Eco-friendly Insecticides Research Articles

Phenolic monoterpene-rich essential oils from Apiaceae and Lamiaceae species: insecticidal activity and safety evaluation on non-target earthworms

The genera Oliveria (Apiaceae), Thymus and Satureja (Lamiaceae) encompass important medicinal and aromatic plants of Iran, which contains noteworthy amounts of essential oils (EOs) that are worthy of exploitation on an industrial level, including pesticide formulation development. In this study, the efficacy of five EOs obtained from O. decumbens, T. daenensis, S. sahendica, S. khuzistanica and S. rechingeri , was evaluated against three insects of economic relevance, the mosquito Culex quiquefasciatus , the housefly Musca domestica, and the moth Spodoptera littoralis . Potential non-target effects of these EOs were assessed on earthworms, Eisenia fetida . The chemical composition of the five EOs was determined by gas chromatography (GC-FID) and gas chromatography-mass spectrometry (GC-MS). EOs from O. decumbens, T. daenensis, S. khuzistanica and S. rechingeri were characterized by oxygenated monoterpenes (70.3, 91.6, 89.7 and 89.4%, respectively), whereas the EO from S. sahendica was dominated by monoterpene hydrocarbons (63.3%) followed by oxygenated monoterpenes (35.3%). In all cases, the biogenetically related thymol (0.3–36.7%), carvacrol (1.3–89.6%), p -cymene (2.1–13.7%) and γ-terpinene (1.5–41.3%) were found as the characteristic volatile compounds of the five EOs, with high quantitative variation according to the species considered. The five EOs exhibited high toxicity on the three target insects, with LC 50 /LD 50 values in the range of 16.2–29.3 µg mL -1 , 18.1–48.1 µg adult -1 and 7.4–23.1 µg larva -1 on C. quinquefasciatus, M. domestica and S. littoralis , respectively. Toxicity of the five EOs on non-target soil invertebrates was minimal, leading to no or very low (5.0–7.5%) mortality on E. fetida when tested at the concentration of 200 mg kg -1 , at variance with the positive control α-cypermetrin, which caused 100% mortality at 0.1 mg kg -1 of soil. Overall, our study discloses new opportunities to farmers growing these Iranian endemic plants, shedding light on the potential of these EOs to formulate effective and eco-friendly insecticides.

Potential source of ecofriendly insecticides: Essential oil induces avoidance and cause lower impairment on the activity of a stingless bee than organosynthetic insecticides, in laboratory

The negative effect of insecticides on bees has been reported as one of the factors associated with the decline in population of these pollinators. Thus, the aim of this study was to evaluate the response of the stingless bee Nannotrigona aff. testaceicornis (Lepeletier, 1836) to a promising source of new insecticide molecules obtained from Lippia sidoides (rosemary pepper) essential oil (EO) and its major compounds (thymol, ρ-cymene, and (E)-caryophyllene), comparing them to commercial insecticides (organosynthetic: imidacloprid, deltamethrin and semisynthetic: spinetoram). For this, stingless bees were exposed by contact with these compounds to evaluate the lethal and sublethal (locomotion and flight orientation) toxicity. The L. sidoides EO and its major compounds have low lethal toxicity to forager worker bees (N. aff. testaceicornis). The organosynthetics imidacloprid (LD50 =0.00146 µgbee−1) and deltamethrin (LD50 =0.0096 µg bee−1) were about 209,589 and 31,875 times more toxic, respectively, than the least toxic natural compound, (E)-caryophyllene (LD50 =306 µgbee−1). Locomotion ability and flight orientation were little affected by spinetoram and by L. sidoides EO and its major compounds, however, were greatly reduced by the imidacloprid and deltamethrin insecticides. Besides shows low lethal and sublethal toxicity, the bioinsecticides were also avoided by the forager bees. Individuals treated with the L. sidoides EO and thymol were avoided by the untreated bees. Therefore, the natural products studied here were promising due to their recognized effectiveness against pest insects and greater safety to bees N. aff. testaceicornis.

Toxic, Oviposition Deterrent and Oxidative Stress Effects of Thymus vulgaris Essential Oil against Acanthoscelides obtectus.

