Does the Use of Different Types of Probiotics Possess Detoxification Properties Against Aflatoxins Contamination in Rabbit Diets?

The present work was carried out to study the ability of five probiotics on the in vitro degradation of Aflatoxins B1 (AFB1). The best results of in vitro were tested on the detoxification of AFB1 in rabbits. A total of 40 growing New Zealand White (NZW) male rabbits were assigned to five experimental groups. Animals were fed the following diets: basal diet (control), basal diet contaminated with 300 ppb AFB1, basal diet contaminated with 300 ppb AFB1. + probiotic 3 (0.5 g/kg diet), basal diet contaminated with 300 ppb AFB1 + ajowan (0.5 g/kg diet), and basal diet contaminated with 300 ppb AFB1 + probiotic 3 (0.5 g/kg diet) + ajowan (0.5 g/kg diet). Live body weight significantly (P < 0.05) decreased in rabbits fed AFB1 contaminated diet compared to the control rabbits. All additives improved (P < 0.05) the live body weight. The best improvement occurred with probiotics + ajowan. The addition of probiotics increased (P < 0.05) daily body weight gain in all weeks except the first week. Adding ajowan or ajowan + probiotic led to a significant (P < 0.05) increase in live body weight gain and feed intake compared to rabbits fed AFB1 alone. The digestion coefficients of dry matter (DM), organic matter (OM), crude fiber (CF), ether extract (EE), nitrogen-free extract (NFE), and digestible crude protein (DCP) significantly (P < 0.05) decreased in rabbits fed AFB1 contaminated diet. All additives improved (P < 0.05) the digestibility coefficients of DM, OM, EE, CF, NFE, and total digested nutrients (TDN)%. The best improvement occurred with probiotics + ajowan. Concentrations of serum total protein, albumin and globulin significantly (P < 0.05) decreased in rabbits fed AFB1 contaminated diet compared with the control rabbits. In conclusion, the addition of probiotic 3 (AVI-5-BAC) + ajowan could be recommended to eliminate the toxicity of AFB1 and improve growth performance criteria in rabbits.

Production, characterization and bio-emulsifying application of exopolysaccharides from Rhodotorula mucilaginosa YMM19.

Microbial exopolysaccharides (EPS) are high molecular weight polymers having different sugar residues. EPS have potential applications in different fields, such as medicine, food and environment. Therefore, there is a growing interest in production, characterization and application of EPS from different microorganisms. The present study designed to investigate the production and characterization of EPS from Rhodotorula mucilaginosa YMM19 isolated from Morus nigra L. fruits as well as to examine their potential emulsifying properties. Effect of NaCl concentration, incubation period and pH on the production of EPS was studied. The maximum EPS production by yeast was achieved at 10% NaCl (9741.84 mg/l). The best incubation time for production of EPS was 5 days. Production of EPS decreased under neutral condition and increased at acidic and alkaline condition. The structural feature of EPS was examined by FT-IR and NMR spectral analysis and confirmed the presence of glucose, glucopyranose and galactose. The isolated EPS showed higher emulsification capacity with emulsification activity of 71% and emulsifying index of 60%. The EPS gave strong emulsification for farnesol and was more effective than sodium dodecyl sulphate, a reference emulsifier, in enhancing the herbicidal activity of farnesol against Melilotus indicus under greenhouse condition. The results suggest that the EPS produced by YMM19 strain has a potential to be used as emulsifying agent in pesticide formulations.

Antibacterial and herbicidal properties of secondary metabolites from fungi.

Twenty-eight compounds were isolated from endophytic, soil and marine fungi and their structures were elucidated through spectroscopic methods. The isolated compounds were tested for their antibacterial and herbicidal activities against phytopathogenic bacteria and barnyard grass weed for the first time. Methyleurotinone (14) was the most potent compound against Pectobacterium carotovorum subsp. carotovorum, Pseudomonas syringae pv. syringae, Rhizobium radiobacter and Ralstonia solanacearum with minimum inhibitory concentration (MIC) values of 31.3, 125, 31.3 and 125 mg/L, respectively. Compounds 13-15 were highly effective in reducing the development of potato tuber soft rot disease caused by P. carotovorum subsp. carotovorum. Furthermore, twelve of the tested compounds induced a significant reduction in seed germination of Echinochloa crus-galli at 2 mM with compounds 8 and 26 causing complete inhibition of seed germination. Also, compounds 4, 22, 5, 8, 18 and 25-27 induced remarkable reduction of root and shoot growth of E. crus-galli at 2 mM.

