scholarly journals Activity of Piperaceae extracts and fractions in the control of Phytomonas serpens

2020 ◽  
Vol 50 (10) ◽  
Author(s):  
Neriani de Souza Cancini ◽  
Jesieli Beraldo-Borrazzo ◽  
Jéssica Lima de Menezes ◽  
Diógenes Aparício Garcia Cortez ◽  
Rodrigo Hinojosa Valdez ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Inhibitory Concentration ◽  
Colorimetric Method ◽  
Agricultural Crops ◽  
Sem Images ◽  
Fractionation Process ◽  
Sulforhodamine B ◽  
Chloroform Phase ◽  
Ic50 Values ◽  
Piper Aduncum

ABSTRACT: Protozoa of the genus Phytomonas are harmful parasites to several agricultural crops of economic importance. Due to their recognized biological activity, crude extracts of Piper aduncum, P. crassinervium, P. hispidum, and P. amalago leaves, were tested using the microdilution plate technique to assess the antiparasitic potential against Phytomonas serpens. Results showed that the ethanolic crude extract of P. crassinervium and P. amalago presented the best inhibitory concentration for 50% of the cells (IC50), 16.5 µg mL-1 in chloroform phase, and 18 µg mL-1 in aqueous phase, respectively, after 48 h treatment. Cytotoxicity analyses were performed using the colorimetric method of sulforhodamine-B in LLCMK2 mammalian cells. The chloroform phase of P. crassinervium was subjected to the fractionation process, in which the ethyl acetate and dichloromethane fractions obtained better IC50 values. Scanning electron microscopy (SEM) images showed alterations in the cell membrane of the treated parasites. The data obtained indicate a potential antiparasitic effect of the Piper species analyzed against P. serpens, being considered promising candidates for formulations of bioproducts to control the parasite.

Synthesis and Structure−Activity Relationship Studies of N-monosubstituted Aroylthioureas as Urease Inhibitors

2020 ◽  
Vol 16 ◽  
Author(s):  
Wei-Wei Ni ◽  
Hai-Lian Fang ◽  
Ya-Xi Ye ◽  
Wei-Yi Li ◽  
Li Liu ◽  
...  
Keyword(s):  
Regression Analysis ◽  
Mammalian Cells ◽  
Intact Cell ◽  
Linear Regression Analysis ◽  
Positive Control ◽  
Acetohydroxamic Acid ◽  
Urease Inhibitors ◽  
Ic50 Value ◽  
Ic50 Values ◽  
Low Cytotoxicity

Background: Thiourea is a classical urease inhibitor usually as a positive control, and many N,N`-disubstituted thioureas have been determined as urease inhibitors. However, due to steric hindrance, N,N`-disubstituted thiourea motif could not bind urease as thiourea. On the contrary, N-monosubstituted thioureas with a tiny thiourea motif could theoretically bind into the active pocket as thiourea. Objective: A series of N-monosubstituted aroylthioureas were designed and synthesized for evaluation as urease inhibitors. Methods: Urease inhibition was determined by the indophenol method and IC50 values were calculated using computerized linear regression analysis of quantal log dose-probit functions. The kinetic parameters were estimated viasurface plasmon resonance (SPR) and by nonlinear regression analysis based on the mixed type inhibition model derived from Michaelis-Menten kinetics. Results: Compounds b2, b11and b19 reversibly inhibited urease with a mixed mechanism, and showed excellent potency against both cell-free urease and urease in intact cell, with IC50 values being 90-to 450-fold and 5-to 50-fold lower than the positive control acetohydroxamic acid, respectively. The most potent compound b11 showed IC50 value of 0.060 ±0.004μM against cell-free urease, which bound to urea binding site with a very low KDvalue (0.420±0.003nM) and a very long residence time (6.7 min). Compound b11was also demonstrated having very low cytotoxicity to mammalian cells. Conclusion: These results revealed that N-monosubstituted aroylthioureas clearly bind the active site of urease as expected, and represent a new class of urease inhibitors for the development of potential therapeutics against infections caused by ure-ase-containing pathogens.

