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Maternal ecdysteroids regulate a variety of cellular processes during early embryonic development of insects, yet little is known about the genes involved in the biosynthesis of these hormones. In this study, we found that ecdysone oxidase (EO) gene, which encodes an enzyme to catalyze ecdysone (or 20-hydroxyecdysone, 20E) to 3-dehydroecdysone (3DE), was highly expressed in the mature ovaries of the domestic silkworm, Bombyx mori. B. mori EO (BmEO) was localized in the cytoplasm around the yolk granules of oocyte. Furthermore, the down-regulated expression of the BmEO gene using RNA interference could not affect normal development of the female silkworm, but lower the 20E titer and hatching rate of its offspring. Rescue experiments by injecting the product (3DE) of BmEO can significantly elevate the 20E level and hatching rate of the BmEO RNAi offspring. Meanwhile, during embryonic stage, the down-regulating expression of 3DE-3β-reductase, which can reduce 3DE into ecdysone, also lowered the 20E titer. Taken together, our results prove that 3DE can be synthesized from ecdysone in maternal ovary yolk granules, and then the maternal 3DE is converted into active ecdysone during the early embryonic development of offspring. Thus, our findings reveal a new pathway to explain the origin of high 20E level before the formation the prothoracic gland in the silkworm.

Purpose/Objective(s) In recent years, anti-programmed death-1 (PD-1) antibody has played an increasingly critical role in the treatment of patients with esophageal squamous cell carcinoma (ESCC), but there is still a lack of credible biomarkers to predict the efficacy of anti-PD-1 therapy. Our study aimed to develop a nomogram to predict the response and survival of patients with ECSS treated with anti-PD-1. Materials/Methods A total of 236 patients who received anti-PD-1 therapy between January 2019 and September 2020 were collected in the study retrospectively. Absolute neutrophil count (ANC), absolute lymphocyte count (ALC), total lymphocyte count, platelet count (PLT), monocyte count, lactate dehydrogenase (LDH), and serum albumin level at baseline were used to calculate the NLR (ANC/ALC), PLR (PLT/ALC), LMR (ALC/monocyte count), and PNI (10×serum albumin value, g/dL+0.005×total lymphocyte count/mm3). The early response was assessed by the RECIST version 1.1 criteria. Logistic and Cox models were used to identify factors associated with early response and survival, respectively. Nomograms were developed based on significant factors and evaluated by Concordance-index (C-index) and calibration curve. The 1,000 bootstrap samples and calibration curves were used to validate the discrimination of the nomogram. Results In multivariate logistic regression analysis, NLR Conclusion The nomogram established by combining the clinical characteristics and peripheral blood markers of patients could effectively predict the prognosis of patients with ESCC treated with anti-PD-1 therapy.

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.

The formation of ecdysone pulse in insects is synergistically controlled by its biosynthesis and degradation. Previous studies have revealed the feedback regulation of the prothoracic gland (PG) activity to affect the hormone synthesis. However, the molecular regulatory mechanism of the ecdysone degradation is still unclear. In this study, we showed that ecdysone oxidase (EO) gene encoding a hormone metabolism enzyme was also induced by hormone itself in the domestic silkworm, Bombyx mori. Furthermore, luciferase reporter, chromatin immunoprecipitation and electrophoretic mobility shift assays showed that ecdysone inducible transcription factor E74A could bind to the cis-regulatory elements of the EO gene. Then, down-regulating the expression of the E74A by RNA interference (RNAi) decreased the expression of the EO gene and caused a higher ecdysone titer compared with the control. Thus, our results demonstrated a new feedback regulation degradation (EO) pathway controlled by ecdysone itself through transcription factor E74A, expanding the knowledge about the regulatory system that determines the formation of ecdysone pulse.

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.

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.

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.

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.

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.

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.

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.

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.

