scholarly journals Bacteria: A novel source for potent mosquito feeding-deterrents

2019 ◽  
Vol 5 (1) ◽  
pp. eaau6141 ◽  
Author(s):  
Mayur K. Kajla ◽  
Gregory A. Barrett-Wilt ◽  
Susan M. Paskewitz
Keyword(s):  
Culex Pipiens ◽  
Feeding Deterrents ◽  
Feeding Deterrent ◽  
Low Molecular Weight ◽  
Feeding Deterrence ◽  
Mosquito Repellents ◽  
Novel Applications ◽  
Deterrent Activity ◽  
Better Than

Antibiotic and insecticidal bioactivities of the extracellular secondary metabolites produced by entomopathogenic bacteria belonging to genusXenorhabdushave been identified; however, their novel applications such as mosquito feeding-deterrence have not been reported. Here, we show that a mixture of compounds isolated fromXenorhabdus budapestensisin vitro cultures exhibits potent feeding-deterrent activity against three deadly mosquito vectors:Aedes aegypti,Anopheles gambiae, andCulex pipiens. We demonstrate that the deterrent active fraction isolated from replicate bacterial cultures is highly enriched in two compounds consistent with the previously described fabclavines, strongly suggesting that these are the molecular species responsible for feeding-deterrence. The mosquito feeding-deterrent activity in the putative fabclavine-rich fraction is comparable to or better than that ofN,N-diethyl-3-methylbenzamide (also known as DEET) or picaridin in side-by-side assays. These findings lay the groundwork for research into biologically derived, peptide-based, low–molecular weight compounds isolated from bacteria for exploitation as mosquito repellents and feeding-deterrents.

scholarly journals Bacteria: A novel source for potent mosquito feeding – deterrents

2018 ◽  
Author(s):  
Mayur K. Kajla ◽  
Gregory A. Barrett-Wilt ◽  
Susan M. Paskewitz
Keyword(s):  
Feeding Deterrents ◽  
Feeding Deterrent ◽  
Low Molecular Weight ◽  
Feeding Deterrence ◽  
Modified Peptides ◽  
Mosquito Repellents ◽  
Novel Applications ◽  
Deterrent Activity ◽  
Better Than

AbstractAntibiotic and insecticidal bioactivities of the extracellular secondary metabolites produced by entomopathogenic bacteria belonging to genus Xenorhabdus have been identified; however, their novel applications such as mosquito feeding-deterrence have not been reported. Here, we show that a mixture of compounds isolated from Xenorhabdus budapestensis in vitro cultures exhibits potent feeding-deterrent activity against three deadly mosquito vectors: Aedes aegypti, Anopheles gambiae and Culex pipiens. We further demonstrate that the deterrent-active fraction isolated from replicate bacterial cultures is consistently highly enriched in two modified peptides identical to the previously described fabclavines, strongly suggesting that these are molecular species responsible for feeding-deterrence. The mosquito feeding-deterrent activity in the fabclavines-rich fraction is comparable to or better than that of N, N-diethyl-3-methylbenzamide (also known as Deet) or picaridin in side-by-side assays. Our unique discovery lays the groundwork for research into biologically derived, peptide-based low molecular weight compounds isolated from bacteria for exploitation as mosquito repellents and feeding-deterrents.

scholarly journals Repellent and Feeding Deterrent Activities of Butanolides and Lignans Isolated from Cinnamomum camphora against Tribolium castaneum

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Yang Wang ◽  
Li-Ting Zhang ◽  
Di Zhang ◽  
Shan-Shan Guo ◽  
Chao Xi ◽  
...  
Keyword(s):  
Tribolium Castaneum ◽  
Spectroscopic Data ◽  
Stem Bark ◽  
Feeding Deterrent ◽  
Cinnamomum Camphora ◽  
Feeding Deterrence ◽  
Comprehensive Utilization ◽  
Low Concentrations ◽  
First Time ◽  
Deterrent Activity

Three lignans (1–3) and three butanolides (4–6) were isolated from the lipophilic extract of the Cinnamomum camphora stem bark. The six compounds were identified as (-)-sesamin (1), 9α-hydroxysesamin (2), 9β-hydroxysesamin (3), obtusilactone A (4), isoobtusilactone A (IOA, 5), and isomahubanolide (6) from their spectroscopic data. Four (1, 2 and 5, 6) of them were evaluated for their repellent and feeding deterrent activities against Tribolium castaneum. In this work, the three butanolides (4–6) were confirmed to exist in C. camphora for the first time. Results of bioassays indicated that (-)-sesamin (1), IOA (5), and isomahubanolide (6) displayed certain repellent activities against T. castaneum at 78.63, 15.73, and 3.15 μg/cm2 at 2 h after exposure. Among the three compounds, (-)-sesamin (1) and IOA (5) exerted stronger effects and maintained longer duration of repellency. Furthermore, IOA (5) and isomahubanolide (6) showed good feeding deterrent activity against T. castaneum. IOA (5) was still potently active at low concentrations with the feeding deterrence index (FDI) ranging from 42.85% to 50.66% at 15–1500 ppm. This work provides some evidence for explaining antiinsect properties of the nonvolatile fraction of the C. camphora stem bark and helps promote the development and comprehensive utilization of this tree species.

