7a-O-methyldeguelol, a modified rotenoid with an open ring-C, from the roots of Derris trifoliata

From the acetone extract of the roots of Derris trifoliata an isoflavonoid derivative, named 7a-O-methyldeguelol, a modified rotenoid with an open ring-C, representing a new sub-class of isoflavonoids (the sub-class is here named as rotenoloid), was isolated and characterised. In addition, the known rotenoids, rotenone, deguelin and alpha-toxicarol, were identified. The structures were determined on the basis of spectroscopic evidence. Rotenone and deguelin were identified as the larvicidal principles of the acetone extract of the roots of Derris trifoliata.     

Mosquito larvicidal activity of Aloe vera (Family: Liliaceae) leaf extract and Bacillus sphaericus,against Chikungunya vector,Aedes aegypti

The bio-efficacy of Aloe vera leaf extract and bacterial insecticide, Bacillus sphaericus larvicidal activity was assessed against the first to fourth instars larvae of Aedes aegypti, under the laboratory conditions. The plant material was shade dried at room temperature and powdered coarsely. A. vera and B. sphaericus show varied degrees of larvicidal activity against various instars larvae of A. aegypti. The LC₅₀ of A. vera against the first to fourth instars larvae were 162.74, 201.43, 253.30 and 300.05 ppm and the LC₉₀ 442.98, 518.86, 563.18 and 612.96 ppm, respectively. B. sphaericus against the first to fourth instars larvae the LC₅₀ values were 68.21, 79.13, 93.48, and 107.05 ppm and the LC₉₀ values 149.15, 164.67, 183.84, and 201.09 ppm, respectively. However, the combined treatment of A. vera + B. sphaericus (1:2) material shows highest larvicidal activity of the LC₅₀ values 54.80, 63.11, 74.66 and 95.10 ppm; The LC₉₀ values of 145.29, 160.14, 179.74 and 209.98 ppm, against A. aegypti in all the tested concentrations than the individuals and clearly established that there is a substantial amount of synergist act. The present investigation clearly exhibits that both A. vera and B. sphaericus materials could serve as a potential larvicidal agent. Since, A. aegypti is a container breeder vector mosquito this user and eco-friendly and low-cost vector control strategy could be a viable solution to the existing dengue disease burden. Therefore, this study provides first report on the mosquito larvicidal activity the combined effect of A. vera leaf extract and B. sphaericus against as target species of A. aegypti.     

Antifeedant and larvicidal activities of Rhein isolated from the flowers of Cassia fistula L.

Antifeedant and larvicidal activities of rhein (1,8-dihydroxyanthraquinone-3-carboxylic acid) isolated from the ethyl acetate extract of Cassia fistula flower were studied against lepidopteron pests Spodoptera litura and Helicoverpa armigera. Significant antifeedant activity was observed against H. armigera (76.13%) at 1000 ppm concentration. Rhein exhibited larvicidal activity against H. armigera (67.5), S. litura (36.25%) and the LC₅₀ values was 606.50 ppm for H. armigera and 1192.55 ppm for S.litura. The survived larvae produced malformed adults.     

Efficacy of leaves extract of Calotropis procera Ait. (Asclepiadaceae) in controlling Anopheles arabiensis and Culex quinquefasciatus mosquitoes

The present study aimed to investigate, the larvicidal, adult emergence inhibition and oviposition deterrent activity of aqueous leaves extract of Calotropis procera against Anopheles arabiensis and Culex quinquefasciatus as natural mosquito larvicide. The larvicidal activity was monitored against 2nd, 3rd and 4th instar larvae of each mosquito species 24 h post-treatment. Adult emergence inhibition activity was tested by exposing 3rd instar larvae of each mosquito species to different concentrations of extracts (200, 400, 600, 800 and 1000 ppm for An. arabiensis and 100, 200, 300, 400, 500 and 600 ppm for Cx. quinquefasciatus). Probit analysis was used to analyze data from bioassay experiments. The oviposition deterrent activity was tested by using three different concentrations of extracts (1000, 500 and 200 for An. arabiensis, and 1000, 500 and 100 for Cx. quinquefasciatus) that caused high, moderate and low larval mortality in the larvicidal experiment against 3rd instar larvae. It was found that, LC50–LC90 values calculated were 273.53–783.43, 366.44–1018.59 and 454.99–1224.62 ppm for 2nd, 3rd and 4th larval instars, respectively, of An. arabiensis and 187.93–433.51, 218.27–538.27 and 264.85–769.13 ppm for 2nd, 3rd and 4th larval instars, respectively, of Cx. quinquefasciatus. Fifty percent of adult emergence inhibition (EI50) was shown at 277.90 and 183.65 ppm for An. arabiensis and Cx. quinquefasciatus, respectively. The pupal stage was not affected till a concentration of 5000 ppm. The extract showed oviposition deterrence and effective repellence against both mosquito species at different concentrations, with the observation on that maximal eggs were laid in low concentration of extract. These results suggest that the leaves extract of C. procera possess remarkable larvicidal, adult emergence inhibitor, repellent and oviposition deterrent effect against both An. arabiensis and Cx. quinquefasciatus, and might be used as natural biocides for mosquito control.     