The aim of this research was to determine the chemical constituents and toxicities of the essential oil derived from Amomum tsaoko Crevost et Lemarie fruits against Tribolium castaneum (Herbst) and Lasioderma serricorne (Fabricius). Essential oil of A. tsaoko was obtained from hydrodistillation and was investigated by gas chromatography-mass spectrometry (GC-MS). GC-MS analysis of the essential oil resulted in the identification of 43 components, of which eucalyptol (23.87%), limonene (22.77%), 2-isopropyltoluene (6.66%) and undecane (5.74%) were the major components. With a further isolation, two active constituents were obtained from the essential oil and identified as eucalyptol and limonene. The essential oil and the two isolated compounds exhibited potential insecticidal activities against two storedproduct insects. Limonene showed pronounced contact toxicity against both insect species (LD50 = 14.97 μg/adult for T. castaneum; 13.66 μg/adult for L. serricorne) and was more toxic than eucalyptol (LD50 = 18.83 μg/adult for T. castaneum; 15.58 μg/adult for L. serricorne). The essential oil acting against the two species of insects showed LD50 values of 16.52 and 6.14 μg/adult, respectively. Eucalyptol also possessed strong fumigant toxicity against both insect species (LC50 = 5.47 mg/L air for T. castaneum; 5.18 mg/L air for L. serricorne) and was more toxic than limonene (LC50 = 6.21 mg/L air for T. castaneum; 14.07 mg/L air for L. serricorne), while the crude essential oil acting against the two species of insects showed LC50 values of 5.85 and 8.70 mg/L air, respectively. These results suggested that the essential oil of A. tsaoko and the two compounds may be used in grain storage to combat insect pests.

The chemical composition of the essential oil from Juniperus formosana leaves and its contact and repellent activities against Tribolium castaneum and Liposcelis bostrychophila adults were investigated. The essential oil of J. formosana leaves was obtained by hydrodistillation and analyzed by GC-MS. A total of 28 components were identified and the main compounds in the essential oil were α-pinene (21.66%), 4-terpineol (11.25%), limonene (11.00%) and β-phellandrene (6.63%). The constituents α-pinene, 4-terpineol and d-limonene were isolated from the essential oil. It was found that the essential oil exhibited contact activity against T. castaneum and L. bostrychophila adults (LD50 = 29.14 μg/adult and 81.50 µg/cm2, respectively). The compound 4-terpineol exhibited the strongest contact activity (LD50 = 7.65 μg/adult). In addition, data showed that at 78.63 nL/cm2, the essential oil and the three isolated compounds strongly repelled T. castaneum adults. The compounds α-pinene and d-limonene reached the same level (Class V) of repellency as DEET (p = 0.396 and 0.664) against L. bostrychophila at 63.17 nL/cm2 after 2 h treatment. The results indicate that the essential oil and the isolated compounds have potential to be developed into natural insecticides and repellents to control insects in stored products.

Eight compounds were isolated from the water extract of Pu-erh tea and their structures were elucidated by NMR and MS as gallic acid (1), (+)-catechin (2), (−)-epicatechin (3), (−)-epicatechin-3-O-gallate (4), (−)-epigallocatechin-3-O-gallate (5), (−)-epiafzelechin- 3-O-gallate (6), kaempferol (7), and quercetin (8). Their in vitro antioxidant activities were assessed by the DPPH and ABTS scavenging methods with microplate assays. The relative order of DPPH scavenging capacity for these compounds was compound 8 > compound 7 > compound 1 > compound 6 > compound 4 ≈ compound 5 > compound 2 > VC (reference) > compound 3, and that of ABTS scavenging capacity was compound 1 > compound 2 > compound 7 ≈ compound 8 > compound 6 > compound 5 > compound 4 > VC (reference) > compound 3. The results showed that these phenolic compounds contributed to the antioxidant activity of Pu-erh tea.