A Note on the Reproducibility of Chaos Simulation.

An evergreen scientific feature is the ability for scientific works to be reproduced. Since chaotic systems are so hard to understand analytically, numerical simulations assume a key role in their investigation. Such simulations have been considered as reproducible in many works. However, few studies have focused on the effects of the finite precision of computers on the simulation reproducibility of chaotic systems; moreover, code sharing and details on how to reproduce simulation results are not present in many investigations. In this work, a case study of reproducibility is presented in the simulation of a chaotic jerk circuit, using the software LTspice. We also employ the OSF platform to share the project associated with this paper. Tests performed with LTspice XVII on four different computers show the difficulties of simulation reproducibility by this software. We compare these results with experimental data using a normalised root mean square error in order to identify the computer with the highest prediction horizon. We also calculate the entropy of the signals to check differences among computer simulations and the practical experiment. The methodology developed is efficient in identifying the computer with better performance, which allows applying it to other cases in the literature. This investigation is fully described and available on the OSF platform.

Ethanedinitrile as a Fumigant for Lasioderma serricorne (Coleoptera: Anobiidae), and Rhyzopertha dominica (Coleoptera: Bostrichidae): Toxicity and Mode of Action.

This study evaluated the fumigant ethanedinitrile (EDN) against the cigarette beetle, Lasioderma serricorne, and phosphine-resistant and susceptible lesser grain borer, Rhyzopertha dominica, life stages under laboratory conditions. Eggs of both species were the most susceptible stage to EDN. EDN is, therefore, a promising alternative because eggs are generally tolerant to most common fumigants. Lasioderma serricorne eggs were the most susceptible with an LC50 estimated of 50.4 ppm, followed by adults, pupae and larvae with LC50 values of 160.2, 192.5, and 446.6 ppm, respectively, after 24-h exposure at 25°C. Eggs of phosphine-susceptible (LC50 = 11.2 ppm) and resistant (LC50 = 12.0 ppm) R. dominica strains were more susceptible to EDN than were adults of both strains, with LC50 values of 27.7 and 36.0 ppm, respectively. Lasioderma serricorne mixed life stage cultures were completely controlled at concentrations ≥2,000 ppm at 24 h. Fumigation with 600 ppm was enough to suppress adult emergence in the case of the phosphine-susceptible R. dominica strain (USDA), while an average of only 4.0 adults emerged from the phosphine-resistant R. dominica strain (Belle Glade) compared with 514.3 adults in the control. Lasioderma serricorne was more tolerant to EDN than both R. dominica strains. EDN caused 61.8 and 68.2 % inhibition of R. dominica (USDA) cytochrome c oxidase activity at concentrations of 0.0038 and 0.0076 mM in vitro, respectively, and it did not inhibit its activity in the case of an in vivo assay. These results suggest that cytochrome c oxidase may not be the main target for EDN toxicity.

Bioherbicidal activity of terpenes and phenylpropenes against Echinochloa crus-galli.