Effects of Unfractionated and Low Molecular Weight Heparins on Platelet Thromboxane Biosynthesis “In Vivo”

1994 ◽  
Vol 72 (06) ◽  
pp. 942-946 ◽  
Author(s):  
Raffaele Landolfi ◽  
Erica De Candia ◽  
Bianca Rocca ◽  
Giovanni Ciabattoni ◽  
Armando Antinori ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Unfractionated Heparin ◽  
Low Molecular Weight Heparin ◽  
Primary Source ◽  
In Vivo Studies ◽  
Low Molecular Weight ◽  
Heparin Administration ◽  
To Receive

SummarySeveral “in vitro” and “in vivo” studies indicate that heparin administration may affect platelet function. In this study we investigated the effects of prophylactic heparin on thromboxane (Tx)A2 biosynthesis “in vivo”, as assessed by the urinary excretion of major enzymatic metabolites 11-dehydro-TxB2 and 2,3-dinor-TxB2. Twenty-four patients who were candidates for cholecystectomy because of uncomplicated lithiasis were randomly assigned to receive placebo, unfractionated heparin, low molecular weight heparin or unfractionaed heparin plus 100 mg aspirin. Measurements of daily excretion of Tx metabolites were performed before and during the treatment. In the groups assigned to placebo and to low molecular weight heparin there was no statistically significant modification of Tx metabolite excretion while patients receiving unfractionated heparin had a significant increase of both metabolites (11-dehydro-TxB2: 3844 ± 1388 vs 2092 ±777, p <0.05; 2,3-dinor-TxB2: 2737 ± 808 vs 1535 ± 771 pg/mg creatinine, p <0.05). In patients randomized to receive low-dose aspirin plus unfractionated heparin the excretion of the two metabolites was largely suppressed thus suggesting that platelets are the primary source of enhanced thromboxane biosynthesis associated with heparin administration. These data indicate that unfractionated heparin causes platelet activation “in vivo” and suggest that the use of low molecular weight heparin may avoid this complication.

The Effect of Dextran of Various Molecular Weight on the Coagulation in Dogs

1961 ◽  
Vol 06 (01) ◽  
pp. 015-024 ◽  
Author(s):  
Sven Erik Bergentz ◽  
Oddvar Eiken ◽  
Inga Marie Nilsson
Keyword(s):  
Molecular Weight ◽  
Body Weight ◽  
High Molecular Weight ◽  
Bleeding Time ◽  
Factor Vii ◽  
Low Molecular Weight ◽  
Factor V ◽  
Coagulation Mechanism ◽  
Coagulation Defects

Summary1. Infusions of low molecular weight dextran (Mw = 42 000) to dogs in doses of 1—1.5 g per kg body weight did not produce any significant changes in the coagulation mechanism.2. Infusions of high molecular weight dextran (Mw = 1 000 000) to dogs in doses of 1—1.5 g per kg body weight produced severe defects in the coagulation mechanism, namely prolongation of bleeding time and coagulation time, thrombocytopenia, pathological prothrombin consumption, decrease of fibrinogen, prothrombin and factor VII, factor V and AHG.3. Heparin treatment of the dogs was found to prevent the decrease of fibrinogen, prothrombin and factor VII, and factor V otherwise occurring after injection of high molecular weight dextran. Thrombocytopenia was not prevented.4. In in vitro experiments an interaction between fibrinogen and dextran of high and low molecular weight was found to take place in systems comprising pure fibrinogen. No such interaction occurred in the presence of plasma.5. It is concluded that the coagulation defects induced by infusions of high molecular weight dextran are due to intravascular coagulation.