In recent years, uses of environment friendly and biodegradable natural insecticides of plant origin have received renewed attention as agents for vector control. The aim of this research was to determine larvicidal activity of the essential oil derived from roots of Saussurea lappa (Compositae) and the isolated constituents against the larvae of the Culicidae mosquito Aedes albopictus. Essential oil of S. lappa roots was obtained by hydrodistillation and analyzed by gas chromatography (GC) and GC-mass spectrometry (MS). A total of 39 components of the essential oil of S. lappa roots were identified. The essential oil has higher content of (79.80%) of sesquiterpenoids than monoterpenoids (13.25%). The principal compounds in S. lappa essential oil were dehydrocostus lactone (46.75%), costunolide (9.26%), 8-cedren-13-ol (5.06%), and α-curcumene (4.33%). Based on bioactivity-directed fractionation, dehydrocostus lactone and costunolide were isolated from S. lappa essential oil. Dehydrocostus lactone and costunolide exhibited strong larvicidal activity against A. albopictus with LC(50) values of 2.34 and 3.26 μg/ml, respectively, while the essential oil had an LC(50) value of 12.41 μg/ml. The result indicated that the essential oil of S. lappa and the two isolated constituents have potential for use in control of A. albopictus larvae and could be useful in search of newer, safer and more effective natural compounds as larvicides.

During our screening program for new agrochemicals from Chinese medicinal herbs, the essential oil of Illicium difengpi stem bark was found to possess strong insecticidal activities against the maize weevil, Sitophilus zeamais (Motschulsky) (Coleoptera: Curculionidae) and red flour beetle, Tribolium castaneum Herbst (Coleoptera: Tenebrionidae). A total of 37 components of the essential oil of I. difengpi were identified. The main components of the essential oil were safrole (23.61%), linalool (12.93%), and germacrene D (5.35%). Bioactivities-directed chromatographic separation on repeated silica gel columns led to the isolation of two compounds: safrole and linalool. Safrole showed pronounced contact toxicity against both insect species and (LD₅₀ = 8.54 for S. zeamais; 4.67 µg/adult for T. castaneum) and was more toxic than linalool (LD₅₀ = 24.88 for S. zeamais; 8.12 µg/adult for T. castaneum). The essential oil acting against the two species of insects showed LD₅₀ values of 13.83 and 6.33 µg/adult, respectively. Linalool also possessed strong fumigant toxicity against both insect species (LC₅₀ = 10.02 for S. zeamais; 9.34 mg/L for T. castaneum) and was more toxic than safrole (LD₅₀ = 32.96 and 38.25 mg/L), while the crude essential oil acting against the two species of insects showed LC₅₀ values of 14.62 and 16.22 mg/L, respectively. These results suggest that the essential oil of I. difengpi stem bark and the two compounds may be used in grain storage to combat insect pests.

In our screening program for new agrochemicals from Chinese medicinal herbs and wild plants, Zanthoxylum schinifolium essential oils were found to possess strong insecticidal activity against the maize weevil Sitophilus zeamais. The essential oils of Z. schinifolium fruits and leaves were extracted via hydrodistillation and investigated by GC and GC-MS. Estragole (69.52%) was the major compound of the essential oil of fresh fruits, followed by linalool (8.63%) and limonene (4.34%) and 94.33% of the total components were monoterpenoids. The main components of the essential oil of fresh leaves were linalool (12.94%), ar-tumerone (8.95%), limonene (6.45%) and elixene (5.43%) and only 50.62% were monoterpenoids. However, the essential oil from purchased fruits contained linalool (33.42%), limonene (13.66%) and sabinene (5.72%), followed by estragole (4.67%), nerol (4.56%) and 4-terpineol (4.27%). Estragole, linalool and sabinene were separated and purified by silica gel column chromatography and preparative thin layer chromatography, and further identified by means of physicochemical and spectrometric analysis. The essential oil from the fresh fruits (LD50 = 15.93 μg/adult) possessed two times more toxicity to the insects compared with that of fresh leaves (LD50 = 35.31 μg/adult). Estragole, linalool and sabinene exhibited contact activity against S. zeamais with LD50 values of 17.63, 13.90 and 23.98 μg/adult, respectively. The essential oils of Z . schinifolium possessed strong fumigant toxicity against S. zeamais adults with LC50 values of 13.19 mg/L (fresh fruits), 24.04 mg/L (fresh leaves) and 17.63 mg/L (purchased fruits). Estragole, linalool and sabinene also exhibited strong fumigant toxicity against the maize weevils with LC50 values of 14.10, 10.46 and 9.12 mg/L, respectively.