Simple SummaryCompounds of botanical origin, including essential oils (EOs), which coevolved as plant defense mechanism against herbivores and pathogens have been proposed as a promising strategy for post-harvest control of stored product insects. Despite several drawbacks, such as low stability, phytotoxicity and food odor changes at high concentrations, EOs are believed to be safe for human and environmental health and thus have an advantage comparing to conventional insecticides. The present study was aimed to examine acute toxicity and effects of thyme (Thymus vulgaris) EO on longevity, behavior and physiology of the bean weevil (Acanthoscelides obtectus), a major pest of stored bean seeds. We found that exposure to thyme oil reduced adult survival and longevity and induced damages to lipids and proteins in a concentration-dependent manner. Sublethal EO concentrations also deterred female egg laying and strongly inhibited adult emergence. Efficacy of such low EO concentrations in suppression of adult emergence implies that thyme EO might be cost-effective and environmentally low risk botanical insecticide for bean seed protection against A. obtectus.The bean weevil Acanthoscelides obtectus Say (Coleoptera: Chrysomelidae: Bruchinae) can cause significant losses in production of its primary host common bean Phaseolus vulgaris L. To avoid bean protection with environmentally risky chemical insecticides and provide sustainable and safe production of food, new pest management methods based on natural compounds are investigated. In the present study, we evaluated protective potential of the essential oil (EO) from the common thyme Thymus vulgaris L. applied on bean seeds. We assessed residual contact toxicity of thyme EO and its effects on A. obtectus longevity, oviposition and adult emergence. Furthermore, to elucidate the role of oxidative stress in thyme EO toxicity, we estimated the levels of oxidatively damaged proteins and lipids, as well as the level of thiols which have important role for antioxidant capacity. We found that thyme oil significantly reduced adult survival and longevity, induced oxidative damage to lipids and proteins and depleted protein and non-protein thiols in a concentration-dependent manner. Females appeared to be more tolerant to thyme oil treatment than males. Sublethal EO concentrations affected oxidative stress indices, deterred oviposition and strongly inhibited adult emergence. The results suggest that thyme oil has the potential to be used as an ecofriendly insecticide for A. obtectus control.

Epidemiology of tomato spotted wilt virus in Chrysanthemum morifolium in South Korea and its management using a soil-dwelling predatory mite (Stratiolaelaps scimitus) and essential oils

Tomato spotted wilt virus (TSWV) is one of most destructive viruses in vegetable and ornamental crop production worldwide. A greenhouse survey to determine the incidence of TSWV in Chrysanthemummorifolium Ramat. was conducted during the 2018 and 2019 growing seasons in South Korea. TSWV was detected using a double antibody sandwich-enzyme-linked immunosorbent assay, and positive results were confirmed using reverse transcription-polymerase chain reaction (RT-PCR). A total of 1569 chrysanthemum plants (70.77 %) tested positive for TSWV among 2217 symptomatic chrysanthemum plants collected from 16 greenhouses. In addition, 116 thrips (72.96 %; Frankliniella occidentalis Pergande) that contained TSWV were identified using RT-PCR from a total of 159 thrips collected from the greenhouses during the survey. A high incidence of viruliferous thrips may have played a role in TSWV occurrence in the chrysanthemum greenhouse. To develop a novel approach for thrips management, the effectiveness of a soil-dwelling predatory mite (Stratiolaelaps scimitus Berlese) and 45 essential oils (as bio-insecticides applied via foliar treatment) was assayed. Four essential oils (cinnamon oil, cinnamon bark oil, oregano oil, and thyme oil) were shown to be significantly toxic to eggs, larvae, and adults of F. occidentalis. For the combined treatment, individuals of S. scimitus (60/m2) were placed on the soil in the chrysanthemum greenhouses. Then, a mixture of the four essential oils was applied as foliar treatment at 4-day intervals. A very low incidence of thrips emerged as adults from the soil (1.2–8.5 %) in the combined treatment in the chrysanthemum greenhouses when surveyed twice per month, compared with the non-treated control or when conventional insecticide sprays were applied. The incidence of TSWV (0.93 %) in chrysanthemum treated with S. scimitus in conjunction with the mixture of four essential oils decreased significantly compared with that treated with chemical insecticides (32.05 %) and in the non-treated controls (84.85 %). Our findings contribute to the development of novel strategies to control TSWV disease in chrysanthemum plants; notably, the control of F. occidentalis using eco-friendly insecticides appears promising.