p13 from group II baculoviruses is a killing-associated gene

p13 gene was first described in Leucania separata multinuclear polyhedrosis virus (Ls-p13) several years ago, but the function of P13 protein has not been experimentally investigated to date. In this article, we indicated that the expression of p13 from Heliothis armigera single nucleocapsid nucleopolyhedrovirus (Ha-p13) was regulated by both early and late promoter. Luciferase assay demonstrated that the activity of Ha-p13 promoter with hr4 enhancer was more than 100 times in heterologous Sf9 cells than that in nature host Hz-AM1 cells. Both Ls-P13 and Ha-P13 are transmembrane proteins. Confocal microscopic analysis showed that both mainly located in the cytoplasm membrane at 48 h. Results of RNA interference indicated that Ha-p13 was a killing-associated gene for host insects H. armigera. The AcMNPV acquired the mentioned killing activity and markedly accelerate the killing rate when expressing Ls-p13. In conclusion, p13 is a killing associated gene in both homologous and heterologous nucleopolyhedrovirus. [BMB Reports 2012; 45(12): 730-735]     

Separation of floridoside and isofloridosides by HPLC and complete (1)H and (13)C NMR spectral assignments for D-isofloridoside

Isofloridosides (1-O-alpha-D-galactopyranosylglycerol) and floridoside (2-O-alpha-D-galactopyranosylglycerol) were extracted from the red alga Porphyra umbilicalis (Linné) Kützing (Bangiales, Rhodophyta). Their separation was achieved by HPLC (NH(2) P50 column) after successive purification of the crude extract by ion-exchange chromatography and HPLC (Sugar-Pak TM1 column). 1D and 2D NMR spectroscopy experiments allowed to completely assign the (1)H and (13)C spectra of D-isofloridoside.     

Assessment of the efficacy of Japanese Bacillus thuringiensis isolates against the cigarette beetle,Lasioderma serricorne (Coleoptera: Anobiidae)

A total of 2,652 Japanese isolates of Bacillus thuringiensis, belonging to at least 54 H serogroups, were examined for assessment of the toxicity against the cigarette beetle, Lasioderma serricorne (Coleoptera: Anobiidae). When tested with spore/parasporal inclusion mixtures, strong larvicidal activities were associated with 28 isolates (1.1%). Serologically, these toxic isolates fell into 4 known H serovars: thuringiensis (9 isolates), kurstaki (2), kenyae (2), and darmstadiensis (15). Purified parasporal inclusions of the 10 selected isolates exhibited no larvicidal activity, while the supernatants of liquid cultures showed larvicidal and/or growth inhibitory effects. The activities were fully retained after heat treatment at 100 degrees C for 10 min. Overall results suggest that beta-exotoxin (or thuringiensin)-related substances are responsible for the toxicity of the present B. thuringiensis isolates against the cigarette beetle.     

Effects of Insect-Growth-Regulatory Benzimidazole Derivatives on Cultured Integument of the Rice Stem Borer and Mitochondria from Rat Liver

The larvicidal activities of benzimidazole derivatives with a terpenoid side chain on the rice stem borer and the silkworm were compared with such in vitro activities as the growth inhibition of the cultured integument of the rice stem borer and the respiration inhibition of rat liver mitochondria. Each larvicidal activity is parallel with these in vitro activities. The comparisons of their activities with those of rotenone and diflubenzuron indicate that the benzimidazoles mainly acted as respiration inhibitors in their larvicidal activity as well as causing cuticular growth inhibition. The activity of 1-(3,7-dimethyl-7-ethoxy-2-octenyl)-2-methylbenzimidazole, the most potent compound tested as a respiration inhibitor, was found to be about 6-fold higher than that of rotenone. In the respiratory chain, the site between NADH and ubiquinone was blocked, indicating that the larvicidal benzimidazoles shared a mode of action with those of rotenone, piericidins, and ubicidines.     