Context: It was found that the essential oil of Acorus calamus rhizomes showed insecticidal activity. Aim: The aim of this study was to determine the chemical composition of the essential oil from A. calamus rhizomes, evaluate insecticidal and repellant activity against Lasioderma serricorne (LS) and Tribolium castaneum (TC), and to isolate any insecticidal constituents from the essential oil. Materials and Methods: Essential oil from A. calamus was obtained by hydrodistillation and analyzed by gas chromatography (GC) flame ionization detector and GC-mass spectrometry. The insecticidal and repellant activity of the essential oil and isolated compounds was tested using a variety of methods. Results: The main components of the essential oil were identified to be isoshyobunone (15.56%), β-asarone (10.03%), bicyclo[6.1.0]non-1-ene (9.67%), shyobunone (9.60%) and methylisoeugenol (6.69%). Among them, the two active constituents were isolated and identified as shyobunone and isoshyobunone. The essential oil showed contact toxicity against LS and TC with LD 50 values of 14.40 and 32.55 μg/adult, respectively. The isolated compounds, shyobunone and isoshyobunone also exhibited strong contact toxicity against LS adults with LD 50 values of 20.24 and 24.19 μg/adult, respectively, while the LD 50 value of isoshyobunone was 61.90 μg/adult for TC adults. The essential oil, shyobunone and isoshyobunone were strongly repellent (98%, 90% and 94%, respectively, at 78.63 nL/cm 2 , after 2 h treatment) against TC. Conclusion: The essential oil, shyobunone and isoshyobunone possessed insecticidal and repellant activity against LS and TC.

The chemical composition of the essential oil of Etlingera yunnanensis rhizomes and its contact and repellent activities against Tribolium castaneum (Herbst) and Liposcelis bostrychophila (Badonnel) were investigated. The essential oil obtained from E. yunnanensis rhizomes with hydrodistillation was performed by gas chromatography-flame ionization detection and gas chromatography-mass spectrometry. The main components of the essential oil were identified to be estragole (65.2%), β-caryophyllene (6.4%), 1,8-cineole (6.4%), limonene (5.2%), and α-pinene (2.4%). It was found that the essential oil of E. yunnanensis rhizomes possessed contact toxicity against T. castaneum and L. bostrychophila (LD50 = 23.33 μg/adult and LD50 = 47.38 μg/cm2, respectively). Estragole, 1,8-cineole, and limonene exhibited stronger contact toxicity (LD50 values of 20.41, 18.86, and 13.40 μg/adult, respectively) than β-caryophyllene (LD50 = 41.72 μg/adult) against T. castaneum adults. Estragole possessed stronger contact toxicity (LD50 = 30.22 µg/cm2) than β-caryophyllene, 1,8-cineole, and limonene (LD50 values of 74.11, 321.20, and 239.62 μg/adult, respectively) against L. bostrychophila adults. Repellency of the crude oil was also evaluated. The essential oil and constituents possessed strong repellent activity against T. castaneum adults. The four individual constituents showed weaker repellent activity than the essential oil against L. bostrychophila adults. The results indicated that the essential oil of E. yunnanensis rhizomes and the individual constituents had the potential to be developed as a natural insecticide and repellent for the control of T. castaneum and L. bostrychophila.

This work aimed to investigate chemical composition of essential oils obtained from Zanthoxylum dissitum leaves and roots and their insecticidal activities against several stored product pests, namely the cigarette beetle (Lasioderma serricorne), red flour beetle (Tribolium castaneum) and black carpet beetle (Attagenus piceus). The analysis by GC-MS of the essential oils allowed the identification of 28 and 22 components, respectively. It was found that sesquiterpenoids comprised a fairly high portion of the two essential oils, with percentages of 74.0% and 80.9% in the leaves and roots, respectively. The main constituents identified in the essential oil of Z. dissitum leaves were δ-cadinol (12.8%), caryophyllene (12.7%), β-cubebene (7.9%), 4-terpineol (7.5%) and germacrene D-4-ol (5.7%), while humulene epoxide II (29.4%), caryophyllene oxide (24.0%), diepicedrene-1-oxide (10.7%) and Z,Z,Z-1,5,9,9-tetramethyl-1,4,7-cycloundecatriene (8.7%) were the major components in the essential oil of Z. dissitum roots. The insecticidal activity results indicated that the essential oil of Z. dissitum roots exhibited moderate contact toxicity against three species of storage pests, L. serricorne, T. castaneum and A. piceus, with LD50 values of 13.8, 43.7 and 96.8 µg/adult, respectively.

