This work aims to analyze a three-dimensional discrete-time biological system, a prey-predator model with a constant harvesting amount. The stage structure lies in the predator species. This analysis is done by finding all possible equilibria and investigating their stability. In order to get an optimal harvesting strategy, we suppose that harvesting is to be a non-constant rate. Finally, numerical simulations are given to confirm the outcome of mathematical analysis.
A first step in this research was to synthesize Schiff's bases(1-3)using an Amoxcilline intensification reaction with different aromatic aldehydes in absolute ethanol. In benzene and refluxing conditions,Schiff's bases were cyclized with succinic and Phthalic anhydride to give a new sequence of 1,3-oxazepine derivatives(4-6) and (7-9),respectively.The last step,cyclization reactions with sodium azide in THF solvent resulted in the formation of [10 and 11], which are supposed to be biologically significant.FT.IR, 1H-NMR and 13C-NMR (for compound 4,7,9, and 11),as well as melting points reported, were used to characterize these prepared compounds ,Bacillus (G+), Staphylococcus (G+), and E.Coli (G-)were screened against these compounds. . To i
... Show MoreIn the present research synthesis and study of biological activity a series of new polymers modified of chitosan with compounds containing azo group. Beginning diazonium salt produced from 3,3'-dimethyl-[1,1'-biphenyl]-4,4'-diamine reacted with concentrated HCl acid and sodium nitrite. The coupling reaction between diazonium salt with substituted aromatic aldehyde to produce Azo derivatives )1-6(. Azo Schiff bases Chitosan )7-12( were synthesized by condensation of Chitosan with Azo derivatives )1-6( in ethanol with some drops of glacial acetic acid. The structural modifications of Chitosan ring (linked to a bioactive azo moiety) were expected to give new derivatives )7-12( with a diverse range of biological functions. These compounds' st
... Show MoreIn this research work, synthesis, antimicrobial and antioxidant bioactivity of a chain of compounds having unsaturated ketones bond and isoxazoline moiety have been described. New chalcone derivatives containing isoxazoline moiety have been synthesized. Generally, Chalcones are unsaturated ketones bearing (-CO-CH=CH-) as reactive ketoethylenic group that give the bright yellow colored compounds due to this chromophore group. Firstly, chalcones (IIa-d) have been prepared by cyclocondensation (Claisen-Schmidt condensation) of triphenyl aminobenzaldehyde with different substituted acetophenone in ethyl alcohol to produce a series of chalcones compounds with bright yellow colored as a
... Show MoreIn this study, the chamomile flowers (Matricaria recutitaL) which grow in Iraqi Kurdistan region during the seasons of (2008) are collected. The percentage of essential oil was determined by using steam distillation and the extraction of flowers performed with petroleum ether (70-80) ºC and methanol 70% using ultrasonic extraction. Total phenolic compounds were determined from methanol extracts by using Folin-Ciocalteu method. The extracts were evaluated by thin layer chromatography, ultraviolet absorption and the biological activities were evaluated through their antibacterial action against two types of bacteria using hole method. The flowers showed a composition of 0.071% ash, 0.4% essential oil, 3.2% non oily compounds, 4% oil, 1.9% mo
... Show MoreThis work involves synthesis of novel Schiff bases derivatives contining isoxazoline or pyrazoline units starting with chalcons . 4-Aminoacetophenone was reacted with 3-nitrobenzaldehyde in basic medium giving chalcone [I] by claisen-schemidt reaction. The chalcone [I] was reacted with hydroxylamine hydrochloride giving isoxazoline [II] in basic medium. The chalcone [I] could also react with hydrazitne hydrate to give pyrazoline [III] . The novel Schiff bases with structural formula [IV] and [V] were prepared by the reaction of amino compounds ; isoxazoline [II] and pyrazolines [III] with p-substituted aldehydes or p-subsituted ketones, respectively in dry benzene using drops of glacial acetic acid as a cat
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A new series of bases of Schiff (H2-H4) derived from phthalic anhydrideweresynthesized. These Schiff bases were prepared by the reaction of different amines (tyrosine methyl ester, phenylalanine methyl ester, and isoniazid) with the phthalimide derived aldehyde with the aid of glacial acetic acid or triethylamine ascatalysts. All the synthesized compounds were characterized by (FT-IR and 1HNMR) analyses and were in vitro evaluated for their antimicrobial activity against six various kinds of microorganisms. All the synthesized compounds had been screened for their antimicrobial activity against two Gram-positive bacteria “Staph. Aureus, and Bacillus subtilis
... Show MoreThe effect of three high temperatures for five exposure periods on the developments of larvae, pupae and adults of Trogoderma granarium (Everts) and their biological performance were investigated. The results revealed that the percent of mortality was increased as the temperature and the exposure period increased, e. g. exposing last instar larvae to 45°C for 6 hrs caused 100% death of this stage, while exposing adults (1-3) days old to the same temperature and exposure time resulted in that these adults did not able to survive more than 24 hrs.; in addition, the results showed that the ability of reproduction of adults was depended on the temperature, duration of exposure and the sex.
A new macrocyclic multidentate Schiff-base ligand Na4L consisting of two submacrocyclic units (10,21-bis-iminomethyl-3,6,14,17- tricyclo[17.3.1.18,12]tetracosa-1(23),2,6,8,10,12(24),13,17,19,21,-decaene-23,24-disodium) and its tetranuclear metal complexes with Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) are reported. Na4L was prepared via a template approach, which is based on the condensation reaction of sodium 2,4,6-triformyl phenolate with ethylenediamine in mole ratios of 2 : 3. The tetranuclear macrocyclic-based complexes were prepared from the reaction of the corresponding metal chloride with the ligand. The mode of bonding and overall geometry of the compounds were determined through physicochemical and spectroscopic methods. These st
... Show MoreLevan is an exopolysaccharide produced by various microorganisms and has a variety of applications. In this research, the aim was to demonstrate the biological activity of levan which produced from B. phenoliresistens KX139300. These were done via study the antioxidant, anti-inflammatory, anticancer and antileishmanial activities in vitro. The antioxidant levan was shown 80.9% activity at 1250 µg/mL concentration. The efficient anti-inflammatory activity of 88% protein inhibition was noticed with levan concentration at 35 µg/mL. The cytotoxic activity of levan at 2500 µg/mL concentration showed a maximum cytotoxic effect on L20B cell line and promastigotes of Leishmani tropica. Levan has dose-dependent anticancer and antileishmanial acti
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