Mexican Annonaceae with insecticidal metabolites

Coelogyne ovalis Lindl. is one of the important medicinal orchid, has been used in traditional medicines for the treatment of various human aliments. The therapetical uses of this orchid may be attributed to the presence of various secondary metabolites ultimately produced via the phenylpropanoid pathway. Amongst the various genes involved in phenylpropanoid pathway, chalcone synthase (CHS) deserves a special mention as it plays a pivotal role in the synthesis of secondary metabolites. In the present research, an attempt has been made to modulate the expressions of CHS transcript and subsequent enhancement in the production of secondary metabolites (phenolics, flavonoids and anthocyanins) and antioxidant activity by the application of biotic (chitosan and yeast extracts) and abiotic (salicylic acid, methyl jasmonate and abscisic acid) stresses to the in vitro-raised plantlets. Amongst the various stress factors taken into consideration, salicylic acid-treated leaves showed the highest tissue-specific expression pattern (13.53-fold at 50 μM), followed by methyl jasmonate (10.80-fold at 100 μM), chitosan (9.04-fold at 100 μM) as compared to control plantlets. The correlation between CHS expression and the presence of secondary metabolites was also studied to find out a suitable condition which would result in higher accumulation of secondary metabolites. Further, elicitations with best three stresses (namely salicylic acid, methyl jasmonate and chitosan) significantly modulated the accumulation of secondary metabolites. Deviations were also detected in terms of phytochemical contents; the salicylic acid-treated leaf tissues showed the highest contents of flavonoids (34.18 mg QE/gm DW) and anthocyanins (24.08 mg / gm FW) whereas phenolic contents were recorded to be highest in pseudobulbs (44.61 mg GAE/ gm DW). The plantlets treated with salicylic acid resulted in enhanced production of secondary metabolites and significantly higher antioxidant activity (DPPH and metal chelating). The present result suggests that stress stimulates CoCHS expression and secondary metabolites production in the treated tissues of C. ovalis.

Application of Biolog FF MicroPlate for substrate utilization and metabolite profiling of closely related fungi

Abstract: The Annonaceae family besides its commercial value ( Annona cherimola, , A. macroprophyllata, A. muricata, A. reticulata, A. purpurea , A. squamosa, Annona x atemoya) also produces several active secondary metabolites. Among these metabolites, Annonaceous acetogenins which are exclusive in this family, are reported with insecticidal activity on various species of insects that are crop pests and disease vectors. This review systematizes what is reported in the scientific literature about them: aspects such as the plant species from which the acetogenins come, and the insecticidal potential using the comparative activity index; it also takes into account lethality, morphological, physiological, and behavioral changes, including deterrent and anti-feeding effects. Eighty-five annonaceous acetogenins are documented on thirty species of insects, as well as toxic activities at various stages of development, broad-spectrum, and differential. The studies on Aedes aegypti (Diptera) and Spodoptera frugiperda (Lepidoptera) and the activity of squamocin on fifteen species of insects stand out. Annonaceous acetogenins are toxic at low concentrations, considering evaluation standards and comparison with commercial insecticides, and are active at various stages of insect development. The low proportion of studied species of the Annonaceae means the opportunity to find molecules with this biological potential, and an argument for its conservation.

Aims: Knowledge on the plant phytochemistry provides a fundamental use of plants as a reservoir of chemical agents. Hence, the study on the presence of Phytochemicals in the aqueous extract of 100 different plant species belonging to 44 families collected from Chennai, India was detected. Place and Duration: Plants distributed in the Chennai district of Tamil Nadu state in India were studied. The study was conducted during the period of November 2012 to January 2013. Methods: Leaves of around 100 plant species belonging to different habit like trees, shrubs, herbs and creepers or climbers from Chennai and its surround districts of India were collected. The aqueous extract of air dried, pulverized leaf samples of collected plants were examined for the presence of Tannins, Phlobatannins, Saponins, Flavonoids, Terpenoids, Cardiac glycosides and Steroids using the standard techniques proposed by Evans (1996). The presence of individual secondary metabolites was calculated in percentage and their prevalence in different plant habit was studied. Results: Around 29%, 20%, 23%, 48%, 22%, 30% and 44% of plants showed the presence of Tannins, Phlobatannins, Saponins, Flavonoids, Terpenoids, Cardiac glycosides and Steroids in that order. Further, the presence of secondary metabolites according to the plant habit like, tree, shrub, herb and creeper or climber was detected. Conclusion: It was evident that the presence of Tannin, Phlobatannin, Flavonoids and Cardiac glycosides are found prevalent in trees, Steroids in herbs and Terpenoids in shrubs. However, further study on this aspect is recommended.