The aims of this research were to determine the chemical composition and insecticidal and repellent activities of theArtemisia mongolicaessential oil againstLasioderma serricorneand to isolate active constituents from the essential oil. The essential oil ofA. mongolicawas obtained by hydrodistillation and 36 components were identified with GC-MS. Eucalyptol (39.88%), (S)-cis-verbenol (14.93%), 4-terpineol (7.20%), (−)-camphor (6.02%), andα-terpineol (4.20%) were found to be major components. With a further isolation process, five constituents obtained from the essential oil were identified as eucalyptol, verbenol, 4-terpineol, camphor, andα-terpineol. In the progress of assay, it showed thatL. serricorneadults had different sensitivities to the crude essential oil and isolated constituents. 4-Terpineol exhibited strongest contact activity againstL. serricorne, showing the LD50value of 8.62 μg/adult. Moreover, camphor andα-terpineol showed stronger fumigant activity (LC50=2.91and 3.27 mg/L air, resp.) againstL. serricornethan crude essential oil and other constituents. In addition, the essential oil, eucalyptol, verbenol, andα-terpineol showed comparable repellency againstL. serricorneadults. The results indicate that the essential oil and isolated compounds have potential to provide more efficient and safer natural insecticides or repellents for control of insects in food and Chinese medicinal materials preservation.

Our previous study described the neuroprotective effects of catalpol in gerbil ischemic model, in which catalpol was shown to prevent hippocampal neurons from death and ameliorate the cognitive ability of the animals. In the study, we focused on investigating the neuroprotective mechanism of catalpol. Animals were randomly assigned three groups as sham-operated, ischemia-treated with saline and ischemia-treated with catalpol. Transient global ischemia was produced by a 5 min occlusion of the bilateral common carotid arteries. Catalpol was intraperitoneally injected at the dose of 5 mg/kg immediately after reperfusion and repeatedly at 12, 24, 48 and 72 h. Histology as well as immunohistochemistry and TUNEL (the terminal deoxynucleotidyl transferase-mediated UTP nick end label) analysis were performed on serial slices through the dorsal hippocampus after gerbils were sacrificed. The results showed that 5 min transient global ischemia followed by 4 days reperfusion caused significant increases in TUNEL-positive and Bax-positive cells in hippocampal CA1 subfield. Catalpol not only significantly reduced TUNEL-positive and Bax-positive cells but also significantly increased Bcl-2-positive cells. All these suggested that catalpol could effectively inhibit apoptosis by modulating the expressions of Bcl-2 and Bax genes.

During our screening program for agrochemicals from Chinese medicinal herbs and wild plants, the essential oils of Evodia calcicola and Evodia trichotoma leaves were found to possess strong repellency against the red flour beetle Tribolium castaneum adults, the cigarette beetle Lasioderma serricorne adults and the booklouse Liposcelis bostrychophila. The two essential oils obtained by hydrodistillation were investigated by GC-MS. The main components of E. calcicola essential oil were identified to be (-)-β-pinene (44.02%), β-phellandrene (20.93%), ocimene (16.49%), and D-limonene (9.87%). While the main components of the essential oil of E. trichotoma were D-limonene (69.55%), 1R-a-pinene (11.48%), caryophyllene (2.80%) and spathulenol (2.24%). Data showed that T. castaneum was the most sensitive than other two stored product insects. Compared with the positive control, DEET (N, N-diethyl-3- methylbenzamide), the two essential oils showed the same level repellency against the red flour beetle. However, the essential oil of E. trichotoma showed the same level repellency against the cigarette beetle, while E. calcicola essential oil possessed the less level repellency against L. serricorne, relative to the positive control, DEET. Moreover, the two crude oils also exhibited strong repellency against L. bostrychophila, but lesser level repellency than the positive control, DEET. Thus, the essential oils of E. calcicola and E. trichotoma may be potential to be developed as a new natural repellent in the control of stored product insects.

