Potentiometric titration of poly(α-D)galacturonic acid

Rudan-Tasic, Darja; Klofutar, Cveto

doi:10.1016/s0921-0423(96)80293-0

Cited by 6 publications

(9 citation statements)

References 14 publications

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“…4A). Safflower oil is not commonly used as solvent for organogelators but its dielectric constant (ε) should be comparable to that of other vegetable oils 27 (2-3 F•m −1 ) and close to that of hexane. 28 In these solvents both van der Waals and H-bond interactions have often been reported as key elements in the gelation mechanism.…”

Section: Discussionmentioning

confidence: 99%

Pharmaceutical organogels prepared from aromatic amino acid derivatives

Bastiat

Leroux

2009

J. Mater. Chem.

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Organogels are semi-solid systems in which an organic liquid phase is immobilized by a 3-dimensional network composed of self-assembled gelator molecules. Although there is a large variety of organogel systems, relatively few have been investigated in the field of drug delivery, owing mostly to the lack of information on their biocompatibility and toxicity. In this work, organogelator-biocompatible structures based on aromatic amino acids, namely, tyrosine, tryptophan, and phenylalanine were synthesized by derivatization with aliphatic chains. Their ability to gel an injectable vegetable oil ( safflower oil) and to sustain the release of a model anti-Alzheimer drug ( rivastigmine) was then evaluated. Organogels and molecular packing were characterized by differential scanning calorimetry, rheology analysis, Fourier-transform infrared spectroscopy and X-ray crystallography. The amino acid derivatives were able to gel safflower oil through van der Waals interactions and H-bonds. Tyrosine-derivatives produced the strongest gels while tryptophan was associated with poor gelling properties. The superior gelling ability of tyrosine derivatives could be explained by their well-structured 2-dimensional packing in the network. The addition of an optimal -methyl-2-pyrrolidone amount to tyrosine gels fluidized the network and allowed their injection through conventional needles. Upon contact with an aqueous medium, the gels formed and released entrapped rivastigmine in a sustained fashion.

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Section: Discussionmentioning

confidence: 99%

Pharmaceutical organogels prepared from aromatic amino acid derivatives

Bastiat

Leroux

2009

J. Mater. Chem.

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“…Recent investigations also consider the fact that the sweet-taste perception is mediated by a cascade of various biochemical complexes and several structure-taste studies have been performed on cyclamates and other artificial sweeteners (exemplified by Pautet et al, 1982;Spillane et al, 1989;Suami et al, 1998;Max et al, 2001;Montmayeur et al, 2001;Bassoli et al, 2002;Li et al, 2002;Spillane & Hanniffy, 2003;Morini et al, 2005;Jiang et al, 2005;Nakajima et al, 2006). Some research was also devoted to their solution chemistry Birch, 2002;Birch et al, 2004;Klofutar et al, 1999;Klofutar et al, 2006a,b;Rudan-Tasič et al, 2006). While there are abundant data on the crystal structures of other artificial sweeteners [saccharin (Okaya, 1969;Wardell et al, 2005), aspartame (Hatada et al, 1985), acesulfame-K (Paulus, 1975), sucralose (Kanters et al, 1988), alitame (Feinstein et al, 1991;Goodman et al, 1997), neotame (Wink et al, 1999)], the literature lacks X-ray structural data on cyclamates (Benson & Spillane, 1980;Lee, 1987;Immel, 1995;Yazicilar et al, 2002).…”

Section: Introductionmentioning

confidence: 99%

Structures of artificial sweeteners – cyclamic acid and sodium cyclamate with other cyclamates

Leban

Rudan-Tasic

Lah

et al. 2007

Acta Crystallogr Sect B

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In the course of a study on artificial sweeteners, new crystal structures of cyclamic acid, sodium cyclamate, potassium cyclamate, ammonium cyclamate, rubidium cyclamate and tetra-n-propylammonium cyclamate have been determined. Cyclamic acid exists in its zwitterionic form in the crystalline state. The zwitterions are connected through hydrogen bonds of the N-H...O type to form two-dimensional sheets. The sodium, potassium, ammonium and rubidium cyclamates are isostructural, with the cyclamate moieties linked through hydrogen bonds into linear chains. Taking into account the connectivity through cations, two-dimensional layers with a hydrophobic surface are constructed. In tetra(n-propyl)ammonium cyclamate the large, non-coordinating cation apparently prevents the formation of chains and thereby facilitates the centrosymmetric head-to-head discrete dimeric arrangement of the cyclamate moieties.

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“…Results in table (3) showed that, the decrease in the rats body weight gain in groups treated with crude and washed oils of 600 mg/kg body weight, was resulted from the decrease in the dietary consumption which may be resulted from some interactions of oils with metabolic status especially in the high dose of sunflower oil whereas the decrease in the fat absorption which seen by the treatment with crude oil 600 mg/kg body weight may resulted from the high amount of fecal fat in this group (4) while the washed oil 600 mg/ kg body weight. showed a less amount of fecal fat with relatively high fat absorption which thought to be resulted from the increase rate of fat intestinal absorption by the treatment with washed oil which considered to be more pure and show it's effect in high doses.…”

Section: Results In Tablementioning

confidence: 99%

“…The consumption of (PUFAs) and (MUFAs) in place of SFAs may lower the risk of atherosclerosis and lowering the mortality due to heart disease by reducing cholesterol levels in the blood (4,5), in addition to the sunflower oil fat soluble vitamins content especially E and A which they are considered a powerful antioxidants (6), Phytosterols are also found in sunflower oil and they are effective because of their cholesterol lowering and antioxidant capacity (4), Sunflower oil has an iodine value about 130 and peroxide value about 0.5 meq/ kg and specific gravity at 25 C ْ is about 0.92 according to some national normal values (3).…”

Section: Introductionmentioning

confidence: 99%

Effect of Washed Sunflower Oil on Lipid Profile in the Experimental Hypercholesterolemia in the Adult Male Rats

Sharaf¹,

Kalo²

2009

J.Edu.Sci.

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Vegetable oils are considered to be active in modulation of the blood lipid profile and profilacting from cardiovascular diseases, oils extracted from plants (sunflower seeds) may also contains some polar substances which can interferes with their action, if these oils are exposed to some washing processes with worm water, these substances will be removed. A thirty adult albino male rats were divided into five groups and exposed to a hyperlipidemic and hypercholesterolemic diet (animal fats 16% of total calories) and H 2 O 2 (0.5%) in the water for a 30 days for induction of hypercholesterolemia in addition to 15 days in which. sunflower oil are administered orally as a crude and washed oils at a doses of 300 and 600 mg/ kg body weight. There was no significant effect of the washing process on the nutritional status but there were a decrease in total cholesterol TC (50 %), phospholipids PL (42%), low density lipoproteins LDL-c (74%) and elevation in high density lipoproteins HDL-c (70%) resulted from the treatment with washed oil (600 mg/ kg body weight) in addition to decrease in liver malondialdehyde (MDA) content. In conclusion, the washing process of sunflower oil will improve it's hypocholesterolemic and antioxidant effects.

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Potentiometric titration of poly(α-D)galacturonic acid

Cited by 6 publications

References 14 publications

Pharmaceutical organogels prepared from aromatic amino acid derivatives

Pharmaceutical organogels prepared from aromatic amino acid derivatives

Structures of artificial sweeteners – cyclamic acid and sodium cyclamate with other cyclamates

Effect of Washed Sunflower Oil on Lipid Profile in the Experimental Hypercholesterolemia in the Adult Male Rats

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