BackgroundBidens pilosa and Dichrostachys cinerea extracts were investigated for the antibacterial properties against waterborne diarrhoeagenic bacteria.MethodsThe plant materials were extracted using the direct and serial exhaustive methods using solvents of varying polarities, namely, hexane, dichloromethane, ethyl acetate, acetone and methanol. Qualitative phytochemical analysis and quantitative determination of total phenolic content of the leaf powders of the two plants were tested. The antioxidant activities of the plants were determined using the 2, 2-diphenyl-1-picrylhydrazyl method. The toxic effect of the extracts on C2C12 muscle cell line were assessed by the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide method and the antibacterial activity was determined using the serial microbroth dilution.ResultsMethanol leaf extracts both plants had the highest yield in both direct and serial exhaustive extraction methods. Phytochemical profiling of the extracts displayed the presence of various secondary metabolites. The Benzene: ethanol: ammonia hydroxide solvent system showed a good resolution of chemical compounds in plant extracts from both plants. Most antioxidant compounds observed were developed in chloroform: ethyl acetate: formic acid and ethyl acetate: methanol: water solvent systems. All the bacterial species tested were sensitive to the effect of different extracts of both plant species, with E. coli being less sensitive to the effect of the extracts from D. cinerea. Following the simulated gastric fluid (SGF) treatment, a decrease in the antibacterial potency of the extracts was observed. No extract was toxic to the C2C12 muscle cell line.ConclusionThe presence of the secondary metabolites and nontoxic effect of the two plants tested may affirm the medicinal value of these leaf extracts. Our results suggest that B. pilosa and D. cinerea contain constituents with antioxidant and antimicrobial activities, which could be used in the treatment of diarrhoea in a case where untreated surface water is used.

Experiments were conducted to investigate the effect of plant energy content and the presence of secondary metabolites on the assirmlation efficiency.ahmentary tract evacuation rate, and feeding rate of the bucktooth parrotfish Sparisoma radians.Alimentary tract evacuation rate was significantly greater (ca 2 .5 ~) when the fish fed on the relatively energy-poor calcareous green alga Halimeda incrassata than on the seagrass Thalassia testudinum.The greater evacuation rate of H. incrassata provided the fish the capacity to increase consumption rate to compensate for low food energy content.However, due to unpalatable secondary chemical metabolites present in H. incrassata.actual biomass consumed per unit time was less than for T testudinum.Experiments using T testudinum blades coated with H. incrassata organic crude extract showed that the secondary metabolites had no effect on the fish's assimilation efficiency or gut evacuation rate.The increased rate of H. incrassata evacuation is more than sufficient to allow compensation for lower gross energy content.S. radians can increase evacuation rate sufficiently to allow compensation for differences in available energy over the normal range for most plants consumed in nature.Studies of herbivorous fish foraging and feeding energetics must consider differences in alimentary tract evacuat~on rate and feeding rate, and the effects of secondary metabolites, in addition to the assimilation efficiency, structural defense and relative plant abundance factors usually considered.

Juvenile hormone antagonistic activity of secondary metabolites from Streptomyces lactacystinicus and their insecticidal activity against Plutella xylostella

omega-Atracotoxin-Hv1a is an insect-specific neurotoxin whose phylogenetic specificity derives from its ability to antagonize insect, but not vertebrate, voltage-gated calcium channels. In order to help understand its mechanism of action and to enhance its utility as a lead compound for insecticide development, we used a combination of protein engineering and site-directed mutagenesis to probe the toxin for key functional regions. First, we constructed a Hairpinless mutant in which the C-terminal beta-hairpin, which is highly conserved in this family of neurotoxins, was excised without affecting the fold of the residual disulfide-rich core of the toxin. The Hairpinless mutant was devoid of insecticidal activity, indicating the functional importance of the hairpin. We subsequently developed a highly efficient system for production of recombinant toxin and then probed the hairpin for key functional residues using alanine-scanning mutagenesis followed by a second round of mutagenesis based on initial "hits" from the alanine scan. This revealed that two spatially proximal residues, Asn(27) and Arg(35), form a contiguous molecular surface that is essential for toxin activity. We propose that this surface of the beta-hairpin is a key site for interaction of the toxin with insect calcium channels.