This study was undertaken to evaluate the herbicidal activity of twelve natural compounds belonging to monoterpenes, phenylpropenes, and sesquiterpenes against Echinochloa crus-galli under laboratory and glasshouse conditions. Experiments were conducted to determine the impact of different concentrations (0.5, 1, 2, 4 and 8 mM) of these compounds on the seed germination and root and shoot growth of barnyard grass. trans-Cinnamaldehyde, eugenol, and thymol caused the highest impact on barnyard grass reducing its seed germination and shoot growth. p-Cymene (EC50 = 0.22 mM) and trans-cinnamaldehyde (EC50 = 0.34 mM) were the most potent compounds in limiting the root growth of the E. crus-galli. In a post-emergent experiment, thymol, trans-cinnamaldehyde, eugenol, farnesol, and nerolidol significantly reduced the shoot growth, fresh and dry weight of two-leaf stage barnyard grass after 2 days of the foliar treatment with the concentrations of 0.5, 1.0 and 2.0%. These compounds induced severe visible injury symptoms where trans-cinnamaldehyde, eugenol, farnesol and nerolidol showed a complete weed control at 1.0 and 2.0%. These compounds were successfully formulated as emulsifiable concentrates and showed higher herbicidal activities against barnyard grass. Altogether, our data showed that trans-cinnamaldehyde, eugenol, thymol, farnesol, and nerolidol can be developed as novel bioherbicides for managing E. crus-galli.

Acaricidal activity, biochemical effects and molecular docking of some monoterpenes against two-spotted spider mite (Tetranychus urticae Koch).

Six natural monoterpenes (1,8-cineole, (-)-citronellal, limonene, α-pinene, pulegone and 4-terpineol) showed high acaricidal activity by fumigant and contact actions against adult females of the two-spotted spider mite, Tetranychus urticae Koch. The monoterpenes exhibited varying degrees of acaricidal potency using contact toxicity test after 24 and 48 h of treatment, where the LC50 values were <160 and 45 mg/L, respectively. In fumigation test, of these six monoterpenes, pulegone exhibited the highest toxicity (LC50 = 3.81 mg/L air), while (-)-citronellal had the lowest fumigant toxicity (LC50 = 15.20 mg/L air). All compounds had high inhibitory effect on acetylcholinesterase (AChE) and gama amino butyric acid transaminase (GABA-T) activities. Pulegone was the most AChE inhibitor (IC50 = 8.79 mg/L), while 4-terpineol revealed the lowest inhibitory effect (IC50 = 32.82 mg/L). However, limonene caused the highest inhibition of GABA-T (IC50 = 11.37 mg/L). The molecular docking studies revealed that the compounds displayed different binding interactions with the amino acid residues at the catalytic sites of AChE and GABA-T enzymes. Noncovalent interactions especially van der Waals, hydrogen bonding as well as hydrophobic was found between the compounds and the enzymes. A significant relationship was found between the docking score and the biological activity of monoterpenes compared to the standard acaricide pyridaben. In silico ADMET properties were also performed and displayed potential for the development of good acaricidal candidates.

Insecticidal potential and repellent and biochemical effects of phenylpropenes and monoterpenes on the red flour beetle, Tribolium castaneum Herbst.

The main objectives of the present study are to introduce new, ecologically safe, and natural compounds for controlling red flour beetle, Tribolium castaneum, and to understand the possible mode of action of these compounds. Therefore, the insecticidal and repellent activities of two phenylpropenes and six monoterpenes have been evaluated against the adults of T. castaneum. The inhibitory effects of these compounds on the activity of adenosine triphosphatases (ATPases) and acetylcholinesterase (AChE) were also tested. In fumigant toxicity assay, (-)-terpinen-4-ol (LC50 = 20.47 µl/l air) and α-terpinene (LC50 = 23.70 µl/l air) exhibited the highest toxicity without significant differences between them. Moreover, (-)-menthone and p-cymene showed strong toxicity, while (-)-citronellal, trans-cinnamaldehde, and eugenol were not active. In contact toxicity assay, the two phenylpropenes, trans-cinnamaldehde and eugenol, had the highest toxicity with same LC50 value of 0.02 mg/cm2. The monoterpenes and phenylpropenes showed pronounced repellent effect on the adults of T. castaneum at 0.001 mg/cm2 with (-)-menthone, trans-cinnamaldehyde, and α-terpinene being the most effective after 2 h of exposure. Repellent activity depended on compound, exposure time, and concentration. On the other hand, the tested compounds exhibited strong inhibition of ATPases form the larvae of T. castaneum as their IC50 values ranged between 1.74 and 19.99 mM. In addition, (-)-citronellal (IC50 = 9.82 mM) and trans-cinnamaldehde (IC50 = 23.93 mM) caused the highest inhibitory effect on AChE, while α-pinene (IC50 = 53.86) and p-cymene (IC50 = 68.97 mM) showed the weakest inhibitory effect. The results indicated that the tested phenylpropenes and monoterpenes had the potential to be developed as natural insecticides and repellents for controlling T. castaneum.

