A study of the effects of various physicochemical parameters governing the solution polycondensation of a system furanic dihydrazide / diacid chloride allowed the most favourable reaction conditions to be determined. The latter procedure gave a novel series of furanic polyhydrazides in higt yields and satisfaction inherent viscosities. The structure and thermal behaviour of these polymers are discussed.
A. Afli, S. Gharbi, R. El Gharbi, A. Gandini
polyhydrazides, solution polycondensation, furanic polymers
The stereochemistry of acids halide and iininoesters is studied. A qualitative molecular orbital interpretation is suggested to explain the stereochemistry of the resulting β-lactams. Stereoselectivity of the reaction is directly related to the stability of the supposed intermediate.
D.A. Sidhoum, A. Krallafa, H. Benhaoua
Stereochemistry, β-lactams, Stereoselectivity, Diastereoselectivity, Molecular Orbitals
The aerial part of Prasium majus afforded Melittoside 1 and a flavone glycoside Chrysoeriol 7-(2"-O-β-D-allopyranosyl)-β-D-glycopyranoside 2. Their structures were established via their uncompletely acetylated derivatives on the basis of spectroscopic measurements, mainly 2D NMR.
S. Hammami, H. Ben Jannet, Z. Mighri, J.M. Nuzillard
Prasium majus, Lamiaciatae, iridoid glycoside, flavonoid glycoside, 2D NMR
New Spiro-isoxazolino-indo1-3-ones and 3-aroylisoxazoles have been synthesized in good yields on KF-Al2O3 in «dry media» and under microwaves irradiation. All synthons and final products have been described and their structures established by spectroscopic methods.
M. Elyazidi, K. Bougrin, B. Daou, H. Doua, M. Soufiaoui
spiro-isoxazolino-indol-3-ones, 3-aroylisoxazoles, arylnitriloxydes, 1,3-dipolar cycloaddition, KF-Al2O3, dry media, microwaves
The chemical composition of Cynara cardunculus L. seed oil has been determined. This oil is rich in oleic and linoleic acids. Twelve triacylglycerols have been identified : LLL. LLO, LnOO, LOO and LOP are present in proportions superior to 1O%.Thirteen sterols have been identified with stigmasterol, β-sitosterol and Δ-7-stigmastenol as major constituents.
I. Koubaa, R. Jarraya, J. Makni, M. Damak
Asteraceae, Cynara cardunculus, oil, triacylglycemls, sterols
The relative study to the variation of the nature, the content in fatty acid composition and content in triacylglycerol composition of olive oil has made the object of a series of works having shown the influence of the variety on contents of these composed and not on their nature. On the other hand, that on the determination of the bonds of dependence that could have exist between fatty acids and the triacylglycerol one rest again not processed clearly. The present work aims to bring elements of reply to this preoccupation and this through the estimation of the relation-ship between the fatty acid composition and the triacylglycerol composition of 21 different olive cultivars installed in an experimental field at the Olive Tree Institute in Sfax. Obtained results by GC and HPLC have confirmed the influence of the variety on the contents of these composed. The multiple correlation calculation and the determination of the multiple regression equations have shown that contents in oleic and linoleic acid depend effectively on those of the triacylglycerol products of the esterification of these acids respectively. On the other hand, the content in the palmitic acid seems to be determined both by the triacylglycerol products of esterification of this acid and the triacylglycerol products of esterification of the other acids.
H. Fourati, M. Ayadi, B. Karray, M. Khlif, M. Cossentini
olive oil, variety, fatty acid composition, triacylglycerol composition, correlations
The GC/MS and the HPLC were used to study the physicochemical features of neutralized oils either by lime or by sodium hydroxide. This study was carried out first on an artificially- acidified olive oil sample and second on a naturally- hydrolysed oil sample, the acid olive oil cabe. The neutralization reaction by sodium hydroxide and that by lime are both accompanied with a triacylglycerol hydrolysis reaction, which attacks the internal positions of the triacylglycerol and particularly those esterified by linoleic acid. Indeed as concerns the sodium hydroxide we noticed in the acid composition analysis that the linoleic acid rate has dramatically dropped. However, the neutralization reaction by lime permitted to limit this triacylglycerol hydrolysis reaction.
K. Essid, M. Chtourou, W. Jahouach, M. Trabelsi, M.H. Frikha
neutralization, olive oil cabe, triacylglycerol, chemical hydrolysis, position isomer
The sparida species are much appreciated by Tunisian consumer's in spite of their small size. The great interest in polyunsaturated fatty acids (n-3) is due to the importance they have in the Mediterranean diet in addition to their ability to prevent and protect against a great number of diseases especially cardiovascular ones. In the present work, we have followed the polyunsaturated fatty acids (n-3) mass progress in an immature sparida species (Diplodus annularis) from the Gulf of Tunis according to seasons. The results obtained by gas chromatograph with polar capillary column reveal a significant variation (P < 0.01) of total fatty acids according to seasons: 0.49; 2.93; 1.55 and 0.77 mg/g wet weight for autumn, winter, spring and summer respectively. These results reveal better polyunsaturated fatty acids (n-3) values during winter in immature Diplodus annularis form the Gulf of Tunis.
A. Chaouch, I. Bouhlel, I. Chraief, M. Hammami, A. El Hani
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