Hordeum distichum

Field Fertiliser irrigation Barley Hordeum distichum) 90... 

Migliore, L., G. Brambilla, P. Casoria, C. Civitareale, S. Cozzolino, and L. Gaudio (1996). Effect of sulphadimethoxine on barley Hordeum distichum L., Poaceae, LiUopsida) in laboratory terrestrial models. Agriculture, Ecosystem, and Environment 60 121-128. 

Definition Extract of the cereal grass Hordeum distichum... 

Seeds of barley (Hordeum distichum L.) cv Marris Otter were grown in John Innes compost no. 2. in a growth chamber at 18 C under... 

In barley (Hordeum vulgare, Poaceae), phenylalanine is converted to tyrosine and then to tyramine. Tyramine (1) is subsequently methylated and converted to hordenine (7) (Fig. 28.13). A related species, Hordeum distichum, converts labeled phenylalanine into A(-methyltyramine (31), a reaction that is believed to procede via the intermediacy of the so-called NIH shift (32) (Fig. 28.13). The half-life of hordenine in barley is about 42 h (Waller and Nowacki, 1978). Hordenine has been suggested to play a role in allelopathy in cultivated barley fields and is a feeding repellent for grasshoppers (Smith, 1977b). 

Support for these observations, and hence the initial hydroxylation step(42 -> 44), was obtained by Leete, Bowman and ManueP who fed D L-3-[ C]-4 -[ H]-phenylalanine to germinating seedlings Hordeum distichum) and isolated N-methyltyramine (46) which had retained 88 per cent of the tritium ortho to the hydroxyl group—a further example of the NIH shift accompanying aromatic hydroxylation in higher plants. 

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