Impact of Rosmarinus officinalis cold-pressed oil on health, growth performance, intestinal bacterial populations, and immunocompetence of Japanese quail.

This study was performed to study the impacts of rosemary cold-pressed oil (RCPO) for biostimulating health, growth performance, and intestinal bacterial populations of Japanese quail. The study included 300 growing 1-wk-old Japanese quails. Birds were divided into 3 groups in a complete randomized design experiment that involved 3 levels of RCPO (0, 1.00 and 2.00 mL/kg diet). Results revealed that the addition of rosemary oil numerically increased values of body weight and body weight gain when compared with the control group, particularly the highest level of RCPO (2.00 mL/kg diet). Birds fed diets supplemented with rosemary oil consumed more feed (P ≤ 0.01) compared with those fed the control diet. Feed conversion ratio tended to be improved in rosemary oil groups during the period 3 to 6 wk of age (P = 0.013). The highest level of rosemary oil (2.00 mL/kg diet) had the best impact on all carcass traits studied. RCPO supplementation showed an increase in serum total protein, metabolic hormones levels, while it reduced serum cholesterol and low-density lipoprotein cholesterol, 8-hydroxy-2'-deoxyguanosine, and protein carbonyl levels. Moreover, RCPO increased antioxidative enzymes, and reduced the lipid peroxidation in quail liver. The supplementation of 2 mL/RCPO kg diet showed significant reduction in populations of total cultural bacterial count, coliforms, Escherichia coli, and Salmonella spp. in the ileum when compared to the control. The current results showed that RCPO supplementation to Japanese quails diet could enhance the growth performance and reduce the intestinal pathogenic bacteria. Therefore, RCPO can be a beneficial antimicrobial and growth-promoting feed supplement for the Japanese quail.

Effective antioxidant, antimicrobial and anticancer activities of essential oils of horticultural aromatic crops in northern Egypt.

BACKGROUND: Identifying ornamental plants as new natural antioxidant and antimicrobial sources is always of great importance for the ornamental and horticultural industries. METHODS: The antimicrobial activities of leaves and fruits peel essential oils of twelve ornamental and horticultural crops were determined by screening against wide spectrum of fungi and bacteria, and their respective in vitro antioxidant capacity was evaluated. Furthermore, the anticancer activities against several cancer cells, and one normal human cell line (HEK-293) were examined. RESULTS: Origanum vulgare L. essential oil showed the best antioxidant, antibacterial and anticancer activities compared to screened crops by means of the DPPH and linoleic acid assays for antioxidants, MIC and MBC values for antibacterial activities and IC50 for antiproliferative activities. Such important activities in O. vulgare was attributed to high pulegone ratio (77.45%) as revealed by the GC/MS assay. Rosmarinus officinallis L. essential oil showed the highest antifungal activities by means of lowest MIC and MFC values which might be attributed to 1, 8-cineole (19.60%), camphor (17.01%) and α-pinene (15.12%). CONCLUSION: We suggest that oxygenated monoterpenes (i.e. linalool, terpinen-4-ol and pulegone) and monoterpene hydrocarbons play an important role in the essential oil antioxidant, antibacterial, antifungal and anticancer activities of diverse Egyptian ornamental and horticultural crops. Some species showed bioactivities similar to standards compounds and might be suitable for pharmaceutical and food industries.

Effects of monoterpenes on mortality, growth, fecundity, and ovarian development of Bactrocera zonata (Saunders) (Diptera: Tephritidae).