Phytol, (E)-nerolidol and spathulenol from Stevia rebaudiana leaf essential oil as effective and eco-friendly botanical insecticides against Metopolophium dirhodum

Stevia rebaudiana (Asteraceae) is a medicinal plant of economic importance in the food market for the manufacture of natural sweeteners, namely steviol glycosides. The plant biomass used on an industrial level may also be the source of an essential oil (EO) of potential interest for developing novel insecticides. Here, the leaf EO chemical composition of S. rebaudiana growing in central Italy was analysed by gas chromatography-mass spectrometry (GC–MS). The EO insecticidal efficacy was evaluated against the aphid Metopolophium dirhodum (Hemiptera: Aphididae), a major pest of cereals. The EO composition was dominated by sesquiterpenes, i.e. caryophyllene oxide (20.7 %), spathulenol (14.9 %) and (E)-nerolidol (8.0 %), and diterpenes, i.e. phytol (9.2 %). The EO was effective against M. dirhodum aphids, showing an LC50(90) of 5.1 and 10.8 mL L−1, respectively. The efficacy of the EO major constituents, namely caryophyllene oxide, spathulenol, (E)-nerolidol and phytol was also tested against M. dirhodum. Phytol was the most effective aphicide (LC50(90) = 1.4(4.2) mL L−1), followed by (E)-nerolidol (LC50(90) = 3.5(9.3) mL L−1) and spathulenol (LC50(90) = 4.3(7.5) mL L−1). The EO was minimally toxic towards non-target Eisenia fetida adults and Harmonia axyridis larvae and adults. Overall, phytol, (E)-nerolidol and spathulenol can be considered further for developing effective and eco-friendly green insecticides against aphids.

Mosquitocidal and Anti-Inflammatory Properties of The Essential Oils Obtained from Monoecious, Male, and Female Inflorescences of Hemp (Cannabis sativa L.) and Their Encapsulation in Nanoemulsions.

Among the various innovative products obtainable from hemp (Cannabis sativa L.) waste biomass originating from different industrial processes, the essential oil (EO) deserves special attention in order to understand its possible application in different fields, such as cosmetics, pharmaceuticals, and botanical insecticides. For the purpose, in the present work, we studied the chemical composition of EOs obtained from different hemp varieties, namely Felina 32 and Carmagnola Selezionata (CS) using monoecious, male, and female inflorescences, and we evaluated their mosquitocidal activities on larvae and pupae of two main malaria vectors, Anopheles gambiae and An. stephensi. Then, in order to evaluate the safe use of hemp EOs for operators, the potential pro- or anti-inflammatory effect of hemp EOs together with their toxicological profile were determined on dermal fibroblasts and keratinocytes. Given the promising results obtained by insecticidal and anti-inflammatory studies, a preliminary evaluation of EOs encapsulation into nanoemulsions (NEs) has been performed with the aim to develop a formulation able to improve their poor physicochemical stability. Felina 32 and CS inflorescences provided EOs with an interesting chemical profile, with monoterpene and sesquiterpene hydrocarbons as the major components. This study highlighted the potential application of male inflorescences, which are usually discharged during hemp product processing. These EOs could be exploited as potential sustainable and eco-friendly insecticides, given their capability to be toxic against mosquitoes and the possibility to use them to prepare stable and safe formulations. The LC50 values found in this study (<80 ppm) are lower, on average, than those of many plant EOs, with the advantage of using an industrial waste product. From MTT assay and gene and protein expression analysis, EOs showed no cytotoxicity at the appropriate doses and exerted an anti-inflammatory effect on the human cell lines tested. These findings encourage further applied research on hemp EOs in order support their industrial exploitation.

