), claulansines J ( 3 ), O-demethylmurrayanine ( 4 ) and pabularinone ( 6 ) were isolated from the Clausena lansium . The chemical structures of the new compound were elucidated by 1D and 2D NMR as well as HR-ESIMS spectral analysis. All the compounds isolated were evaluated for cytotoxic effects against human breast cancer (MCF-7), non-small lung carcinoma (H1299) and liver cancer (SMMC-7721). Compounds 2 and 4 exhibited strong cytotoxicity against MCF-7 and SMMC-7721 with IC 50 values in the range 2.63–7.59 μg/ml, and Compounds 1 and 5 showed moderate cytotoxicity against MCF-7, H1299 and SMMC-7721 tumor cell lines.

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.

Fourteen essential oils of common spices in China were evaluated for insecticidal activities against the booklouse, Liposcelis bostrychophila . Five essential oils ( Allium sativum , Cinnamomum cassia , Foeniculum vulgare, Illicium verum , and Perilla frutescens ) exhibited strong contact toxicity against the booklice at a concentration of 0.16 μL/cm 2 while only C. cassia , F . vulgare and P. frutescens essential oils possessed fumigant toxicity at a concentration of 0.04 μL/L. Based on bioactivity-directed fractionation, estragole, trans -anethole and fenchone were isolated from the essential oil of F . vulgare . Estragole and trans -anethole exhibited contact toxicity against the booklouse with LD 50 values of 49.95 μg/cm 2 and 57.98 μg/cm 2 , respectively while F . vulgare essential oil had an LD 50 value of 90.36 μg/cm 2 . trans -Anethole (LC 50 = 15.96 μg/L) possessed stronger fumigant toxicity against the booklouse than fenchone (LC 50 = 73.23 μg/L), estragole (LC 50 = 160.33 μg/L) and the essential oil of F . vulgare (LC 50 = 34.07 μg/L).