3-N-oxalyl-L-2,3-diaminopropanoic acid, a multifunctional plant metabolite of toxic reputation

3-N-oxalyl-L-2,3-diaminopropanoic acid (beta-ODAP) is a neuroexcitatory non- protein amino acid identified in grass pea (Lathyrus sativus L.) and in ginseng (Panax spp). Its presence in the drought tolerant grass pea is thought to be responsible for the crippling disease neurolathyrism, while in the longevity promoting ginseng it is named dencichine and praised for its haemostatic properties. Some properties of beta-ODAP are put in perspective

Is stress a factor in the susceptibility to neurolathyrism?

A

Grain legumes and human health

Since early civilisation in different continents, grain legumes have been a part of balanced diets together with cereals. In general the seeds from those two plant families give together a good source of essential amino acids and may have given an evolutionary advantage. A sustainable diet for vegetarians may not be possible without the protein-rich legumes. Consumed alone, legumes can be a mixed blessing because of their deficiency of some essential amino acids. This deficiency can be balanced in a varied diet containing components richer in tryptophan and the sulphur amino acid methionine and cysteine. Many legume species are exceptionally rich in secondary metabolites, some of which are beneficial to human health while without adequate processing through heating or leaching many can be detrimental to the health of the consumer. Soybean (Glycine max) is one of the most popular and also one of the more healthy species. The presence of genistein and other isoflavones makes it famous as an anti-cancer nutraceutical. Isoflavones and other phytoestrogens, occurring mainly in legumes, might be a factor promoting longevity. Other beneficial secondary metabolites are found among the non-protein amino acids. Legumes are very rich in an enormous variety of non-protein amino acids that can be beneficial or toxic. A beneficial non-protein amino acid occurs in high concentration in fenugreek seeds (Trigonella foenum-graecum), a component of curry, while a variety of toxic amino acids occurs in the genera Lathyrus and Vicia. Legume seeds also contain a variety of anti-nutritional factors that can be reduced by post-harvest processing such as fermentation or germination. Fermentation also improves the balance of essential amino acids. Numerous dietary products such as soy sauce or tempeh are traditional food ingredients derived from legumes