Discovery of 3-Cinnamamido-N-Substituted Benzamides as Potential Antimalarial Agents

2020 ◽  
Vol 16 ◽  
Author(s):  
Haicheng Liu ◽  
Yushi Futamura ◽  
Honghai Wu ◽  
Aki Ishiyama ◽  
Taotao Zhang ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Antimalarial Activity ◽  
In Vitro Assays ◽  
Compound Library ◽  
Antimalarial Agents ◽  
Phenotypic Screen ◽  
Ic50 Values ◽  
Substituted Benzamides

Background: Malaria is one of the most devastating parasitic diseases, yet the discovery of antimalarial agents remains profoundly challenging. Very few new antimalarials have been developed in the past 50 years, while the emergence of drug-resistance continues to appear. Objective: This study focuses on the discovery, design, synthesis, and antimalarial evaluation of 3-cinnamamido-N-substituted benzamides. Method: In this study, a screening of our compound library was carried out against the multidrug-sensitive Plasmodium falciparum 3D7 strain. Derivatives of the hit were designed, synthesized and tested against P. falciparum 3D7 and the in vivo antimalarial activity of the most active compounds was evaluated using the method of Peters’ 4-day suppressive test. Results: The retrieved hit compound 1 containing a 3-cinnamamido-N-substituted benzamide skeleton showed moderate antimalarial activity (IC50 = 1.20 µM) for the first time. A series of derivatives were then synthesized through a simple four-step workflow, and half of them exhibited slightly better antimalarial effect than the precursor 1 during the subsequent in vitro assays. Additionally, compounds 11, 23, 30 and 31 displayed potent activity with IC50 values of approximately 0.1 µM, and weak cytotoxicity against mammalian cells. However, in vivo antimalarial activity is not effective which might be ascribed to the poor solubility of these compounds. Conclusion: In this study, phenotypic screen of our compound library resulted in the first report of 3-cinnamamide framework with antimalarial activity and 40 derivatives were then designed and synthesized. Subsequent structure-activity studies showed that compounds 11, 23, 30 and 31 exhibited the most potent and selective activity against P. falciparum 3D7 strain with IC50 values around 0.1 µM. Our work herein sets another example of phenotypic screen-based drug discovery, leading to potentially promising candidates of novel antimalarial agents once given further optimization.

scholarly journals Reduction in the in vitro sensitivity oF Drechslera tritici-repentis, isolated from wheat, to strobilurin and triazole fungicides

2017 ◽  
Vol 43 (1) ◽  
pp. 20-25
Author(s):  
Rosane Baldiga Tonin ◽  
Erlei Melo Reis ◽  
Aveline Avozani
Keyword(s):  
Inhibitory Concentration ◽  
In Vitro Sensitivity ◽  
Randomized Design ◽  
Inhibition Data ◽  
Ic50 Values ◽  
Control Failure ◽  
Quinone Outside Inhibitors ◽  
Completely Randomized Design

ABSTRACT Reports of failure in the chemical control of wheat yellow leaf spot led to determination of the sensitivity of Drechslera tritici-repentis (Dtr) to the fungicides quinone outside inhibitors (QoIs) and demethylation inhibitors (DMIs). The IC50 was obtained for strobilurins (azoxystrobin, kresoxim-methyl, picoxystrobin and pyraclostrobin) and for triazoles (cyproconazole, epoxiconazole, propiconazole, prothioconazole and tebuconazole), using five Dtr isolates. Seven concentrations of the fungicides were tested in the bioassay: 0.00; 0.01; 0.10; 1.00; 10:00 and 20.00 and 40.00 mg/L active ingredient (a.i.). Assays consisted of completely randomized design and four replicates. Each experiment was performed twice, using the average of the two tests for statistical analysis. The percentage inhibition data for conidial germination (QoIs) and for mycelial growth (DMIs) were subjected to logarithmic regression analysis, calculating the 50% inhibitory concentration (IC50) based on the generated equation. There was a reduction in the sensitivity of Dtr isolates to strobilurins. IC50 values ranged from 0.58 to > 40.00 mg/L. The lowest sensitivity of isolates was detected for azoxystrobin, kresoxim-methyl, picoxystrobin and trifloxystrobin. Pyraclostrobin was most efficient, showing IC50 between 0.58 and 1.03 mg/L. The IC50 ranged from 0.35 to 1.37 mg/L for epoxiconazole, from 0.49 to 1.28 mg/L for propiconazole and from 1.41 to 2.34 mg/L for tebuconazole. Prothioconazole was most potent, showing IC50 between 0.09 and 0.21 mg/L. The hypothesis that the control failure can be attributed to the reduced Dtr sensitivity to the fungicides QoIs and DMIs was confirmed.