Mosquito larvicidal activities of farnesol and farnesyl acetate via regulation of juvenile hormone receptor complex formation in Aedes mosquito

Abstract Due to their target specificity and low-toxicity, insect growth regulators (IGRs) are regarded as promising alternatives to chemical insecticides. In this study, farnesol and farnesyl acetate exhibited juvenile hormone (JH)-based IGR activities. While farnesyl acetate showed JH agonist (JHA) activity in concentration-dependent manner, farnesol was identified as JH antagonist (JHAN) by interfering pyriproxyfen-mediated binding JH receptor complex. Both compounds showed mosquito larvicidal activities and caused retardation of ovarian growth of female Aedes albopictus by modulating the formation of JH receptor complex, expression of JH-inducible genes, and thereby disrupting JH-based endocrine regulations. These results suggested that farnesol and farnesyl acetate could be applicable for investigating underlying mechanisms of JH-regulated insect physiologies as well as developing novel eco-friendly insecticides.

Susceptibility of Rhynchophorus ferrugineus (Olivier) (Coleoptera: Curculionidae) to entomopathogenic nematodes with regard to its immune response

The red palm weevil (RPW) Rhynchophorus ferrugineus Olivier is the most devastating pest of date palm, with a severe impact on cultivation and production. The virulence of five species/strains of entomopathogenic nematodes (EPNs), Steinernema scapterisci (Ss), Steinernema sp. (SII), Steinernema abbasi (Ab), Steinernema glaseri (Sg), and Heterorhabditis bacteriophora (HP88) was tested against larval and adult stages of RPW under semi-field laboratory conditions. Total and differential haemocyte counts were determined, and protein analysis and histopathological study of larvae injected with SII and HP88 were performed. Susceptibility results revealed that the larval stage was much more susceptible to Sg and HP88 than the adult stage. Larval mortality rate was as high as 100% and 92%, respectively, with concentrations of 1250infective juveniles (IJs)/pot, while adult mortality reached 48% and 60%, respectively, with concentrations of 20000IJs/pot at 9 d post infection with Sg and HP88. In general, SS, SII, and Ab appeared to be more virulent during the adult stage than the larval stage. They recorded mortality rates of 88%, 88%, and 72%, respectively, for the larval stage, and 100%, 100%, and 84%, respectively, for the adult stage at concentrations of 20000IJs/pot at 9 d post infection. A severe decline in the total and differential haemocyte counts (THCs and DHCs) at 12 h post-injection with SII and HP88 at 20IJs/larvae was observed. Similarly, the effect on total haemolymph protein of the normal and infected larvae was reflected by the appearance and disappearance of protein bands in addition to changes in the protein band concentration. Notably, remarkable changes in the cuticle, in the form of disruption to the outer epicuticle, splitting of the epidermal layer, and disorganization of the musculature region, were observed. In addition, notable histological effects were seen in the midgut region at 12 h post injection with 20IJs/larvae of HP88 and SII. Our results demonstrate that R. ferrugineus is unable to defend itself against EPNs. These results indicate an effective and natural biological control strategy with potential for application as an eco-friendly and inexpensive insecticide against the adult and larval stages of the RPW.

Optimization and Characterization of Essential Oil Nanoemulsions Using Ultrasound for New Ecofriendly Insecticides

This study developed and evaluated the toxicological effects of new stable nanoemulsions (NEs) of peppermint essential oils (EOs) and palmarosa EO + linalyl acetate (LA) using ultrasound cavitation...

Natural insecticidal proteins, the promising bio-control compounds for future crop protection

Insect predation problem in agriculture and forestry has challenged researchers worldwide to identify newer eco-friendly insecticides. Among them Bacillus thuringiensis δ-endotoxin (Bt) has been the most widely used commercial insecticide till date. The advantages of Bt as a “green” insecticide are its high specificity to target insects (it is nontoxic to mammals, birds and even to most beneficial insects) and the slow rate of development of resistance against it by insects. This toxin used either in the form of bio formulations or through its expression in crop plants, is found to be sensitive against insect pests belonging to the family Lepidoptera, Coleoptera and Diptera. However, the sap sucking homopteran group of insects generally remain insensitive to Bt toxin and show susceptibility to various plant lectins when fed with artificial diet or through expression in transgenic plants. This review demonstrates the insecticidal potential of some candidate proteins and their possible mode of action by identifying their target molecules in insects’ tissue. We also provide an overview of the applicability of these proteins in crop protection.

Larvicidal and ovicidal activity of carvacrol, p-cymene, and γ-terpinene from Origanum vulgare essential oil against the cotton bollworm, Helicoverpa armigera (Hübner).