Isolation and chemotaxonomic significance of tuberostemospironine-type alkaloids from Stemona tuberosa

An alkaloid named 6alpha-hydroxycroomine (1) as well as the known croomine (2), both belonging to the tuberostemospironine-alkaloid type, were isolated from Stemona tuberosa as the major components. The structure of 1 was elucidated through extensive spectroscopic analyses. Comparison of the HPLC profiles of the total alkaloids and the crude methanol extract showed that both compounds are naturally occurring. The first isolation of 1 and 2 from S. tuberosa has chemotaxonomic significance, confirming the close relationship between Stemona and Croomia. The trnL sequences of plants from the four genera of Stemonaceae cluster together as a clade, further lending support to retaining them in a single family.     

Polar acyclic diterpenoids from Bifurcaria bifurcata (Fucales, Phaeophyta)

From the lipophilic extract of the brown alga Bifurcaria bifurcata collected off the Atlantic coast of Southern Brittany (Quiberon, France), five polar linear diterpenoids have been isolated. These metabolites have been identified as hydroxylated derivatives of 13-oxo- and 13-hydroxygeranylgeraniol. Their structures were characterized on the basis of chemical and spectral evidence including two-dimensional NMR experiments and mass spectrometric techniques. The absolute configuration of the 13-position has been determined, for the 13-hydroxygeranylgeraniol derivatives, to be R by means of a modified Mosher's method and therefore that of 13-hydroxygeranylgeraniol (eleganediol) has been revised. Along with these compounds, three related known geranylgeraniol derivatives were also identified, and these data were used for chemotaxonomical purposes.     

Quantitative analysis of the microbial metabolome by isotope dilution mass spectrometry using uniformly 13C-labeled cell extracts as internal standards

A novel method was developed for the quantitative analysis of the microbial metabolome using a mixture of fully uniformly (U) (13)C-labeled metabolites as internal standard (IS) in the metabolite extraction procedure the subsequent liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) analysis. This mixture of fully U (13)C-labeled metabolites was extracted from biomass of Saccharomyces cerevisiae cultivated in a fed-batch fermentation on fully U (13)C-labeled substrates. The obtained labeled cell extract contained, in principle, the whole yeast metabolome, allowing the quantification of any intracellular metabolite of interest in S. cerevisiae. We have applied the labeled cell extract as IS in the analysis of glycolytic and tricarboxylic acid (TCA) cycle intermediates in S. cerevisiae sampled in both steady-state and transient conditions following a glucose pulse. The use of labeled IS effectively reduced errors due to variations occurring in the analysis and sample processing. As a result, the linearity of calibration lines and the precision of measurements were significantly improved. Coextraction of the labeled cell extract with the samples also eliminates the need to perform elaborate recovery checks for each metabolite to be analyzed. In conclusion, the method presented leads to less workload, more robustness, and a higher precision in metabolome analysis.     

Bioefficacy of Aristolochia tagala Cham. against Spodoptera litura Fab. (Lepidoptera: Noctuidae)

Bioefficacy of leaf and root extracts of Aristolochia tagala Cham. at different concentrations was evaluated at room temperature against Spodoptera litura Fab. Effects on feeding, larvicidal and pupicidal activities and larval–pupal duration were studied. Higher antifeedant activity (56.06%), lethal concentration for feeding inhibition (3.69%), larvicidal (40.66%), pupicidal (28%), total mortality (68.66%) and prolonged larval–pupal duration (12.04–13.08 days) were observed in ethyl acetate leaf extract at 5.0% concentration. Dose dependant effect of test extracts was observed. This plant could be used to isolate active principles and to develop a new botanical formulation in pest management programmes.     

Identification and quantitative determination of carbohydrates in ethanolic extracts of two conifers using 13C NMR spectroscopy

We developed a method for the direct identification and quantification of carbohydrates in raw vegetable extracts using (13)C NMR spectroscopy without any preliminary step of precipitation or reduction of the components. This method has been validated (accuracy, precision and response linearity) using pure compounds and artificial mixtures before being applied to authentic ethanolic extracts of pine needles, pine wood and pine cones and fir twigs. We determined that carbohydrates represented from 15% to 35% of the crude extracts in which pinitol was the principal constituent accompanied by arabinitol, mannitol, glucose and fructose.     

Prenylated isoflavonoids from Millettia pervilleana

From the root bark of Millettia pervilleana, which had shown significant cytotoxic activity, a 3-phenylcoumarin, named pervilleanine, two new pterocarpans, pervilline and pervillinine, and one known, emoroidocarpan, were isolated in addition to rotenone and 3alpha-hydroxyrotenone. The anticancer activity of two previously isolated isoflavanones, pervilleanone and 3'-O-demethylpervilleanone is reported.     