scholarly journals New Antimalarial and Antimicrobial Tryptamine Derivatives from the Marine Sponge Fascaplysinopsis reticulata

Marine Drugs ◽  
2019 ◽  
Vol 17 (3) ◽  
pp. 167 ◽  
Author(s):  
Pierre-Eric Campos ◽  
Emmanuel Pichon ◽  
Céline Moriou ◽  
Patricia Clerc ◽  
Rozenn Trépos ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Minimum Inhibitory Concentration ◽  
Marine Sponge ◽  
Nmr Spectra ◽  
Inhibitory Concentration ◽  
Chemical Study ◽  
2D Nmr ◽  
Antimicrobial Activities ◽  
2D Nmr Spectra ◽  
Ic50 Values

Chemical study of the CH2Cl2-MeOH (1:1) extract of the sponge Fascaplysinopsis reticulata collected in Mayotte highlighted three new tryptophan derived alkaloids, 6,6′-bis-(debromo)-gelliusine F (1), 6-bromo-8,1′-dihydro-isoplysin A (2) and 5,6-dibromo-8,1′-dihydro-isoplysin A (3), along with the synthetically known 8-oxo-tryptamine (4) and the three known molecules from the same family, tryptamine (5), (E)-6-bromo-2′-demethyl-3′-N-methylaplysinopsin (6) and (Z)-6-bromo-2′-demethyl-3′-N-methylaplysinopsin (7). Their structures were elucidated by 1D and 2D NMR spectra and HRESIMS data. All compounds were evaluated for their antimicrobial and their antiplasmodial activities. Regarding antimicrobial activities, the best compounds are (2) and (3), with minimum inhibitory concentration (MIC) of 0.01 and 1 µg/mL, respectively, towards Vibrio natrigens, and (5), with MIC values of 1 µg/mL towards Vibrio carchariae. In addition the known 8-oxo-tryptamine (4) and the mixture of the (E)-6-bromo-2′-demethyl-3′-N-methylaplysinopsin (6) and (Z)-6-bromo-2′-demethyl-3′-N-methylaplysinopsin (7) showed moderate antiplasmodial activity against Plasmodium falciparum with IC50 values of 8.8 and 8.0 µg/mL, respectively.

scholarly journals Two Novel Quassinoid Glycosides with Antiviral Activity from the Samara of Ailanthus altissima

Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5679
Author(s):  
Qing-Wei Tan ◽  
Jian-Cheng Ni ◽  
Jian-Ting Shi ◽  
Jian-Xuan Zhu ◽  
Qi-Jian Chen
Keyword(s):  
Data Analysis ◽  
Herbal Medicine ◽  
Inhibitory Concentration ◽  
Biological Activities ◽  
Virus Multiplication ◽  
Ailanthus Altissima ◽  
Inhibitory Effects ◽  
Traditional Herbal Medicine ◽  
Virus Activity ◽  
Ic50 Values

Phytochemistry investigations on Ailanthus altissima (Mill.) Swingle, a Simaroubaceae plant that is recognized as a traditional herbal medicine, have afforded various natural products, among which C20 quassinoid is the most attractive for their significant and diverse pharmacological and biological activities. Our continuous study has led to the isolation of two novel quassinoid glycosides, named chuglycosides J and K, together with fourteen known lignans from the samara of A. altissima. The new structures were elucidated based on comprehensive spectra data analysis. All of the compounds were evaluated for their anti-tobacco mosaic virus activity, among which chuglycosides J and K exhibited inhibitory effects against the virus multiplication with half maximal inhibitory concentration (IC50) values of 56.21 ± 1.86 and 137.74 ± 3.57 μM, respectively.

scholarly journals Isolation of Endophytic Fungi QPS 05 from Quercus phillyraeoides A. Gray and Its Potential for α-Glucosidase Inhibitory Activity

2018 ◽  
Vol 20 (1) ◽  
pp. 1-7
Author(s):  
Anastasia Wheni Indrianingsih ◽  
Amalia Indah Prihantini ◽  
Sanro Tachibana
Keyword(s):  
Fatty Acids ◽  
Endophytic Fungi ◽  
Inhibitory Activity ◽  
Endophytic Fungus ◽  
Inhibitory Concentration ◽  
Life Cycles ◽  
Ic50 Values ◽  
Quercus Phillyraeoides ◽  
Alternaria Sp ◽  
Harmful Effects