This study evaluated the larvicidal activity, and ovicidal activity of Origanum vulgare EO and its major components against the cotton bollworm, Helicoverpa armigera. The chemical composition of the O. vulgare EO was analyzed by gas chromatography-mass spectroscopy. GC-MS analysis revealed that the O. vulgare EO was composed of ten compounds. The major constituents were carvacrol (78.35%), followed by p-cymene (6.85%) and γ-terpinene (3.70%). In larvicidal activity assay, the O. vulgare EO achieved a LC50 value of 265.51μg/ml. The three major constituents from the O. vulgare EO were tested individually for toxicity against larvae of H. armigera. Carvacrol, p-cymene, and γ-terpinene appeared to be most effective against H. armigera, with LC50 values of 51.53, 121.32, and 150.15μg/ml, respectively. Moreover, EC50 values of carvacrol, p-cymene, and γ-terpinene against H. armigera eggs were 33.48, 47.85, and 56.54μg/ml, respectively. Overall, this study showed that O. vulgare EO and its major constituents have the potential to develop as new eco-friendly insecticides against H. armigera.

Synthesis, aphicidal activity and conformation of novel insect kinin analogues as potential eco-friendly insecticides.

The discovery of ecofriendly insecticides through a new strategy for aphid control is important because of the substantial resistance and unexpected eco-toxicity to honeybees caused by traditional insecticides. The insect kinins, a class of multifunctional insect neuropeptides, are considered for potential application in pest control. In our previous work we developed several series of insect kinin analogues and found a promising lead II-1 with good aphicidal activity. To seek further eco-friendly aphicides, the optimization of II-1 is carried out in this study. Fifteen novel Yaa3 modified analogues based on the lead II-1 were synthesized. The aphicidal tests indicated that IV-3, IV-5 and IV-10 exhibited significant activity against the soybean aphid Aphis glycines with LC50 values of 0.0029, 0.0072 and 0.0086 mmol L-1 , respectively, higher than that of lead II-1 and the commercial Pymetrozine. The molecular modeling results showed that analogues II-1, IV-3, IV-5, IV-7 and IV-10 formed a β-turn-like conformation, while the conformation of analogues IV-1, IV-2 and IV-9 seemed to be linear. Some structural elements favorable for the activity were proposed based on the conformation-activity relationship of the analogues. Insect kinin analogues derived from lead II-1 by modifying the hydrolysis site Yaa3 with natural, sterically hindered α- and β-amino acids showed great potential as eco-friendly insecticides. Inspiringly, the most active analogue IV-3 can be a candidate for further development. The β-turn-like conformation and the orientation of the aromatic rings of the side chain of Phe2 and Trp4 may be critical factors beneficial to activity. © 2019 Society of Chemical Industry.

Integration of entomopathogenic fungi and eco-friendly insecticides for management of red palm weevil, Rhynchophorus ferrugineus (Olivier).

Red palm weevil (Rhynchophorus ferrugineus) is a voracious pest of date palm worldwide. Pakistan ranks sixth in date palm production globally. Losses to date palm plantations in Pakistan sometimes surpass 10%-20%. Most of the traditional management strategies used by farmers have been found insignificant to combat this voracious pest. The entomopathogenic fungi, Beauveria bassiana [QA-3(L) and QA-3(H)] and insecticides, Nitenpyram (Active 10% SL) [NIT (L) and NIT (H)] were applied to larval (2nd, 4th, and 6th), pupal and adult stages of R. ferrugienus. Integration or alone application of fungi with insecticides at different concentration under laboratory conditions. Combined application was depicted additive and synergistic interactions. Contrarily, highest cumulative mortality (100%) was recorded in 2nd instar larvae as compared to later instar larvae at combined application. The maximum pupal and adult mortality remained 89% and 66% respectively after treatment with [QA-3 (H) + NIT (L)]. The combination of B. bassiana at higher concentration whereas Nitenpyram at lower dose was found more lethal to larvae, pupae and adults of R. ferrugineus. This signifies the need of combining B. bassiana and bio-rational insecticides that can reduce the cost of management with least harm to environment and natural enemies.

