Soybean structural stability

Srinivasulu, S. and Rao, A.G.A. 1995. Structure and kinetic thermal stability studies of the interaction of monohydric alcohols with lipoxygenase 1 from soybeans (Glycine max). J. Agric. Food Chem. 43 562-567. ... 

The oxidative stability of an oil depends on the fatty acid (FA) composition and triacyl-glycerol (TAG) structure, as well as on non-TAG components, such as tocopherols, carotenoids, ascorbic acid, citric acid, free fatty acids, and sterols, which may either prevent or promote oxidation. Several investigations have reported correlations of FA composition, TAG structure, and oxidative stability (135-140). For example, the oxidative stability of purified TAG from soybean oil (SBO) in air in the dark at 60°C is correlated positively with a greater concentration of oleic acid (O) and lower concentrations of linoleic (L) and linolenic (Ln) acids of SBO TAG. 

The importance of polyepoxides is increased by the fact that epoxides of unsaturated oils (linseed or soybean oil) can be used as stabilizing plasticizers. The general structure of such products is shown below. 

Henriksen A, Mirza O, Indiana C et al (2001) Structure of soybean seed coat peroxidase a plant peroxidase with unusual stability and haem-apoprotein interactions. Protein Sci 10 108-115... 

It is likely that protein binding and other macromolecular interactions also play a role in stabilizing the rRNA structures. A recent analysis12 reveals that the binding of specific ribosomal protein to rRNA in vitro results in changes within the rRNA modification patterns. Because the experiments detailed herein examine a population of rRNA within the cell, and thus may be analyzing a variety of RNA conformations, it is remarkable that very consistent results are observed. However, the consequence of polysome assembly and translation on the structure of the rRNA and how these structures might be distinct are not addressed in this analysis. In vitro DMS modification of soybean RNA has revealed some differences in base reactivity relative to that observed on RNA modified in vivo as described herein.36 ... 

When sequences involved in base pairing are clearly identified, the weighting of a transversion in these regions in rRNA can be more fully evaluated. Furthermore, when the Watson and Crick strands of each base-paired region are both known, then the impact of transversion on structure and stability can be taken into account. For example, based only on numbers of sequence differences in the rather limited 3 region analyzed for the four plant rRNAs, the dicot sequence from soybean appears as closely related to the sequence from the monocot (maize) as it does to that from a distant dicot, Arabidopsis. The aquatic monocot Lemna is the most distant in sequence. An overview of secondary structure suggests that Arabidopsis and maize are more closely related (compare the terminal stems in Fig. 5A, nucleotides 46-67). However, as discussed earlier, a... 

Phenol, the simplest and most important phenolic compound in industrial fields, is a multifunctional monomer for oxidative polymerization, and hence, conventional polymerization catalysts afford an insoluble product with uncontrolled structure. On the other hand, the peroxidase catalysis induced the polymerization in aqueous organic solvent to give a powdery polymer consisting of phenylene and ox-yphenylene units showing relatively high thermal stability (Scheme 2).5,6 In the HRP and soybean peroxidase (SBP)-catalyzed polymerization in the aqueous 1,4-dioxane, the resulting polymer showed low solubility the polymer was partly soluble in N,N-dimethylformamide (DMF) and dimethyl sulfoxide and insoluble in other common organic solvents.5 On the other hand, the aqueous methanol solvent af-... 

Several 2-aryl- and 2-phenylmethyl-3,5-isoxazolidine-dlones were synthesized and found to be bleaching herbicides with good tolerance by soybeans. The most active member, 2-(2-chlorophenyl)methyl-4,4-dimethyl-3,5-isoxazolidinedione, failed to perform in the field due to its instability in soil. To improve the chemical stability by molecular modifications, a series of 3-isoxazolidinones were prepared and found to be highly active bleaching herbicides with excellent soybean tolerance. Synthesis and structure-activity relationships are discussed. One of the most active compounds,... 

The three commonly observed fat crystal forms are the a, ( >, and ( > forms. The ( ) form, with small and needle-like crystals which form smooth and fine-grained structures, is the most desired form in shortening and margarine applications. Oil composition plays an important role in crystal formation. Unmodified soybean oil has a tendency to form -crystals but the hydrogenated soybean oil can be crystallized in the ( /-form. Controlled crystallization (under defined conditions of temperature, time and mixing) and tempering is used to manipulate or stabilize the crystal forms to achieve products with the desired functional properties. 

List, G.R. T.L. Mounts F. Orthoefer WE. Neff. Effect of interesterification on the structure and physical properties of high-stearic acid soybean oils./. Am. Oil Chem. Soc. 1997, 74, 327-329. Liu, H.R. P.J. White. High-temperature stability of soybean oils with altered fatty acid compositions./. Am. Oil Chem. Soc. 1992a, 69, 533-537. 

---