Soybean plants were grown at day/night temperatures of 24/19 C until the beginning of seed development, and then transferred to 5 different temperature regimes (18/13, 24/19, 27/22, 30/25 and 33/28 C) in the CSIRO phytotron. Mature seeds that developed under these conditions were analyzed for variances in composition. Fatty acid composition was strongly affected by temperature: linolenic and linoleic acids decreased markedly whereas oleic acid increased as the temperature increased; palmitic and stearic acids remained unchanged. Oil content was positively correlated with temperature, and protein content increased at the highest temperature. Of the sugars analyzed, sucrose concentration decreased by 56% with a 15 C increase in temperature, and stachyose showed a slight reduction; other sugars remained unchanged. Amino acid composition was generally stable; however, methionine increased with increased temperature during seed development. Moisture content was unaffected.

Silylation of hydroxyl groups in methyl esters of unsaturated hydroxy acids provides compounds that give mass spectra which can be readily interpreted, whereas spectra of underivatized esters are extremely difficult to evaluate. The relationship of the double bond(s) to the trimethylsiloxy (TMS) group results in specific mass spectral patterns. In esters that have the TMS group separated from the double bond by one methylene group, the ions caused by a-cleavage at the TMS group on the side closest to the olefinic group are much more abundant than those produced from a-cleavage on the other side of the TMS group. In esters that have the TMS group and the double bond separated by two methylene groups, a-cleavage ions are approximately equal. When the TMS group and the double bond are allylic, no fragmentation results between them. Cleavage does occur on either side of thig system, and those ions resulting from cleavage

An isomeric mixture of linoleic acid hydroperoxides, 13‐hydroperoxy‐cis‐9,trans‐11‐octadecadienoic acid (79%) and 9‐hydroperoxy‐cis‐12,trans‐10‐octadecadienoic acid (21%), was decomposed homolytically by Fe(II) in an ethanol‐water solution. In one series of experiments, the hydroperoxides were decomposed by catalytic concentrations of Fe(II). The 10−5 M Fe(III) used to initiate the decomposition was kept reduced as Fe(II) by a high concentration of cysteine added to the reaction in molar excess of the hydroperoxides. Nine different monomeric (no detectable dimeric) fatty acids were identified from the reaction. Analyses of these fatty acids revealed that they were mixtures of positional isomers identified as follows: (I) 13‐oxo‐trans,trans‐(andcis,trans‐) 9,11‐octadecadienoic and 9‐oxo‐trans,trans‐ (andcis,trans‐) 10,12‐octadecadienoic acids; (II) 13‐oxo‐trans‐9,10‐epoxy‐trans‐11‐octadecenoic and 9‐oxo‐trans‐12, 13‐epoxy‐trans‐10‐octadecenoic acids; (III) 13‐oxo‐cis‐9,10‐epoxy‐trans‐11‐octadecenoic and 9‐oxo‐cis‐12, 13‐epoxy‐trans‐10‐octadecenoic acids; (IV) 13‐hydroxy‐9,11‐octadecadienoic and 9‐hydroxy‐10,12‐octadecadienoic acids; (V) 11‐hydroxy‐trans‐12, 13‐epoxy‐cis‐9‐octadecenoic and 11‐hydroxy‐trans‐9, 10‐epoxy‐cis‐12‐octadecenoic acids; (VI) 11‐hydroxy‐trans‐12, 13‐epoxy‐trans‐9‐octadecenoic and 11‐hydroxy‐trans‐9,10‐epoxy‐trans‐12‐octadecenoic acids; (VII) 13‐oxo‐9‐hydroxy‐trans‐10‐octadecenoic acids; (VIII) isomeric mixtures of 9, 12, 13‐dihydroxyethoxy‐trans‐10‐octadecenoic and 9, 10, 13‐dihydroxyethoxy‐trans‐11‐octadecenoic acids; and (IX) 9, 12, 13‐trihydroxy‐trans‐10‐octadecenoic and 9, 10, 13‐trihydroxy‐trans‐11‐octadecenoic acids. In another experiment, equimolar amounts of Fe(II) and hydroperoxide were reacted in the absence of cysteine. A large proportion of dimeric fatty acids and a smaller amount of monomeric fatty acids resulted. The monomeric fatty acids were examined by gas liquid chromatography‐mass spectroscopy. Spectra indicated that the monomers were largely similar to those produced by the Fe(III)‐cysteine reaction.