The peach fruit fly (PFF), Bactrocera zonata, is a serious insect pest infesting fruits and vegetables. The insecticidal activity of three monoterpenes, namely, (R)-camphor, (R)-carvone, and (1R,2S,5R)-menthol, was evaluated on the second-instar larvae of B. zonata. In addition, the latent effects of monoterpenes on pupation, adult emergence, deformation, oviposition, adult longevity, and ovarian development were also examined. The three tested monoterpenes showed pronounced insecticidal activity against B. zonata larvae with (R)-carvone being the most potent toxicant. When the second-instar larvae of B. zonata were treated with monoterpenes at concentrations of 20, 50, and 70 mg/kg for 72 h, significant reduction in pupation and adult emergence was observed. The three monoterpenes caused complete suppression of adult emergence at 100 mg/kg. Moreover, monoterpenes induced complete inhibition of egg deposition at all tested concentrations. Some adult deformations were also noticed at 20, 50, and 70 mg/kg. However, (R)-carvone was more effective than (1R,2S,5R)-menthol and (R)-camphor on the examined biological parameters. On the other hand, histological examination of the ovaries of emerged females from larvae that fed on diet treated with (R)-carvone, (1R,2S,5R)-menthol, and (R)-camphor at 20 and 50 mg/L indicated that both concentrations caused retardation in the development of ovarioles. It is clear that all the egg chambers are empty; the germarium region is constricted at base due to the failure of oocyte formation. Many vacant spaces were present between ovarioles.

Effects of occupational exposure to aluminium on some oxidative stress and DNA damage parameters.

AIM: The aim of this work was to investigate the relationships between aluminium levels, oxidative status and DNA damage in workers occupationally exposed to aluminium. SUBJECTS AND METHODS: This study was conducted in a secondary aluminium smelter. It included 96 male workers occupationally exposed to aluminium fume and dust compared to 96 male nonexposed individuals. Full history and clinical examination were done for all participants. Laboratory investigations in the form of serum aluminium, total antioxidant capacity (TAC), urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) and comet assay test were performed. RESULTS: Serum aluminium level ranged from 4 to 30 µg/L of median: 10 µg/L; urinary 8-OHdG ranged from 2.7 to 17.2 ng/mg creatinine of median: 7.6 ng/mg creatinine; comet tail length (CTL) ranged from 19.7 to 50.5 µm of median: 45 µm, were statistically significantly increased in the exposed group compared to nonexposed group. In exposed workers, a statistically significant positive correlations were found between serum aluminium level and urinary 8-OHdG ( r = 0.75, p < 0.001); aluminium level and CTL ( r = 0.71, p < 0.001); and urinary 8-OHdG and CTL ( r = 0.71, p < 0.001). There was a statistically significant negative correlation between serum aluminium and TAC ( r = -0.76, p < 0.001). CONCLUSION: Occupational exposure to aluminium in secondary aluminium smelters was related to the induction of oxidative stress and DNA damage. This may promote the development of adverse health hazards in the exposed workers.

Insecticidal properties of essential oils against Tribolium castaneum (Herbst) and their inhibitory effects on acetylcholinesterase and adenosine triphosphatases.

Essential oils from 20 Egyptian plants were obtained by using hydrodistillation. The chemical composition of the isolated oils was identified by gas chromatograph/mass spectrometer. Fumigant and contact toxicities of the essential oils were evaluated against the adults of Tribolium castaneum. In fumigation assays, the oil of Origanum vulgare (LC50 = 9.97 mg/L air) displayed the highest toxicity towards the adults of T. castaneum. In contact assays, the oils of Artemisia monosperma (LC50 = 0.07 mg/cm(2)) and O. vulgare (LC50 = 0.07 mg/cm(2)) were the most potent toxicants against the adults of T. castaneum. Biochemical studies showed that the tested oils caused pronounced inhibition of acetylcholinesterase (AChE) and adenosine triphosphatases (ATPases) isolated from the larvae of T. castaneum. The oil Cupressus macrocarpa (IC50 = 12.3 mg/L) was the most potent inhibitor of AChE, while the oil of Calistemon viminals (IC50 = 4.4 mg/L) was the most potent inhibitor of ATPases.