Developing green insecticides to manage olive fruit flies? Ingestion toxicity of four essential oils in protein baits on Bactrocera oleae

Effective and eco-friendly plant-borne insecticides for developing lure and kill control tools against tephritid flies are scarce. Herein, the activity of four essential oils (EOs) obtained from two Apiaceae, Pimpinella anisum L. and Trachyspermum ammi (L.) Sprague, and two Lamiaceae, Thymbra spicata L. and Ocimum gratissimum L., was evaluated against the olive fruit fly, Bactrocera oleae (Rossi), a key pest of olive groves. The EO chemical composition was determined by gas chromatography coupled with mass spectrometry (GC-MS) analyses. The four EOs incorporated in protein baits were tested for ingestion toxicity on B. oleae adults, mimicking lure and kill assays. Results showed concentration-dependent toxicity, with mortality rates ranging from 6.5% (P. anisum EO at 0.03% w/v concentration) to 100% (P. anisum EO at 0.5% w/v concentration, T. ammi EO at 1% w/v). The best efficacy was achieved by EOs from T. ammi and P. anisum, showing LC50 values of 633 ppm and 771 ppm, respectively, far encompassing currently published findings on the ingestion toxicity of EOs on tephritid adults. Thymol (58.3%), p-cymene (24.7%) and γ-terpinene (14.2%), and (E)-anethole (98.3%) were the major constituents of T. ammi and P. anisum EOs, respectively. Thymol (57.0%), p-cymene (12.4%) and γ-terpinene (6.9%), and carvacrol (41.4%) and p-cymene (41.2%) were the predominant components in O. gratissimum and Th. spicata EOs, respectively. Further field research on the efficacy of these EOs incorporated in food baits against the olive fruit fly is ongoing to boost their real-world application, contributing to develop alternative tools for the sustainable management of B. oleae.

Cost-benefit economics under evaluation of ecofriendly insecticides against major insect pests of rice in eastern Uttar Pradesh conditions

Cost-benefit economics under evaluation of ecofriendly insecticides against major insect pests of rice in eastern Uttar Pradesh conditions

Efficacy of Origanum syriacum Essential Oil against the Mosquito Vector Culex quinquefasciatus and the Gastrointestinal Parasite Anisakis simplex, with Insights on Acetylcholinesterase Inhibition.

Developing effective and eco-friendly antiparasitic drugs and insecticides is an issue of high importance nowadays. In this study, we evaluated the anthelminthic and insecticidal potential of the leaf essential oil obtained from Origanum syriacum against the L3 larvae of the parasitic nematode Anisakis simplex and larvae and adults of the mosquito Culex quinquefasciatus. Tests on A. simplex were performed by standard larvicidal and penetration assays, while mosquito toxicity was assessed relying on larvicidal, tarsal contact, and fumigation tests. To shed light on the possible mode of action, we analyzed the oil impact as acetylcholinesterase (AChE) inhibitor. This oil was particularly active on L3 larvae of A. simplex, showing a LC50 of 0.087 and 0.067 mg mL−1 after 24 and 48 h treatment, respectively. O. syriacum essential oil was highly effective on both larvae and adults of C. quinquefasciatus, showing LC50 values of 32.4 mg L−1 and 28.1 µg cm−2, respectively. Its main constituent, carvacrol, achieved larvicidal LC50(90) of 29.5 and 39.2 mg L−1, while contact toxicity assays on adults had an LC50(90) of 25.5 and 35.8 µg cm−2, respectively. In fumigation assays, the LC50 was 12.1 µL L−1 after 1 h and decreased to 1.3 µL L−1 in 24 h of exposure. Similarly, the fumigation LC50 of carvacrol was 8.2 µL L−1 after 1 h of exposure, strongly decreasing to 0.8 µL L−1 after 24 h of exposure. These results support the folk usage of Lebanese oregano as an antiparasitic agent, providing new insights about its utilization for developing new effective and eco-friendly nematocidal and insecticidal products.

Bioefficacy of some newer ecofriendly insecticides against rice hispa (Dicladispa armigera Oliver) under rice ecosystem of eastern Uttar Pradesh

Bioefficacy of some newer ecofriendly insecticides against rice hispa (Dicladispa armigera Oliver) under rice ecosystem of eastern Uttar Pradesh

Butterfly Pea (Clitoria ternatea), a Cyclotide-Bearing Plant With Applications in Agriculture and Medicine.

