scholarly journals Bioassay-guided isolation and identification of Aedes aegypti larvicidal and biting deterrent compounds from Veratrum lobelianum

2018 ◽  
Vol 16 (1) ◽  
pp. 324-332 ◽  
Author(s):  
Nurhayat Tabanca ◽  
Zulfiqar Ali ◽  
Ulrich R. Bernier ◽  
Nancy Epsky ◽  
Ayse Nalbantsoy ◽  
...  
Keyword(s):  
Larvicidal Activity ◽  
Ethanol Extract ◽  
Ethyl Linoleate ◽  
Significant Activity ◽  
Isolation And Identification ◽  
Human Carcinoma ◽  
Ethyl Palmitate ◽  
H Nmr ◽  
Bioassay Guided Fractionation ◽  
Nmr Techniques

AbstractAn ethanol extract fromVeratrum lobelianumBernh. rhizomes showed larvicidal activity with LC50values of 11.79 ppm and 89.9 ppm against 1stand 4thinstar larvae, respectively, at 24 h post-treatment. The extract also showed proportion not biting (PNB) value of 0.76 at 100 μg/cm2against females ofAe.aegypti. Systematic bioassay-guided fractionation ofV.lobelianumextract resulted in the isolation of five compounds that were identified as ethyl palmitate (1), ethyl linoleate (2), β-sitosterol (3), resveratrol (4) and oxyresveratrol (5) by GC-MS,1H-NMR, and13C-NMR techniques, comparison with literature data, and confirmation with authentic compounds. Compound2exhibited larvicidal activity with an LC50value of 24.1 (22.0-26.2) ppm whereas1was inactive. β-Sitosterol (3) displayed the highest larvicidal activity with LC50= 1.7 (1.3-12.3) ppm and LC90= 5.1 (3.4-13.8) ppm. Compounds4and5had larvicidal activity with LC50values of 18.5 (15.3-23.3) and 22.6 (19.0-26.8) ppm, respectively, and had an equivalent PNB values of 0.75 at 25 nmol/cm2. In addition,4and5were explored for their human-based repellency againstAe.aegypti, attractiveness against male medfliesCeratitis capitata, and also evaluated against series of human carcinoma cells (A549, HEK293, HeLa, SH-SY5Y); however, no significant activity was found.

scholarly journals Antioxidant flavonol glycosides from Nectandra grandiflora (Lauraceae)

2002 ◽  
Vol 27 (spe) ◽  
pp. 35-44 ◽  
Author(s):  
Alan Bezerra Ribeiro ◽  
Dulce Helena Siqueira Silva ◽  
Vanderlan da Silva Bolzani
Keyword(s):  
Ethanol Extract ◽  
Beta Carotene ◽  
Molecular Structures ◽  
Flavonol Glycosides ◽  
Bioassay Guided Fractionation ◽  
Nmr Techniques

The bioassay-guided fractionation of the ethanol extract from Nectandra grandiflora leaves led to the isolation of two flavonol glycosides which inhibited the bleaching of beta -carotene on the TLC assay. Both compounds had their molecular structures elucidated by means of extensive use of uni- and bidimensional NMR techniques and were identified as 3-O-beta -rhamnosylkaempferol and 3-O-beta -rhamnosylquercetine.

scholarly journals Identification of a New Antibacterial Sulfur Compound fromRaphanus sativusSeeds

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Jeries Jadoun ◽  
Ahmad Yazbak ◽  
Salwa Rushrush ◽  
Amira Rudy ◽  
Hassan Azaizeh
Keyword(s):  
Antibacterial Activity ◽  
Sulfamic Acid ◽  
Ethanol Extract ◽  
Inhibitory Effect ◽  
Plant Parts ◽  
H Nmr ◽  
Microbial Infections ◽  
Bioassay Guided Fractionation ◽  
Isolated Compound ◽  
Red Radish

Raphanus sativusL. (radish), a member of Brassicaceae, is widely used in traditional medicine in various cultures for treatment of several diseases and disorders associated with microbial infections. The antibacterial activity of the different plant parts has been mainly attributed to several isothiocyanate (ITC) compounds. However, the low correlation between the ITC content and antibacterial activity suggests the involvement of other unknown compounds. The objective of this study was to investigate the antibacterial potential of red radish seeds and identify the active compounds. A crude ethanol seed extract was prepared and its antibacterial activity was tested against five medically important bacteria. The ethanol extract significantly inhibited the growth of all tested strains. However, the inhibitory effect was more pronounced againstStreptococcus pyogenesandEscherichia coli. Bioassay-guided fractionation of the ethanol extract followed by HPLC,1H-NMR,13C-NMR,15N-NMR, and HMBC analysis revealed that the active fraction consisted of a single new compound identified as [5-methylsulfinyl-1-(4-methylsulfinyl-but-3-enyl)-pent-4-enylidene]-sulfamic acid, which consisted of two identical sulfur side chains similar to those found in ITCs. The minimal inhibitory concentration values of the isolated compound were in the range of 0.5–1 mg/mL. These results further highlight the role of radish as a rich source of antibacterial compounds.

scholarly journals Larvicidal Compounds Extracted from Helicteres velutina K. Schum (Sterculiaceae) Evaluated against Aedes aegypti L.