Rings B,D-seco limonoid antifeedants from Swietenia mahogani.

Three phragmalin-type limonoids, swietephragmin H (1), swietephragmin I (2) and 11-hydroxyswietephragmin B (3), and a mexicanolide-type limonoid 2-hydroxy-6-deacetoxyswietenine (4), together with known compounds, 6-O-acetyl-2-hydroxyswietenin (5), 2-hydroxyswietenine (6), swietemahonin G (7), methyl 6-hydroxyangolensate (8) and 7-deacetoxy-7-oxogedunin (9) were isolated from the leaves of Swietenia mahogani (Meliaceae). Their structures were established by extensive NMR experiments in conjunction with mass spectrometry. The antifeedant activity of the isolated compounds was evaluated.

Synthesis of some quinolinyl chalcone analogues and investigation of their anticancer and synergistic anticancer effect with doxorubicin.

Two derivatives of 2-(4-acetylanilino)quinolines (IIIa, b) were synthesized as scaffolds for synthesis of open chalcone analogues (Va-f) through Claisen-Schmidt condensation with a set of aromatic aldehydes (IVa-d). Derivatives (Va, b) were further manipulated into cyclic alpha,beta-unsaturated ketones by Michael-addition of acetylacetone and ethylacetoacetate affording derivatives (VI-VII). Deethoxycarboxylation of derivatives (VIIa, b) afforded cyclohexenons (VIIIa, b) allowing formation of a mini library of alpha,beta-unsaturated ketones for screening their anticancer and synergistic anticancer effect with doxorubicin using colon cancer cell line (Caco-2). Two open enones, (Vb) and (Ve), showed significant anticancer activity with IC50 of 5.0 and 2.5 microM respectively. Only one cyclic enone, (VIa) showed synergistic anticancer activity with doxorubicin at 10 microM.

Acaricidal and quantitative structure activity relationship of monoterpenes against the two-spotted spider mite, Tetranychus urticae.

The acaricidal activity of 12 monoterpenes against the two-spotted spider mite, Tetranychus urticae Koch, was examined using fumigation and direct contact application methods. Cuminaldehyde and (-)-linalool showed the highest fumigant toxicity with LC(50) = 0.31 and 0.56 mg/l, respectively. The other monoterpenes exhibited a strong fumigant toxicity, the LC(50) values ranging from 1.28 to 8.09 mg/l, except camphene, which was the least effective (LC(50) = 61.45 mg/l). Based on contact activity, the results were rather different: menthol displayed the highest acaricidal activity (LC(50) = 128.53 mg/l) followed by thymol (172.0 mg/l), geraniol (219.69 mg/l) and (-)-limonene (255.44 mg/l); 1-8-cineole, cuminaldehyde and (-)-linalool showed moderate toxicity. At 125 mg/l, (-)-Limonene and (-)-carvone caused the highest egg mortality among the tested compounds (70.6 and 66.9% mortality, respectively). In addition, the effect of molecular descriptors was also analyzed using the quantitative structure activity relationship (QSAR) procedure. The QSAR model showed excellent agreement between the estimated and experimentally measured toxicity parameter (LC(50)) for the tested monoterpenes and the fumigant activity increased significantly with the vapor pressure. Comparing the results of the fumigant and contact toxicity assays of monoterpenes against T. urticae with the results of acetylcholinesterase (AChE) inhibitory effect revealed that some of the tested compounds showed a strong acaricidal activity and a potent AChE inhibitory activity, such as cuminaldehyde, (-)-linalool, (-)-limonene and menthol. However, other compounds such as (-)-carvone revealed a strong fumigant activity but a weak AChE inhibitory activity.

Fumigant and contact toxicities of monoterpenes to Sitophilus oryzae (L.) and Tribolium castaneum (Herbst) and their inhibitory effects on acetylcholinesterase activity.

