1H-Pyrrolo[2,3-b]pyridine-3-propanoic acid, .alpha.-amino-, (-)- 1H-Pyrrolo[2,3-b]pyridine-3-propanoic acid, .alpha.-amino-, (.+-.)- 1H-Pyrrolo[2,3-b]pyridine-3-propionic acid, .alpha.-amino-, dl- 7303-50-6 NSC19495