Molecules ◽  
2019 ◽  
Vol 24 (12) ◽  
pp. 2315 ◽  
Author(s):  
Diégina A. Fernandes ◽  
Renata P. C. Barros ◽  
Yanna C. F. Teles ◽  
Louise H. G. Oliveira ◽  
Jéssica B. Lima ◽  
...  
Keyword(s):  
Larvicidal Activity ◽  
Ethanol Extract ◽  
Endemic Plant ◽  
Isolation And Identification ◽  
Traditional Use ◽  
Phytochemical Study ◽  
Liquid Liquid Extraction ◽  
Screening Protocol ◽  
Sterol Carrier Protein 2

Helicteres velutina K. Schum (Sterculiaceae), a member of Malvaceae sensu lato, is a Brazilian endemic plant that has been used by the indigenous tribe Pankarare as an insect repellent. A previous study has reported the isolation of terpenoids, flavonoids and pheophytins, in addition to the larvicidal activity of crude H. velutina extracts derived from the aerial components (leaves, branches/twigs, and flowers). The present study reports the biomonitoring of the effects of fractions and isolated compounds derived from H. velutina against A. aegypti fourth instar larvae. A crude ethanol extract was submitted to liquid–liquid extraction with hexane, dichloromethane, ethyl acetate and n-butanol to obtain their respective fractions. Larvicidal evaluations of the fractions were performed, and the hexane and dichloromethane fractions exhibited greater activities than the other fractions, with LC50 (50% lethal concentration) values of 3.88 and 5.80 mg/mL, respectively. The phytochemical study of these fractions resulted in the isolation and identification of 17 compounds. The molecules were subjected to a virtual screening protocol, and five molecules presented potential larvicidal activity after analyses of their applicability domains. When molecular docking was analysed, only three of these compounds showed an ability to bind with sterol carrier protein-2 (1PZ4), a protein found in the larval intestine. The compounds tiliroside and 7,4′-di-O-methyl-8-O-sulphate flavone showed in vitro larvicidal activity, with LC50 values of 0.275 mg/mL after 72 h and 0.182 mg/mL after 24 h of exposure, respectively. This is the first study to demonstrate the larvicidal activity of sulphated flavonoids against A. aegypti. Our results showed that the presence of the OSO3H group attached to C-8 of the flavonoid was crucial to the larvicidal activity. This research supports the traditional use of H. velutina as an alternative insecticide for the control of A. aegypti, which is a vector for severe arboviruses, such as dengue and chikungunya.

scholarly journals Analysis on the Fatty Acids and Volatile Components in Pleurotus geesteranus by HS-SPME-GC-MS

2020 ◽  
Vol 2020 ◽  
pp. 1-5
Author(s):  
Zhenhua Liang ◽  
Shanei Li ◽  
Qiongxin Liang ◽  
Liqiang Ji ◽  
Jinmei Wang ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Petroleum Ether ◽  
Solid Phase ◽  
Petroleum Ether Extract ◽  
Ethanol Extract ◽  
Ethyl Linoleate ◽  
Ion Current ◽  
Volatile Components ◽  
Ether Extract ◽  
Ethyl Palmitate

The volatile constituents and fatty acids in Pleurotus geesteranus were assayed by headspace solid-phase microextraction coupled with GC-MS. There were 5 volatile compounds in P. geesteranus that accounted for 43.43% of the total ion current peak area, and its main compounds were 2-undecanone (13.99%), 3-ethyl-2,5-dimethyl pyrazine (12.67%), and l-β-bisabolene (6.79%). Fourteen compounds were identified in the ethanol extract of P. geesteranus and 6 fatty acids were identified from the petroleum ether extract, which accounted for 93.72% and 98.48% of the total ion current peak area, the main compounds in the ethanol extract were ethyl linoleate (67.36%) and ethyl palmitate (21.83%), and the main fatty acids in the petroleum ether extract were linoleic acid (78.22%), palmitic acid (10.74%), and oleic acid (8.13%).