Secondary metabolites in Cordyceps javanica with insecticidal potential

Relationship between lichen species composition, secondary metabolites and soil pH, organic matter, and grain characteristics in Manitoba

In lichens, secondary metabolites have been shown to protect against biotic stresses such as pathogen attacks and grazing, and abiotic stresses such as ultraviolet (UV) and high photosynthetically active radiation (PAR). Lichen secondary metabolites are known to have strong antioxidant activity, and while theoretically they may have roles in tolerance to other abiotic stresses, these roles remain largely unclear. Here, we used the acetone rinsing method to harmlessly remove most of the secondary metabolites from the thalli of six lichen species. This enabled us to compare the effects of desiccation on thalli with and without the presence of secondary metabolites. Results showed that in general, the presence of lichen substances reduces the effects of desiccation stress. For all species, substances significantly improved the photosystem two (PSII) activity of the photobiont during either desiccation or rehydration. In the mycobiont, in four of the six species, the presence of substances reduced membrane damage, which was assessed by measuring ion leakage during rehydration following desiccation. However, in one species, secondary metabolites had no effect, while in another the presence of substances increased membrane damage. Nevertheless, it seems clear that in addition to their more established roles in protecting lichens against pathogen attacks and grazing, lichen substances can also play a role in aiding desiccation tolerance.

1. Many animals that consume freshwater macrophytes are omnivorous (i.e., they include both plant and animal matter in their diet). For invertebrate omnivorous consumers, selection of macrophyte species depends partly on the presence of secondary metabolites in plants, plant carbon/nutrient balances and/or physical structure of plants. However, little is known about the mechanisms influencing consumption of macrophytes in aquatic vertebrates. 2. For two fish species, the omnivorous rudd (Scardinius erythrophthalmus) and herbivorous grass carp (Ctenopharyngodon idella), feeding preferences were determined in three choice experiments. We tested (i) whether the presence of secondary metabolites and macrophyte stoichiometry affects macrophyte species selection by fish, (ii) the importance of macrophyte stoichiometry by manipulating the macrophytes experimentally and (iii) the rate of herbivory when the most palatable macrophyte is offered simultaneously with a common animal prey. 3. In a choice experiment with five species of submerged macrophytes (Callitriche sp., Chara globularis, Elodea nuttallii, Myriophyllum spicatum and Potamogeton pectinatus), Myriophyllum was clearly consumed least by both fishes, which strongly correlated with the highest phenolic concentration of this macrophyte. Additionally, a significant negative relationship was found between consumption and C : N ratio of the five macrophytes. The two most consumed macrophytes also had the lowest dry matter concentration (DMC). 4. In a second choice experiment, the C : N ratio of the least (Myriophyllum) and most (Potamogeton) palatable plants was manipulated by growing the macrophytes under fertilised and unfertilised conditions and subsequently feeding them to rudd. The avoidance of consumption of the chemically defended Myriophyllum by rudd was partly alleviated by the lowered C : N ratio. 5. The third choice experiment showed that both fishes preferred animal prey (the amphipod Gammarus pulex) over the most palatable macrophyte (Potamogeton) when offered simultaneously. The C : N ratio of the amphipods was about half that of the lowest C : N ratio measured in the macrophytes. Consumption by the fishes could not clearly be related to C : P or N : P ratios of prey items in any of the experiments. 6. We conclude that omnivorous fish avoid macrophytes that are chemically defended. However, when these defences are only minor, stoichiometry (C : N ratio) in combination with DMC may be a determining factor for consumption by vertebrate facultative herbivores.

In an effort to determine its cytotoxicity as well as antigen specific immune activity of aqueous leaves extract of Strychnos nux-vomica using hepatitis B vaccine containing surface antigen (HBsAg; 20 µg/ml) pertaining to antibody production and scrutinize its proliferative response along with cytokines in lysed human whole blood. For these studies, phytochemical (qualitative) analysis was determined and evaluates the presence of secondary metabolites through high performance thin layer chromatography (HPTLC) and bio-inorganic fingerprinting. In addition, indirect Elisa was performed using HBsAg as coating antigen using variable doses (1-30 mg/ml) of Strychnos nux-vomica. In continuation of these immunological studies, antigen specific immune response along with cytotoxicity was determined through MTT assay in infected human whole blood using HBsAg (20 µg/ml, 50 µl). The results showed that Strychnos nux-vomica showed qualitatively as well as quantitatively determined the presence of secondary metabolites along with bio-inorganic compounds. In addition, Strychnos nux-vomica showed enhancement in anti-HBsAg IgG titre as compared to standard and control but there is sudden decline in proliferation with HBsAg and also showed decline in cytokines (IL-2 and IL-12) level at higher doses as compared to control. Our data suggest that Strychnos nux-vomica may help to raise antibodies against HBsAg but sudden decline in HBsAg proliferative response along with cytokines (IL-2 and IL-12) in infected lysed human whole blood and also showed some cytotoxic effect at higher doses. In other words, Strychnos nux-vomica could be a potent immune enhancer of B cells and inhibitor of T cells against HBsAg. DOI: http://dx.doi.org/10.5281/zenodo.3244227

Metabolomics of the interaction between a consortium of entomopathogenic fungi and their target insect: Mechanisms of attack and survival

Chemical composition, Insecticidal and antifungal activities of Pinus halepensis mill. and Acacia cyanophylla sp. wood tars