Campesterol, brassinosteroids

The Arabidopsis mutant dwf7/ste 1 is defective in C5-desaturation of episterol (Fig. (2)) [18], thus impaired in an enzyme function involved in a very early step of brassinosteroid precursor biosynthesis. The enzymatic block of dwf7/stel was determined by feeding experiments using l3C-labelled mevalonic acid and a subsequent analysis of endogenous sterol and brassinosteroid precursors. The mutant accumulates episterol with a simultaneous decrease of downstream intermediates (24-methylenecholesterol, campesterol, castasterone, brassinolide). 

Fig. 2. Biosynthesis of typical plant sterols. Boxed sterols are probable precursors of various brassinosteroids. Among these sterols, sitosterol, stigmasterol, campesterol, 24-epicampesterol and cholesterol are the most common end-of-pathway sterols in plants. Italic letters refer to the lesions in the biosynthesis mutants of Arabidopsis (dim) and pea (Ikb).

Phenolic acids of E. arvense include di- -caffeoyl-me50-tartaric acid methy esters of protocatechuic and caffeic acids aconitic, oxalic, malic, tannic, arahinoic, and threonic acids minerals, including silicic acid and silicates (5-8%) water soluble up to 80%, potassium, aluminum, and manganese sterols, including campesterol isocuosterol, and brassinosteroids and others. Trace amounts of nicotine have been found in E. arvense ... 

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