1951 Volume 25 Issue 2 Pages 63-66
In the previous paper (Part 3, 1944)(1) it was reported that 1, 4-dihydro-, 3, 4-dihydro- and 1, 2, 3, 4-tetrahydro-naphthoic acid have the activity of producing the adventitious roots and in the last paper (Part 5)(2) it was found that two of these (1, 4-dihydro- and 1, 2, 3, 4-tetrahydro-naphthoic acid) have also the strong epinasty-activity for the tomato-plant.
It had been supposed that these substances had no activity for plant growth, because these did not satisfy one of the minimum structural requirements for the plant-hormones suggested by KOEPFLI et al.(3) As the continuation of the last experiment, twenty carboxylic acid derivatives were synthesized and the activities were tested by the previously reported method(Part 4)(4). All of these compouds have carboxyl group(s) attached directly to the carbon ring.
The results obtained are illustrated in Fig.1.
No active substance has been found among these twenty compounds.