One new alkaloid, together with 10 known compounds were isolated from the aerial parts of Chelidonium majus L. by repeated silica gel column chromatography. Their chemical structures were elucidated on the basis of physicochemical and spectroscopic data. Among them, 6-acetonyldihydrochelerythrine (4), 6-acetonyldihydrosanguinarine (5), 6-ketenesanguinarine (6), demethylchelerythrine (7) and demethylsanguinarine (11) were isolated for the first time from this plant. Compound 6 was identified as a new compound. These compounds were screened for cytotoxicity against human non-small lung carcinoma (H1299), breast cancer (MCF-7) and liver cancer (SMMC-7721). In a series of cytotoxic tests, compounds 9 and 10 displayed potent cytotoxic activity against H1299, MCF-7 and SMMC-7721, with the IC50 values of 8.16–35.25 μg/mL.

A new compound and seven known compounds were isolated from Murraya tetramera Huang for the first time, and they were identified with NMR and MS spectral analysis. It was confirmed that the new compound was 10-methoxy-7-methyl-2H-benzo[g]chromen-2-one (3) and the others were β-eudesmol (1), trans-3β-(1-hydroxy-1-methylethyl)-8aβ-methyl-5-methylenedecalin-2-one (2), 5,7-dimethoxy-8-[(Z)-3'-methyl-butan-1',3'-dienyl]coumarin (4), 7-geranyloxy-6-methoxycoumarin (5), 5,7-dimethoxy-8-(3-methyl-2-oxo-butyl)coumarin (6), murrangatin acetate (7) and toddalenone (8). Furthermore, the cytotoxic activity against human lung adenocarcinoma (A549), human hepatocellular carcinoma cells (SMMC-7721), human bladder tumor cells (EJ), human cervical carcinoma cells (HeLa), and human B-lineage acute lymphoblastic leukemia 1 cells (BALL-1) was evaluated for all compounds. It was found that five of them displayed various degrees of cytotoxicity against different testing targets. Compound 1 showed significant cytotoxic activity against the five cell lines (A549, SMMC-7721, EJ, Hela and BALL-1). Compounds 2 and 5 showed significant cytotoxicity against three cell lines (A549, SMMC-7721 and BALL-1). Compound 4 showed significant cytotoxicity against three cell lines (A549, EJ and BALL-1). However, compound 3 only showed fair cytotoxicity against the BALL-1 cell line. The structure-active relationships were investigated as well. These active compounds might be potential lead compounds for the treatment of cancer.

Essential oil extracted from nutmeg seeds (Myristica fragrans Houtt.) by hydrodistillation was subjected to GC/MS and GC analysis. A total of 27 constituents were identified, of which eugenol (19.9%), methylisoeugenol (16.8%), methyleugenol (16.7%), sabinene (11.8%), and terpinen-4-ol (8.5%) were the major components. The essential oil was tested against Lasioderma serricorne for insecticidal and repellent activity, the LD50 value at the end of 24 h exposure period was 19.3 μg/adult. Six active compounds were isolated by bioassay-guided fractionation. They were identified as eugenol (1), methyleugenol (2), methylisoeugenol (3), elemicin (4), myristicin (5), and safrole (6). Among these isolates, 4 showed the strongest contact toxicity against L. serricorne adults with an LD50 value of 9.8 μg/adult. Repellency of crude oil and active compounds were also determined. Compounds 1, 2, 4, and 5 were strongly repellent against the cigarette beetle and exhibited the same level of repellency compared with the positive control, DEET. The results indicate that the essential oil of M. fragrans and its active constituents have potential for development as natural insecticides and repellents to control L. serricorne.