Neutralization of a Low Molecular Weight Heparin (LHN-1) and Conventional Heparin by Protamine Sulfate in Rats

1986 ◽  
Vol 56 (03) ◽  
pp. 318-322 ◽  
Author(s):  
V Diness ◽  
P B Østergaard
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight Heparin ◽  
Thrombus Formation ◽  
Experimental Models ◽  
Protamine Sulfate ◽  
Low Molecular Weight ◽  
Antithrombotic Effect ◽  
Higher Doses

SummaryThe neutralization of a low molecular weight heparin (LHN-1) and conventional heparin (CH) by protamine sulfate has been studied in vitro and in vivo. In vitro, the APTT activity of CH was completely neutralized in parallel with the anti-Xa activity. The APTT activity of LHN-1 was almost completely neutralized in a way similar to the APTT activity of CH, whereas the anti-Xa activity of LHN-1 was only partially neutralized.In vivo, CH 3 mg/kg and LHN-1 7.2 mg/kg was given intravenously in rats. The APTT and anti-Xa activities, after neutralization by protamine sulfate in vivo, were similar to the results in vitro. In CH treated rats no haemorrhagic effect in the rat tail bleeding test and no antithrombotic effect in the rat stasis model was found at a protamine sulfate to heparin ratio of about 1, which neutralized APTT and anti-Xa activities. In LHN-1 treated rats the haemorrhagic effect was neutralized when APTT was close to normal whereas higher doses of protamine sulfate were required for neutralization of the antithrombotic effect. This probably reflects the fact that in most experimental models higher doses of heparin are needed to induce bleeding than to prevent thrombus formation. Our results demonstrate that even if complete neutralization of APTT and anti-Xa activities were not seen in LHN-1 treated rats, the in vivo effects of LHN-1 could be neutralized as efficiently as those of conventional heparin. The large fall in blood pressure caused by high doses of protamine sulfate alone was prevented by the prior injection of LHN-1.

MICROPROPAGATION OF CHICKPEA FROM SHOOT TIP AND NODE SEGMENT

2018 ◽  
Vol 24 (2) ◽  
Author(s):  
J. D. BARSHILE
Keyword(s):  
Shoot Tip ◽  
Root Induction ◽  
Multiple Response ◽  
Ms Medium ◽  
Growth Responses ◽  
Rapid Multiplication ◽  
Micro Propagation ◽  
G 12 ◽  
Better Than

Present investigation was undertaken to standardize technique for in vitro micro-propagation of chickpea( Cicer arietinum ) cultivar Vishwas (Phule G 12). Micropropagation method for chickpea was established and this method enabled much more efficient propagation of plants. The present work was aimed at evolving a protocol for rapid multiplication of chickpea using micropropagation technique. Explants from shoot tip and node segment were cultured on MS medium supplemented with different concentrations of BAP and Kinetin (1.0 to 2.5 mg/l) and their growth responses like shooting were elucidated. The maximum multiple response was observed with 2 mg/l concentration of BAP from both types of explant. The highest number of shoots (12.5 ± 0.3) was achieved on MS medium with 2 mg/l BAP using node segments. The medium supplemented with 2 mg/l of BAP was found better than all other concentrations. Individual shoots were transferred to IBA and IAA (1.0-1.5 mg/l) for root induction. MS medium supplemented with 2 mg/l of IBA proved better for rooting. Rooted plantlets were successfully hardened in greenhouse and established in the pot.

Ferula hermonis: A Review of Current Use and Pharmacological Studies of its Sesquiterpene Ester Ferutinin

2020 ◽  
Vol 21 (5) ◽  
pp. 499-508 ◽  
Author(s):  
Rémi Safi ◽  
Marwan El-Sabban ◽  
Fadia Najjar
Keyword(s):  
Wide Spectrum ◽  
Endemic Plant ◽  
Anti Cancer ◽  
Pharmacological Studies ◽  
Sexual Impotence ◽  
Novel Applications ◽  
Anti Fungal ◽  
Sesquiterpene Ester

Ferula hermonis Boiss, is an endemic plant of Lebanon, locally known as “shilsh Elzallouh”. It has been extensively used in the traditional medicine as an aphrodisiac and for the treatment of sexual impotence. Crude extracts and isolated compounds of ferula hermonis contain phytoestrogenic substances having a wide spectrum of in vitro and in vivo pharmacological properties including anti-osteoporosis, anti-inflammatory, anti-microbial and anti-fungal, anti-cancer and as sexual activity enhancer. The aim of this mini-review is to highlight the traditional and novel applications of this plant’s extracts and its major sesquiterpene ester, ferutinin. The phytochemical constituents and the pharmacological uses of ferula hermonis crude extract and ferutinin specifically will be discussed.

INDUCTIVE AND INHIBITORY ACTIONS OF A LOW MOLECULAR WEIGHT SERUM FACTOR ON IN VITRO MATURATION OF OOCYTES OF THE MEDAKA

1987 ◽  
Vol 8 (5) ◽  
pp. 313-322 ◽  
Author(s):  
TAKASHI IWAMATSU ◽  
SUSUMU Y. TAKAHASHI ◽  
NORIYOSHI SAKAI ◽  
KAORI ASAI
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight ◽  
Serum Factor
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