The perennial leguminous herb Clitoria ternatea (butterfly pea) has attracted significant interest based on its agricultural and medical applications, which range from use as a fodder and nitrogen fixing crop, to applications in food coloring and cosmetics, traditional medicine and as a source of an eco-friendly insecticide. In this article we provide a broad multidisciplinary review that includes descriptions of the physical appearance, distribution, taxonomy, habitat, growth and propagation, phytochemical composition and applications of this plant. Notable amongst its repertoire of chemical components are anthocyanins which give C. ternatea flowers their characteristic blue color, and cyclotides, ultra-stable macrocyclic peptides that are present in all tissues of this plant. The latter are potent insecticidal molecules and are implicated as the bioactive agents in a plant extract used commercially as an insecticide. We include a description of the genetic origin of these peptides, which interestingly involve the co-option of an ancestral albumin gene to produce the cyclotide precursor protein. The biosynthesis step in which the cyclic peptide backbone is formed involves an asparaginyl endopeptidase, of which in C. ternatea is known as butelase-1. This enzyme is highly efficient in peptide ligation and has been the focus of many recent studies on peptide ligation and cyclization for biotechnological applications. The article concludes with some suggestions for future studies on this plant, including the need to explore possible synergies between the various peptidic and non-peptidic phytochemicals.

Computational insight to putative anti-acetylcholinesterase activity of Commiphora myrrha (Nees), Engler, Burseraceae: a lessen of archaeopharmacology from Mesopotamian Medicine I.

Commiphora spp., Burseraceae family and their resinous matter, myrrh, are used in Mesopotamian medicine as fragrance or antiinsectant. Based on in vitro, leaves, bark, and resin methyl alcohol extract of C. myrrha showed similar inhibitory effects of 17.00, 26.00, and 29.33% for acetylcholinesterase (AChE) as compared to eserine, respectively. The ADMET properties and putative anticholinesterase activity of phytochemicals of myrrh were computationally predicted using in silico tools. Phytochemicals of C. myrrha had acceptable binding affinity (BA) towards principal sites of AChE ranging from - 5.8 (m-cresol) to - 10.5 (abietic acid) kcal/mol. In this regard, all terpenoid compounds (25 out of 28) of myrrh were dual inhibitors since they hydrophobically interacted with both catalytic triad and peripheral anionic site (PAS) of AChE while alpha-terpineol, elemol, and eugenol employed hydrogen bonds with AChE. Cuscohygrine as a pyrrolidine alkaloid has been docked with AChE through hydrogen bonds with PAS and through hydrophobic interactions with catalytic triad thereby we initially proposed it as dual inhibitor of AChE. M-cresol as a methylphenol has been loosely docked with AChE via hydrogen bond and would be a hit molecule for further drug synthesis. This study not only confirmed archaeopharmacological applications of myrrh as antiinsectant or nootropics but also offered an array of terpenoid compounds, cuscohygrine, and m-cresol as a good starting point for hit-to-lead-to-drug optimization phase in synthesis of phyto-nootropics and ecofriendly insecticides.

MODIFICATION OF THE NANO TITANIUM BAND GAP REACTIONS OF SOLID DIOXIDE WITH (ANTIMONY) STIBIUM S AND ITS DETERMINATION PHOTOCATALYTIC ACTIVITY

This study includes preparation of nanoparticles of titanium dioxide using the sol-gel method and then, the band gap was modified by solid-state reaction with (Antimony) Stibium Sb reductive compounds. Modification reduced the band gap separating energy levels between valance band (VB) and conduction band (CB), therefore; facilitating the transfer of excited electrons from (VB) to (CB). Absorption of the energy from incident photons having the same or larger energy than the energy of the band gap promote the formation of the couple (electron-hole). The resulting (e--h+) couple acts to produce (OH.) radicals. OH. radicals having a high capability to inhibition of glutathione S-transferase activity in Aedes aegypti, mosquitoes that adsorbed on the surface of the photocatalytic TiO2 as a new model of eco-friendly insecticide.