During our screening program for new agrochemicals from traditional medicinal herbs, Dictamnus dasycarpus was found to possess contact toxicity and repellent activity against the cigarette beetle Lasioderma serricorne and the booklouse Liposcelis bostrychophila. The essential oil obtained by hydrodistillation of D. dasycarpus roots was characterized by GC-FID and GC/MS analyses, and the main components identified were syn-7-hydroxy-7-anisylnorbornene (1, 49.9%), 1,3,4,5,6,7-hexahydro-2H-inden-2-one (2, 11.6%), 5,6-diethenyl-1-methylcyclohexene (3, 7.4%), and 3,9-dimethyltricyclo[4.2.1.1(2,5)]dec-3-en-9-ol (4, 6.35%). The D. dasycarpus root oil exhibited strong contact toxicity against L. serricorne adults and L. bostrychophila, with LD50 values of 12.4 μg/adult and 27.2 μg/cm(2), respectively. Moreover, the essential oil also showed strong repellency against both stored-product insects tested.

Nine alkaloids with three different structural skeletons were isolated fromDicranostigma leptopodum(Maxim.) Fedde (Papaveraceae) by repeated silica gel column chromatography. Their chemical structures were identified on the basic of physicochemical and spectroscopic data. Among them, 10-O-methylhernovine (1), nantenine (2), corytuberine (3), lagesianine A (4), and dihydrocryptopine (9) were first isolated from this plant. With a series of cytotoxic tests, compounds2,3, and7displayed cytotoxicity against SMMC-7721 with IC50values of 70.08 ± 4.63, 73.22 ± 2.35, and 27.77 ± 2.29μM, respectively.

Six compounds were isolated from the stems of Clausena lansium (Lour.) Skeels by repeated sillica gel column chromatography. Their chemical structures were elucidated on the basic of physicochemical and spectroscopic data. Among them, 8-geranyloxypsolaren (3) and 2-methoxy-1-(3-methyl-buten-1-yl)-9H-carbazole-3-carbaldehyde (6) were isolated for the first time from this plant. These compounds were screened for cytotoxicity in human cervical cancer (Hela), leukemia (K562), lung cancer (A549), non-small lung carcinoma (H1299) and liver cancer (SMMC-7721). Within the series of cytotoxic tests, compounds 4-6 displayed potent cytotoxic activity against H1299 and SMMC-7721, with the IC₅₀ values of 6.19 to 26.84 μg/mL.

To investigate the chemical composition and insecticidal activity of the essential oils of certain Chinese medicinal herbs and spices, the essential oils were extracted from the stem barks, leaves, and fruits of Cinnamomum camphora (L.) Presl, which were found to possess strong fumigant toxicity against Tribolium castaneum and Lasioderma serricorne adults. The essential oils of the plants were extracted by the method of steam distillation using a Clavenger apparatus. Their composition was determined by gas chromatography/mass spectrometric (GC-MS) analyses (HP-5MS column), and their insecticidal activity was measured by seal-spaced fumigation. D-camphor (51.3%), 1,8-cineole (4.3%), and α-terpineol (3.8%), while D-camphor (28.1%), linalool (22.9%), and 1,8-cineole (5.3%) were the main constituents of its fruits. The essential oils of the C. camphora all showed fumigant and contact toxicity. Other compounds exhibited various levels of bioactivities. The results indicate that the essential oils of C. camphora and its individual compounds can be considered a natural resource for the two stored-product insect management.

The aim of this research was to determine acute toxicity of the essential oil of Lonicera japonica Thunb. (Caprifoliaceae) flower buds against the booklouse (Liposcelis bostrychophila Badonnel) and the maize weevils (Sitophilus zeamais Motschulsky). Essential oil of L. japonica flower buds was obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry (GC-MS). A total of 25 components of the essential oil were identified. The principal compounds in the essential oil were estragole (80.17%) and linalool (6.05%). The essential oil exhibited strong contact toxicity against S. zeamais and L. bostrychophila with LD50 values of 21.54 µg/adult and 64.04 µg/cm2, respectively. The constituent compounds, estragole (LD50 = 49.95 µg/cm2) and linalool (LD50 = 172.54 µg/cm2) also possessed contact toxicity against L. bostrychophila. L. japonica essential oil and its constituent compounds (estragole and linalool) exhibited fumigant toxicity against S. zeamaiswith LC50 values of 13.36, 14.10 and 10.46 mg/L, respectively. The essential oil of L. japonica(LC50 = 0.20 mg/L) and its constituent compounds, estragole (LC50 = 0.16 mg/L) and linalool (LC50 = 0.41 mg/L) possessed fumigant toxicity against L. bostrychophila. The results indicated that the essential oil of L. japonica and its constituent compounds showed potential in terms of contact and fumigant toxicity against grain storage insects. Key words: Lonicera japonica, Liposcelis bostrychophila, Sitophilus zeamais, contact toxicity, fumigant, essential oil composition, estragole, linalool.