AbstractEndophytic fungi are the microorganisms that spend all or part of their life cycles within plant tissue without causing harmful effects on the plant. In this study, 14 endophytic fungus from Quercus phillyraeoides A. Gray were isolated. Alternaria sp. QPS 05, an endophytic fungi which was isolated from the stem of Q. phillyraeoides A. Gray showed the highest α-glucosidase inhibitory activity. Further separation of ethyl acetate extract from the fungus led to the isolation of active substance from hexane-soluble fraction which give fatty acids mixture consist of palmitic acid, oleic acid, linoleic acid and linolenic acid (1) strong inhibitory activity against α-glucosidase. Isolated fatty acids (1) had inhibitory concentration (IC50) values against Saccharomyces cerevisiae was 12.10 μg/mL. The results of the present study showed that endophytic fungus from Alternaria sp. QPS 05 potentially contained a rich source of natural antidiabetic medicine.

A Synergistic Antimicrobial Mechanism of GO: Why Oxidative Stress Can Inactivate E. coli

NANO ◽  
2020 ◽  
Vol 15 (04) ◽  
pp. 2050054 ◽  
Author(s):  
Xin Li ◽  
Haoqi Zhao ◽  
Shidong Wang ◽  
Weiwu Zou ◽  
Peiyan Yang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Antibacterial Activity ◽  
Mammalian Cells ◽  
Water Solubility ◽  
Direct Interaction ◽  
Medical Application ◽  
Future Application ◽  
Sem Images ◽  
E Coli ◽  
Low Cytotoxicity

Graphene oxide (GO), a 2D nanomaterial, is a promising material for medical application, thanks to its water solubility, antibacterial activity and relatively low cytotoxicity. However, many factors, such as lateral dimension, purity and surface chemistry, may influence its antibacterial activity, its exact mechanism is still unknown. In this work, E. coli was used as model bacterium to determine the antibacterial activity of well-dispersed GO which was obtained by a modified Hummer method and dialyzed to remove the salts and acid used in the oxidation process. After co-culture with GO for 2[Formula: see text]h, up to 90% E. coli cells were inactivated when GO concentration at 8[Formula: see text][Formula: see text]g/mL. The direct interaction was not detected in FE-SEM images and the results of [Formula: see text] potential showed that the interaction between GO and E. coli are repulsive[Formula: see text] Our results showed that GO can produce ROS and inactivate SOD and CAT enzymes in low concentration after co-cultured with E. coli which explained the antibacterial activity of GO in aqueous solution. Meanwhile, GO, with high purity, showed low cytotoxicity towards mammalian cells and did not cause any observable hemoglobin after co-cultured with blood cells. The data presented here prove that GO is effectively inhibit E. coli through inactivating SOD, CAT enzymes and the oxidative stress produced by ROS. Furthermore, the good biocompatibility promised its future application.

scholarly journals DEVELOPMENT OF NANOPARTICULATE DRUG DELIVERY SYSTEM FROM MARINE SOURCE AGAINST HUMAN IMMUNODEFICIENCY VIRUS

2019 ◽  
pp. 38-40
Author(s):  
HARIKRISHNAN N ◽  
ANAS S MOHAMIED ◽  
GEJALAKSHMI S
Keyword(s):  
Human Immunodeficiency Virus ◽  
Protein Separation ◽  
Chemical Method ◽  
Inhibitory Concentration ◽  
Treatment Modalities ◽  
Standard Drug ◽  
Immunodeficiency Virus ◽  
Ic50 Values ◽  
Infection Inhibition ◽  
Anti Hiv

Objective: Nanotechnology techniques are a creation and exploitation of materials, devices, and systems through the control of matter on the nanometer length scale, i.e., involvement of atoms, molecules, and supramolecular structures. Every existing treatment modalities against human immunodeficiency virus (HIV) offer a marginal increase in the life expectancy as chitosan was converted to its derivative aminoethyl chitosan by chemical method evaluated for anti-HIV activity. Methods: Isolation of chitosan from crab shell by chemical method involves four basic steps; protein separation, calcium carbonate separation, deproteinization, and demineralization. Results: The results revealed the anti-HIV activity of the prepared nanoparticulate system. Cytotoxicity assay of the nanoparticulate system was carried out and the cytotoxic concentration 50% (CC50) value was found to be 38.07±1.42 μg/ml, indicating that the nanoparticulate system is not cytotoxic. HIV-1 infection inhibition assay was carried out and the nanoparticulate system showed excellent inhibitory activity with a half-maximal inhibitory concentration (IC50) value of 3.75±0.57 μg/ml. Conclusions: It concludes, the CC50 and inhibitory concentration 50% IC50 values, the selectivity index of the nanoparticle was found to be 17.65 compared to the standard drug nevirapine (82.32), indicating the usefulness of the formulated nanoparticulate system as potential anti-HIV agent.

