Legumin synthesis

Eserine (physostigmine) has a pyrroloindole skeleton. This alkaloid is used as an anticholinesterase drug, which is fairly important in the treatment of Alzheimer s disease. Eserine is synthesized in Physostigma venenosum and stored in the seeds of this leguminous plant. The synthesis pathway starts with tryptamine, which is transformed into eserine (Eigure 45). 

L-Canavanine and L-canaline are non-protein amino acids of certain leguminous plants, that function as protective allelochemicals. L-Canavanine is incorporated into de novo synthesized proteins in place of arginTne there is suggestive evidence that formation of such anomalous proteins figures significantly in canavanine s adverse biological effects. Canavanine, however, does not appear to inhibit overall protein synthesis. Thus, an important basis for canavanine s antimetabolic properties resides in the sustained production of biologically aberrant proteins. 

Nitrogenase converts N2 to NH3 in leguminous plants. Mnch work has been reported on the synthesis of model coordination compounds and clnsters for nitrogenase. This... 

The precursors of flavonoid biosynthesis include shikimic acid, phenylalanine, cinnamic acid, and p-coumaric acid. Shikimic acid acts as an intermediate in the biosynthesis of aromatic acid. The basic pathways to the core isoflavonoid skeletons have been established both enzymatically and genetically [16]. The synthesis of isoflavones can be broadly divided into three main synthetic pathways the formylation of deoxybenzoins, the oxidative rearrangement of chalcones and flavanones, and the arylation of a preformed chromanone ring. In leguminous plants, the major isoflavonoids are produced via two branches of the isoflavonoid biosynthetic pathway, and the different branches share a majority of common reactions [1]. Unlike the common flavonoid compotmds, which have a 2-phenyl-benzopyrone core structure, isoflavones, such as daidzein and genistein, are 3-phenyl-benzopyrone compounds. Biochemically, the synthesis of isoflavones is an offshoot of the flavonoids biosynthesis pathway. Several attempts have aimed to increase... 

Although the actual rate for the preindustrial natural fixation cannot be pinpointed, it is most likely that in the absence of human activities terrestrial processes fixed between 150 and 200 Mt N annually. Fixation by lightning is a minor component of the natural production of reactive nitrogen, which is dominated by symbiotic diazotrophs. Of the three principal types of human interference in the nitrogen cycle—synthesis of ammonia, planting of leguminous crops, and combustion of fossil fuels—the first one is by far the largest. 

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