The aim of this research was to determine the chemical composition and toxicities of essential oil derived from Illicium fargesii Finet et Gagnep fruits against the maize weevil ( Sitophilus zeamais Motsch). Essential oil of I. fargesii fruits was obtained from hydrodistillation and was investigated by GC (Gas Chromatography) and GC–Mass Spectrometry (GC-MS). A total of 43 components of the essential oil of I. fargesii fruits were identified. The principal compounds in I. fargesii essential oil were α-terpineol (11.4%), carvone (10.9%), d-limonene (9.8%), trans-carveol (6.6%) and trans-pinocarveol (5.5%). The essential oil of I. fargesii possessed strong fumigant toxicity against the maize weevil with an LC 50 value of 11.36 mg/L air. The essential oil of I. fargesii also exhibited contact toxicity against S. zeamais adults with an LD 50 value of 28.95 μg/adult. The result indicate that the essential oil of I. fargesii show potential in terms of fumigant and contact toxicities against grain storage insects. Key words : Illicium fargesii, Sitophilus zeamais, fumigant, contact toxicity, essential oil composition.

The screening of several Chinese medicinal plants for insecticidal principles showed that essential oil of Rhododendron anthopogonoides flowering aerial parts possessed significant toxicity against maize weevils, Sitophilus zeamais. A total of 37 components were identified in the essential oil and the main constituents of the essential oil were 4-phenyl-2-butanone (27.22%), nerolidol (8.08%), 1,4-cineole (7.85%), caryophyllene (7.63%) and γ-elemene (6.10%), followed by α-farnesene (4.40%) and spathulenol (4.19%). Repeated bioactivity-directed chromatographic separation on silica gel columns led us to isolate three compounds, namely 4-phenyl-2-butanone, 1,4-cineole, and nerolidol. 4-Phenyl-2-butanone shows pronounced contact toxicity against S. zeamais (LD₅₀ = 6.98 mg/adult) and was more toxic than either 1,4-cineole or nerolidol (LD₅₀ = 50.86 mg/adult and 29.30 mg/adult, respectively) against the maize weevils, while the crude essential oil had a LD₅₀ value of 11.67 mg/adult. 4-Phenyl-2-butanone and 1,4-cineole also possessed strong fumigant toxicity against the adults of S. zeamais (LC₅₀ = 3.80 mg/L and 21.43 mg/L) while the crude essential oil had a LC₅₀ value of 9.66 mg/L.

The essential oil obtained from Citrus wilsonii Tanaka stem barks with hydrodistillation was investigated by GC-FID and GC-MS. The main components of the essential oil were identified to be nerol acetate (44.5%), nerol (13.6%), citronellyl propionate (13.5%) and α-terpineol (3.6%). Among them, the four active constituents, predicted with a bioactivity-test, were isolated and identified as nerolacetate, nerol, citronellyl propionate and α-terpineol. It was found that the essential oil of C. wilsonii stem barks possessed strong repellency (86% and 92%, respectively, at 78.6 nL/cm2, after 2 and 4 h treatment) against Tribolium castaneum adults. Repellency of the four active compounds was also determined. Nerolacetate, nerol, citronellyl propionate and α-terpineol were strongly repellent (100%, 100%, 90% and 96%, respectively, at 15.7 nL/cm2, after 2h treatment) against T. castaneum. Nerol exhibited the same level of repellency as the positive control, DEET. The results indicate that the essential oil of C. wilsonii stem barks and its active compounds have the potential to be developed as natural repellents for control of T. castaneum.