scholarly journals Characterization of Hapten-Protein Conjugates: Antibody Generation and Immunoassay Development for Chlorophenoxyacetic Acid Pesticides

2009 ◽  
Vol 92 (6) ◽  
pp. 1773-1779 ◽  
Author(s):  
Robin C Boro ◽  
K Vikas Singh ◽  
C Raman Suri
Keyword(s):  
Inhibitory Concentration ◽  
Dichlorophenoxyacetic Acid ◽  
Protein Conjugation ◽  
Protein Conjugates ◽  
Highly Sensitive ◽  
Ic50 Values ◽  
Chlorophenoxyacetic Acid ◽  
2,4 Dichlorophenoxyacetic Acid

Abstract The generation of specific and sensitive antibodies against small molecules is greatly dependent upon the characteristics of the hapten-protein conjugates. In this study, we report a new fluorescence-based method for the characterization of hapten-protein conjugates. The method is based on an effect promoted by hapten-protein conjugation density upon the fluorescence intensity of the intrinsic tryptophan chromophore molecules of the protein. The proposed methodology is applied to quantify the hapten-protein conjugation density for two different chlorophenoxyacetic acid pesticides, 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4-dichlorophenoxybutyric acid (2,4-DB), coupled to carrier protein. Highly sensitive anti-2,4-D and anti-2,4-DB antibodies were obtained using these well-characterized hapten-protein conjugates. The generated antibodies were used in an immunoassay format demonstrating inhibitory concentration (IC50) values equal to 30 and 7 ng/mL for 2,4-D and 2,4-DB, respectively. Linearity was observed in the concentration range between 0.1500 ng/mL with LODs around 4 and 3 ng/mL for 2,4-D and 2,4-DB, respectively, in standard water samples. The proposed method was successfully applied for the determination of the extent of hapten-protein conjugation to produce specific antibodies for immunoassay development against pesticides.

scholarly journals EVALUATION OF IN VITRO ANTIOXIDANT AND α-AMYLASE INHIBITORY ACTIVITY OF PHYLLANTHUS INDOFISCHERI BENNET

2016 ◽  
Vol 8 (11) ◽  
pp. 131 ◽  
Author(s):  
Kalpana S ◽  
Ramakrushna B. ◽  
Anitha S.
Keyword(s):  
Inhibitory Activity ◽  
Colorimetric Method ◽  
Radical Scavenging ◽  
Total Flavonoid ◽  
Aluminium Chloride ◽  
Total Phenolic ◽  
Total Flavonoid Content ◽  
Flavonoid Content ◽  
Ic50 Values

Objective: The present study evaluates the antioxidant and α-amylase inhibitory activity of leaf and bark extracts of Phyllanthus indofischeri with methanol and water as solvents. In addition to this, the total phenolic content and total flavonoid content was determined.Methods: The total phenolic and total flavonoid content of the extracts was determined by folin ciocaletus reagent method and aluminium chloride colorimetric method respectively. The antioxidant and α-amylase inhibitory activity were measured by various assays, including α, α-diphenyl-ẞ-dipicryl-hydrazyl (DPPH) free radical scavenging, 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonicacid) (ABTS) radical scavenging, superoxide radical scavenging, total antioxidant capacity by phosphomolybdate method and porcine pancreatic α-amylase inhibitory assay. The IC50 values were calculated and compared with standards such as gallic acid, ascorbic acid and α-acarbose.Results: The results illustrated that all the extracts of Phyllanthus indofischeri exhibit significant antioxidant and α-amylase inhibitory activity. Among the extracts, methanolic leaf extract showed high levels of activity followed by bark water extract.Conclusion: Phyllanthus indofischeri extracts had shown antioxidant and α-amylase inhibitory activity. On the basis of these results, Phyllanthus indofischeri can be used as a natural antioxidant and hypoglycemic agent against various disorders related to oxidative stress; and the isolation of bioactive compounds was warranted. 

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