Inhibition of Site I mitochondrial electron transport by an extract of the seeds of Millettia thonningii: a potential mechanism for the plant's molluscicidal and schistosome larvicidal activity

A dichloromethane extract of the seeds of Millettia thonningii (Leguminosae) which contains a mixture of isoflavonoids (predominantely robustic acid, alpinumisoflavone and dimethylalpinumisoflavone) is known to have larvicidal activity towards the miracidia and cercariae of schistosomes and to possess significant molluscicidal activity. The present investigation has assayed the effects of this extract on the electron transport systems of isolated rat liver mitochondria. The extract was found to inhibit mitochondrial electron transport at Site I (NADH dehydrogenase) at concentrations of 30-159 mg x l(-1). Although the extract is not as potent an inhibitor at Site I as rotenone, a known inhibitor of NADH dehydrogenase, such observations could explain the molluscicidal and schistosomicidal activity of dichloromethane extracts of the seeds of M. thonningii.     

3 beta,13-dihydroxylated C20 gibberellins from inflorescences of Rumex acetosa L

Using full scan GC-MS a wide range of gibberellins (GAs) was identified in the young inflorescences of the dioecious species Rumex acetosa L., consistent with the ubiquitous early 13-hydroxylation pathway in both male and female plants. In addition, R. acetosa is the first species in which all three 3beta,13-dihydroxylated C(20)-GAs-GA(18), GA(38) and GA(23)-have been identified in the same organism, suggesting an early 3beta,13-dihydroxylation biosynthesis pathway in this species. Authentic GA(18), GA(38) and GA(23) were synthesized and their effects and that of GA(1), a GA common to both pathways, on the time to inflorescence emergence was investigated. GA(1) accelerated the emergence of inflorescences in both male and female plants. In addition some evidence for biological activity per se of the C(20)-GA(38) was obtained.     

Larvicidal activity of extracts from Artemisia species against Culex pipiens L. mosquito: comparing endemic versus ubiquist species for effectiveness

The larvicidal activity of ethanolic leaf extracts from two Artemisia species, Artemisia campestris var. glutinosa and A. molinieri, on mosquito Culex pipiens Linnaeus (Diptera, Culicidae) larvae was investigated. Since A. molinieri is a rare and protected species confined to temporary ponds of Southern France, its toxic activity may help to value this species and to finance its conservation. A. molinieri extracts showed a higher larvicidal activity (from 50 ppm (K=9.488, DDL=4, P<0.001)) than those from A. campestris var glutinosa (from 500 ppm (K=9.488, DDL=4, P<0.01)) after 48 h of exposure. Calculated lethal concentrations, after 48 h of exposure, (LC(50)) were low, 9091 and 9898 ppm for A. molinieri and A. campestris var. glutinosa extracts, respectively, but using a non-pollutant solvent (ethanol). However, A. molinieri may be valued as an environmentally friendly biocide and developing its culture may be of interest for both pesticide activity and conservation purpose.     

Lanosterol and tetranorlanosterol glycosides from the bulbs of Muscari paradoxum

Three tetranorlanostane glycosides, named lucilianosides C-E, and three lanostane glycosides, named scillasaponins E-G, together with a known lanostane glycoside, were isolated from the MeOH extract of Muscari paradoxum (Liliaceae) bulbs, as confirmed by detailed analysis of their 1H, 13C, and two-dimensional NMR spectroscopic data, and by the results of hydrolytic cleavage. The isolated compounds were evaluated for their cytotoxic activity against HSC-2 human oral squamous cell carcinoma cells.     

C-methylated and C-prenylated isoflavonoids from root extract of Desmodium uncinatum

A pterocarpan, 1,9-dihydroxy-3-methoxy-2-methylpterocarpan (named uncinacarpan) and two isoflavanones, 5,7-dihydroxy-2',3',4'-trimethoxy-6-(3-methylbut-2-enyl)isoflavanone (named uncinanone D) and 5,4'-dihydroxy-7,2'-dimethoxy-6-methylisoflavanone (named uncinanone E), were isolated from the CH(2)Cl(2) root extract of Desmodium uncinatum (Jacq.) DC and characterised by spectroscopic methods. In addition, a rare pterocarpan edudiol and two known abietane diterpenes, 7-oxo-15-hydroxydehydroabietic acid and 7-hydroxycallitrisic acid were identified. The fraction of the root extract that was analysed induced germination of Striga hermonthica seeds, but none of the isolated compounds showed this activity.