Brassin purification

Barley field experiments, description for brassin evaluation, 12 Barley leaf cell ultrastructure, protective effect of brassinosteroids under saline stress, 150,152/153,154/ Bean first-intemode bioassay, 321 Bean second-intemode bioassay activities of compounds, 65,68,69-7Of application, 321 brassin purification, 3-4 brassinosteroids, description, 109-110 development, 321 scheme, 63,65,66/... 

Prior to his retirement from the USDA in 1974, Mitchell sought increased support to establish field trials to evaluate the effects of brassins for enhancing yields of several crop plants. Because the purification, isolation, and identification of the active component(s) were proving to be so very difficult, Mitchell also sought additional support for a concerted research effort in these area. The ARS administration considered both aspects to be of importance and plans for a multi-disciplined, multilocation project were made. 

Purification, Isolation, and Identification of Active Component(s) of Brassins As indicated, the brassins complex was found to contain glucosyl esters of fatty acids (17) which were thought to be the active brassins constituents. Starting with this information, glucosyl esters from rape pollen were purified and esters of these types were synthesized (18, 19, 20). However, neither the esters purified from pollen nor those synthesized proved to have brassins-like biological activity in the bean 2nd internode test. It was therefore concluded that components other than glucosyl esters, most likely present in very small amounts, were responsible for the biological activity of brassins. 

Figure 3. Responses of bean internode segments in the bean 2nd internode assay to increases in concentration (left to right) of the active component of brassins nearing final purification. (Reproduced with permission from reference 22. Copyright 1981 Butterworth-Heinemann.)...

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