A comparative study was conducted to assess the contact and fumigant toxicities of eleven monoterpenes on two important stored products insects--, Sitophilus oryzae, the rice weevil, and Tribolium castaneum, the rust red flour beetle. The monoterpenes included: camphene, (+)-camphor, (-)-carvone, 1-8-cineole, cuminaldehyde, (L: )-fenchone, geraniol, (-)-limonene, (-)-linalool, (-)-menthol, and myrcene. The inhibitory effect of these compounds on acetylcholinesterase (AChE) activity also was examined to explore their possible mode(s) of toxic action. Although most of the compounds were toxic to S. oryzae and T. castaneum, their toxicity varied with insect species and with the bioassay test. In contact toxicity assays, (-)-carvone, geraniol, and cuminaldehyde showed the highest toxicity against S. oryzae with LC(50) values of 28.17, 28.76, and 42.08 microg/cm(2), respectively. (-)-Carvone (LC(50) = 19.80 microg/cm(2)) was the most effective compound against T. castaneum, followed by cuminaldehyde (LC(50) = 32.59 microg/cm(2)). In contrast, camphene, (+)-camphor, 1-8-cineole, and myrcene had weak activity against both insects (i.e., LC(50) values above 500 microg/cm(2)). In fumigant toxicity assays, 1-8-cineole was the most effective against S. oryzae and T. castaneum (LC(50) = 14.19 and 17.16 mg/l, respectively). Structure-toxicity investigations revealed that (-)-carvone--, a ketone--, had the highest contact toxicity against the both insects. 1-8-Cineole--, an ether--, was the most potent fumigant against both insects. In vitro inhibition studies of AChE from adults of S. oryzae showed that cuminaldehyde most effectively inhibited enzyme activity at the two tested concentrations (0.01 and 0.05 M) followed by 1-8-cineole, (-)-limonene, and (L)-fenchone. 1-8-Cineole was the most potent inhibitor of AChE activity from T. castaneum larvae followed by (-)-carvone and (-)-limonene. The results of the present study indicate that (-)-carvone, 1,8-cineole, cuminaldehyde, (L)-fenchone, and (-)-limonene could be effective biocontrol agents against S. oryzae and T. castaneum.

Bioactivity of two major constituents isolated from the essential oil of Artemisia judaica L.

The essential oil of Artemisia judaica L., grown on Sinai Peninsula of Egypt, was extracted via hydrodistillation. Chromatographic separation on repeated silica gel columns led to isolate two compounds namely piperitone and trans-ethyl cinnamate. Insecticidal, antifeedant and antifungal properties of the isolated compounds were examined. Both compounds showed pronounced insecticidal and antifeedant activity against the third instar larvae of Spodoptera littoralis (Boisd). trans-Ethyl cinnamate (LD(50)=0.37 microg/larva) was more toxic than piperitone (LD(50)=0.68microg/larva). The two isolated compounds revealed antifeedant activity in a concentration dependent manner, with complete feeding inhibition at a concentration of 1,000microg/ml. When tested for antifungal activity against four plant pathogenic fungi, the isolated compounds exhibited a moderate to high activity.

Rings B,D-seco limonoids from the leaves of Swietenia mahogani.

Seven phragmalin limonoids of swietephragmins A-G, and two other different types of 2-hydroxy-3-O-tigloylswietenolide and deacetylsecomahoganin, were isolated along with three known limonoids from the leaves of Swietenia mahogani (Meliaceae). Their structures were determined by spectroscopic methods.

Antibacterial activity of an eudesmane sesquiterpene isolated from common Varthemia, Varthemia iphionoides.

The ethyl acetate extract of the whole aerial parts of Varthemia iphionoides (Compositae) showed a pronounced antibacterial activity. The bioassay-guided fractionation of the ethyl acetate extract and further purification of the most antibacterially active fraction led to the isolation and identification of an antibacterial sesquiterpene, selina-4,11(13)-dien-3-on-12-oic acid. This compound exhibited potent antimicrobial activity against six bacterial species (Staphylococcus aureus, Bacillus subtilis, Micrococcus luteus, Escherichia coli, Bacillus cereus and Salmonella enteritides). The minimum inhibitory concentrations (MICs) of this compound which was determined by the agar dilution method ranged between 250 and 500 microg/ml.