ISOLATION AND IDENTIFICATION OF 16-OXOOESTRADIOL-17β IN HUMAN PLACENTAE

1959 ◽  
Vol XXXII (II) ◽  
pp. 195-208 ◽  
Author(s):  
E. Diczfalusy ◽  
Anne-Marie v. Münstermann
Keyword(s):  
Ethanol Extract ◽  
Full Term ◽  
Free Form ◽  
Isolation And Identification ◽  
Human Placentae

ABSTRACT From the ethanol extract of 100 full term placentae approximately 200 μg of an α-ketolic Kober chromogen have been isolated in a »free« form. The evidence obtained indicates that this α-ketolic Kober chromogen is identical with 16-oxooestradiol-17β.

Six-Sided Heptaporphyrin Array: Towards a Nano-Sized Cube

2004 ◽  
Vol 69 (5) ◽  
pp. 996-1008 ◽  
Author(s):  
Steven J. Langford ◽  
Clint P. Woodward
Keyword(s):  
Single Step ◽  
One Pot ◽  
H Nmr ◽  
The Core ◽  
Nmr Techniques ◽  
Axial Vertex

A strategy in preparing a family of hexameric porphyrin cubes based on the interplay of Sn(IV)-O and Ru(II)-N interactions is described. In this first iteration, we have prepared the heptamer [SnIV(TPyP)·(4)2][Ru(CO)(TPP)]6 (4 = (E)-(3-(4-pyridyl)acrylate)) constituting a 5,10,15,20-tetra(4-pyridyl)porphyrin (TPyP) core and 5,10,15,20-tetraphenylporphyrin (TPP) faces and compared its formation by stepwise and "one-pot" strategies where up to nine components are assembled in a single step in a regiospecific manner. In one example, the heptamer is formed around the template [SnIV(TPyP)·(4)2] bearing pyridine groups in which the nitrogens radiate octahedrally along each vertex. The ability to modulate the axial vertex through choice of pyridine is also demonstrated. 1H NMR measurements on [SnIV(TPyP)·(4)2][Ru(CO)(TPP)]6 indicate that the protons on the core template are extremely shielded as a result of the anisotropy of the peripheral porphyrin units. Various NMR techniques, including NOESY experiments, have been used to characterise the heptamer in solution.

E-Homolupane Derivatives Substituted in Position 17 and 22a. 1H NMR, 13C NMR and IR Spectra

1995 ◽  
Vol 60 (4) ◽  
pp. 619-635 ◽  
Author(s):  
Václav Křeček ◽  
Stanislav Hilgard ◽  
Miloš Buděšínský ◽  
Alois Vystrčil
Keyword(s):  
Nmr Spectra ◽  
2D Nmr ◽  
Coupling Constants ◽  
Side Chain ◽  
Oxidation Reactions ◽  
H Nmr ◽  
Complete Assignment ◽  
Nmr Techniques ◽  
Intramolecular Association ◽  
C Nmr

A series of derivatives with various oxygen functionalities in positions 17,22a or 19,20 was prepared from diene I and olefin XVI by addition and oxidation reactions. The structure of the obtained compounds was confirmed by 1H NMR, 13C NMR and IR spectroscopy. The kind of intramolecular association of the 17α-hydroxy group was studied in connection with modification of the side chain and substitution in position 22a. Complete assignment of the hydrogen signals and most of the coupling constants was accomplished using a combination of 1D and 2D NMR techniques. The 1H and 13C NMR spectra are discussed.

scholarly journals LARVICIDAL ACTIVITY OF Caesalpinia ferrea MART. AND Lippia origanoides CHAM. AGAINST Aedes aegypti (LINNAEUS, 1762) (DIPTERA: CULICIDAE)

2020 ◽  
Vol 49 (1) ◽  
pp. 45-54
Author(s):  
Thiago Andre Santos de Andrade ◽  
Ivanise Maria de Santana ◽  
George Chaves Jimenez ◽  
Eulina Tereza Nery Farias ◽  
Lucia Oliveira de Macedo ◽  
...  
Keyword(s):  
Public Health ◽  
Aedes Aegypti ◽  
Larvicidal Activity ◽  
Ethanol Extract ◽  
Chemical Compounds ◽  
Botanical Insecticide ◽  
Plant Metabolites ◽  
Important Public Health ◽  
Public Health Challenges ◽  
Ethanol Extracts

