The glycoalkaloids alpha-chaconine, alpha-solamargine, alpha-solanine, solasonine, sycophantine, and tomatine, as well as the aglycones demissidine, solanidine, solanocapsine, solasodine, tomatidine, and veratrine were tested as growth inhibitors of Trypanosoma cruzi, strain EP, in LIT medium. Their activity was compared with the antifungal ketoconazole. Glycoalkaloids containing alpha-chacotriose showed trypanolytic activity against the epimastigote form and trypanocidal activity against the bloodstream and metacyclic trypomastigote form of Trypanosoma cruzi in culture medium in micromolar concentrations. Ketoconazole showed a lower activity, at the same concentrations of alpha-chaconine and alpha-solamargine. The observations indicate that the initial target of the compound is at the membrane level with a concomitant change in the parasite morphology. Moreover, internal compartments of the parasites were observed to be affected by the drugs, revealing the dissolution of some organelles as mitocondrias and glycosomes.

Following a new four-step route, we prepared a family of "extended" glucidoamphiphiles from Dglucose, D-galactose, and xylitol in which the n-dodecyl chain is attached to the glucidic moiety by the linkage Z = O-Et-O-Et-O-(α-PP-O-) n , where -O-(α-PP-O-) n is a poly-(α-propyloxy) commercial oligomeric mixture (with average length n = 6, 10, and 14). This amphiphilic behavior study showed that (i) the glucose derivative exhibits water solubility and hydrophilic-lipophilic balance values that are close to those found for the glucose compound with Z = -O-(α-PP-O-) n (without the Et-O-Et group), (ii) all these compounds are more strongly hydrophilic than the corresponding glucidic derivatives with Z = O, (iii) the increase of the poly-(α-propyloxy) chain length from ñ = 6 to ñ = 14 tends to reduce the hydrophilicity slightly.In a companion paper (1) comparing of the surfactant properties of 3-O-n-dodecyl-D-glucopyranose (23) and its "extended" homolog 3-O-n-dodecyl-O-(α-PP-O-) n -D-glucopyranose (8) in which (α-PP-O-) n = poly-(α-propyloxy) with ñ = 6, we showed that compound 8 exhibited a 100-fold increase in water solubility and a four-unit increase in hydrophiliclipophilic balance (HLB) with respect to compound 23. These results stimulated us to prepare and study the properties of the structural analogs of 8 with different glucidic moieties and of variable poly-(α-propyloxy) length. Before proceeding further, we tried to analyze the reasons for the low overall yield (10%) encountered in the synthesis of the "extended" species 8 along a six-step route (Scheme 1). This was obviously a consequence of the key step e, which required an activated substrate with a leaving group (OMs) linked to a primary carbon to introduce the glucose derivative 6. In the starting oligomeric mixture, 1, there was a secondary carbon at one of the extremities and a primary carbon at the other. Therefore, we first protected this position regiospecifically by a trityl group (step a). Subsequently, the alkyl chain, R, was introduced at the terminal secondary carbon with n-dodecyl bromide (step b). To obtain the activated intermediate, 5, the trityl group was then removed (step c) to introduce the mesylate group (step d), which was substituted by 1,2:5,6-di-O-isopropylidene-α-D-glucopyranose (6). Final desacetalation (step f ) produced the expected compound 8.In the present paper, we describe an alternative four-step route to attain slightly different "extended" glucidoamphiphiles such as compound 18 (Scheme 2), in which a diethyloxy group is introduced between the glucidic moiety and the poly-(α-propyloxy) spacer arm. This strategy is applied in preparing the corresponding D-glucose, D-galactose, and DL-xylitol derivatives with poly-(α-propyloxy) oligomers having an average degree of condensation, ñ, ranging from 6 to 14. This new "extended" glucidoamphiphile family includes enough members that some conclusions can be drawn on the influence of the di-ethyloxy group, the poly-(α-propyloxy) oligomer chain length, and the glucidic moiety on the ...

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New extended anionic surfactants with a carboxylate or sulfate polar head were synthesized from polypropoxylated alcohols, and their structures were confirmed by 1 H and 13 C nuclear magnetic resonance analysis. The extended surfactant critical micelle concentration was found to decrease with the length of the polypropylene glycol spacer. Surfactants containing a diethylene glycol link to the head group exhibited a higher critical micelle concentration than did their nondiethoxylated homologs.

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A new class of extended surfactants was prepared in which the spacer arm between the polar portion and the hydrophobic alkyl chain was a polymer of propylene glycol with an average length of six propylene oxide units. The polar head was a single or double xylitol moiety or a xylitol molecule with carboxylic acid functionality. Surfactants containing double xylitol polar head groups showed a much higher critical micelle concentration value than surfactants with a single polar head.Paper no. S1456 in JSD 8, 193-198 (April 2005).