Structural requirements for lathyrogenic agents.

Using the chick embryo assay system, a series of organic compounds was tested for lathyrogenic activity; lathyrogenic compounds were shown to fall into 4 groups-nitriles, ureides, and 2 new groups-hydrazides and hydrazines, forming a spectrum of diminishing potency in their ability to produce solubility of collagen and skeletal deformities. Pyridoxal was seen to reverse to a great degree the effects on collagen solubility and skeletal deformity produced by the ureides and hydrazides, though not by the nitriles; its effect was considered to be due to the formation of a Schiff's complex between the aldehyde and the terminal amine of the lathyrogen. Evidence is presented to show that lathyrogens do not act as inhibitors of monoamine oxidases or as chelate-forming agents, nor, in the case of isoniazid, as an anti-nicotinamide agent.