The control of Aedes aegypti has been considered one of the most important public health challenges worldwide. Chemical compounds have long been used for this purpose, but resistance to these molecules has also increased. Therefore, over the last few years several studies have focused on the development of alternative tools, particularly those based on plant metabolites. The purpose of this study was to assess the larvicidal activity of Caesalpinia ferrea and Lippia origanoides against Ae. aegypti. Larvae (L3) of Ae. aegypti Liverpool and Rockefeller strains, as well as of the Recife population were exposed to different concentrations  of C. ferrea (ranging from 13.1 to 105 mg/mL) and L. origanoides (ranging from 16.3 to 130 mg/mL), and the mortality rate was evaluated up to 48 hours after the beginning of the experiment. All tested groups and  ontrol group were quadruplicated. For C. ferrea, mortality ranged from 42.5% to 100% for Ae. aegypti Liverpool strain,from 67% to 100% for Ae. aegypti Rockfeller strain, and 57% to 100% for Ae. aegypti Recife population after 48 hours of larval exposure. For L. origanoides, the larvicidal activity ranged from 75% to 100% for Ae. aegypti Liverpool strain, from 61.5% to 100% for Ae. aegypti Rockfeller strain, and from 60.5% to 100% for Ae.aegypti Recife population. The hydro ethanol extract of C. ferrea and L. origanoides presented larvicidal activity against Ae. aegypti.KEY WORDS: Aedes aegypti; hydro ethanol extracts; Caesalpinia ferrea; Lippia sidoides; botanical insecticide; mosquitoes.

scholarly journals STUDY OF CONFORMATIONAL PREFERENCES OF ERYTHRO-CAROLIGNAN E ASSESSED BY THE COUPLING BETWEEN H7'-H8' IN DIFFERENT NMR SOLVENTS

2016 ◽  
Vol 11 (1) ◽  
pp. 1
Author(s):  
Rudiyansyah Rudiyansyah ◽  
Ajuk Sapar ◽  
Masriani Masriani
Keyword(s):  
Ethanol Extract ◽  
Coupling Constant ◽  
Relative Configuration ◽  
H Nmr ◽  
Nmr Data ◽  
Conformational Preferences ◽  
Wood Bark

<p><em>Erythro</em>-carolignan E (<strong>1</strong>) has been obtained from the ethanol extract of the wood bark of <em>Durio affinis</em> Becc. This research was conducted in order to prove that conformational preferences of compound <strong>1</strong> were solvent dependent. On the basis of <sup>1</sup>H-NMR data, the relative configuration of compound <strong>1</strong> was characterized by a coupling constant (<sup>3</sup><em>J</em><sub>HH</sub>) value of 3.3 Hz at H-7' in CDCl<sub>3</sub>. The coupling constant (<sup>3</sup><em>J</em><sub>HH</sub>) values of H-7' in compound <strong>1</strong> has changed to 4.1 Hz and 5.3 Hz in pyridine-<em>d</em><sub>5</sub> and acetonitrile-<em>d</em><sub>3</sub> respectively. As a result, the conformation of compound <strong>1</strong> at C7'-C8' has changed in different NMR solvents.  In conclusion, structure of<em>erythro</em>-carolignan E that contains a dihydroxy group at C7'-C8' is able to change in different NMR solvent.</p>

scholarly journals New Sensitive Kinetic Spectrophotometric Methods for Determination of Omeprazole in Dosage Forms

2009 ◽  
Vol 2009 ◽  
pp. 1-11 ◽  
Author(s):  
Ashraf M. Mahmoud
Keyword(s):  
Reference Method ◽  
Fixed Time ◽  
Dosage Forms ◽  
Charge Transfer Complexes ◽  
Specific Rate ◽  
Spectrophotometric Methods ◽  
H Nmr ◽  
Nmr Techniques ◽  
Kinetic Spectrophotometric

New rapid, sensitive, and accurate kinetic spectrophotometric methods were developed, for the first time, to determine omeprazole (OMZ) in its dosage forms. The methods were based on the formation of charge-transfer complexes with both iodine and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ). The variables that affected the reactions were carefully studied and optimized. The formed complexes and the site of interaction were examined by UV/VIS, IR, and1H-NMR techniques, and computational molecular modeling. Under optimum conditions, the stoichiometry of the reactions between OMZ and the acceptors was found to be 1 : 1. The order of the reactions and the specific rate constants were determined. The thermodynamics of the complexes were computed and the mechanism of the reactions was postulated. The initial rate and fixed time methods were utilized for the determination of OMZ concentrations. The linear ranges for the proposed methods were 0.10–3.00 and 0.50–25.00   with the lowest LOD of 0.03 and 0.14   for iodine and DDQ, respectively. Analytical performance of the methods was statistically validated; RSD was <1.25% for the precision and <1.95% for the accuracy. The proposed methods were successfully applied to the analysis of OMZ in its dosage forms; the recovery was 98.91–100.32%  0.94–1.84, and was found to be comparable with that of reference method.

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