Diana O. Labuckas

Seed composition of soybean cultivars evaluated in different environmental regions

In Argentina, the soybean growing area comprises an extensive ecological region with great variations in environmental conditions. The purpose of the work was to study the influence of environment on some chemical parameters of soybeans grown in four geographic locations. Protein and oil contents ranged from 329 to 436 g kg−1 and from 198 to 267 g kg−1, respectively. Saturated fatty acids were relatively constant over regions, while significant variation was observed among environments for the unsaturated acids. There were significant varietal differences, but no important interaction of genotypes and environmental factors was observed. The results obtained are important for Argentinean farmers and will be used in soybean breeding programmes to obtain new genotypes with improved oil quality.

Lipophilicity of some GABAergic phenols and related compounds determined by HPLC and partition coefficients in different systems

Some phenolic compounds, like propofol and thymol, have been shown to act on the GABA(A) receptor. Taking into account the hydrophobicity of these compounds, their interaction with the membrane surrounding the receptor and consequent non-specific effect on receptor modulation cannot be neglected. In the present work, we determined and correlated several lipophilic parameters for both GABAergic agents and three other related phenolic compounds (eugenol, carvacrol and chlorothymol), including logP(o/w), retention data in high performance liquid chromatography (HPLC) by using C18 and immobilized artificial membrane (IAM) columns at different temperatures, and partition coefficients determined in phospholipid liposomes. The correlation results demonstrated the high capacity of the compounds assayed to interact with phospholipid membrane phases, which can be predicted by simple model systems as logP(o/w) or HPLC. The values obtained by HPLC using a fast screening IAM column were the quantitatively closest to the partition coefficients determined in liposome systems, due to the capacity of this column to permit the establishment of molecular interactions like those found in phospholipid membranes. Finally, the fact that all the compounds studied are able to interact with membranes would suggest the participation of some alteration of the GABA(A) receptor lipid environment as part of the receptor modulation exerted by phenolic compounds.

Proximate Composition and Seed Lipid Components of Sorghum Cultivars from Argentina

Seeds of 11 sorghum cultivars (Sorghum bicolor) from Argentina were analysed for proximate composition, fatty acids and sterols. Oil, protein, carbohydrate and ash contents varied between 41 and 66 g kg -1 , 111 and 156 g kg -1 , 670 and 730 g kg -1 and 13.8 and 20.6 g kg -1 of dry matter, respectively. Fatty acid profiles revealed that the major acids were palmitic (15.1-24.8%), oleic (29.9-41.8%) and linoleic (35.9-51.3%). Unsaponifiable matter was examined for sterols. Sitosterol was the prominent component in all cultivars (43.8-57.9%), followed by campesterol (18.7-29.1%) and stigmasterol (12.4-20.5%).

Electrophoretic analysis of Geoffroea (Leguminosae, Papilionoideae): taxonomic inferences in Argentinean populations

The genus Geoffroea Jacq. was circumscribed to two species without varietal division. Nevertheless, in the taxonomic treatment of Argentinean dry-forest flora, on the basis of habit and foliar and floral features, it was possible to distinguish G. decorticans (Hook. & Arn.) Burkart var. decorticans from var. subtropicalis (Lillo) Burkart and to recognise intraspecific variation among the populations of G. spinosa. The purposes of the present study were to provide seed-protein data of Geoffroea species, and to analyse the relationships among them. Sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS–PAGE) was carried out on mature seeds harvested at different locations. Electrophoretic profile analysis showed outstanding differences between G. decorticans var. decorticans and var. subtropicalis and supported the view that these two taxa are less closely related than previously assumed, warranting their recognition at the varietal level. Moreover, attentive to the differences in the protein patterns from the analysed population of G. spinosa (Argentina: Chaco and Salta provinces), in addition to phenotypic differences, materials from other disjunct areas where this species grows need to be studied to verify their taxonomic status.

Volatile constituents of Lithraea ternifolia (Gillies) Barkley fruit

Abstract The fruit volatiles of Lithraea ternifolia (Gillies) Barkley were isolated by hydrodistillation and analysed by capillary GC and GC/MS. Nine compounds were identified, representing 86.6% of the total volatiles with carvone (34.7%), limonene (21.6%) and linalool (12.1%) dominant. Among the sesquiterpenoids found, elemol and spathulenol were the most abundant.