Inhibitory activities of 2-pyridinecarboxylic acid analogs on phytogrowth and enzymes

Five 2-pyridinecarboxylic acid-related compounds (1, 2 and 5-7) showed germ ination inhibition against the seed of Brassica campestris L. subsp, rapa H OOK fil et ANDERS at a concentration of 5.0 x 10(-4) M. These compounds als o demonstrated inhibitory activity on the growth of the root of this plant at a concentration of 3.0 x 0(-4) M; among these compounds, 2-pyridylacetic acid (5) showed the strongest inhibitory activity, and the effect was slig htly stronger than that of sodium 2,4-dichlorophenoxyacetate (2,4-D) used a s a positive control. The amounts of chlorophyll in the cotyledons of this plant treated with these active compounds was lower than that of the contro l group, Four compounds (1 and 5-7) with germination inhibition also showed inhibitory activities against alpha-amylase and carboxypeptidase A,and 5 w as the strongest inhibitor toward both enzymes.